http://www.mdpi.com/journal/forests Latest open access articles published in Forests at http://www.mdpi.com/journal/forests http://www.mdpi.com/1999-4907/4/2/364 Partial harvesting has been proposed as a key aspect to implementing ecosystem management in the Canadian boreal forest. We report on a replicated experiment located in boreal mixedwoods of Northwestern Quebec. In the winter of 2000–2001, two partial harvesting treatments, one using a dispersed pattern, and a second, which created a (400 m2) gap pattern, were applied to a 90-year-old aspen-dominated mixed stand. The design also included a clear cut and a control. Over the course of the following eight years, live tree, coarse woody debris, regeneration and ground beetles were inventoried at variable intervals. Our results indicate that all harvesting treatments created conditions favorable to balsam fir (Abies balsamea) sapling growth and trembling aspen (Populus tremuloides) sapling recruitment. However, balsam fir and trembling aspen regeneration and ground beetles response to gap cuts were closer to patterns observed in clear cuts than in dispersed harvesting. The underlying reasons for these differing patterns can be linked to factors associated with the contrasting light regimes created by the two partial harvesting treatments. The study confirms that partially harvesting is an ecologically sound approach in boreal mixedwoods and could contribute to maintaining the distribution of stand ages at the landscape level. Forests 2013-05-22 4 2 Article 10.3390/f4020364 364 385 1999-4907 2013-05-22 doi: 10.3390/f4020364 Suzanne Brais Timothy Work Émilie Robert Christopher O'Connor Manuella Strukelj Arun Bose Danielle Celentano Brian Harvey http://www.mdpi.com/1999-4907/4/2/343 With the current complexity of issues facing forest and land management, the implementation of the REDD+ initiative comes with significant risks, including conflict. While the exact nature and shape of conflict in REDD+ implementation is difficult to pinpoint, this study aims to build a preliminary predictive framework to identify possible sources of impairment that may result in conflict over management of forests and natural resources. The framework was developed from an extensive literature review and was tested in three REDD+ pilot project sites in Nepal. The results indicate that most of the sources of impairment are present in all study sites, particularly issues relating to benefit sharing, which have been main drivers of conflict prior to REDD+. While we found that the application of the framework has been useful in the Nepalese context, there are some limitations in its scope and precision. Nonetheless, this study points to important implications with regards to REDD+ implementation and conflict management that can be useful for policy makers and practitioners involved in REDD+ strategy designs, as well as other areas of forest management involving outsiders and communities. Forests 2013-05-10 4 2 Article 10.3390/f4020343 343 363 1999-4907 2013-05-10 doi: 10.3390/f4020343 Toral Patel Ahmad Dhiaulhaq David Gritten Yurdi Yasmi Toon De Bruyn Naya Paudel Harisharan Luintel Dil Khatri Chandra Silori Regan Suzuki http://www.mdpi.com/1999-4907/4/2/329 The complex problems associated with global change processes calls for close collaboration between science disciplines to create new, integrated knowledge. In the wake of global change processes, forests and other natural environments have been rapidly changing, highlighting the need for collaboration and integrative research development. Few tools are available to explore the potential for collaborations in research ventures that are just starting up. This study presents a useful approach for exploring and fostering collaborations between academics working in research teams and organizations comprising multiple science disciplines (i.e., multi-disciplinary). The research aim was to reveal potential barriers, common ground, and research strengths between academics working in a new centre focused on forest and climate change research. This aim was based on the premise that raising awareness and working with this acquired knowledge fosters collaborations and integrative research development. An email survey was deployed amongst the academics to obtain: (i) their understanding of common themes (e.g., climate change, scale of investigation, woodland/forest health/decline); (ii) descriptions of the spatial and temporal scales of their research; and (iii) their approach and perceived contributions to climate change research. These data were analysed using a semi-quantitative content analysis approach. We found that the main potential barriers were likely to be related to differences in understanding of the common research themes, whilst similarities and disciplinary strengths provided critical elements to foster collaborations. These findings were presented and discussed amongst the centre academics to raise awareness and create a dialogue around these issues. This process resulted in the development of four additional research projects involving multiple disciplines. The approach used in this study provides a useful methodology of broader benefit to similar multi-disciplinary research teams and organizations elsewhere. Forests 2013-05-10 4 2 Article 10.3390/f4020329 329 342 1999-4907 2013-05-10 doi: 10.3390/f4020329 Niels Brouwers Susan Moore Thomas Lyons Giles Hardy Jérôme Chopard George Matusick Katinka Ruthrof Leonie Valentine http://www.mdpi.com/1999-4907/4/2/319 Histological examinations of the host reaction types (RTs); short galls, rough galls and smooth galls in slash pine seedlings inoculated with Cronartium quercuum f. sp. fusiforme revealed host reaction zone(s) [RZ(s)]. These RZs differed among the host RTs in location and pattern of occurrence in the stem, staining reaction, periderm formation and amount of fungal colonization. The RZ within short galls were wide, deep in the cortex, continuous around the stem, bordered on both sides by a well-developed periderm encircling the stem with limited fungal colonization. The RZ of the rough galls lacked a periderm, were small, numerous and discontinuous around the stem circumference, being separated by symptomatic tissue typical of a susceptible reaction. Fungal colonization of the rough galls was limited and hyphae and haustoria were encrusted. The RZ of the smooth galls were small and narrow conforming to the stem circumference, shallow in the cortex and interconnected by symptomatic tissues typical of a susceptible reaction. A narrow periderm developed along the innermost portion of the RZ in smooth galls and fungal colonization was abundant in the cortex. We suggest that the RTs large galls (rough and smooth), short galls, and hypersensitive-like stem lesions represent increasing resistance to the fusiform rust pathogen. Forests 2013-05-10 4 2 Article 10.3390/f4020319 319 328 1999-4907 2013-05-10 doi: 10.3390/f4020319 Karina Gramacho Thomas Miller Robert Schmidt http://www.mdpi.com/1999-4907/4/2/296 The advent of initiatives to reduce emissions from deforestation and degradation and enhance forest carbon stocks (REDD+) in developing countries has raised much concern regarding impacts on local communities. To inform this debate, we analyze the initial outcomes of those REDD+ projects that systematically report on their socio-economic dimensions. To categorize and compare projects, we develop a participation and benefits framework that considers REDD+’s effects on local populations’ opportunities (jobs, income), security (of tenure and ecosystem services), and empowerment (participation in land use and development decisions). We find material benefits, in terms of jobs and income, to be, thus far, modest. On the other hand, we find that many projects are helping populations gain tenure rights. A majority of projects are obtaining local populations’ free, prior, and informed consent (FPIC). However, for those projects interacting with multiple populations, extent of participation and effects on forest access are often uneven. Our participation and benefits framework can be a useful tool for identifying the multi-faceted socio-economic impacts of REDD+, which are realized under different timescales. The framework and initial trends reported here can be used to build hypotheses for future REDD+ impact evaluations and contribute to evolving theories of incentive-based environmental policy. Forests 2013-05-10 4 2 Article 10.3390/f4020296 296 318 1999-4907 2013-05-10 doi: 10.3390/f4020296 Kathleen Lawlor Erin Madeira Jill Blockhus David Ganz http://www.mdpi.com/1999-4907/4/2/279 The current outbreak of mountain pine beetle, Dendroctonus ponderosae Hopkins, has led to extensive tree mortality in British Columbia and the western United States. While the greatest impacts of the outbreak have been in British Columbia, ongoing impacts are expected as the outbreak continues to spread eastward towards Canada’s boreal and eastern pine forests. Successful mitigation of this outbreak is dependent on understanding how the beetle’s host selection behaviour is influenced by the patchwork of tree mortality across the landscape. While several studies have shown that selective mechanisms operate at the individual tree level, less attention has been given to beetles’ preference for variation in spatial forest patterns, namely forest fragmentation, and if such preference changes with changing population conditions. The objective of this study is to explore the influence of fragmentation on the location of mountain pine beetle caused mortality. Using a negative binomial regression model, we tested the significance of a fragmentation measure called the Aggregation Index for predicting beetle-caused tree mortality in the central interior of British Columbia, Canada in 2000 and 2005. The results explain that mountain pine beetle OPEN ACCESS Forests 2013, 4 280 exhibit a density-dependent dynamic behaviour related to forest patterns, with fragmented forests experiencing greater tree mortality when beetle populations are low (2000). Conversely, more contiguous forests are preferred when populations reach epidemic levels (2005). These results reinforce existing findings that bark beetles exhibit a strong host configuration preference at low population levels and that such pressures are relaxed when beetle densities are high. Forests 2013-04-29 4 2 Article 10.3390/f4020279 279 295 1999-4907 2013-04-29 doi: 10.3390/f4020279 Christopher Bone Joanne White Michael Wulder Colin Robertson Trisalyn Nelson http://www.mdpi.com/1999-4907/4/2/270 This study aimed at evaluating the potential of Schizolobium parahyba to produce laminated veneer lumber (LVL) and the feasibility of a nondestructive method for grading the veneers. Initially, 64 S. parahyba veneers were nondestructively tested using the stress wave method, and stress wave velocity (wv) and veneer dynamic modulus of elasticity (EdV) were determined. Afterwards, the veneers were graded according to EdV descending values and used to manufacture 8-ply LVL boards. After the manufacturing, the boards were also nondestructively tested, and the board dynamic modulus of elasticity (EdB) was determined. Simple linear regression analysis was run to evaluate the relationship between the nondestructive and mechanical properties of veneers/boards. A positive effect of veneer stress wave properties on the LVL properties was found. Therefore, the higher the EdV values, the higher the LVL properties. The relationships between EdV and EdB properties were highly significant with all mechanical properties. It was clearly observed that when this grading procedure was used, the veneers were indirectly graded by their density. Finally, it could be concluded that S. parahyba showed good potential to produce LVL. Forests 2013-04-29 4 2 Article 10.3390/f4020270 270 278 1999-4907 2013-04-29 doi: 10.3390/f4020270 Cláudio Del Menezzi Luana Mendes Mário de Souza Geraldo Bortoletto http://www.mdpi.com/1999-4907/4/2/251 Specific gravity is an important consideration for traditional uses of hybrid poplars for pulp and solid wood products, as well as for biofuels and bioenergy production. While specific gravity has been shown to be under strong genetic control and subject to within-tree variability, the role of genotype × environment interactions is poorly understood. Most specific gravity reports are for a limited number of locations, resulting in a lack of information about the interactions between clones and sites over a wide range of climate and soil conditions. The objective of the current study was to characterize the effects of bole position, site, clone, and site × clone interactions for twelve hybrid poplar genotypes grown in Iowa, Minnesota, Wisconsin, and Michigan, USA. Observed specific gravities ranged from 0.267 to 0.495 (mean = 0.352 ± 0.001 for 612 samples taken from 204 trees), with bole position and site × clone interactions having significant effects on specific gravity. Further investigation of the site × clone interactions indicated that environmental conditions related to water stress were key predictors of specific gravity. These data are important for informing genotypic selection and silvicultural management decisions associated with growing hybrid poplars. Forests 2013-04-23 4 2 Article 10.3390/f4020251 251 269 1999-4907 2013-04-23 doi: 10.3390/f4020251 William Headlee Ronald Jr. Richard Hall Edmund Bauer Bradford Bender Bruce Birr Raymond Miller Jesse Randall Adam Wiese http://www.mdpi.com/1999-4907/4/2/234 Forest products are commodities and subject to cyclical trends; yet resource-hungry countries offer exporters a period of sustained growth for those with the right products. Products have their distinctive requirements, e.g., finishing timber (colour, stability), structural (strength stiffness, stability), paper (fibre length and tear strength). The failure to incorporate such key properties in radiata pine (Pinus radiata) breeding programmes has been a lost opportunity for New Zealand forestry that constrains exports. Radiata pine remains a utilitarian, undifferentiated commodity. A complementary opportunity in international markets lies in naturally-durable eucalypts grown on New Zealand’s east coast drylands. These are species whose properties mimic those of the finest tropical hardwoods that are in most demand in Asian markets. Forests 2013-04-22 4 2 Review 10.3390/f4020234 234 250 1999-4907 2013-04-22 doi: 10.3390/f4020234 John Walker http://www.mdpi.com/1999-4907/4/2/218 Regrowth and planted trees in agricultural landscapes are rarely protected from clearing under national Forest Acts. There is, therefore, some question over the long-term security of any value they might provide to biodiversity and the global carbon cycle. Engaging landholders in carbon credits that are conditioned on planted areas being maintained into the future could improve the situation. To begin carbon trading, landholders need precise and accurate estimates of the carbon sequestered by the trees in their fields. Accurate estimates of carbon stocks depend to a greater degree on the availability and adequacy of the allometric equations that are used to estimate tree biomass. The present study has developed an allometric model for estimating the woody biomass of Jatropha trees planted as boundary hedges in agricultural landscapes under smallholder farming systems in Malawi. The predictive performance of the model was assessed and was subsequently compared with the published Jatropha models. The results showed that the statistical fits of our model were generally good, enabling one to use it with confidence for estimating wood biomass in Jatropha stands from which they were derived. The published Jatropha models consistently overestimated the woody biomass by as much as 55%, rendering them unsuitable for application in estimating woody biomass in our study sites. Forests 2013-04-11 4 2 Article 10.3390/f4020218 218 233 1999-4907 2013-04-11 doi: 10.3390/f4020218 Stephy Makungwa Abbie Chittock David Skole George Kanyama-Phiri Iain Woodhouse http://www.mdpi.com/1999-4907/4/1/197 Using 100 years of fire perimeter maps, we investigate the existence of geographical patterns in fire orientation across California. We computed fire perimeter orientation, at the watershed level, using principal component analysis. Circular statistics were used to test for the existence of preferential fire perimeter orientations. Where perimeters displayed preferential orientation, we searched for evidence of orographic channeling by comparing mean fire orientation with watershed orientation. Results show that in California, 49% of the burnt area is associated with watersheds, where fires displayed preferential orientation. From these, 25% of the burnt area is aligned along the NE/SW orientation and 18% in the E/W orientation. In 27 out of 86 watersheds with preferential fire alignment, there is also correspondence between mean fire orientation and watershed orientation. Topographic influence on fire spread and dominant wind patterns during the fire season can account for the consistency in fire perimeter orientation in these regions. Our findings highlight the historical pattern of fire perimeter orientation and identify watersheds with potential orographic channeling. Forests 2013-03-22 4 1 Article 10.3390/f4010197 197 217 1999-4907 2013-03-22 doi: 10.3390/f4010197 Ana Barros José Pereira Max Moritz Scott Stephens http://www.mdpi.com/1999-4907/4/1/179 Forest managers need accurate biomass equations to plan thinning for fuel reduction or energy production. Estimates of carbon sequestration also rely upon such equations. The current allometric equations for ponderosa pine (Pinus ponderosa) commonly employed for California forests were developed elsewhere, and are often applied without consideration potential for spatial or temporal variability. Individual-tree aboveground biomass allometric equations are presented from an analysis of 79 felled trees from four separate management units at Blacks Mountain Experimental Forest: one unthinned and three separate thinned units. A simultaneous set of allometric equations for foliage, branch and bole biomass were developed as well as branch-level equations for wood and foliage. Foliage biomass relationships varied substantially between units while branch and bole biomass estimates were more stable across a range of stand conditions. Trees of a given breast height diameter and crown ratio in thinned stands had more foliage biomass, but slightly less branch biomass than those in an unthinned stand. The observed variability in biomass relationships within Blacks Mountain Experimental Forest suggests that users should consider how well the data used to develop a selected model relate to the conditions in any given application. Forests 2013-03-21 4 1 Article 10.3390/f4010179 179 196 1999-4907 2013-03-21 doi: 10.3390/f4010179 Martin Ritchie Jianwei Zhang Todd Hamilton http://www.mdpi.com/1999-4907/4/1/155 Pinus patula and Pinus tecunumanii play an important role in the forestry sector in the tropics and subtropics and, in recent decades, members of the International Tree Breeding and Conservation Program (Camcore) at North Carolina State University have established large, multi-site provenance trials for these pine species. The data collected in these trials provide valuable information about species and provenance choice for plantation establishment in many regions with different climates. Since climate is changing rapidly, it may become increasingly difficult to choose the right species and provenance to plant. In this study, growth performance of plantings in Colombia, Brazil and South Africa was correlated to the degree of climatic dissimilarity between planting sites. Results are used to assess the suitability of seed material under a changing climate for four P. patula provenances and six P. tecunumanii provenances. For each provenance, climate dissimilarities based on standardized Euclidean distances were calculated and statistically related to growth performances. We evaluated the two methods of quantifying climate dissimilarity with extensive field data based on the goodness of fit and statistical significance of the climate distance relation to differences in height growth. The best method was then used as a predictor of a provenance change in height growth. The provenance-specific models were used to predict provenance performance under different climate change scenarios. The developed provenance-specific models were able to significantly relate climate similarity to different growth performances for five out of six P. tecunumanii provenances. For P. patula provenances, we did not find any correlation. Results point towards the importance of the identification of sites with stable climates where high yields are achievable. In such sites, fast-growing P. tecunumanii provenances with a high but narrow growth optimum can be planted. At sites with climate change of uncertain direction and magnitude, the choice of P. patula provenances, with greater tolerance towards different temperature and precipitation regimes, is recommended. Our results indicate that the analysis of provenance trial data with climate similarity models helps us to (1) maintain plantation productivity in a rapidly changing environment; and (2) improve our understanding of tree species’ adaptation to a changing climate. Forests 2013-03-20 4 1 Article 10.3390/f4010155 155 178 1999-4907 2013-03-20 doi: 10.3390/f4010155 Christoph Leibing Johannes Signer Maarten van Zonneveld Andrew Jarvis William Dvorak http://www.mdpi.com/1999-4907/4/1/137 Willow (Salix spp.) is currently being researched as a source of biomass energy in Canada. However, it is not certain whether afforestation with willow plantations will enhance or diminish soil C storage and nutrient availability. Trees are known to have pronounced effects on biologically mediated nutrient cycling processes which can increase nutrient availability, but willows are known to be nutrient demanding. In this paper, the net effect of plantation establishment is examined at nine sites across the prairie and southern Ontario regions of Canada. Carbon, N, P, K, Ca and Mg levels in soils and harvestable biomass were compared between willow plantations and paired reference sites at the end of the first three-year rotation. Soils were depleted in total C (−2.22 mg·g−1, p < 0.05), inorganic N (−3.12 μg·N·g−1, p < 0.10), exchangeable K (−0.11 cmolc·kg−1, p < 0.10) and leachable P (−0.03 mg·g−1, p < 0.10). Exchangeable Ca was found to be consistently depleted only at the 20–40 depth. Depletion of soil K was more heavily influenced by disturbance, whereas soil N was directly affected by willow N uptake. Sites with greater growth and biocycling stabilized soil P concentrations. Forests 2013-03-12 4 1 Article 10.3390/f4010137 137 154 1999-4907 2013-03-12 doi: 10.3390/f4010137 Joels Ens Richard Farrell Nicolas Bélanger http://www.mdpi.com/1999-4907/4/1/122 Managing forests for multiple ecosystem services such as timber, carbon, and biodiversity requires information on ecosystem structure and management characteristics. National forest inventory data are increasingly being used to quantify ecosystem services, but they mostly provide timber management and overstory data, while data on understory shrub and herbaceous diversity are limited. We obtained species richness and stand management data from relevant literature to develop a regression tree model that can be used to predict understory species richness from forest inventory data. Our model explained 57% of the variation in herbaceous species richness in the coastal plain pine forests of the southeastern USA. Results were verified using field data, and important predictors of herbaceous richness included stand age, forest type, time since fire, and time since herbicide-fertilizer application. This approach can make use of available forest inventories to rapidly and cost-effectively estimate understory species richness for subtropical pine forests. Forests 2013-02-22 4 1 Article 10.3390/f4010122 122 136 1999-4907 2013-02-22 doi: 10.3390/f4010122 Nilesh Timilsina Wendell Cropper Francisco Escobedo Joanna Lima http://www.mdpi.com/1999-4907/4/1/106 Pruning of live branches is a management option to enhance wood quality in plantation trees. It may also alter whole-tree water use, but little is known about the extent and duration of changes in transpiration. In this study, sap flow sensors were used to measure transpiration for 14 days prior to, and 75 days following the removal, through pruning, of the lower 50% of the live-crown length of 10–11 m tall four-year old Eucalyptus pilularis Sm. and E. cloeziana F. Muell. trees. Pruning had no effect on stem growth, sapwood water content or radial pattern of sap velocity in either species. Pruning reduced mean daily water use by 39% in E. pilularis and 59% in E. cloeziana during the first eight days after pruning. Thirty six days after pruning there were no longer any significant differences in transpiration rates between pruned and unpruned trees in either species. Our results show that pruning of live branches had only a short-term effect on whole-tree transpiration in these sub-tropical eucalypt species. Forests 2013-02-05 4 1 Article 10.3390/f4010106 106 121 1999-4907 2013-02-05 doi: 10.3390/f4010106 Philip Alcorn David Forrester Dane Thomas Ryde James R. Smith Adrienne Nicotra Jürgen Bauhus http://www.mdpi.com/1999-4907/4/1/104 Poised between soil and sky, forest canopies represent a critical point of exchange between the atmosphere and the earth, yet until recently, they remained a largely unexplored frontier. For a long time, problems with access and the lack of tools and methods suitable for monitoring these complex bioscopes made canopy analysis extremely difficult. Fortunately, canopy research has advanced dramatically in recent decades. Methods in Forest Canopy Research is a comprehensive overview of these developments for explorers of this astonishing environment. The authors describe methods for reaching the canopy and the best ways to measure how the canopy, atmosphere, and forest floor interact. They address how to replicate experiments in challenging environments and lay the groundwork for creating standardized measurements in the canopy — essential tools for understanding our changing world. Forests 2013-01-28 4 1 New Book Received 10.3390/f4010104 104 105 1999-4907 2013-01-28 doi: 10.3390/f4010104 Shu-Kun Lin http://www.mdpi.com/1999-4907/4/1/85 Recent studies have shown that, owing to a lack of seed trees, the natural rate of recovery of fire-disturbed bog forests previously dominated by the endemic and endangered conifer Pilgerodendron uviferum (D. Don) Florin is extremely slow. Hence, increasing the number of seed trees in the landscape through restoration planting could remove the principal biotic filter, limiting recovery of these forests. Here, we analyzed how the success of restoration plantings may be improved through the choice or manipulation of microsites in P. uviferum forests on Chiloé Island in North Patagonia. For this purpose, we manipulated microtopography in water-logged sites in bogs (mounds, flat terrain, mineral soil) and changed canopy conditions (gaps, semi-open, closed canopy) in upland sites with better drainage. In bogs, there was no significant effect of microtopography on growth and survival of P. uviferum plantings. However, fluorescence measurements indicated lower stress in seedlings established on mounds. Seedlings in upland areas established beneath a nurse canopy had lower mortality and higher relative shoot growth, foliar nutrients, photosynthetic light use efficiency and chlorophyll fluorescence values than those planted in the open. This indicates that seedlings of the slow growing P. uviferum can tolerate extremely wet conditions, yet suffer from stress when grown in the open. Here, the removal of canopy appeared to have also removed or reduced mycorrhizal networks for seedlings, leading to poorer nutrition and growth. Based on these results, recommendations for restoration plantings in highly degraded P. uviferum forests are presented. Forests 2013-01-16 4 1 Article 10.3390/f4010085 85 103 1999-4907 2013-01-16 doi: 10.3390/f4010085 Jan Bannister Rafael Coopman Pablo Donoso Jürgen Bauhus http://www.mdpi.com/1999-4907/4/1/70 Rusts are important pathogens of angiosperms and gymnosperms including cereal crops and forest trees. With respect to cereals, rust fungi are among the most important pathogens. Cereal rusts are heteroecious and macrocyclic requiring two taxonomically unrelated hosts to complete a five spore stage life cycle. Cereal rust fungi are highly variable for virulence and molecular polymorphism. Leaf rust, caused by Puccinia triticina is the most common rust of wheat on a worldwide basis. Many different races of P. triticina that vary for virulence to leaf rust resistance genes in wheat differential lines are found annually in the US. Molecular markers have been used to characterize rust populations in the US and worldwide. Highly virulent races of P. triticina are selected by leaf rust resistance genes in the soft red winter wheat, hard red winter wheat and hard red spring wheat cultivars that are grown in different regions of the US. Cultivars that only have race-specific leaf rust resistance genes that are effective in seedling plants lose their effective resistance and become susceptible within a few years of release. Cultivars with combinations of race non-specific resistance genes have remained resistant over a period of years even though races of the leaf rust population have changed constantly. Forests 2013-01-16 4 1 Review 10.3390/f4010070 70 84 1999-4907 2013-01-16 doi: 10.3390/f4010070 James Kolmer http://www.mdpi.com/1999-4907/4/1/43 Forestry-based carbon sequestration projects demand a comprehensive quantification of the different climate change mitigation effects. In our study, we modeled a life cycle of managed pure stands consisting of the four main tree species in Bavaria (spruce, pine, beech and oak). For spruce and beech, an unmanaged stand was additionally integrated in order to analyze the differences in climate change mitigation effects compared to the managed stands. We developed a climate change mitigation model, where stand development and silvicultural treatments including harvested timber volumes were conducted using the tree growth model Silva 2.3. The harvested wood products (HWP), including their substitution effects were calculated with a subsequent model. For unmanaged beech forests, we compiled measured data from the literature, and Bavarian strict forest reserves for validating our model results. The results for the managed stands reveal that spruce provides the highest total climate change mitigation effects. After a simulation period of 180 years, one hectare leads to a mean mitigation benefit of 13.5 Mg CO2 ha−1 year−1. In comparison, results for pine, beech and oak reveal lesser benefits with 10.1 Mg CO2 ha−1 year−1, 9.1 Mg CO2 ha−1 year−1 and 7.2 Mg CO2 ha−1 year−1, respectively. However, these results assume current growing conditions. Considering climate change, it is very likely that spruce will not be suitable in several regions of Bavaria in the future. Furthermore, excessive disturbances could affect spruce more drastically than the other tree species. In that case, the order could change and beech could exceed spruce. Thus the results cannot be seen as a general recommendation to establish spruce stands in order to achieve optimal climate change mitigation benefits. Nevertheless, results for spruce illustrate that high increment and especially wood use in long-lived products is crucial for high climate change mitigation effects. Mitigation effects in unmanaged spruce and beech stands do not differ in the first decades from their managed counterparts, but are below them in the long term with a total climate change mitigation benefit of 8.0 Mg CO2 ha−1 year−1 and 7.2 Mg CO2 ha−1 year−1, respectively. These differences are mainly caused by the missing substitution effects in the unmanaged stands. However, the precise dimensions of substitution effects still remain uncertain and the lack of data should be reduced via additional life cycle assessments for more products and product classes. However, neglecting substitution effects in climate change mitigation models leads to severe underestimations of the mitigation effects in managed forests. Forests 2013-01-14 4 1 Article 10.3390/f4010043 43 69 1999-4907 2013-01-14 doi: 10.3390/f4010043 Daniel Klein Sebastian Höllerl Markus Blaschke Christoph Schulz http://www.mdpi.com/1999-4907/4/1/28 Swedish owners of poplar stands are interested in both the wood quality and the use of poplars that are soon to be harvested. An important concern is the frequency of false heartwood (FHW) in the stems. We have presented an overview of the factors causing discolored wood as well as the industrial use and quality of the end products. We have studied poplar stems growing at 22 sites in Sweden between latitudes 55° N and 60° N. The mean age of the poplar was 23 years (range 14–41), the mean stand density 1011 stems ha−1 (range 155–3493) and the diameter at breast height (DBH) (over bark) 246 mm (range 121–447). All stands were growing on clay soils (light and medium clay and light clay tills). All of the sampled stems (42) contained false heartwood. At 0%–50% of stem height, all sampled trees were discolored and at 90% of stem height, 33% were discolored. The percentage of false heartwood area by stem area was highest at 1% and 10% of stem height (26.6% and 24.7% respectively). The “FHW” part of the stem had a radius of 47 mm (range 9–93) at 30% of stem height, which corresponds to 50% of the total stem radius. A log of six meters represents about 30% of stem height. Equations describing the correlation between DBH and the diameter of FHW at different stem heights (1%, 10%, 30%, 50%, 70% and 90%) and table describing FHW volume % by total stem volume at the first 50% of stem height were constructed. These might be helpful for estimating the percentage of fresh wood in a stem. However, most of the fast-growing poplars will be harvested as biofuel. Forests 2013-01-09 4 1 Article 10.3390/f4010028 28 42 1999-4907 2013-01-09 doi: 10.3390/f4010028 Tord Johansson Birger Hjelm http://www.mdpi.com/1999-4907/4/1/1 We evaluated the Mixedwood Growth Model (MGM) at a whole model scale for pure and mixed species stands of aspen and white spruce in the western boreal forest. MGM is an individual tree-based, distance-independent growth model, designed to evaluate growth and yield implications relating to the management of white spruce, black spruce, aspen, lodgepole pine, and mixedwood stands in Alberta, British Columbia, Saskatchewan, and Manitoba. Our validation compared stand-level model predictions against re-measured data (volume, basal area, diameter at breast height (DBH), average and top height and density) from permanent sample plots using combined analysis of residual plots, bias statistics, efficiency and an innovative application of the equivalence test. For state variables, the model effectively simulated juvenile and mature stages of stand development for both pure and mixed species stands of aspen and white spruce in Alberta. MGM overestimates increment in older stands likely due to age-related pathology and weather-related stand damage. We identified underestimates of deciduous density and volume in Saskatchewan. MGM performs well for increment in postharvest stands less than 30 years of age. These results illustrate the comprehensive application of validation metrics to evaluate a complex model, and provide support for the use of MGM in management planning. Forests 2013-01-07 4 1 Article 10.3390/f4010001 1 27 1999-4907 2013-01-07 doi: 10.3390/f4010001 Mike Bokalo Kenneth Stadt Philip Comeau Stephen Titus http://www.mdpi.com/1999-4907/3/4/1157 Successful management of national forests in the United States requires Forest Service personnel to collaborate with the public, including individuals living in communities near national forest lands. Collaboration enables agency personnel to build long-term trusting and reciprocal relationships with local communities through their ongoing planning processes. However, frequently agency personnel do not have the tools or data necessary to measure the strength of relationships that exist between the agency and local communities. A rapid social capital assessment protocol is presented that can be used by agency personnel and social scientists as a tool for gauging the existence and strength of Forest Service—community relationships. The utility of the protocol is illustrated by describing findings from two pilot tests conducted in communities near the Tombigbee National Forest in Mississippi and the Nantahala National Forest in North Carolina. Barriers to effective Forest Service—community relationships are highlighted and opportunities for social capital development, such as utilizing local news outlets, are presented. Forests 2012-12-18 3 4 Article 10.3390/f3041157 1157 1179 1999-4907 2012-12-18 doi: 10.3390/f3041157 Jordan Smith http://www.mdpi.com/1999-4907/3/4/1133 We perform simulations using the integrated Land Use in Rural New Zealand (LURNZ) model to analyze the effect of various New Zealand emissions trading scheme (ETS) scenarios on land use, emissions and output in a temporally and spatially explicit manner. We compare the impact of afforestation to the impact of other land-use change on net greenhouse gas emissions and evaluate the importance of the forestry component of the ETS relative to the agricultural component. We find that the effect of including agriculture in the ETS is small relative to the effect of including forestry. We also examine the effect of land-use change on the time profile of net emissions from the forestry sector. Finally, we present projections of future agricultural output under various policy scenarios. Forests 2012-12-18 3 4 Article 10.3390/f3041133 1133 1156 1999-4907 2012-12-18 doi: 10.3390/f3041133 Suzi Kerr Simon Anastasiadis Alex Olssen William Power Levente Timar Wei Zhang http://www.mdpi.com/1999-4907/3/4/1104 Longleaf pine (Pinus palustris Mill.) is an important tree species of the southeast U.S. Currently there is no comprehensive stand-level growth and yield model for the species. The model system described here estimates site index (SI) if dominant height (Hdom) and stand age are known (inversely, the model can project Hdom at any given age if SI is known). The survival (N) equation was dependent on stand age and Hdom, predicting greater mortality on stands with larger Hdom. The function that predicts stand basal area (BA) for unthinned stands was dependent on N and Hdom. For thinned stands BA was predicted with a competition index that was dependent on stand age. The function that best predicted stand stem volume (outside or inside bark) was dependent on BA and Hdom. All functions performed well for a wide range of stand ages and productivity, with coefficients of determination ranging between 0.946 (BA) and 0.998 (N). We also developed equations to estimate merchantable volume yield consisting of different combinations of threshold diameter at breast height and top diameter for longleaf pine stands. The equations presented in this study performed similarly or slightly better than other reported models to estimate future N, Hdom and BA. The system presented here provides important new tools for supporting future longleaf pine management and research. Forests 2012-12-18 3 4 Article 10.3390/f3041104 1104 1132 1999-4907 2012-12-18 doi: 10.3390/f3041104 Carlos Gonzalez-Benecke Salvador Gezan Daniel Leduc Timothy Martin Wendell Cropper Lisa Samuelson http://www.mdpi.com/1999-4907/3/4/1086 Changes in climate are predicted to significantly affect the productivity of trees in the Great Lakes region over the next century. Forest management decisions, such as initial stand density, can promote climatic resiliency and moderate decreased productivity through the reduction of tree competition. The influences of climate (temperature and precipitation) and forest management (initial stand density) on the productivity of red pine (Pinus resinosa) across multiple sites within Huron National Forest, Michigan, were examined using dendrochronological methods. Two common planting regimes were compared in this analysis; low initial density (<988 trees per hectare) and high initial density (>1977 trees per hectare). Low initial density stands were found to have a higher climatic resilience by combining equal or greater measures of productivity, while having a reduced sensitivity to monthly and seasonal climate, particularly to summer drought. Forests 2012-12-17 3 4 Article 10.3390/f3041086 1086 1103 1999-4907 2012-12-17 doi: 10.3390/f3041086 Matthew Magruder Sophan Chhin Andrew Monks Joseph O'Brien http://www.mdpi.com/1999-4907/3/4/1071 Phosphorus is widely deficient throughout the southern pine region of the United States. Growth responses to P fertilization are generally long-lasting in a wide range of soil types, but little is known about fertilization rates and long-term P cycling and availability. In 1982, exceptionally high P fertilization rates (0, 81, 162, and 324 kg P ha−1) were applied to a loamy Ultisol in central Louisiana, USA. We measured vegetation responses at age 27 years and sequentially extracted soil P to 1 m to elucidate potential P availability into the next rotation. Loblolly pine responded well to the lowest fertilization rate; total biomass was 39% greater in the fertilized plots compared to the unfertilized plots, but higher fertilization rates had no effect, presumably due to induced N-limitations. What little fertilizer P was found in the soils was in the moderately labile NaOH fraction in the surface 20 cm, and may be slowly available to the next pine rotation. Normal rates of P fertilizer will maintain elevated available P well into a second rotation in loamy Pleisteocene Ultisols of the western Gulf Coastal Plain. Exceptionally high rates were not effective at increasing potentially available P beyond normal rates. Forests 2012-11-22 3 4 Article 10.3390/f3041071 1071 1085 1999-4907 2012-11-22 doi: 10.3390/f3041071 D. Andrew Scott Christine M. Bliss http://www.mdpi.com/1999-4907/3/4/1034 Fire-adapted forests of the Lake States region are poorly studied relative to those of the western and southeastern United States and our knowledge base of regional short- and long-term fire effects on soils is limited. We compiled and assessed the body of literature addressing fire effects on soils in Lake States forests to facilitate the re-measurement of previous studies for the development of new long-term datasets, and to identify existing gaps in the regional knowledge of fire effects on forest soils. Most studies reviewed addressed fire effects on chemical properties in pine-dominated forests, and long-term (>10 years) studies were limited. The major gaps in knowledge we identified include: (1) information on fire temperature and behavior information that would enhance interpretation of fire effects; (2) underrepresentation of the variety of forest types in the Lake States region; (3) information on nutrient fluxes and ecosystem processes; and (4) fire effects on soil organisms. Resolving these knowledge gaps via future research will provide for a more comprehensive understanding of fire effects in Lake States forest soils. Advancing the understanding of fire effects on soil processes and patterns in Lake States forests is critical for designing regionally appropriate long-term forest planning and management activities. Forests 2012-11-19 3 4 Review 10.3390/f3041034 1034 1070 1999-4907 2012-11-19 doi: 10.3390/f3041034 Jessica R. Miesel P. Charles Goebel R. Gregory Corace David M. Hix Randall Kolka Brian Palik David Mladenoff http://www.mdpi.com/1999-4907/3/4/1017 The ability to restore American chestnut (Castanea dentata) through the planting of blight-resistant (Cryphonectria parasitica) trees is currently being tested. Forest-based research on the species’ silvicultural requirements and chestnut blight development are lacking. Pure American chestnut seedlings were planted in a two-age shelterwood forest with low residual basal area and in a midstory-removal treatment with high residual basal area. Survival did not differ between silvicultural treatments and averaged 67 percent across both treatments by the fifth year. Trees in the two-age shelterwood were 2.36 m and 16.8 mm larger in height and ground-line diameter, respectively, compared to trees in the midstory-removal by the fifth growing season. Blight occurrence was not affected by silvicultural treatment. Exploratory analyses indicated that seedling grading at planting and keeping trees free-to-grow through competition control would have resulted in a two-year gain in height and GLD growth in the two-age shelterwood treatment. The two-age shelterwood represented the most efficacious prescription for chestnut restoration, but the midstory-removal prescription may offer a reasonable alternative in areas where harvesting must be delayed. Forests 2012-11-09 3 4 Article 10.3390/f3041017 1017 1033 1999-4907 2012-11-09 doi: 10.3390/f3041017 Stacy Clark Henry McNab David Loftis Stanley Zarnoch http://www.mdpi.com/1999-4907/3/4/997 The impact of invasive plant species in national parks and forests in Vietnam is undocumented and management plans have yet to be developed. Ten national parks, ranging from uncut to degraded forests located throughout Vietnam, were surveyed for invasive plant species. Transects were set up along roads, trails where local people access park areas, and also tracks through natural forest. Of 134 exotic weeds, 25 were classified as invasive species and the number of invasive species ranged from 8 to 15 per park. An assessment of the risk of invasive species was made for three national parks based on an invasive species assessment protocol. Examples of highly invasive species were Chromolaena odorata and Mimosa diplotricha in Cat Ba National Park (island evergreen secondary forest over limestone); Mimosa pigra, Panicum repens and Eichhornia crassipes in Tram Chim National Park (lowland wetland forest dominated by melaleuca); and C. odorata, Mikania micrantha and M. diplotricha in Son Tra Nature Conservation area (peninsula evergreen secondary forest). Strategies to monitor and manage invasive weeds in forests and national parks in Vietnam are outlined. Forests 2012-10-30 3 4 Article 10.3390/f3040997 997 1016 1999-4907 2012-10-30 doi: 10.3390/f3040997 Dang Tan Pham Thu Bernard Dell http://www.mdpi.com/1999-4907/3/4/986 Over 400 species of insects have been found in association with eastern hemlock in the southern Appalachians. Eastern hemlock stands provide an ideal habitat for all life stages of mycetophilids. However, the diversity, distribution and co-occurrence patterns of these species throughout the tree canopy are unknown. This study was initiated to evaluate abundance, species richness and species composition within three designated strata in the canopy of eastern hemlock, assess species for vertical stratification patterns, and determine if co-occurrence patterns of mycetophilid species are random or non-random. During this study, 24 species representing 14 genera were identified and evaluated. Mycetophilid abundance, species richness and composition differed among the lower, middle, and upper strata. Unique assemblages were identified in each stratum, indicating vertical stratification. The upper stratum of the canopy had four exclusive species, the middle had six exclusive species, and the lower stratum had nine exclusive species. The co-occurrence pattern of mycetophilid species in the canopy of eastern hemlock was non-random. Forests 2012-10-24 3 4 Article 10.3390/f3040986 986 996 1999-4907 2012-10-24 doi: 10.3390/f3040986 Carla Coots Paris Lambdin Jerome Grant Rusty Rhea http://www.mdpi.com/1999-4907/3/4/959 To assess effects of low-intensity fire, we combined two silvicultural prescriptions with prescribed fire in the California Cascade Range. In the first treatment, two 100-ha stands were thinned to reduce density while retaining old-growth structural characteristics, yielding residual stands with high structural diversity (HSD). Two other 100-ha plots were thinned to minimize old growth structure, producing even-aged stands of low structural diversity (LSD), and one 50-ha split-plot from each treatment was burned. In addition, two 50 ha old-growth Research Natural Areas (RNA) were selected as untreated reference plots, one of which was also burned. Fire treatments profoundly altered mite assemblages in the short term, and forest structure modification likely exacerbated that response. Sampling conducted two years following treatment confirmed a continuing decline in oribatid mite abundance. Oribatid species richness and assemblage heterogeneity also declined, and community dominance patterns were disrupted. Oribatid responses to fire were either more intense or began earlier in the LSD treatments, suggesting that removal of old-growth structure exacerbated mite responses to fire. Prostigmatids recovered quickly, but their populations nonetheless diminished significantly in burned split-plots. Mite assemblage responses to prescribed fire were continuing nearly two years later, with no clear evidence of recovery. Forests 2012-10-24 3 4 Article 10.3390/f3040959 959 985 1999-4907 2012-10-24 doi: 10.3390/f3040959 Michael Camann Karen Lamoncha Nancy Gillette http://www.mdpi.com/1999-4907/3/4/944 Temperate conifer forests in the Colorado Front Range are fire-adapted ecosystems where wildland fires leave a legacy in the form of char and charcoal. Long-term soil charcoal C (CC) pools result from the combined effects of wildland fires, aboveground biomass characteristics and soil transfer mechanisms. We measured CC pools in surface soils (0–10 cm) at mid-slope positions on east facing aspects in five continuous foothills shrubland and conifer forest types. We found a significant statistical effect of vegetation type on CC pools along this ecological gradient, but not a linear pattern increasing with elevation gain. There is a weak bimodal pattern of CC gain with elevation between foothills shrublands (1.2 mg CC ha−1) and the lower montane, ponderosa pine (1.5 mg CC ha−1) and Douglas-fir (1.5 mg CC ha−1) forest types prior to a mid-elevation decline in upper montane lodgepole pine forests (1.2 mg CC ha−1) before increasing again in the spruce/subalpine fir forests (1.5 mg CC ha−1). We propose that CC forms and accumulates via unique ecological conditions such as fire regime. The range of soil CC amounts and ratios of CC to total SOC are comparable to but lower than other regional estimates. Forests 2012-10-22 3 4 Article 10.3390/f3040944 944 958 1999-4907 2012-10-22 doi: 10.3390/f3040944 Christopher Licata Robert Sanford http://www.mdpi.com/1999-4907/3/4/923 Recreation activity preferences in forest settings were explored in a scene preference study. The importance of type of human intervention and the level of biodiversity for preference and intention to engage in recreation activities were examined in a sample of forestry and social science students in Sweden. Results showed that forestry students displayed an almost equally strong preference for natural-looking scenes as for scenes with traces of recreation (e.g., paths), whereas social science students preferred recreational scenes the most. Least preferred were scenes with traces of forest management. Different forest settings were furthermore preferred for different recreation activities. Recreational settings were favored for walking and going on outings, and natural-looking settings were more appreciated for picking berries or mushrooms. Respondents displayed a stronger intention to study plants and animals in high biodiversity settings and the intention to exercise was stronger in low biodiversity settings. Implications for future land use planning and forest management are discussed. Forests 2012-10-18 3 4 Article 10.3390/f3040923 923 943 1999-4907 2012-10-18 doi: 10.3390/f3040923 Louise Eriksson Annika M. Nordlund Olof Olsson Kerstin Westin http://www.mdpi.com/1999-4907/3/4/903 Plants alter soil characteristics causing changes in their subsequent growth resulting in positive or negative feedback on both their own fitness and that of other plants. In a greenhouse study, we investigated whether the sign and strength of feedback changed across two distinct soil types, and whether effects were due to shifts in biotic or abiotic soil traits. Using soils from two different locations, we examined growth of the exotic invasive shrub, Lonicera maackii and the related native shrub, Diervilla lonicera, in unconditioned soils and in soils conditioned by previous growth of L. maackii, D. lonicera, and Fraxinus pennsylvanica. In a sandy acidic soil, L. maackii showed positive feedback in unsterilized soils, but its growth decreased and positive feedback became negative with sterilization in this soil. In a loamy circumneutral soil, L. maackii displayed neutral to negative feedback in unsterilized soils, but sterilization significantly increased growth in all conditioning treatments and caused feedback to become strongly negative. Native D. lonicera displayed negative feedback in unsterilized soil of both the sandy and loamy types, but sterilization either eliminated or reversed feedback relationships. Soil conditioning by L. maackii and F. pennsylvanica had very similar feedbacks on L. maackii and D. lonicera. While some abiotic soil traits varied across soil types and were affected by conditioning, soil biota sensitive to sterilization were apparently important mediators of both positive and negative feedback effects. Forests 2012-10-16 3 4 Article 10.3390/f3040903 903 922 1999-4907 2012-10-16 doi: 10.3390/f3040903 Kelly Schradin Don Cipollini http://www.mdpi.com/1999-4907/3/4/896 Native or exotic woody plants can proliferate in dry and moist eucalypt ecosystems shading out many other native species, contributing to chronic decline of eucalypts and reinforcing unnatural fire regimes and nutrient cycling processes. Whether native or exotic, they proliferate as a consequence of disturbances which impact directly on these ecosystems. The most extensive ongoing disturbance since European occupation of Australia has been the disruption of frequent mild burning by humans. This burning maintained dynamically stable nutrient cycling processes and a competitive balance in dry and moist eucalypt systems and prevented plant “invasions”. Forests 2012-10-08 3 4 Communication 10.3390/f3040896 896 902 1999-4907 2012-10-08 doi: 10.3390/f3040896 Vic Jurskis http://www.mdpi.com/1999-4907/3/4/881 A recent policy response to halting global forest deforestation and degradation, and any resulting greenhouse gas emissions is REDD+, which also includes the role of conservation, sustainable management of forests and enhancement of forest carbon stocks. Although still in its infancy, the success of REDD+ will depend significantly on whether it can be economically viable and if any resulting payments are sufficient to cover the opportunity cost plus any transaction cost. Where tenure security over forest is weak, REDD+ can pose a risk for forest communities, who could be dispossessed, excluded and marginalized. This review of existing studies explores how payment for avoided deforestation, and forest tenure impact the success of REDD+ projects in terms of effectiveness, efficiency and equity. Effectiveness refers to the difference between deforestation with and without REDD+, efficiency refers to avoiding deforestation at minimal cost, and equity refers to the implication of REDD+ on benefit sharing. We conclude that the potential success or failure of REDD+ as a means to reduce deforestation and carbon emission on forest commons depends critically on designing projects that work within existing informal tenure institutions to ensure that carbon storage benefits align with livelihood benefits. Forests 2012-10-01 3 4 Review 10.3390/f3040881 881 895 1999-4907 2012-10-01 doi: 10.3390/f3040881 Edward B. Barbier Anteneh T. Tesfaw http://www.mdpi.com/1999-4907/3/4/864 A field-based study was performed to broaden our knowledge of operational efficiency losses associated with the neglect of the proper maintenance of the delimbing and feeding mechanisms of a harvester. The post-harvest assessments of industrial round-wood (IRW) processing damage, fuel consumption and productivity were examined in clearcutting operations. Observations were made of seven combinations of wear levels of feed rollers (A—heavy, B—medium, C and C’—without wear) and sharpening states of delimbing knives (1—incorrect, 2—correct), depending on the degree of feed roller wear and matching of angles of knife blades to the technical requirements. The processing defects of IRW were broken down into unprocessed branches, bark stripping, and damage caused by feed roller spikes. The results were then compared with the effective quality requirements, and the IRW losses in terms of the reject rates (RR) were determined in the context of the technical condition. The most frequent damage was by unprocessed branches. The harvester with correctly sharpened knives produced the minimum RR (4% of pine, 6% of spruce and 6% birch logs). The quality of IRW harvested under B1 and C1 resulted in 6%, 6% and 8%. A1 turned out to be the lowest (12%, 10% and 8%). Improvement in the maintenance of delimbing knives can reduce the RR of IRW by 5%. Timely restoration of worn-out rollers can increase productivity by 2% and reduce fuel consumption by 5%. Forests 2012-09-27 3 4 Article 10.3390/f3040864 864 880 1999-4907 2012-09-27 doi: 10.3390/f3040864 Yuri Gerasimov Alexander Seliverstov Vladimir Syunev http://www.mdpi.com/1999-4907/3/4/853 Imperata cylindrica is an invasive plant species that threatens diversity and forest productivity in southeastern ecosystems. We examined the effects of disturbance events, particularly fire and hurricane/salvage harvesting, to determine the effects on I. cylindrica abundance in longleaf pine (Pinus palustris) forests in the Florida panhandle. Areas that were burned or had greater biomass removal following a hurricane had a greater number of I. cylindrica patches and larger patch size. These results highlight the importance of disturbance events on expanding invasive species populations in this region and are likely applicable for other invasive species as well. Monitoring and treatment should follow disturbance events to ensure that invasive species populations do not exceed unmanageable levels. Forests 2012-09-26 3 4 Article 10.3390/f3040853 853 863 1999-4907 2012-09-26 doi: 10.3390/f3040853 Eric J. Holzmueller Shibu Jose http://www.mdpi.com/1999-4907/3/3/840 Invasive plant species have long been known to cause extensive damage, both economically and ecologically, to native ecosystems. They have historically been introduced by the public, both intentional and not, for a variety of reasons. Many of the woody shrubs, such as Lonicera maackii and Rosa multiflora were introduced for wildlife cover, forage, and ornamental value. These invasives have quickly out-competed native flora, in many cases drastically impacting and changing the environment they inhabit. In this review, chosen species characteristics have been described, their pathway to invasion explained, and their impacts to native wildlife highlighted. Based on a review of the scientific literature, we determined that not all effects by invasive plants are negative. Many positive impacts can be seen throughout the literature, such as native frogs utilizing Microstegium vimineum for cover and nesting habitat. However, some important invasive plant species were not included in this review due to a lack of literature on the subject of the effects on fauna. While much is known about their economic impact and the impact on native plant species, additional work needs to be done in the field of wildlife research to determine current impacts and future implications of non-native, invasive plants on native fauna. Forests 2012-09-12 3 3 Review 10.3390/f3030840 840 852 1999-4907 2012-09-12 doi: 10.3390/f3030840 Stephanie J. Hayes Eric J. Holzmueller http://www.mdpi.com/1999-4907/3/3/818 Species-specific and mixed-species volume and above ground biomass allometric equations were developed for 15 indigenous tree species and four tree fern species in New Zealand. A mixed-species tree equation based on breast height diameter (DBH) and tree height (H) provided acceptable estimates of stem plus branch (>10 cm in diameter over bark) volume, which was multiplied by live tree density to estimate dry matter. For dead standing spars, DBH, estimated original height, actual spar height and compatible volume/taper functions provided estimates of dead stem volume, which was multiplied by live tree density and a density modifier based on log decay class from field assessments to estimate dry matter. Live tree density was estimated using ratio estimators. Ratio estimators were based on biomass sample trees, and utilized density data from outerwood basic density surveys which were available for 35 tree species sampled throughout New Zealand. Foliage and branch ( < 10 cm in diameter over bark) dry matter were estimated directly from tree DBH. Tree fern above ground dry matter was estimated using allometric equations based on DBH and H. Due to insufficient data, below ground carbon for trees was estimated using the default IPCC root/shoot ratio of 25%, but for tree ferns it was estimated using measured root/shoot ratios which averaged 20%. Forests 2012-09-10 3 3 Article 10.3390/f3030818 818 839 1999-4907 2012-09-10 doi: 10.3390/f3030818 Peter N. Beets Mark O. Kimberley Graeme R. Oliver Stephen H. Pearce J. Doug Graham Andrea Brandon http://www.mdpi.com/1999-4907/3/3/799 Distribution models of invasive plants are very useful tools for conservation management. There are challenges in modeling expanding populations, especially in a dynamic environment, and when data are limited. In this paper, predictive habitat models were assessed for three invasive plant species, at differing levels of occurrence, using two different habitat modeling techniques: logistic regression and maximum entropy. The influence of disturbance, spatial and temporal heterogeneity, and other landscape characteristics is assessed by creating regional level models based on occurrence records from the USDA Forest Service’s Forest Inventory and Analysis database. Logistic regression and maximum entropy models were assessed independently. Ensemble models were developed to combine the predictions of the two analysis approaches to obtain a more robust prediction estimate. All species had strong models with Area Under the receiver operator Curve (AUC) of >0.75. The species with the highest occurrence, Ligustrum spp., had the greatest agreement between the models (93%). Lolium arundinaceum had the most disagreement between models at 33% and the lowest AUC values. Overall, the strength of integrative modeling in assessing and understanding habitat modeling was demonstrated. Forests 2012-09-07 3 3 Article 10.3390/f3030799 799 817 1999-4907 2012-09-07 doi: 10.3390/f3030799 Dawn Lemke Jennifer A. Brown http://www.mdpi.com/1999-4907/3/3/787 The Glentress Trial Area is an extensive research area in southern Scotland of 117 ha where a long-term trial of the transformation of even-aged plantations to continuous cover has been in progress since 1952. During the assessment of permanent sample plots in 1990 information on the species and spatial position of saplings (trees taller than 1.3 m with a diameter at breast height of < 7 cm) was recorded. This provided a unique opportunity to investigate the long-term survival of saplings during the transformation process when the Trial Area was reassessed in 2009. The main finding was that 37% of saplings survived the 19-year period and the majority developed into trees (≥7 cm diameter at breast height). There was considerable variation between species, the lowest survival of saplings was European larch (Larix decidua Mill.) (13%) and the highest European beech (Fagus sylvatica L.) (55%); however differences between species were not significant. There were, however, significant differences between the six management areas with three with high sapling survival (55% to 61%) but others much lower (27% to 32%). If this result is confirmed by other studies, covering a broader range of sites, management guidance that assumes 90% survival will need to be revised. Forests 2012-09-07 3 3 Article 10.3390/f3030787 787 798 1999-4907 2012-09-07 doi: 10.3390/f3030787 Gary Kerr Hamish Mackintosh http://www.mdpi.com/1999-4907/3/3/764 Understanding the spatial pattern of ecosystem services is important for effective environmental policy and decision-making. In this study, we use a geospatial decision-support tool (Marxan) to identify conservation priorities for habitat and a suite of ecosystem services (storage carbon, soil retention and water yield) in the Upper Paraná Atlantic Forest from Misiones, Argentina—an area of global conservation priority. Using these results, we then evaluate the efficiency of existing protected areas in conserving both habitat and ecosystem services. Selected areas for conserving habitat had an overlap of carbon and soil ecosystem services. Yet, selected areas for water yield did not have this overlap. Furthermore, selected areas with relatively high overlap of ecosystem services tended to be inside protected areas; however, other important areas for ecosystem services (i.e., central highlands) do not have legal protection, revealing the importance of enforcing existing environmental regulations in these areas. Forests 2012-08-27 3 3 Article 10.3390/f3030764 764 786 1999-4907 2012-08-27 doi: 10.3390/f3030764 Andrea E. Izquierdo Matthew L. Clark http://www.mdpi.com/1999-4907/3/3/745 Long-term changes for invasive trees and shrubs presence in 16 floras encompassing four remnant urban forests of the coastal northeastern United States were examined for relationships with arboricultural introductions’ residence time and planting intensity, and state level recognition of regional invasive woody taxa. The number of invasive woody taxa significantly increased over the period 1818 to 2011 which encompasses the 16 floras. No significant Pearson product moment correlations were found for residence time as the year of introduction to arboriculture with presence in the 16 floras as well as with the 4 most recent floras. In contrast to residence time, planting intensity from the North American flora and two botanical gardens floras of the region from 1811 to 1818 and New York and Philadelphia parks floras from 1857 to 1903 did have significant correlations with the 16 floras and the 4 most recent floras. State level recognition of regional invasive woody taxa showed significant correlations with presence in all 16 floras as well as the 4 most recent floras. Monitoring for range expansion by the regional invasive woody taxa is essential because only 18% of the 98 taxa are present in all 4 of the most recent floras. Forests 2012-08-27 3 3 Article 10.3390/f3030745 745 763 1999-4907 2012-08-27 doi: 10.3390/f3030745 Robert E. Loeb http://www.mdpi.com/1999-4907/3/3/736 Forest management strategies and policies such as REDD (reduced emissions from deforestation and forest degradation) may have unintentional implications for forest sectors in countries not targeted by such policies. The success of a policy effort like REDD would result in a significant reduction in deforestation and forest degradation and an ensuing reduction in the supply of natural forest timber production within participating countries. This could in turn result in price increases, inducing a supply response outside project boundaries with possible implications for forest management as well as global carbon emissions. This paper reviews the literature to discern potential timber market implications for countries sourcing wood products from developing countries affected by REDD related conservation efforts. The literature reviewed shows varying degrees of market effects leakage—policy actions in one place creating incentives for third parties to increase timber harvesting elsewhere through the price mechanism—ranging from negligible to substantial. However, wood products in the studies reviewed are dealt with on quite an aggregated scale and are assumed to be more or less perfect substitutes for wood products outside conservation effort boundaries. The review suggests that a thorough mapping of the end-uses of tropical timber is needed to comprehensively analyze impacts on wood-product markets in regions such as Europe from conservation efforts in tropical developing countries. The types of tropical timber expected to be affected, in which applications they are used, which are the most likely substitutes and where they would be sourced, are issues that, along with empirical analysis of supply and demand price elasticities and degree of substitutability, should be investigated when assessing the overall effectiveness of REDD. Forests 2012-08-27 3 3 Article 10.3390/f3030736 736 744 1999-4907 2012-08-27 doi: 10.3390/f3030736 Ragnar Jonsson Werner Mbongo Adam Felton Mattias Boman http://www.mdpi.com/1999-4907/3/3/723 Site index (SI) curves for H20 (dominant height at 20 years total age) were constructed for hybrid larch (Larix × eurolepis Henry) growing in 26 stands on former farmland in southern and central Sweden (Latitude 56–60° N.). The mean total age of the stands was 23 ± 10 (range 17–49) years; the mean diameter at breast height (ob) was 16 (7–34) cm; the mean height was 14 (8–29) m; and the stands had a mean density of 993 (266–2195) stems ha−1. A model derived by Cieszewski (2001) performed best for the data. The model explained 99% of the observed variation in height development. No apparent bias across the range of predicted site indices was found. SI was examined in relation to soil types. Multiple samples were available for three soil types: light clay, medium clay and till. There were no significant differences between these soil types with respect to the choice of SI curve. Forests 2012-08-21 3 3 Article 10.3390/f3030723 723 735 1999-4907 2012-08-21 doi: 10.3390/f3030723 Tord Johansson http://www.mdpi.com/1999-4907/3/3/700 In dry western Unites States forests where past resource management has altered the ecological role of fire and stand characteristics alike, mechanical thinning and prescribed burning are commonly applied in wildfire hazard abatement. The reduced surface fuel loads and stand structures resulting from fuels modifications are temporary, yet few studies have assessed the lifespan of treatment effects. We sampled forest fuels and vegetation following fuels reduction in a chronosequence of time since treatment in the northern Sierra Nevada and southern Cascade regions of California. Treatments altered overstory characteristics including stand density, basal area, and species composition. These effects were still present on the oldest treatment sites (8–15 years post-treatment). Other stand characteristics, particularly timelag fuel loads, seedling density, and shrub cover, exhibited substantial variability, and differences between treatment age classes and between treatment and control groups were not statistically significant. Forests 2012-08-20 3 3 Article 10.3390/f3030700 700 722 1999-4907 2012-08-20 doi: 10.3390/f3030700 Lindsay A. Chiono Kevin L. O’Hara Michael J. De Lasaux Glenn A. Nader Scott L. Stephens http://www.mdpi.com/1999-4907/3/3/684 Longleaf pine has been classified as very shade intolerant but leaf physiological plasticity to light is not well understood, especially given longleaf pine’s persistent seedling grass stage. We examined leaf morphological and physiological responses to light in one-year-old grass-stage seedlings and young trees ranging in height from 4.6 m to 6.3 m to test the hypothesis that young longleaf pine would demonstrate leaf phenotypic plasticity to light environment. Seedlings were grown in a greenhouse under ambient levels of photosynthetically active radiation (PAR) or a 50% reduction in ambient PAR and whole branches of trees were shaded to provide a 50% reduction in ambient PAR. In seedlings, shading reduced leaf mass per unit area (LMA), the light compensation point, and leaf dark respiration (RD), and increased the ratio of light-saturated photosynthesis to RD and chlorophyll b and total chlorophyll expressed per unit leaf dry weight. In trees, shading reduced LMA, increased chlorophyll a, chlorophyll b and total chlorophyll on a leaf dry weight basis, and increased allocation of total foliar nitrogen to chlorophyll nitrogen. Changes in leaf morphological and physiological traits indicate a degree of shade tolerance that may have implications for even and uneven-aged management of longleaf pine. Forests 2012-08-20 3 3 Article 10.3390/f3030684 684 699 1999-4907 2012-08-20 doi: 10.3390/f3030684 Lisa J. Samuelson Tom A. Stokes http://www.mdpi.com/1999-4907/3/3/653 To quantify the climate change impacts of forestry and forest management options, we must consider the entire forestry system: the carbon dynamics of the forest, the life cycle of harvested wood products, and the substitution benefit of using biomass and wood products compared to more greenhouse gas intensive options. This paper presents modelled estimates of the greenhouse gas balance of two key native forest areas managed for production in New South Wales for a period of 200 years, and compares it to the option of managing for conservation only. These two case studies show that forests managed for production provide the greatest ongoing greenhouse gas benefits, with long-term carbon storage in products, and product substitution benefits critical to the outcome. Thus native forests could play a significant part in climate change mitigation, particularly when sustainably managed for production of wood and non-wood products including biomass for bioenergy. The potential role of production forestry in mitigating climate change, though substantial, has been largely overlooked in recent Australian climate change policy. Forests 2012-08-17 3 3 Article 10.3390/f3030653 653 683 1999-4907 2012-08-17 doi: 10.3390/f3030653 Fabiano de Aquino Ximenes Brendan H. George Annette Cowie Justin Williams Georgina Kelly http://www.mdpi.com/1999-4907/3/3/632 Pitfall traps were used to sample beetles (Coleoptera) in plots with or without inputs of dead loblolly pine (Pinus taeda L.) wood at four locations (Louisiana, Mississippi, North Carolina and Texas) on the coastal plain of the southeastern United States. The plots were established in 1998 and sampling took place in 1998, 1999, and 2002 (only 1998 for North Carolina). Overall, beetles were more species rich, abundant and diverse in dead wood addition plots than in reference plots. While these differences were greatest in 1998 and lessened thereafter, they were not found to be significant in 1998 due largely to interactions between location and treatment. Specifically, the results from North Carolina were inconsistent with those from the other three locations. When these data were excluded from the analyses, the differences in overall beetle richness for 1998 became statistically significant. Beetle diversity was significantly higher in the dead wood plots in 1999 but by 2002 there were no differences between dead wood added and control plots. The positive influence of dead wood additions on the beetle community can be largely attributed to the saproxylic fauna (species dependent on dead wood), which, when analyzed separately, were significantly more species rich and diverse in dead wood plots in 1998 and 1999. Ground beetles (Carabidae) and other species, by contrast, were not significantly affected. These results suggest manipulations of dead wood in pine forests have variable effects on beetles according to life history characteristics. Forests 2012-08-15 3 3 Article 10.3390/f3030632 632 652 1999-4907 2012-08-15 doi: 10.3390/f3030632 Kier D. Klepzig Michael L. Ferro Michael D. Ulyshen Matthew L. Gimmel Jolie B. Mahfouz Allan E. Tiarks Chris E. Carlton http://www.mdpi.com/1999-4907/3/3/614 At the forest landscape/region level, based on annual Forest Inventory and Analysis plot data from 1999 to 2010, oak decline and mortality trends for major oak species (groups) were examined in the Ozark Highlands of Arkansas and Missouri. Oak decline has elevated cumulative mortality of red oak species to between 11 and 15 percent in terms of relative density and basal area of standing dead oak trees, respectively. These values are three to five times higher than for white oak group and non-oak species. Oak decline and associated escalating mortality have occurred primarily in red oak species while the white oak group has maintained a relatively stable mortality rate that is comparable to non-oak species. Cross-correlation analyses indicate that mortality in the red oak group was significantly correlated with the growing season Palmer drought severity index (PDSI) and usually lagged two to three years following single drought events. Moreover, based on the past 17 years PDSI data, it appears that the cumulative impacts of drought may last up to 10 years. The Ozark Highlands experienced a severe drought extending from 1998 to 2000 and another milder drought from 2005 to 2006. These drought events triggered the escalation of mortality starting around year 2000. Spatially, high red oak mortality sites (hot spots with proportional basal area mortality > 0.12) initially occurred in the central Ozarks and spread gradually over most of the Ozark Highlands as regional droughts continued. In contrast, sites with elevated white oak and non-oak mortality occurred sporadically, mainly in the southern portion (Arkansas) of the Ozark Highlands. During the most recent inventory period (2006–2010), over 60%, 7% and 5% of red oak, white oak and non-oak groups, respectively, had relative mortality rates of > 12%. Forests 2012-08-06 3 3 Article 10.3390/f3030614 614 631 1999-4907 2012-08-06 doi: 10.3390/f3030614 Zhaofei Fan Xiuli Fan Michael K. Crosby W. Keith Moser Hong He Martin A. Spetich Stephen R. Shifley http://www.mdpi.com/1999-4907/3/3/605 Garlic mustard, an invasive exotic biennial herb, has been identified in the Upper Peninsula of Michigan, but is not yet widely distributed. We tested the effectiveness and impact of management tools for garlic mustard in northern hardwood forests. Six treatment types (no treatment control, hand-pull, herbicide, hand-pull/herbicide, scorch, and hand-pull/scorch) were applied within a northern hardwood forest invaded by garlic mustard. We sampled understory vegetation within plots to compare garlic mustard abundance (distinguishing first and second year plants) and native plant diversity before and after treatment. Results immediately following treatment indicated that garlic mustard seedling abundance was significantly reduced by herbicide, hand-pull/herbicide, scorch, and hand-pull/scorch treatments, and that adult abundance was reduced by all treatments. However, sampling of treatment sites one year later showed an increase in seedling abundance in herbicide and hand-pull/herbicide plots. Adult garlic mustard abundance after one year was lower than the control with the exception of the hand-pull plots where adult abundance did not differ. After one year, understory species richness and Shannon’s Diversity were lower in the herbicide and pull/herbicide treatments. Based on these results, we conclude that single-year treatment of garlic mustard with hand-pulling, herbicide, and/or scorching is ineffective in reducing garlic mustard abundance and may inadvertently increase the success of garlic mustard, while negatively impacting native understory species. Forests 2012-08-03 3 3 Article 10.3390/f3030605 605 613 1999-4907 2012-08-03 doi: 10.3390/f3030605 Lindsey M. Shartell Linda M. Nagel Andrew J. Storer http://www.mdpi.com/1999-4907/3/3/591 The objectives of this study were to (1) characterize tree-based spatial patterning of soil properties and understory vegetation in frequently burned (“reference state”) and fire-suppressed longleaf pine forests; and (2) determine how restoration treatments affected patterning. To attain these objectives, we used an experimental manipulation of management types implemented 15 years ago in Florida. We randomly located six mature longleaf pine trees in one reference and four restoration treatments (i.e., burn, control, herbicide, and mechanical), for a total of 36 trees. In addition to the original treatments and as part of a monitoring program, all plots were subjected to several prescribed fires during these 15 years. Under each tree, we sampled mineral soil and understory vegetation at 1 m, 2 m, 3 m and 4 m (vegetation only) away from the tree. At these sites, soil carbon and nitrogen were higher near the trunk while graminoids, forbs and saw palmetto covers showed an opposite trend. Our results confirmed that longleaf pine trees affect the spatial patterning of soil and understory vegetation, and this patterning was mostly limited to the restoration sites. We suggest frequent burning as a probable cause for a lack of spatial structure in the “reference state”. We attribute the presence of spatial patterning in the restoration sites to accumulation of organic materials near the base of mature trees. Forests 2012-08-03 3 3 Article 10.3390/f3030591 591 604 1999-4907 2012-08-03 doi: 10.3390/f3030591 Martin Lavoie Michelle C. Mack John K. Hiers Scott Pokswinski http://www.mdpi.com/1999-4907/3/3/573 Japanese honeysuckle is one of the most aggressive invasive vines in forestlands of the southern United States. We analyzed field data collected by the U.S. Forest Service to identify potential determinants of invasion and to predict likelihood of further invasion under a variety of possible management strategies. Results of logistic regression, which classified 74% of the field plots correctly with regard to species presence and absence, indicated probability of invasion is correlated positively with adjacency to water bodies, temperature, site productivity, species diversity, and private land ownership, and is correlated negatively with slope, stand age, artificial regeneration, distance to the nearest road, and fire disturbance. Habitats most at risk to further invasion under current conditions occur throughout Mississippi, stretching northward across western Tennessee and western Kentucky, westward across southern Arkansas, eastward across north-central Alabama, and also occur in several counties scattered within Virginia. Invasion likelihoods could be increased by global climate change and reduced most by conversion to public land ownership, followed by artificial regeneration, and fire disturbance. While conversion of land ownership may not be feasible, this result suggests the opportunity for decreasing the likelihood of invasions on private lands via using selected management practices. Forests 2012-07-27 3 3 Article 10.3390/f3030573 573 590 1999-4907 2012-07-27 doi: 10.3390/f3030573 Hsiao-Hsuan Wang Carissa L. Wonkka William E. Grant William E. Rogers http://www.mdpi.com/1999-4907/3/3/546 Reducing emissions from agriculture, forestry, and other land uses is considered an essential ingredient of an effective strategy to mitigate global warming. Required changes in land use and forestry, however, often imply foregoing returns from locally more attractive resource use strategies. We assess and compare the prospects of mitigating climate change through emission reductions from forestry and agriculture in the Brazilian Amazon. We use official statistics, literature, and case study material from both old and new colonization frontiers to identify the scope for emission reductions, in terms of potential additionality, opportunity costs, technological complexity, transaction costs, and risks of economic and environmental spillover effects. Our findings point to a comparative advantage in the Brazilian Amazon of forest conservation-based over land-use modifying mitigation options, especially in terms of higher potential additionality in emission reductions. Low-cost mitigation options do exist also in use-modifying agriculture and forestry, but tend to be technologically complex thus requiring more costly intervention schemes. Our review points to a series of regional development deficits that may come to hamper attempts to tap into the large-scale climate change mitigation potential often associated with the Amazon. Low-hanging fruits for mitigation do exist, but must be carefully identified based on the performance indicators we discuss. Forests 2012-07-27 3 3 Article 10.3390/f3030546 546 572 1999-4907 2012-07-27 doi: 10.3390/f3030546 Jan Börner Sven Wunder http://www.mdpi.com/1999-4907/3/3/528 We investigated the sprouting capacity of poplar stumps in ten 8–21-year old stands growing on former farmland in Sweden situated between 55°N and 60°N. Seven of the stands were planted with the clone OP-42 (Populus maximowiczii Henry × Populus trichocarpa Torr. and Gray), one with black cottonwood (Populus trichocarpa Torr. and Gray) and two with unidentified clones. The poplars’ mean age was 17 years (range 8–21); six of the stands were growing on clay soils, two on tills and two on loam. The studied sprouts were 1–7 years old. Stump sprouting was observed in all studied stands. The number of sprouts per living stump decreased as sprout age increased. The mean dry mass of all sprouts stump−1 was 16.1 ± 14.0 (range 3.3–37.2) kg. A biomass equation was constructed for estimating sprout biomass from the sprouts’ diameter at 10 cm above the ground (D10). The mean total sprout weight per hectare for sprouts amounted to 16.9 ± 14.6 (range 1.2–41.3) tons ha−1 when calculated for the actual living stumps in the studied areas. Forests 2012-07-24 3 3 Article 10.3390/f3030528 528 545 1999-4907 2012-07-24 doi: 10.3390/f3030528 Tord Johansson Birger Hjelm http://www.mdpi.com/1999-4907/3/3/506 Biological activity and the physical environment regulate greenhouse gas fluxes (CH4, N2O and NO) from upland soils. Wildfires are known to alter these factors such that we collected daily weather records, fire return intervals, or specific fire years, and soil data of four specific sites along the Colorado Front Range. These data were used as primary inputs into DAYCENT. In this paper we test the ability of DAYCENT to simulate four forested sites in this area and to address two objectives: (1) to evaluate the short-term influence of fire on trace gas fluxes from burned landscapes; and (2) to compare trace gas fluxes among locations and between pre-/post- fire suppression. The model simulations indicate that CH4 oxidation is relatively unaffected by wildfire. In contrast, gross nitrification rates were reduced by 13.5–37.1% during the fire suppression period. At two of the sites, we calculated increases in gross nitrification rates (>100%), and N2O and NO fluxes during the year of fire relative to the year before a fire. Simulated fire suppression exhibited decreased gross nitrification rates presumably as nitrogen is immobilized. This finding concurs with other studies that highlight the importance of forest fires to maintain soil nitrogen availability. Forests 2012-07-24 3 3 Article 10.3390/f3030506 506 527 1999-4907 2012-07-24 doi: 10.3390/f3030506 Mark A. Gathany Ingrid C. Burke http://www.mdpi.com/1999-4907/3/3/467 Based on theoretical underpinnings and an empirical review of forest laws and regulations of selected countries throughout the Americas, we examine key components of natural forest management and how they are addressed in the legal frameworks of Argentina, Brazil, Chile, Costa Rica, Guatemala, Nicaragua, Paraguay, Uruguay, and the U.S. We consider forest policy directives in terms of legislative, planning, operational, environmental/ecological, social, and economic aspects and classify them by the type of policy obligation: (1) non-discretionary laws or rules; or (2) discretionary, voluntary directives; and, further, by the type of policy approach: (1) a specific technology or practice required or recommended; (2) a process or system requirement or recommendation; or (3) a performance or outcome based requirement or recommendation. Protection of at-risk species and riparian buffers are required in all countries and include specific prescriptions in most; forest management planning and secure, legal land title or tenancy are commonly required; and mandatory processes to protect soil and water quality are customary. Less common requirements include forest monitoring and social and economic aspects, and, when in place, they are usually voluntary. Implications for improved policies to achieve sustainable forest management (SFM) are discussed. Forests 2012-07-06 3 3 Article 10.3390/f3030467 467 505 1999-4907 2012-07-06 doi: 10.3390/f3030467 Kathleen McGinley Raquel Alvarado Frederick Cubbage Diana Diaz Pablo J. Donoso Laércio Antônio Gonçalves Jacovine Fabiano Luiz de Silva Charles MacIntyre Elizabeth Monges Zalazar http://www.mdpi.com/1999-4907/3/3/445 Many scientists and managers have an interest in describing the environment following a fire to understand the effects on soil productivity, vegetation growth, and wildlife habitat, but little research has focused on the scientific rationale for classifying the post-fire environment. We developed an empirically-grounded soil post-fire index (PFI) based on available science and ecological thresholds. Using over 50 literature sources, we identified a minimum of five broad categories of post-fire outcomes: (a) unburned, (b) abundant surface organic matter ( > 85% surface organic matter), (c) moderate amount of surface organic matter ( ≥ 40 through 85%), (d) small amounts of surface organic matter ( < 40%), and (e) absence of surface organic matter (no organic matter left). We then subdivided each broad category on the basis of post-fire mineral soil colors providing a more fine-tuned post-fire soil index. We related each PFI category to characteristics such as soil temperature and duration of heating during fire, and physical, chemical, and biological responses. Classifying or describing post-fire soil conditions consistently will improve interpretations of fire effects research and facilitate communication of potential responses or outcomes (e.g., erosion potential) from fires of varying severities. Forests 2012-07-06 3 3 Article 10.3390/f3030445 445 466 1999-4907 2012-07-06 doi: 10.3390/f3030445 Theresa B. Jain David S. Pilliod Russell T. Graham Leigh B. Lentile Jonathan E. Sandquist http://www.mdpi.com/1999-4907/3/2/431 Forest carbon stocks—both in terms of the standing biomass and the soil organic carbon (OC)—were monitored in the mangrove plantation reforested from an abandoned shrimp pond for the 10 years following land excavation. Excavation to a level of 25 cm below the existing ground level increased the inundation time of tidal water from 463 to 7,597 hours per year, resulting in a significant increase of survival/growth rates for planted mangrove species, Rhizophora mucronata (RM) and Bruguiera cylindrica (BC), and of carbon stocks as well. RM showed high rates of standing biomass accumulation with 98.7 ton/ha while 28.8 ton/ha for BC was measured over 10 years in the excavated area. In contrast, the unexcavated area showed low rates of biomass accumulation, 1.04 ton/ha for RM and 0.53 ton/ha for BC in the same period. The excavated area recorded a twofold increase of soil OC in the upper 5 cm of the surface soil from 71.8 to 154.8 ton/ha in 10 years, however it decreased to 68.3 ton/ha in the unexcavated area where soil OC is susceptible to decomposition. These results imply that the potential of carbon sinks in reforested land from abandoned areas cannot be developed unless hydraulic conditions are properly recovered. The fast growing species Avicennia marina (AM) grew quickly for the first two years after colonization but its growth slowed down afterwards, showing a limited ability of carbon capture. Forests 2012-06-20 3 2 Article 10.3390/f3020431 431 444 1999-4907 2012-06-20 doi: 10.3390/f3020431 Naohiro Matsui Keiyo Morimune Wijarn Meepol Jirasak Chukwamdee http://www.mdpi.com/1999-4907/3/2/417 As part of its efforts to curb greenhouse gas emissions, China has committed to expanding the country’s forest area by 40 million hectares and stocking volume by 1.3 billion m3 from 2006 to 2020. Our analysis suggests that it is very likely that China will realize its goal of forest area expansion; but the target of volume increase represents only a modest gain, which may absorb about 2% of its cumulative carbon emissions. However, China’s forests can be a much more significant carbon sequester and ecosystem services provider if its forest growth rate and stocking level are boosted by improving forest quality and productivity. To that end, however, the silvicultural practices and governance structure must be transformed. Forests 2012-06-20 3 2 Article 10.3390/f3020417 417 430 1999-4907 2012-06-20 doi: 10.3390/f3020417 Ping Liu Runsheng Yin http://www.mdpi.com/1999-4907/3/2/398 This paper compares carbon (C) and nutrient contents in soils (Alfisols derived from andesite), forest floor and vegetation in a former fire (1960) and an adjacent forest in the Sagehen Watershed in the Sierra Nevada Mountains of California. Soils from the former fire (now occupied predominantly by Ceanothus velutinus, a nitrogen-fixing shrub) had significantly lower contents of extractable SO42− and P (both Bray and bicarbonate) but significantly greater contents of exchangeable Ca2+ than the adjacent forested site (dominated by Pinus jeffreyii). 15N data suggested that N fixation had occurred in the former fire site, but N contents did not differ between the two sites. O horizon C and nutrient contents did not differ between the two sites, but vegetation C and nutrient contents were significantly greater in the forested than former fire site. These results contrast with those from a nearby, previous study at Little Valley Nevada, also dominated by P. jeffreyii growing on a different soil type (Entisols derived from granite). In the Little Valley study, soil C, N, Ca2+, Mg2+, and K+ contents within the former fire (1981, now also occupied predominantly by Ceanothus velutinus) were greater than in the adjacent forest (Pinus jeffreyii) but soil extractable P contents either did not differ or were greater in the former fire. We conclude that soil parent material is an indirect but strong mediator of the effects of post-fire vegetation on soils in this region, especially with respect to soil P changes, which vary substantially between andesite- and granite-derived soils. Forests 2012-06-20 3 2 Article 10.3390/f3020398 398 416 1999-4907 2012-06-20 doi: 10.3390/f3020398 Dale W. Johnson Roger F. Walker Michelle McNulty Benjamin M. Rau Watkins W. Miller http://www.mdpi.com/1999-4907/3/2/370 Eastern forests of the US are valued both as a carbon sink and a wood resource. The amount of biomass that can be harvested sustainably from this biome for bioenergy without compromising the carbon sink is uncertain. Using past literature and previously validated models, we assessed four scenarios of biomass harvest in the eastern US: partial harvests of mixed hardwood forests, pine plantation management, short-rotation woody cropping systems, and forest residue removal. We also estimated the amount and location of abandoned agricultural lands in the eastern US that could be used for biomass production. Greater carbon storage was estimated to result from partial harvests and residue removals than from plantation management and short-rotation cropping. If woody feedstocks were cultivated with a combination of intensive management on abandoned lands and partial harvests of standing forest, we estimate that roughly 176 Tg biomass y−1 (~330,000 GWh or ~16 billion gallons of ethanol) could be produced sustainably from the temperate forest biome of the eastern US. This biomass could offset up to ~63 Tg C y−1 that are emitted from fossil fuels used for heat and power generation while maintaining a terrestrial C sink of ~8 Tg C y−1. Forests 2012-06-19 3 2 Review 10.3390/f3020370 370 397 1999-4907 2012-06-19 doi: 10.3390/f3020370 Sarah C. Davis Michael Dietze Evan DeLucia Chris Field Steven P. Hamburg Scott Loarie William Parton Matthew Potts Benjamin Ramage Dan Wang Heather Youngs Stephen P. Long http://www.mdpi.com/1999-4907/3/2/353 In 2002, the Biscuit Wildfire burned a portion of the previously established, replicated conifer unthinned and thinned experimental units of the Siskiyou Long-Term Ecosystem Productivity (LTEP) experiment, southwest Oregon. Charcoal C in pre and post-fire O horizon and mineral soil was quantified by physical separation and a peroxide-acid digestion method. The abrupt, short-term fire event caused O horizon charcoal C to increase by a factor of ten to >200 kg C ha−1. The thinned wildfire treatment produced less charcoal C than unthinned wildfire and thinned prescribed fire treatments. The charcoal formation rate was 1 to 8% of woody fuels consumed, and this percentage was negatively related to woody fuels consumed, resulting in less charcoal formation with greater fire severity. Charcoal C averaged 2000 kg ha−1 in 0–3 cm mineral soil and may have decreased as a result of fire, coincident with convective or erosive loss of mineral soil. Charcoal C in 3–15 cm mineral soil was stable at 5500 kg C ha−1. Long-term soil C sequestration in the Siskiyou LTEP soils is greatly influenced by the contribution of charcoal C, which makes up 20% of mineral soil organic C. This research reiterates the importance of fire to soil C in a southwestern Oregon coniferous forest ecosystem. Forests 2012-06-19 3 2 Article 10.3390/f3020353 353 369 1999-4907 2012-06-19 doi: 10.3390/f3020353 Melissa R. A. Pingree Peter S. Homann Brett Morrissette Robyn Darbyshire http://www.mdpi.com/1999-4907/3/2/332 Assessing the potential for forest carbon (C) capture and storage requires accurate assessments of C in live tree tissues. In the vast majority of local, regional, and global assessments, C content has been assumed to be 50% of tree biomass; however, recent studies indicate that this assumption is not accurate, with substantial variation in C content among tree species as well as among tissue types. Here we conduct a comprehensive literature review to present a global synthesis of C content in tissues of live trees. We found a total of 253 species-specific stem wood C content records in 31 studies, and an additional 34 records of species with C content values of other tissues in addition to stem wood. In all biomes, wood C content varied widely across species ranging from 41.9–51.6% in tropical species, 45.7–60.7% in subtropical/Mediterranean species, and 43.4–55.6% in temperate/boreal species. Stem wood C content varied significantly as a function of biome and species type (conifer, angiosperm). Conifer species exhibited greater wood C content than angiosperm species (50.8 ± 0.7% (95% C.I.) and 47.7 ± 0.3%, respectively), a trend that was consistent among all biomes. Although studies have documented differences in C content among plant tissues, interspecific differences in stem wood appear to be of greater importance overall: among species, stem wood C content explained 37, 76, 48, 81, and 63% respectively of the variation in bark, branch, twig, coarse root, and fine root C content values, respectively. In each case, these intraspecific patterns approximated 1:1 linear relationships. Most published stem wood C content values (and all values for other tree tissues) are based on dried wood samples, and so neglect volatile C constituents that constitute on average 1.3–2.5% of total C in live wood. Capturing this volatile C fraction is an important methodological consideration for future studies. Our review, and associated data compilation, provides empirically supported wood C fractions that can be easily incorporated into forest C accounting, and may correct systematic errors of ~1.6–5.8% in forest C assessments. Forests 2012-06-19 3 2 Review 10.3390/f3020332 332 352 1999-4907 2012-06-19 doi: 10.3390/f3020332 Sean C. Thomas Adam R. Martin http://www.mdpi.com/1999-4907/3/2/317 Longleaf pine (Pinus palustris) ecosystems have been reduced dramatically throughout their range. Prescribed burning is considered the best way to restore and maintain plant communities associated with longleaf pine, but little is known about its effects on coarse woody debris and associated organisms. We conducted a 5-year study on the Osceola National Forest in northeastern Florida to determine how dormant-season prescribed burns at different frequencies (annual, biennial, quadrennial or unburned) applied over a 40-year period affected coarse woody debris volume, decomposition and nitrogen content, and subterranean termite (Reticulitermes spp.) activity. Burn frequency had no effect on standing dead tree or log volumes. However, freshly cut longleaf pine logs placed in the plots for four years lost significantly less mass in annually burned plots than in unburned plots. The annual exponential decay coefficient estimate from all logs was 0.14 yr−1 (SE = 0.01), with the estimated times for 50 and 95% loss being 5 and 21.4 years, respectively. Termite presence was unaffected by frequent burning, suggesting they were able to survive the fires underground or within wood, and that winter burning did not deplete their food resources. Forests 2012-06-06 3 2 Article 10.3390/f3020317 317 331 1999-4907 2012-06-06 doi: 10.3390/f3020317 James L. Hanula Michael D. Ulyshen Dale D. Wade http://www.mdpi.com/1999-4907/3/2/300 Enhancement of forest growth through silvicultural modification of stand density is one strategy for increasing carbon (C) sequestration. Using the Fire and Fuels Extension of the Forest Vegetation Simulator, the effects of even-aged, uneven-aged and no-action management scenarios on C sequestration in a southern Appalachian red spruce-Fraser fir forest were modeled. We explicitly considered C stored in standing forest stocks and the fate of forest products derived from harvesting. Over a 100-year simulation period the even-aged scenario (250 Mg C ha−1) outperformed the no-action scenario (241 Mg C ha−1) in total carbon (TC) sequestered. The uneven-aged scenario approached 220 Mg C ha−1, but did not outperform the no-action scenario within the simulation period. While the average annual change in C (AAC) of the no-action scenario approached zero, or carbon neutral, during the simulation, both the even-aged and uneven-aged scenarios surpassed the no-action by year 30 and maintained positive AAC throughout the 100-year simulation. This study demonstrates that silvicultural treatment of forest stands can increase potential C storage, but that careful consideration of: (1) accounting method (i.e., TC versus AAC); (2) fate of harvested products and; (3) length of the planning horizon (e.g., 100 years) will strongly influence the evaluation of C sequestration. Forests 2012-06-04 3 2 Article 10.3390/f3020300 300 316 1999-4907 2012-06-04 doi: 10.3390/f3020300 Patrick T. Moore R. Justin DeRose James N. Long Helga van Miegroet http://www.mdpi.com/1999-4907/3/2/283 The documented role of United States forests in sequestering carbon, the relatively low cost of forest-based mitigation, and the many co-benefits of increasing forest carbon stocks all contribute to the ongoing trend in the establishment of forest-based carbon offset projects. We present a broad analysis of forest inventory data using site quality indicators to provide guidance to managers planning land acquisition for forest-based greenhouse gas mitigation projects. Specifically, we summarize two condition class indicators of site productivity within the FIA forest inventory database—physclcd and siteclcd—as they relate to current aboveground live tree carbon stocks. Average carbon density is higher on more productive sites, but compared to the overall variability among sites, the differences are relatively small for all but the highest and lowest site classes. Some minor differences in eastern- versus western-forests were apparent in terms of how carbon on the least productive sites differed from most other forest land over time. Overall results suggest that xeric sites in most regions as well as sites that correspond to the lowest, non-productive classifications of forest land should preferentially not be used forestry-based greenhouse gas mitigation projects, but all other forest areas appear to be suitable. Forests 2012-06-04 3 2 Article 10.3390/f3020283 283 299 1999-4907 2012-06-04 doi: 10.3390/f3020283 Coeli M. Hoover James E. Smith http://www.mdpi.com/1999-4907/3/2/265 Wildfire occurrence and intensity have increased over the last few decades and, at times, have been national news. Wildfire occurrence is somewhat predictable based on physical factors like meteorological conditions, fuel loads, and vegetation dynamics. Socioeconomic factors have been not been widely used in wildfire occurrence models. We used a geospatial (or geographical information system) analysis approach to identify socioeconomic variables that contribute to wildfire occurrence. Key variables considered were population change, population density, poverty rate, educational level, geographic mobility, and road density (transportation network). Hot spot analysis was the primary research tool. Wildfire occurrence seemed to be positively related to low population densities, low levels of population change, high poverty rate, low educational attainment level, and low road density. Obviously, some of these variables are correlated and this is a complex problem. However, socioeconomic variables appeared to contribute to wildfire occurrence and should be considered in development of wildfire occurrence forecasting models. Forests 2012-05-25 3 2 Article 10.3390/f3020265 265 282 1999-4907 2012-05-25 doi: 10.3390/f3020265 Joel A. Feltman Thomas J. Straka Christopher J. Post Stephen L. Sperry http://www.mdpi.com/1999-4907/3/2/244 The REDD Programme is predicated on the assumption that developed countries will provide sufficient funds to offset opportunity costs associated with avoiding deforestation. The role of non-market values in indigenous land management may challenge the efficacy of compensation schemes targeted at meeting opportunity costs as calculated in traditional opportunity cost analysis (OCA). Furthermore it is unclear how these economic incentives might affect social and cultural values linked to land-use norms, livelihoods, and local governance. This study explores the economic, social and cultural values of forest uses for a Miskito community in the Rio Plátano Biosphere Reserve in Honduras. Data were collected using household surveys, farm visits, and community workshops. OCA indicates potential for successful REDD+ payment schemes; however it is an inadequate method to account for subsistence and cultural opportunity costs associated with avoided deforestation. Compensation to change land-use practices may undermine governance institutions necessary to address deforestation in the region. Our results indicate that small-scale agriculture and other forest-based subsistence activities are important cultural practices for maintaining Miskito identity and forest management institutions. Recommendations are offered for using OCA to develop REDD+ projects that recognize the linkages between social and cultural values and forest management by focusing on approaches that consider a full range of economic, social and cultural opportunity costs. Forests 2012-05-24 3 2 Article 10.3390/f3020244 244 264 1999-4907 2012-05-24 doi: 10.3390/f3020244 Spencer T. Plumb Erik A. Nielsen Yeon-Su Kim http://www.mdpi.com/1999-4907/3/2/230 Three large-scale, experimental, dispersed residual tree sites established in coastal British Columbia, Canada were measured for planted Douglas-fir tree growth and survival five to six years after planting. The dispersed trees were predominantly large diameter (60 cm+) Douglas-fir left with a range of 0% to 30% of the original forest stand basal area (0 m2 ha−1 to 14 m2 ha−1). Two sites had 0%, 5% and 15% retention, while one site had 0%, 5%, 10% and 30% retention. The trees were measured in sector plots established to randomly sample the range of microsites in each treatment. There was no detectable difference between height and basal diameter growth or mortality rates between the retention treatments over the measurement period, except for a reduction of basal diameter growth at the 30% retention level (p < 0.05). Thus a statistically significant impact on growth was demonstrated for the 30% retention compared to the 0% retention level. We expected intermediate growth rates between the 0% and the other lower retention levels but were unable to demonstrate this due to the low statistical power of the test (10 observations) and high site variability for these very young trees. Forests 2012-05-16 3 2 Article 10.3390/f3020230 230 243 1999-4907 2012-05-16 doi: 10.3390/f3020230 Nicholas J. Smith William J. Beese http://www.mdpi.com/1999-4907/3/2/207 Anthropogenic soils of the Amazon Basin (Terra Preta, Terra Mulata) reveal that pre-Colombian peoples made lasting improvements in the agricultural potential of nutrient-poor soils. Some have argued that applying similar techniques could improve agriculture over much of the humid tropics, enhancing local livelihoods and food security, while also sequestering large quantities of carbon to mitigate climate change. Here, we present preliminary evidence for Anthropogenic Dark Earths (ADEs) in tropical Asia. Our surveys in East Kalimantan (Indonesian Borneo) identified several sites where soils possess an anthropogenic development and context similar in several respects to the Amazon’s ADEs. Similarities include riverside locations, presence of useful fruit trees, spatial extent as well as soil characteristics such as dark color, high carbon content (in some cases), high phosphorus levels, and improved apparent fertility in comparison to neighboring soils. Local people value these soils for cultivation but are unaware of their origins. We discuss these soils in the context of local history and land-use and identify numerous unknowns. Incomplete biomass burning appears key to these modified soils. More study is required to clarify soil transformations in Borneo and to determine under what circumstances such soil improvements might remain ongoing. Forests 2012-05-07 3 2 Article 10.3390/f3020207 207 229 1999-4907 2012-05-07 doi: 10.3390/f3020207 Douglas Sheil Imam Basuki Laura German Thomas W. Kuyper Godwin Limberg Rajindra K. Puri Bernard Sellato Meine van Noordwijk Eva Wollenberg http://www.mdpi.com/1999-4907/3/2/190 Invasive shade tolerant species can have profound and long-lasting detrimental effects even on previously undisturbed forests. In North American forests, the invasive Acer platanoides is capable of dominating the understory where it could displace the native Acer saccharum. To understand the relative importance of various ecological factors in a forest understory on their establishment, we transplanted A. platanoides and A. saccharum seedlings in an urban sugar maple forest understory and their growth and survival were compared over a growing season. Seedlings did not differ in height, but biomass growth and assimilation rates were twice as high for the invasive species. Ecological variables accounted for only 23–24% of variation in growth. Seedlings of A. platanoides appeared to capture light more efficiently, with over 150% greater foliage biomass and surface area. A. saccharum seedlings were more negatively affected by herbivory. The more robust A. platanoides seedlings presented characteristics that could allow them to better grow and survive in shaded understories than their native congeners. Forests 2012-05-03 3 2 Article 10.3390/f3020190 190 206 1999-4907 2012-05-03 doi: 10.3390/f3020190 Marie Lapointe Jacques Brisson http://www.mdpi.com/1999-4907/3/2/179 Although double sampling has been shown to be an effective method to estimate timber volume in forest inventories, only a limited body of research has tested the effectiveness of double sampling on forest biomass estimation. From forest biomass inventories collected over 9,683 ha using systematic point sampling, we examined how a double sampling scheme would have affected precision and efficiency in these biomass inventories. Our results indicated that double sample methods would have yielded biomass estimations with similar precision as systematic point sampling when the small sample was ≥ 20% of the large sample. When the small to large sample time ratio was 3:1, relative efficiency (a combined measure of time and precision) was highest when the small sample was a 30% subsample of the large sample. At a 30% double sample intensity, there was a < 3% deviation from the original percent margin of error and almost half the required time. Results suggest that double sampling can be an efficient tool for natural resource managers to estimate forest biomass. Forests 2012-05-03 3 2 Article 10.3390/f3020179 179 189 1999-4907 2012-05-03 doi: 10.3390/f3020179 David L. Parrott John M. Lhotka Songlin Fei B. Scott Shouse http://www.mdpi.com/1999-4907/3/2/166 Today there is an increasing demand for biomass for use in energy production. In this study we investigated stumps and roots from six poplar (Populus sp.) stands growing on former farmland in Sweden, situated between latitudes 55 and 60°N. The mean age of the poplar was 20 years (range 16–23), the mean stand density 1151 stems ha−1 (range 361–3279), and the mean diameter at breast height (over bark) 288 mm (range 81–574). All poplar stands were on clay soils (light and medium clay and light clay tills).The mean dry mass weight of the 72 excavated stumps was 45 ± 39 kg (range 1–185), with the roots ≥ 50 mm weighing 14 ± 16 kg (range 0.2–87). Dry mean stump weight represented 21% (by dry weight) of the stem. The mean total dry weight per hectare for stumps amounted to 34.9 ± 21.8 (range 12.9–66.9) tons and the equivalent value for roots was 12.0 ± 9.6 (range 4.7–10.9) tons. The excavation of below-ground biomass can either focus on the stump or the stump and parts of the root system. Depending on the combination of soil type and soil moisture the weight of soil adhering to stumps and the cleaning requirements will vary. Forests 2012-04-18 3 2 Article 10.3390/f3020166 166 178 1999-4907 2012-04-18 doi: 10.3390/f3020166 Tord Johansson Birger Hjelm http://www.mdpi.com/1999-4907/3/2/155 Visitor information often serves as the basis for the management plan of parks. However, there exist few scientific and fundamental surveys for parks and open spaces in Japan. We analyzed the correlation between the number of visitors and the various factors in a suburban open space in a northern Japanese city, Takino Park. To explain the fluctuations in the number of visitors in Takino Park, multiple regression analyses with the stepwise method were conducted. The analyses employed social factors and meteorological factors, such as the day of the week, school vacations, temperature and the weather. The results show that the most influential factor is the day of the week, i.e., Sundays and holidays. The weather is also influential as the number of visitors decreases on rainy and snowy days. Comparing different seasons of the year, we found that influential factors varied from one season to the other. A key distinguishing finding of our results is that the weather conditions at the departure site and the weather forecast are also determining factors. These findings will help park managers understand the current situations and examine future management strategies to maintain and enhance visitor satisfaction, and improve information services. Forests 2012-04-12 3 2 Article 10.3390/f3020155 155 165 1999-4907 2012-04-12 doi: 10.3390/f3020155 Tetsuya Aikoh Reina Abe Ryo Kohsaka Mari Iwata Yasushi Shoji http://www.mdpi.com/1999-4907/3/1/137 The objective of REDD+ is to create incentives for the reduction of emissions from deforestation and forest degradation and for the increase of carbon stocks through the enhancement, conservation and sustainable management of forests in developing countries. As part of the international negotiations under the United Nations Framework Convention on Climate Change (UNFCCC), compensation would be estimated in relation to national performance but how these incentives will be channeled within countries has not been specified and there are concerns about how the benefits will be shared among different stakeholders. One central issue is that under the national approach good performance in one region can be offset by underperformance in other regions of the country thus preventing the generation of predictable local incentives. Other issues relate to the need to provide incentives to a wide range of stakeholders and to avoid perverse reactions. To address these and other issues we propose separating the accounting of reduced deforestation, reduced degradation and enhancement of forests. The local attribution of credits would be easier for carbon enhancement, and possibly reduced degradation, than for reduced deforestation, since carbon gains can, in principle, be measured locally in the first two cases, while estimating achievements in reduced deforestation requires a regional approach. This separation in attribution of rewards can help to create adequate incentives for the different stakeholders and overcome some of the problems associated with the design and implementation of national REDD+ programs. Forests 2012-03-21 3 1 Article 10.3390/f3010137 137 154 1999-4907 2012-03-21 doi: 10.3390/f3010137 Arturo Balderas Torres Margaret Skutsch http://www.mdpi.com/1999-4907/3/1/127 Of the more than 300 species of Psocoptera described in North America, 44 species have been documented on eastern hemlock, Tsuga canadensis (L.) Carrière, in the southern Appalachians. However, the distribution and co-occurrence patterns of these species throughout the tree canopy are unknown. This study was initiated to evaluate specimen abundance, species richness and species composition among three designated strata in the canopy of eastern hemlock, assess species for vertical stratification patterns, and determine if co-occurrence patterns of Psocoptera species are random or non-random. During this study, 27 species representing 18 genera and 10 families were evaluated. Psocopteran specimen abundance, species richness and composition differed among the lower, middle, and upper strata. Unique assemblages were identified in each stratum, indicating vertical stratification. The upper stratum of the canopy had five exclusive species, the middle had four exclusive species, and the lower stratum had 14 exclusive species. The co-occurrence pattern of Psocoptera species in the canopy of eastern hemlock was non-random. Forests 2012-03-21 3 1 Article 10.3390/f3010127 127 136 1999-4907 2012-03-21 doi: 10.3390/f3010127 Carla Coots Paris Lambdin Jerome Grant Rusty Rhea Edward Mockford http://www.mdpi.com/1999-4907/3/1/114 Sector sampling is a new and simple approach to sampling objects or borders. This approach would be especially useful for sampling objects in small discrete areas or “polygons” with lots of internal or external edge, but it may be extended to sampling any object regardless of polygon size. Sector plots are wedge-shaped with a fixed sector angle. The probability of object selection is constant and equal to the sector angle in degrees divided by 360°. A unique property of sector sampling is that the point from which the angle originates may be located subjectively when the sector direction is at random. Another advantage over traditional sampling (such as fixed or variable area plots) is that there is no edge effect; that is, there is no altering of selection probabilities of objects close to polygon boundaries. Various approaches are described for deriving polygon means and totals with their associated variances. We review the genesis of sector sampling and develop two new components: sub-sampling using fixed area plots and line sampling using the sector arcs as transects. Sector sampling may be extended to measuring a variety of objects such as trees, shrubs, plants, birds, animal trails and polygon borders. Forests 2012-03-20 3 1 Review 10.3390/f3010114 114 126 1999-4907 2012-03-20 doi: 10.3390/f3010114 Nicholas J. Smith Kim Iles http://www.mdpi.com/1999-4907/3/1/95 Prosopis alba seedlings, that grew at the 45 dS m−1 salinity level in a previous study of growth and survival of Argentine and Peruvian Prosopis, were propagated by rooting cuttings and established in a seed orchard/long term evaluation trial on soils with low salinity (EC 5.1–7.5 dS m−1) but high pH (8.9 to 10.2). A pH gradient occurred in the field with values ranging from pH 9.4 in block 1 to pH 10.3 in block 5. After five years growth, almost all of the clones had a mean height greater than 4 m and one clone was more than 5 m. Ten of the 21 tested clones had significantly greater biomass growth than the three seed propagated check varieties. The broad-sense (i.e., clone mean) heritability was estimated to be 0.45 for biomass, 0.53 for diameter and 0.59 for height indicating that strong genetic gains should be possible by selecting and vegetatively propagating the best genotypes. In the block with the highest pH values, two clones that appear to be P. alba × P. ruscifolia hybrids (i.e., P. vinallilo) had the greatest biomass. Correlations between growth during the last two months in the high salinity hydroponic greenhouse selection system and growth in the field were significant (R2 = 0.262) and positive, although the relationship was negative for putative P. vinallilo clones (R2 = 0.938). The several fold increase in biomass of some of the clones over the three check varieties, suggests that the greenhouse screen was successful in identifying superior salt tolerant clones. Apparently whether the greenhouse seedlings had lesser (~1 cm) to greater (~3 cm) height growth was not as important as just having a healthy live apical meristem. The observed salt tolerance of the putative P. vinalillo clones may prove useful as rootstocks for recently described high pod producing P. alba clones. Forests 2012-03-16 3 1 Article 10.3390/f3010095 95 113 1999-4907 2012-03-16 doi: 10.3390/f3010095 Mauricio Ewens Salvador Gezan Peter Felker http://www.mdpi.com/1999-4907/3/1/83 Cyclaneusma needle-cast has a major impact on the New Zealand forest industry. The causal agent, Cyclaneusma minus, causes most severe damage to 11–20 year-old trees and currently there are no economically viable procedures for control of the disease in New Zealand. Here we present a method for genetic transformation of C. minus using protoplasts generated by incubation with Glucanex™ enzyme. C. minus was transformed with a gene encoding green fluorescent protein (GFP) and expression was stable after successive sub-culturing of the strain in the absence of selective pressure. Expression of the gfp gene allowed us to utilize an in vitro GFP-based screening method to identify strains of Trichoderma with potential for biocontrol of this disease. The strain that showed the most promise as a potential biocontrol candidate exhibited a low level of inhibition by uncharacterized metabolite(s) that C. minus secretes into the medium, and consistently caused a loss of GFP expression from the GFP-labeled C. minus strain. The interaction between C. minus and the biocontrol strain, in the interaction zone where GFP expression was lost, was determined to be fungicidal. The utility of such biocontrol strains is discussed. This study represents the first genetic manipulation of C. minus and will pave the way for further studies of the life cycle and infection biology of this organism. Forests 2012-02-01 3 1 Article 10.3390/f3010083 83 94 1999-4907 2012-02-01 doi: 10.3390/f3010083 Rebecca McDougal Alison Stewart Rosie Bradshaw http://www.mdpi.com/1999-4907/3/1/75 Climate change presents potential risks to forests and challenges for forest managers. Adaptation to climate change involves monitoring and anticipating change and undertaking actions to avoid the negative consequences and take advantage of potential benefits of those changes. Forest managers are accustomed to considering the long-term implications of their decisions. However, many are now responding to much shorter term economic or political imperatives. Climate change potentially increases the consequences of many existing challenges associated with environmental, social or economic change. Some current management measures may continue to be suitable in responding to increasing pressures under climate change, while for other situations new measures will be required. This special issue presents papers from Africa, Europe, and North America that provide examples of the type of analysis being implemented to support forest management in a changing climate. The implications in the context of uncertainty in climate projections and ecosystem responses are discussed. Forests 2012-01-30 3 1 Communication 10.3390/f3010075 75 82 1999-4907 2012-01-30 doi: 10.3390/f3010075 Rodney J. Keenan http://www.mdpi.com/1999-4907/3/1/59 The proposed hierarchy of production forest management provides modus operandi for forest concessions to move incrementally towards Sustainable Forest Management (SFM) via Reduced-Impact Logging (RIL) and forest certification. Financial benefits are sourced in the “Additionality Zone”, financing the rise in the hierarchy and offsetting prohibitive forest and carbon certification costs. RIL carbon registration components consist of developing credible baseline, additionality and leakage arguments around the business-as-usual scenario through the quantification of historical forest inventory and production records, forest infrastructure records and damage to the residual forest. If conventional harvesting is taken as a baseline, research indicates RIL can potentially reduce emissions by approximately 1–7 tCO2e ha−1yr−1. The current market price of USD $7.30 per tCO2e may result in over USD $50 ha−1yr−1 in additional revenue, well above the estimated USD $3–5 ha−1 in carbon transaction costs. Concessions in Sabah Malaysia demonstrate the financial viability of long-term RIL and certification planning. This may act as a basis for future planned forest management activities involving RIL, carbon and forest certification through the hierarchy of production forest management. Forests 2012-01-20 3 1 Article 10.3390/f3010059 59 74 1999-4907 2012-01-20 doi: 10.3390/f3010059 Michael Victor Galante Michael Dutschke Genevieve Patenaude Ben Vickers http://www.mdpi.com/1999-4907/3/1/33 This paper assesses quantification methods for carbon leakage from forestry activities for their suitability in leakage accounting in a future Reducing Emissions from Deforestation and Forest Degradation (REDD) mechanism. To that end, we first conducted a literature review to identify specific pre-requisites for leakage assessment in REDD. We then analyzed a total of 34 quantification methods for leakage emissions from the Clean Development Mechanism (CDM), the Verified Carbon Standard (VCS), the Climate Action Reserve (CAR), the CarbonFix Standard (CFS), and from scientific literature sources. We screened these methods for the leakage aspects they address in terms of leakage type, tools used for quantification and the geographical scale covered. Results show that leakage methods can be grouped into nine main methodological approaches, six of which could fulfill the recommended REDD leakage requirements if approaches for primary and secondary leakage are combined. The majority of methods assessed, address either primary or secondary leakage; the former mostly on a local or regional and the latter on national scale. The VCS is found to be the only carbon accounting standard at present to fulfill all leakage quantification requisites in REDD. However, a lack of accounting methods was identified for international leakage, which was addressed by only two methods, both from scientific literature. Forests 2012-01-16 3 1 Article 10.3390/f3010033 33 58 1999-4907 2012-01-16 doi: 10.3390/f3010033 Sabine Henders Madelene Ostwald http://www.mdpi.com/1999-4907/3/1/22 Mechanical site preparation is frequently proposed to alleviate problematic soil conditions when afforesting retired agricultural fields. Without management of soil problems, any seedlings planted in these areas may exhibit poor growth and survival. While mechanical site preparation methods currently employed in hardwood afforestation are proven, there is a substantial void in research comparing subsoiling, bedding, and combination plowing treatments. A total of 4,320 bare-root Nuttall oak (Quercus texana Buckley), Shumard oak (Quercus shumardii Buckley), and swamp chestnut oak (Quercus michauxii Nutt.) seedlings were planted in February 2008 on three Mississippi sites. All sites were of comparable soils and received above average precipitation throughout the three-year duration of the study. Four site preparation treatments were replicated at each site, with 480 seedlings planted in each of nine replications, and a total of 1,440 seedlings per species planted across all sites. Mechanical treatments were installed using 3.1 m row centers, with treatments as follows: control, subsoiling, bedding, and combination plowing. Treatment effects on seedling height, groundline diameter (GLD), and survival were analyzed. Seedlings exhibited greater height in bedded and combination plowed areas (79.7 cm to 102.7 cm and 82.6 cm to 100.1 cm, respectively) compared to subsoiled or control areas (70.4 cm to 84.6 cm and 71.4 cm to 86.9 cm, respectively). Greater GLD was observed in bedded and combination plowed areas (11.9 mm to 18.4 mm and 12.2 mm to 18.3 mm, respectively) compared to subsoiled or control areas (10.2 mm to 14.6 mm and 10.5 mm to 15.6 mm, respectively). Survival was high for this study (94.%), and no differences were detected among treatments. Forests 2011-12-28 3 1 Article 10.3390/f3010022 22 32 1999-4907 2011-12-28 doi: 10.3390/f3010022 Andrew Self Andrew W. Ezell Dennis Rowe Emily B. Schultz John D. Hodges http://www.mdpi.com/1999-4907/3/1/1 This study analyzes the latent demand to outdoor recreation participation and identifies what factors are constraining people from realizing this demand. In Sweden, recreation in the outdoors is seen as a public right as articulated in public policy and much of the outdoor recreation centre around forested landscapes—over 60 percent of the land area is classified as forest. Using data from a nationwide survey of 43 recreation activities, the study takes a time-contextual approach to reveal variations in recreation constraints across weekdays, weekends and holidays. Results show that almost half the population has a latent demand to increase their participation in outdoor recreation. Three categories of time contextual constraints are identified and several of the constraints studied show variations across outdoor activities and socio-economic factors. Practical implications for the promotion of outdoor recreation participation by public agencies, recreation managers and tourism businesses are discussed based on the study findings. Forests 2011-12-23 3 1 Article 10.3390/f3010001 1 21 1999-4907 2011-12-23 doi: 10.3390/f3010001 Peter Fredman Ulla Romild Mike Yuan Daniel Wolf-Watz http://www.mdpi.com/1999-4907/2/4/1031 Bhutan was an inhabited wilderness until 1961, when road construction started after the closure of the Tibetan border. Since then, the road network has expanded from the Indian boarder, often tracing traditional trails. This has accelerated commerce as well as movement of people from India, benefitting both the Bhutanese and foreign tourists. At the same time, dependence on imported automobiles and fossil fuel has risen, and roadless areas have begun to shrink. This brought an inevitable loss of traditional environmental knowledge, such as the care of mules for packing, and reduction in physical and mental health among the Bhutanese. People who lost jobs as horsemen moved into towns to find jobs. Road extension is also a double-edged sword for visitors. It has resulted in shrinking trekking areas and loss of traditional culture, both of which have been sacrificed for easy access. Protected areas often function as fortifications against mechanical civilization. However, protected-area status or its zoning does not guarantee that an area will remain roadless where there is considerable resident population. An analysis in Jigme Dorji National Park showed the gradual retreat of trailheads and increasing dependence on automobiles among residents and trekkers. B. MacKaye, a regional planner in the Eastern United States, proposed using trails as a tool to control such mechanical civilization. His philosophy of regional planning suggests two measures; one is consolidated trailheads as dams, and the other is confinement of roads by levees, consisting of new trails and wilderness belts. According to case studies, the author proposed six options for coexistence of trails with roads. Forests 2011-12-09 2 4 Article 10.3390/f2041031 1031 1048 1999-4907 2011-12-09 doi: 10.3390/f2041031 Taiichi Ito http://www.mdpi.com/1999-4907/2/4/1013 Since climate change projections contain many uncertainties and are normally unable to predict the direction and magnitude of change at the small scale needed by forest managers, some understanding about the functioning of the target forest should be obtained before a robust management strategy can be applied. Structure and regeneration patterns are related to key ecosystem processes which, on the other hand, can be modified by silvicultural treatments. In this research, the structure and recruitment dynamics of two stands with different histories of management were investigated in the southern limit of the range of Pinus nigra subsp. salzmannii (Southeast Spain). We described forest structure and facilitation effects by forest canopies and nurse shrubs, and quantified the processes affecting each stage of regeneration (dispersed seed, first year seedling and second year seedling) in different microhabitats. Forest structure was more complex in the stand scarcely influenced by human activities. Juniperus communis shrubs seemed to facilitate the establishment of tree saplings. Most seedlings died of desiccation during their first summer. At best, 190 out of 10,000 emerged seedlings survived the first summer. In light of these results, the possibilities of applying close-to-nature forestry in the study forests and other aspects of silviculture under a frame of adaptive forest management are discussed. Forests 2011-12-09 2 4 Article 10.3390/f2041013 1013 1030 1999-4907 2011-12-09 doi: 10.3390/f2041013 Pedro A. Tíscar Juan C. Linares http://www.mdpi.com/1999-4907/2/4/993 Despite the widespread agreement on the importance of preserving ecological integrity in conservation and outdoor recreation decision-making processes, traditional metrics analyzing the supply of and demand for conservation and recreation resources have focused on geographical and population-centric units of measurement rather than ecological ones. One tool past researchers have used to inform recreation resource planning is the recreation location quotient (RLQ). While simple park-to-population ratios or acres-per-capita metrics provide a base measure of carrying capacity and are often useful to set broad recreation supply standards, the RLQ offers a more nuanced snapshot of supply and demand by comparing regional ratios to a standardized reference region. The RLQ is thus able to provide a statistic or quotient that highlights regions where recreation resources are particularly abundant and/or scarce relative to a reference area. This project expands the past RLQ analyses by investigating the distribution of recreation resources across the 10 ecological sections found within the US state of Minnesota. RLQs were calculated using recreation trail mileage, natural resource and recreation area acreage data, and recreation facility data from federal, state, and local agencies. Results found notable differences in supply of recreation resources across ecological sections. Some sections were considerably underrepresented in recreation resources-per area (e.g., Red River Valley and North Central Glaciated Plains) while others were underrepresented in recreation resources-per capita (e.g., Minnesota and Northeast Iowa Morainal). The RLQ statistics and resulting maps illustrating relative surplus or deficiencies can inform future land acquisition decisions and highlight the need for cross-jurisdictional planning in order to ensure outdoor recreation systems are ecologically representative. Possible implications and recommendations for future planning decisions are discussed. Forests 2011-12-02 2 4 Article 10.3390/f2040993 993 1012 1999-4907 2011-12-02 doi: 10.3390/f2040993 Andrew Oftedal Mae Davenport Ingrid E. Schneider Cindy Zerger Brian Schreurs Mary Vogel http://www.mdpi.com/1999-4907/2/4/984 Changes in understory light levels following a partial overstory harvest with three retention levels, combined with midstory/understory removal of selected species were examined. Overstory retention levels were set at basal areas (ba) 16.1 (BA16), 11.6 (BA11), and 6.9 (BA6) m2 per hectare (ha). Prior to mechanical overstory removal, non-oak unmerchantable midstory/understory stems ≥ 5.1 cm were injected with an aqueous herbicide solution. Hemispherical photographs were used to calculate percent canopy closure and total understory light at 1.4 m above ground. Percent canopy closure was reduced 3, 14, 24, and 30 percent for injection only (IO), BA16, BA11, and BA6, respectfully, compared to the non-harvest control (NHC) (~95 percent canopy closure). Understory light levels for NHC, IO, BA16, BA11, and BA6 were 7–9 percent, 11–14 percent, 24–28percent, 37–46 percent, and 44–52 percent of full sunlight, respectively. Post-harvest understory light of BA16 was significantly lower than BA11 and BA6, which were similar. Understanding partial harvest impacts on canopy closure and subsequent understory light conditions will aid forest managers with regeneration harvest planning to promote oak reproduction. Forests 2011-11-17 2 4 Article 10.3390/f2040984 984 992 1999-4907 2011-11-17 doi: 10.3390/f2040984 K. Kyle Cunningham Stephen E. Peairs Andrew W. Ezell Keith L. Belli John D. Hodges http://www.mdpi.com/1999-4907/2/4/983 The use of woody biomass feedstocks for bioenergy and bioproducts involves multiple sources of material that together create year round supplies. The main sources of woody biomass include residues from wood manufacturing industries, low value trees including logging slash in forests that are currently underutilized and dedicated short-rotation woody crops. Conceptually a ton of woody biomass feedstocks can replace a barrel of oil as the wood is processed (refined) through a biorefinery. As oil is refined only part of the barrel is used for liquid fuel, e.g., gasoline, while much of the carbon in oil is refined into higher value chemical products-carbon in woody biomass can be refined into the same value-added products. Forests 2011-11-15 2 4 Editorial 10.3390/f2040983 983 983 1999-4907 2011-11-15 doi: 10.3390/f2040983 Edwin H. White http://www.mdpi.com/1999-4907/2/4/961 Developing adaptation measures in forestry is an urgent task because the forests regenerated today will have to cope with climate conditions that may drastically change during the life of the trees in the stand. This paper presents a comprehensive review of potential adaptation options in forestry in Europe based on three pillars: a review of the scientific literature, an analysis of current national response strategies, and an expert assessment based on a database compiled in the COST Action ECHOES (Expected Climate Change and Options for European Silviculture). The adaptation measures include responses to both risks and opportunities created by climate change and address all stages of forestry operations. Measures targeted to reduce vulnerability to climate change may either aim to reduce forest sensitivity to adverse climate change impacts or increase adaptive capacity to cope with the changing environmental conditions. Adaptation measures mitigating drought and fire risk such as selection of more drought resistant species and genotypes are crucial. For adaptation to be successful it is of the utmost importance to disseminate the knowledge of suitable adaptation measures to all decision makers from the practice to the policy level. The analysis of the ECHOES database demonstrates that this challenge is well recognized in many European countries. Uncertainty about the full extent of climate change impacts and the suitability of adaptation measures creates a need for monitoring and further research. A better understanding of how to increase adaptive capacity is also needed, as well as regional vulnerability assessments which are crucial for targeting planned adaptation measures. Forests 2011-11-11 2 4 Review 10.3390/f2040961 961 982 1999-4907 2011-11-11 doi: 10.3390/f2040961 Marja Kolström Marcus Lindner Terhi Vilén Michael Maroschek Rupert Seidl Manfred J. Lexer Sigrid Netherer Antoine Kremer Sylvain Delzon Anna Barbati Marco Marchetti Piermaria Corona http://www.mdpi.com/1999-4907/2/4/948 Recently, tree planting has become popular under NAPA. For decades, many tree planting projects were implemented to reduce the vulnerability of ecosystems and societies. Despite all of these, tree-dependent livelihoods remain vulnerable, which leaves doubt on the benefit of tree planting to enhance the resilience of livelihoods to climatic shocks. This suggests that much can be learned from the past to improve future tree planting adaptation projects. This paper draws on the experience of farmers involved in gum arabic agroforestry in Sudan in order to understand the needs of tree-related adaptation projects that should be addressed. Surveyed farmers appreciated the different environmental services rendered by trees. Their priority areas for an adaptation project however, remain issues tied to gum producer price, rainfall pattern, and locust attacks as well as extension services and to a lesser extent access to micro credits. Moreover, Sudan’s Gum Arabic Company (GAC) and Forests National Corporation play key roles in governance but are not yet considered as key adaptation players particularly the unsupportive role of the monopoly of gum exportation by GAC to tree planting as an adaptation activity. By focusing the design and implementation on tree related livelihood obstacles, adaptation projects are likely to be more responsive to the needs of vulnerable groups. Forests 2011-11-09 2 4 Communication 10.3390/f2040948 948 960 1999-4907 2011-11-09 doi: 10.3390/f2040948 Fobissie Blese Kalame Olavi Luukkanen Markku Kanninen http://www.mdpi.com/1999-4907/2/4/929 While there may be many reasons why very interesting science ideas never reach commercial practice, one of the more prevalent is that the reaction or process, which is scientifically possible, cannot be made efficient enough to achieve economic viability. One pathway to economic viability for many business sectors is the multi-product portfolio. Research, development, and deployment of viable biorefinery technology must meld sound science with engineering and business economics. It is virtually axiomatic that increased value can be generated by isolating relatively pure substances from heterogeneous raw materials. Woody biomass is a heterogeneous raw material consisting of the major structural components, cellulose, lignin, and hemicelluloses, as well as minor components, such as extractives and ash. Cellulose is a linear homopolymer of D-glucopyrano-units with β-D(1®4) connections and is the wood component most resistant to chemical and biological degradation. Lignin is a macromolecule of phenylpropanoid units, second to cellulose in bio-resistance, and is the key component that is sought for removal from woody biomass in chemical pulping. Hemicelluloses are a collection of heteropolysaccharides, comprised mainly of 5- and 6-carbon sugars. Extractives, some of which have high commercial value, are a collection of low molecular weight organic and inorganic woody materials that can be removed, to some extent, under mild conditions. Applied Biorefinery Sciences, LLC (a private, New York, USA based company) is commercializing a value-optimization pathway (the ABS Process™) for generating a multi-product portfolio by isolating and recovering homogeneous substances from each of the above mentioned major and minor woody biomass components. The ABS Process™ incorporates the patent pending, core biorefinery technology, “hot water extraction”, as developed at the State University of New York College of Environmental Science and Forestry (SUNY-ESF). Hot water extraction in the absence of mineral acids and bases is preferred because of its ability to generate multiple high value output products without chemical input, recovery, or disposal costs. Instead of added chemicals in the cooking phase, the ABS Process™ relies upon an autocatalytic reaction in which acetyl groups, bound through an ester linkage to hemicellulose chains, are hydrolyzed at high temperature in water. The resulting acidic conditions (final pH ~3.5) and temperatures of 160–170 °C permit further solubilization and diffusion of oligomeric 5- and 6-carbon sugars, acetic acid, aromatic substances, monomeric sugars, and other trace compounds into the extract solution. These conditions also avoid extensive degradation of monosaccharides, enabling membrane fractionation and other chemical separation techniques to be used in the following separations. A range of separation techniques are applied on the extract solution to isolate and purify fermentable sugars, acetic acid, lignin, furfural, formic acid, other hemicellulose related compounds, lignin, lignin degradation products, and phenolic extractives for commercial sale. The extracted lignocellulosic biomass, with reduced hemicellulose content and is thus less heterogeneous, carries the value-added advantages of: (1) enhanced product characteristics, and (2) reduced energy and chemical manufacturing costs. Thus, by fractionating woody biomass into more homogeneous substances, the ABS Process™ holds potential as an economically viable pathway for capturing sustainable, renewable value not currently realized from lignocellulosic biomass. Forests 2011-11-09 2 4 Review 10.3390/f2040929 929 947 1999-4907 2011-11-09 doi: 10.3390/f2040929 Thomas E. Amidon Biljana Bujanovic Shijie Liu Joel R. Howard http://www.mdpi.com/1999-4907/2/4/913 Despite the importance of protected areas (PAs) worldwide to protect biodiversity, reduce poverty and promote sustainable development, throughout the world governments struggle to adequately fund PAs to meet conservation goals. Tourism is seen as a viable financial option for PAs, with tourism concessions through private sector partnerships gaining momentum that allows the overarching goal of preservation and conservation to remain with the state. However, without appropriate planning or best practices in place, tourism concessions can lead to such problems as waste, habitat destruction and the displacement of local people and wildlife. We analyzed tourism concession agreements in government documents from 22 countries to provide an overview of what best practices for tourism concessions are being established and what practices might need to be better incorporated into agreements. The greatest weaknesses of best practices appear to be with concession qualifications, legal, and financial responsibilities, while the strengths included environmental and empowerment/social responsibilities. This initial assessment of contract components will provide a baseline to further develop best practices and assist protected area managers, local communities, and conservation practitioners working with tourism in PAs to ensure that tourism has a positive impact on protected area management. Forests 2011-11-02 2 4 Article 10.3390/f2040913 913 928 1999-4907 2011-11-02 doi: 10.3390/f2040913 Miriam Wyman James R. Barborak Neel Inamdar Taylor Stein http://www.mdpi.com/1999-4907/2/4/894 Forestry, as a large industry, has significant impacts on the quality of nature-based tourism landscapes in boreal forests. In Finland, the rapid growth of nature-based tourism has expanded outdoor recreation activities from protected areas into timber production forests; this is particularly so in northern Finland. This paper focuses on assessing balanced local net impacts of three alternative land-use scenarios, in which the level of integration between nature-based tourism (NBT) and traditional forestry is varied. The study is located in northern Finland in the area between two top-rated tourist resorts, Ylläs and Levi. The results of the case study support the idea of an eligible integration between NBT and forestry, which takes into account scenic qualities of forested landscapes by restricting traditional management practices. In our case, the increased number of tourists (due to a more attractive forest environment) offset the losses accrued in forestry (due to restricted forest management). Forests 2011-10-28 2 4 Article 10.3390/f2040894 894 912 1999-4907 2011-10-28 doi: 10.3390/f2040894 Anssi Ahtikoski Seija Tuulentie Ville Hallikainen Vesa Nivala Eero Vatanen Liisa Tyrväinen Hannu Salminen http://www.mdpi.com/1999-4907/2/4/875 This research analyzes the relationships between off-highway vehicle (OHV) riders’ patterns of prior experience and the social-psychological benefits they desire from the activity; it also examines the relationships between patterns of prior experience and environmental attitudes. The sample consists of 600 OHV riders in Utah drawn from the entire population of OHV owners within the state. The sample was segmented into experience use history groups based upon respondents’ number of OHV trips within the past 12 months and the total number of years they have been riding OHVs. Results show that patterns of prior experience are related to certain desired social-psychological benefits. Personal achievement benefits were significantly more important for more frequent riders when compared to those who rode less often. The analysis also reveals no relationship between patterns of prior experience and general environmental attitudes. Forests 2011-10-26 2 4 Article 10.3390/f2040875 875 893 1999-4907 2011-10-26 doi: 10.3390/f2040875 Jordan Smith Steven Burr http://www.mdpi.com/1999-4907/2/4/861 The growing interest in US biofuels has been motivated by two primary national policy goals, (1) to reduce carbon emissions and (2) to achieve energy independence. However, the current low cost of fossil fuels is a key barrier to investments in woody biofuel production capacity. The effectiveness of wood derived biofuels must consider not only the feedstock competition with low cost fossil fuels but also the wide range of wood products uses that displace different fossil intensive products. Alternative uses of wood result in substantially different unit processes and carbon impacts over product life cycles. We developed life cycle data for new bioprocessing and feedstock collection models in order to make life cycle comparisons of effectiveness when biofuels displace gasoline and wood products displace fossil intensive building materials. Wood products and biofuels can be joint products from the same forestland. Substantial differences in effectiveness measures are revealed as well as difficulties in valuing tradeoffs between carbon mitigation and energy independence. Forests 2011-10-19 2 4 Article 10.3390/f2040861 861 874 1999-4907 2011-10-19 doi: 10.3390/f2040861 Bruce Lippke Richard Gustafson Richard Venditti Timothy Volk Elaine Oneil Leonard Johnson Maureen Puettmann Phillip Steele http://www.mdpi.com/1999-4907/2/4/832 Climate change is projected to profoundly influence vegetation patterns and community compositions, either directly through increased species mortality and shifts in species distributions or indirectly through disturbance dynamics such as increased wildfire activity and extent, shifting fire regimes, and pathogenesis. Mountainous landscapes have been shown to be particularly sensitive to climate changes and are likely to experience significant impacts under predicted future climate regimes. Western white pine (Pinus monticola), a five-needle pine species that forms the most diverse of the white pine forest cover types in the western United States, is vulnerable to an interacting suite of threats that includes climate change, fire suppression, white pine blister rust (Cronartium ribicola), and mountain pine beetles (Dendroctonus ponderosae) that have already caused major changes in species distribution and abundance. We used the mechanistic simulation model FireBGCv2 to simulate effects of climate change and fire management on western white pines in a mountainous watershed in Glacier National Park, Montana, USA. Our results suggest that warming temperatures favor increased abundance of western white pine over existing climax and shade tolerant species in the study area, mainly because warmer conditions potentiate fire dynamics, including increased wildfire frequency and extent, which facilitates regeneration. Suppression of wildfires reduced the area dominated by western white pine, but fire suppression was less effective at limiting burned area extent and fire frequency in a warmer and drier climate. Wildfires created canopy gaps that allowed for western white pine regeneration at a high enough rate to escape local extirpation from white pine blister rust. Western white pine appears to be a resilient species even under fairly extreme warming trajectories and shifting fire regimes, and may provide a hedge against vegetation community shifts away from forest types and toward grass and shrublands. Forests 2011-10-12 2 4 Article 10.3390/f2040832 832 860 1999-4907 2011-10-12 doi: 10.3390/f2040832 Rachel A. Loehman Jason A. Clark Robert E. Keane