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Forests, Volume 7, Issue 9 (September 2016) – 27 articles

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668 KiB  
Editorial
Incentives and Constraints of Community and Smallholder Forestry
by Wil De Jong, Glenn Galloway, Pia Katila and Pablo Pacheco
Forests 2016, 7(9), 209; https://doi.org/10.3390/f7090209 - 16 Sep 2016
Cited by 12 | Viewed by 4912
Abstract
This editorial introduces the special issue: Incentives and constraints of community and smallholder forestry. The special issue contains nine papers, listed in a table in the main text. The editorial reviews briefly some key elements of our current understanding of community and [...] Read more.
This editorial introduces the special issue: Incentives and constraints of community and smallholder forestry. The special issue contains nine papers, listed in a table in the main text. The editorial reviews briefly some key elements of our current understanding of community and smallholder forestry. The editorial also briefly introduces the nine papers of the special issue and points out how they link to the debate among academics and specialists on community and smallholder forestry. Finally, the editorial highlights the new elements that the nine papers contribute to our understanding of community and smallholder forestry, before it concludes at the end. Full article
(This article belongs to the Special Issue Incentives and Constraints of Community and Smallholder Forestry)
688 KiB  
Article
Urban Forest Indicators for Planning and Designing Future Forests
by Sara Barron, Stephen R.J. Sheppard and Patrick M. Condon
Forests 2016, 7(9), 208; https://doi.org/10.3390/f7090208 - 16 Sep 2016
Cited by 30 | Viewed by 9859
Abstract
This paper describes a research project exploring future urban forests. This study uses a Delphi approach to develop a set of key indicators for healthy, resilient urban forests. Two groups of experts participated in the Delphi survey: International academics and local practitioners. The [...] Read more.
This paper describes a research project exploring future urban forests. This study uses a Delphi approach to develop a set of key indicators for healthy, resilient urban forests. Two groups of experts participated in the Delphi survey: International academics and local practitioners. The results of the Delphi indicate that “urban tree diversity” and “physical access to nature” are indicators of high importance. “Tree risk” and “energy conservation” were rated as indicators of relatively low importance. Results revealed some differences between academics and practitioners in terms of their rating of the indicators. The research shows that some indicators rated as high importance are not necessarily the ones measured or promoted by many municipal urban forestry programs. In particular, social indicators of human health and well-being were rated highly by participants, but not routinely measured by urban forestry programs. Full article
(This article belongs to the Special Issue Urban and Periurban Forest Diversity and Ecosystem Services)
2951 KiB  
Article
Single Tree Stem Profile Detection Using Terrestrial Laser Scanner Data, Flatness Saliency Features and Curvature Properties
by Kenneth Olofsson and Johan Holmgren
Forests 2016, 7(9), 207; https://doi.org/10.3390/f7090207 - 16 Sep 2016
Cited by 54 | Viewed by 7311
Abstract
A method for automatic stem detection and stem profile estimation based on terrestrial laser scanning (TLS) was validated. The root-mean-square error was approximately 1 cm for stem diameter estimations. The method contains a new way of extracting the flatness saliency feature using the [...] Read more.
A method for automatic stem detection and stem profile estimation based on terrestrial laser scanning (TLS) was validated. The root-mean-square error was approximately 1 cm for stem diameter estimations. The method contains a new way of extracting the flatness saliency feature using the centroid of a subset of a point cloud within a voxel cell that approximates the point by point calculations. The loss of accuracy is outweighed by a much higher computational speed, making it possible to cover large datasets. The algorithm introduces a new way to connect surface patches belonging to a stem and investigates if they belong to curved surfaces. Thereby, cylindrical objects, like stems, are found in the pre-filtering stage. The algorithm uses a new cylinder fitting method that estimates the axis direction by transforming the TLS points into a radial-angular coordinate system and evaluates the deviations by a moving window convex hull algorithm. Once the axis direction is found, the cylinder center is chosen as the position with the smallest radial deviations. The cylinder fitting method works on a point cloud in both the single-scan setup, as well as a multiple scan setup of a TLS system. Full article
(This article belongs to the Special Issue Forest Ground Observations through Terrestrial Point Clouds)
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2103 KiB  
Article
Tree Stem Diameter Estimation from Mobile Laser Scanning Using Line-Wise Intensity-Based Clustering
by Mona Forsman, Johan Holmgren and Kenneth Olofsson
Forests 2016, 7(9), 206; https://doi.org/10.3390/f7090206 - 16 Sep 2016
Cited by 42 | Viewed by 8195
Abstract
Diameter at breast height has been estimated from mobile laser scanning using a new set of methods. A 2D laser scanner was mounted facing forward, tilted nine degrees downwards, on a car. The trajectory was recorded using inertial navigation and visual SLAM (simultaneous [...] Read more.
Diameter at breast height has been estimated from mobile laser scanning using a new set of methods. A 2D laser scanner was mounted facing forward, tilted nine degrees downwards, on a car. The trajectory was recorded using inertial navigation and visual SLAM (simultaneous localization and mapping). The laser scanner data, the trajectory and the orientation were used to calculate a 3D point cloud. Clusters representing trees were extracted line-wise to reduce the effects of uncertainty in the positioning system. The intensity of the laser echoes was used to filter out unreliable echoes only grazing a stem. The movement was used to obtain measurements from a larger part of the stem, and multiple lines from different views were used for the circle fit. Two trigonometric methods and two circle fit methods were tested. The best results with bias 2.3% (6 mm) and root mean squared error 14% (37 mm) were acquired with the circle fit on multiple 2D projected clusters. The method was evaluated compared to field data at five test areas with approximately 300 caliper-measured trees within a 10-m working range. The results show that this method is viable for stem measurements from a moving vehicle, for example a forest harvester. Full article
(This article belongs to the Special Issue Forest Ground Observations through Terrestrial Point Clouds)
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7650 KiB  
Article
Fires of the Last Millennium Led to Landscapes Dominated by Early Successional Species in Québec’s Clay Belt Boreal Forest, Canada
by Maxime Asselin, Pierre Grondin, Martin Lavoie and Bianca Fréchette
Forests 2016, 7(9), 205; https://doi.org/10.3390/f7090205 - 15 Sep 2016
Cited by 6 | Viewed by 5718
Abstract
This study presents the long-term (over the last 8000 years) natural variability of a portion of the Picea mariana-moss bioclimatic domain belonging to Québec’s Clay Belt. The landscapes are dominated by mesic-subhydric clay and early successional forests composed of Populus tremuloides, [...] Read more.
This study presents the long-term (over the last 8000 years) natural variability of a portion of the Picea mariana-moss bioclimatic domain belonging to Québec’s Clay Belt. The landscapes are dominated by mesic-subhydric clay and early successional forests composed of Populus tremuloides, Pinus banksiana and Picea mariana. The natural variability (fires and vegetation) of one of these landscapes was reconstructed by means of pollen and macroscopic charcoal analysis of sedimentary archives from two peatlands in order to assess when and how such landscapes were formed. Following an initial afforestation period dominated by Picea (8000–6800 cal. Years BP), small and low-severity fires favored the development and maintenance of landscapes dominated by Picea and Abies balsamea during a long period (6800–1000 BP). Over the last 1000 years, fires have become more severe and covered a larger area. These fires initiated a recurrence dynamic of early successional stands maintained until today. A decline of Abies balsamea has occurred over the last centuries, while the pollen representation of Pinus banksiana has recently reached its highest abundance. We hypothesize that the fire regime of the last millennium could characterize Québec’s Clay Belt belonging to the western Picea mariana-moss and Abies balsamea-Betula papyrifera domains. Full article
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3026 KiB  
Article
A Simulation of Image-Assisted Forest Monitoring for National Inventories
by Francis A. Roesch
Forests 2016, 7(9), 204; https://doi.org/10.3390/f7090204 - 15 Sep 2016
Cited by 3 | Viewed by 3614
Abstract
The efficiency of national forest monitoring efforts can be increased by the judicious incorporation of ancillary data. For instance, a fixed number of ground plots might be used to inform a larger set of annual estimates by observing a smaller proportion of the [...] Read more.
The efficiency of national forest monitoring efforts can be increased by the judicious incorporation of ancillary data. For instance, a fixed number of ground plots might be used to inform a larger set of annual estimates by observing a smaller proportion of the plots each year while augmenting each annual estimate with ancillary data in order to reduce overall costs while maintaining a desired level of accuracy. Differencing successive geo-rectified remotely sensed images can conceivably provide forest change estimates at a scale and level of accuracy conducive to the improvement of temporally relevant forest attribute estimates. Naturally, the degree of improvement in the desired estimates is highly dependent on the relationships between the spatial-temporal scales of ground plot and remotely sensed observations and the desired spatial-temporal scale of estimation. In this paper, fixed scales of observation for each data source are used to explore the value of three different levels of information available from the remotely sensed image-change estimates. Four populations are simulated and sampled under four sampling error structures. The results show that the image change estimates (ICE) can be used to significantly reduce bias for annual estimates of harvest and mortality and that improved estimation of harvest and mortality can sometimes, but not always, contribute to better estimates of standing volume. Full article
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3796 KiB  
Article
Response of Mid-Rotation Loblolly Pine (Pinus taeda L.) Physiology and Productivity to Sustained, Moderate Drought on the Western Edge of the Range
by Adam Maggard, Rodney Will, Duncan Wilson and Cassandra Meek
Forests 2016, 7(9), 203; https://doi.org/10.3390/f7090203 - 14 Sep 2016
Cited by 10 | Viewed by 4801
Abstract
The productivity of the approximately 11 million ha of loblolly pine plantations in the southeastern USA could be threatened by decreased water availability in a future climate. To determine the effects of sustained drought on leaf gas exchange, whole-tree water use, and individual [...] Read more.
The productivity of the approximately 11 million ha of loblolly pine plantations in the southeastern USA could be threatened by decreased water availability in a future climate. To determine the effects of sustained drought on leaf gas exchange, whole-tree water use, and individual tree growth, we examined the response of loblolly pine trees to 100% throughfall exclusion cumulatively spanning the sixth and seventh growing seasons of a plantation in southeastern Oklahoma. Throughfall exclusion reduced volumetric soil water content for 0–12 cm soil depth from 10.8% to 4.8% and for 12–45 cm soil depth from 24.2% to 15.6%. Compared to ambient throughfall trees, leaf water potential of the throughfall exclusion trees became more negative, −0.9 MPa vs. −1.3 MPa for predawn measurements and −1.5 MPa vs. −1.9 MPa for midday measurements. Throughfall exclusion did not significantly reduce leaf gas exchange or tree water use. However, throughfall exclusion significantly reduced leaf biomass by 21% and stem volume growth by 23%. These results indicate that sustained drought may cause downward shifts in leaf quantity to conserve water rather than reducing leaf-level water use. Full article
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4415 KiB  
Article
Natural and Anthropogenic Transformations of A Baltic Raised Bog (Bagno Kusowo, North West Poland) in the Light of Dendrochronological Analysis of Pinus sylvestris L.
by Anna Cedro and Zofia Sotek
Forests 2016, 7(9), 202; https://doi.org/10.3390/f7090202 - 13 Sep 2016
Cited by 6 | Viewed by 5204
Abstract
This study was conducted in a drained, exploited, and afforested Baltic bog Bagno Kusowo, located in North West Poland. The study aimed (i) to assess if human activity has a stronger impact on tree-ring width of Pinus sylvestris than climatic conditions in this [...] Read more.
This study was conducted in a drained, exploited, and afforested Baltic bog Bagno Kusowo, located in North West Poland. The study aimed (i) to assess if human activity has a stronger impact on tree-ring width of Pinus sylvestris than climatic conditions in this transformed Baltic bog; (ii) to investigate how much the human modification of the ecosystem has influenced tree growth; (iii) to use this knowledge to reconstruct changes in the ecosystem further back in time, in the study area and its immediate neighbourhood. Wood samples for dendrochronological analyses were collected from 45 trees. Next, using classic dating methods and standard procedures (cross-dating methods, COFECHA program), chronologies were constructed (raw tree-ring width and residual chronologies: de-trended, autocorrelation removed, ARSTAN program). They formed a basis for further analyses: signature years, correlation and response function, as well as percentage growth change. The results of dendroclimatological analyses show weak increment–climate relationships and the analysis of weather conditions in the identified signature years did not detect any unambiguous relations with tree-ring width. However, results of the analyses indicate that the dominant factors affecting tree growth dynamics in the bog are changes in the hydrological system. Moreover, our results show many phases of human impact on environmental changes. Dendrochronological methods, combined with an analysis of old maps and other historical records, allowed us to reconstruct transformations of the ecosystem with a high resolution. Full article
(This article belongs to the Special Issue Forest Growth Response to Environmental Stress)
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1812 KiB  
Article
How Time since Forest Fire Affects Stand Structure, Soil Physical-Chemical Properties and Soil CO2 Efflux in Hemiboreal Scots Pine Forest Fire Chronosequence?
by Kajar Köster, Egle Köster, Argo Orumaa, Kristi Parro, Kalev Jõgiste, Frank Berninger, Jukka Pumpanen and Marek Metslaid
Forests 2016, 7(9), 201; https://doi.org/10.3390/f7090201 - 12 Sep 2016
Cited by 19 | Viewed by 6761
Abstract
We compared the changes in aboveground biomass and initial recovery of C pools and CO2 efflux following fire disturbances in Scots pine (Pinus sylvesteris L.) stands with different time since stand-replacing fire. The study areas are located in hemiboreal vegetation zone, [...] Read more.
We compared the changes in aboveground biomass and initial recovery of C pools and CO2 efflux following fire disturbances in Scots pine (Pinus sylvesteris L.) stands with different time since stand-replacing fire. The study areas are located in hemiboreal vegetation zone, in north-western Estonia, in Vihterpalu. Six areas where the last fire occurred in the year 1837, 1940, 1951, 1982, 1997, and 2008 were chosen for the study. Our results show that forest fire has a substantial effect on the C content in the top soil layer, but not in the mineral soil layers. Soil respiration showed a chronological response to the time since the forest fire and the values were lowest in the area where the fire was in the year 2008. The respiration values also followed seasonal pattern being highest in August and lowest in May and November. The CO2 effluxes were lowest on the newly burned area through the entire growing season. There was also a positive correlation between soil temperature and soil respiration values in our study areas. Full article
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3908 KiB  
Article
Quantifying Tree and Soil Carbon Stocks in a Temperate Urban Forest in Northeast China
by Hailiang Lv, Wenjie Wang, Xingyuan He, Lu Xiao, Wei Zhou and Bo Zhang
Forests 2016, 7(9), 200; https://doi.org/10.3390/f7090200 - 10 Sep 2016
Cited by 36 | Viewed by 7777
Abstract
Society has placed greater focus on the ecological service of urban forests; however, more information is required on the variation of carbon (C) in trees and soils in different functional forest types, administrative districts, and urban-rural gradients. To address this issue, we measured [...] Read more.
Society has placed greater focus on the ecological service of urban forests; however, more information is required on the variation of carbon (C) in trees and soils in different functional forest types, administrative districts, and urban-rural gradients. To address this issue, we measured various tree and soil parameters by sampling 219 plots in the urban forest of the Harbin city region. Averaged tree and soil C stock density (C stocks per unit tree cover) for Harbin city were 7.71 (±7.69) kg C·m−2 and 5.48 (±2.86) kg C·m−2, respectively. They were higher than those of other Chinese cities (Shenyang and Changchun), but were much lower than local natural forests. The tree C stock densities varied 2.3- to 3.2-fold among forest types, administrative districts, and ring road-based urban-rural gradients. In comparison, soil organic C (SOC) densities varied by much less (1.4–1.5-fold). We found these to be urbanization-dependent processes, which were closely related to the urban-rural gradient data based on ring-roads and settlement history patterns. We estimated that SOC accumulation during the 100-year urbanization of Harbin was very large (5 to 14 thousand tons), accounting for over one quarter of the stored C in trees. Our results provide new insights into the dynamics of above- and below-ground C (especially in soil) during the urbanization process, and that a city’s ability to provide C-related ecosystem services increases as it ages. Our findings highlight that urbanization effects should be incorporated into calculations of soil C budgets in regions subject to rapid urban expansion, such as China. Full article
(This article belongs to the Special Issue Urban and Periurban Forest Diversity and Ecosystem Services)
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693 KiB  
Article
Failure to Communicate: Inefficiencies in Voluntary Incentive Programs for Private Forest Owners in Michigan
by Mark D. Rouleau, Jennifer F. Lind-Riehl, Miranda N. Smith and Audrey L. Mayer
Forests 2016, 7(9), 199; https://doi.org/10.3390/f7090199 - 06 Sep 2016
Cited by 18 | Viewed by 4988
Abstract
Coordinating forest management across thousands of nonindustrial private forest (NIPF) owners is a difficult yet necessary task for state land management agencies. Voluntary Incentive Programs (VIPs) can coordinate the decentralized activities of these owners in return for services or financial incentives. However, many [...] Read more.
Coordinating forest management across thousands of nonindustrial private forest (NIPF) owners is a difficult yet necessary task for state land management agencies. Voluntary Incentive Programs (VIPs) can coordinate the decentralized activities of these owners in return for services or financial incentives. However, many VIPs typically have low enrollment. Our study investigates the implementation of VIPs to increase forest management coordination among NIPFs in Michigan. We present findings from 20 semi-structured interviews with leaders of state and local land management organizations, and government officials at state natural resource agencies, and contrast their answers with those recorded from 37 interviews of NIPF owners regarding their knowledge and attitudes toward VIPs. Our interviews highlight a critical disconnect between NIPF owner motivations and VIP incentives, as well as misallocated resources for VIP promotion by state agencies, driving low enrollment. At the core, low enrollment in VIPs is generated by inadequate communication between NIPF owners and program managers, along with distrust of government agency objectives. Viewing managers as “street level bureaucrats”, civil servants whose job discretion is impacted heavily by available resources, may increase our understanding of the issues plaguing VIPs and help identify improvements to VIP design and implementation. Full article
771 KiB  
Review
Full-Waveform Airborne Laser Scanning in Vegetation Studies—A Review of Point Cloud and Waveform Features for Tree Species Classification
by Kristina Koenig and Bernhard Höfle
Forests 2016, 7(9), 198; https://doi.org/10.3390/f7090198 - 06 Sep 2016
Cited by 51 | Viewed by 9646
Abstract
In recent years, small-footprint full-waveform airborne laser scanning has become readily available and established for vegetation studies in the fields of forestry, agriculture and urban studies. Independent of the field of application and the derived final product, each study uses features to classify [...] Read more.
In recent years, small-footprint full-waveform airborne laser scanning has become readily available and established for vegetation studies in the fields of forestry, agriculture and urban studies. Independent of the field of application and the derived final product, each study uses features to classify a target object and to assess its characteristics (e.g., tree species). These laser scanning features describe an observable characteristic of the returned laser signal (e.g., signal amplitude) or a quantity of an object (e.g., height-width ratio of the tree crown). In particular, studies dealing with tree species classification apply a variety of such features as input. However, an extensive overview, categorization and comparison of features from full-waveform airborne laser scanning and how they relate to specific tree species are still missing. This review identifies frequently used full-waveform airborne laser scanning-based point cloud and waveform features for tree species classification and compares the applied features and their characteristics for specific tree species detection. Furthermore, limiting and influencing factors on feature characteristics and tree classification are discussed with respect to vegetation structure, data acquisition and processing. Full article
(This article belongs to the Special Issue LiDAR Remote Sensing of Forest Resources)
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2625 KiB  
Article
Genetic Diversity of the Black Mangrove Avicennia germinans (L.) Stearn in Northwestern Mexico
by Olivia Millán-Aguilar, Marlenne Manzano-Sarabia, Alejandro Nettel-Hernanz, Richard S. Dodd, Miguel Ángel Hurtado-Oliva and Ernesto Velázquez-Velázquez
Forests 2016, 7(9), 197; https://doi.org/10.3390/f7090197 - 03 Sep 2016
Cited by 10 | Viewed by 5440
Abstract
Mangrove forests of Mexico have been threatened by the effects of anthropogenic activities during the last decades, mostly related to aquaculture, agriculture, livestock and urban development. Genetic diversity and fine-scale genetic structure of two generations of the black mangrove Avicennia germinans (L.) Stearn [...] Read more.
Mangrove forests of Mexico have been threatened by the effects of anthropogenic activities during the last decades, mostly related to aquaculture, agriculture, livestock and urban development. Genetic diversity and fine-scale genetic structure of two generations of the black mangrove Avicennia germinans (L.) Stearn were investigated in perturbed and preserved sites from three lagoon systems in Sinaloa, Mexico. Genetic diversity and overall genetic structure were similar between perturbed and preserved sites. However, lower levels of fine-scale spatial genetic structure were observed in two of the younger (sapling) generations. We attribute this to differences in local dynamics of each lagoon system, their status of conservation and levels of fragmentation. Also, low connectivity and the effects of disturbance could restrict the movement of pollinators and seed dispersal capabilities, resulting in low levels of genetic diversity and signs of inbreeding. Perturbed populations of A. germinans may play an important role in in situ conservation of this complex ecosystem. Full article
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610 KiB  
Correction
Correction: Lopatin, E., et al. Assessment of Compliance with PEFC Forest Certification Indicators with Remote Sensing. Forests 2016, 7, 85
by Eugene Lopatin, Maxim Trishkin and Olga Gavrilova
Forests 2016, 7(9), 196; https://doi.org/10.3390/f7090196 - 01 Sep 2016
Cited by 2 | Viewed by 3091
Abstract
The authors wish to make the following correction to their paper [1].[...] Full article
1126 KiB  
Article
Does REDD+ Ensure Sectoral Coordination and Stakeholder Participation? A Comparative Analysis of REDD+ National Governance Structures in Countries of Asia-Pacific Region
by Taiji Fujisaki, Kimihiko Hyakumura, Henry Scheyvens and Tim Cadman
Forests 2016, 7(9), 195; https://doi.org/10.3390/f7090195 - 31 Aug 2016
Cited by 28 | Viewed by 6736
Abstract
Reducing emissions from deforestation and forest degradation in developing countries (REDD+) requires harmonizing different policy sectors and interests that have impacts on forests. However, these elements have not been well-operationalized in environmental policy-making processes of most developing countries. Drawing on five cases—Cambodia, Indonesia, [...] Read more.
Reducing emissions from deforestation and forest degradation in developing countries (REDD+) requires harmonizing different policy sectors and interests that have impacts on forests. However, these elements have not been well-operationalized in environmental policy-making processes of most developing countries. Drawing on five cases—Cambodia, Indonesia, Lao PDR, Papua New Guinea, and Vietnam, this article aims to determine whether emerging governance arrangements help REDD+ development by delivering participatory mechanisms for policy coordination. Building upon literature on environmental governance and stakeholder participation, the article examines national governance structures for REDD+ and identifies who participates where, and what decision-making powers they have. Despite structural differences between the countries, our analysis illustrates that REDD+ potentially encourages a new form of environmental governance promoting a cross-sectoral approach and stakeholder participation. Cohesiveness of the structures within a broader governance system is key to defining the capacity of REDD+ governance. The result also poses a question as to the inclusiveness of the state actors involved in order to tackle the different pressure on forests. Considering structural inequalities, the analysis further suggests a need of policy support for those who are affected by REDD+ to ensure that their voices could be heard in decision-making processes. Full article
(This article belongs to the Special Issue REDD+ Crossroads Post Paris: Politics, Lessons and Interplays)
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Article
Developing an Improved Parameter Estimation Method for the Segmented Taper Equation through Combination of Constrained Two-Dimensional Optimum Seeking and Least Square Regression
by Lifeng Pang, Yongpeng Ma, Ram P. Sharma, Shawn Rice, Xinyu Song and Liyong Fu
Forests 2016, 7(9), 194; https://doi.org/10.3390/f7090194 - 31 Aug 2016
Cited by 6 | Viewed by 4017
Abstract
The segmented taper equation has great flexibility and is widely applied in exiting taper systems. The unconstrained least square regression (ULSR) was generally used to estimate parameters in previous applications of the segmented taper equations. The joint point parameters estimated with ULSR may [...] Read more.
The segmented taper equation has great flexibility and is widely applied in exiting taper systems. The unconstrained least square regression (ULSR) was generally used to estimate parameters in previous applications of the segmented taper equations. The joint point parameters estimated with ULSR may fall outside the feasible region, which leads to the results of the segmented taper equation being uncertain and meaningless. In this study, a combined method of constrained two-dimensional optimum seeking and least square regression (CTOS & LSR) was proposed as an improved method to estimate the parameters in the segmented taper equation. The CTOS & LSR was compared with ULSR for both individual tree-level equation and the population average-level equation using data from three tropical precious tree species (Castanopsis hystrix, Erythrophleum fordii, and Tectona grandis) in the southwest of China. The differences between CTOS & LSR and ULSR were found to be significant. The segmented taper equation estimated using CTOS & LSR resulted in not only increased prediction accuracy, but also guaranteed the parameter estimates in a more meaningful way. It is thus recommended that the combined method of constrained two-dimensional optimum seeking and least square regression should be a preferred choice for this application. The computation procedures required for this method is presented in the article. Full article
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1222 KiB  
Article
Smallholder Forestry in the Western Amazon: Outcomes from Forest Reforms and Emerging Policy Perspectives
by Pablo Pacheco, Elena Mejía, Walter Cano and Wil De Jong
Forests 2016, 7(9), 193; https://doi.org/10.3390/f7090193 - 31 Aug 2016
Cited by 24 | Viewed by 6204
Abstract
The forest reforms unfolding during the last two decades in the western Amazon have embraced policy regimes founded on the principles of sustainable forest management. The policy frameworks adopted for smallholder forestry aimed to clarify forest rights including those of the indigenous people [...] Read more.
The forest reforms unfolding during the last two decades in the western Amazon have embraced policy regimes founded on the principles of sustainable forest management. The policy frameworks adopted for smallholder forestry aimed to clarify forest rights including those of the indigenous people and smallholders, support the adoption of sustainable forest management and put a system in place to assure a legal timber supply. The emerging forest policy regimes have significantly shaped who has access to the forest, how the forest resources are used and the benefits that are utilized. We argue that forest reforms have not addressed some critical constraints facing smallholders in managing their forests either individually or collectively. Informal timber extraction persists with contradictory effects on smallholders and forests. Local participants continue to make a significant contribution in meeting a growing demand for timber through vigorous market networks that combine legal and illegal sources of timber supply. Some recent changes to forest policy frameworks emphasize approaches towards additional integrated forest management, simplification of regulations and incentives for improved forest management. We critically reflect on the scope, implementation and expected outcomes of these policy frameworks. Full article
(This article belongs to the Special Issue Incentives and Constraints of Community and Smallholder Forestry)
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Article
Variation in the Growth Traits and Wood Properties of Chinese Fir from Six Provinces of Southern China
by Hongjing Duan, Sen Cao, Huiquan Zheng, Dehuo Hu, Jun Lin, Huazhong Lin, Ruiyang Hu, Yuhan Sun and Yun Li
Forests 2016, 7(9), 192; https://doi.org/10.3390/f7090192 - 31 Aug 2016
Cited by 34 | Viewed by 4660
Abstract
To determine the phenotypic variation in 700 ten-year grafted Chinese fir collected from six provinces in southern China, 10 phenotypic traits were investigated: tree height, diameter at breast height, bark thickness, volume of timber, heartwood ratio, density of wood, hygroscopicity, tracheid length, tracheid [...] Read more.
To determine the phenotypic variation in 700 ten-year grafted Chinese fir collected from six provinces in southern China, 10 phenotypic traits were investigated: tree height, diameter at breast height, bark thickness, volume of timber, heartwood ratio, density of wood, hygroscopicity, tracheid length, tracheid diameter, and ratio of tracheid length to tracheid diameter. Abundant phenotypic variation was found among the six populations; the phenotypic variation coefficients all exceeded 10%, and the largest was for volume of timber. Significant variation (p < 0.01 or 0.05) in traits was found among the populations, except for diameter at breast height, heartwood ratio, and tracheid diameter, while all traits differed significantly (p < 0.01) within populations. The high value of repeatability (broad-sense heritability) suggested moderate genetic control of the traits. The 10 traits were strongly correlated within the entire population; strong positive correlations (p < 0.01) were observed between growth traits, and significant negative correlations (p < 0.01 or 0.05) were found between the density of wood and most other characteristics, except for heartwood ratio and ratio of tracheid length to tracheid diameter. Using diameter at breast height and density of wood as criteria, 98 relatively fast-growing genotypes with relatively high wood basic density were identified. Full article
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2407 KiB  
Article
Eliminating Illegal Timber Consumption or Production: Which Is the More Economical Means to Reduce Illegal Logging?
by Xiaobiao Zhang, Bin Xu, Lei Wang, Aijun Yang and Hongqiang Yang
Forests 2016, 7(9), 191; https://doi.org/10.3390/f7090191 - 29 Aug 2016
Cited by 11 | Viewed by 9047
Abstract
Illegal logging, with its related trade of illegally harvested timber, is one of the main environmental and economic problems worldwide. Eliminating illegal timber consumption and production are two practical means to reduce illegal logging. However, the problem of determining which of the two [...] Read more.
Illegal logging, with its related trade of illegally harvested timber, is one of the main environmental and economic problems worldwide. Eliminating illegal timber consumption and production are two practical means to reduce illegal logging. However, the problem of determining which of the two means is more economical remains to be analyzed. In this study, an input–output analysis was conducted to evaluate the consumption and production of illegal timber in different countries. The Global Forest Products Model (GFPM) was employed to analyze the effects of eliminating illegal timber consumption and production on the added value of the forest sector at global and national levels. Results indicated that eliminating illegal timber production is more economical than eliminating consumption at the global level. The former is estimated to decrease the added value of the global forest sector only by 3.37% compared to 7.31% by the latter in 2030. Eliminating the production of illegal timber will result in uneven distribution of social wealth in the forest sector, and will pass the cost of reducing illegal logging onto developing countries. Developed countries would gain more added value and market scale than the global average, whereas developing countries would suffer a loss if illegal timber production is eliminated. Hence, developed countries are encouraged to provide financial support to help developing countries reduce illegal logging. Full article
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1880 KiB  
Article
Strategies to Combat Mycosphaerella Leaf Disease in Eucalyptus globulus Plantations in Northern Spain
by Severiano Pérez, Carlos Renedo, Alfredo Ortiz, Felix Ortiz and Carlos Tejedor
Forests 2016, 7(9), 190; https://doi.org/10.3390/f7090190 - 29 Aug 2016
Cited by 3 | Viewed by 4206
Abstract
Eucalyptus globulus is widely planted in temperate regions to produce pulp for its high performance but few studies of the impact of Mycosphaerella Leaf Disease (MLD) have been documented. This study aimed to explore and provide knowledge on disease in the management of [...] Read more.
Eucalyptus globulus is widely planted in temperate regions to produce pulp for its high performance but few studies of the impact of Mycosphaerella Leaf Disease (MLD) have been documented. This study aimed to explore and provide knowledge on disease in the management of young Eucalyptus globulus stands in the north of Spain. The influences of subspecies, cloning, and fertilization on the degree of severity of the disease were analyzed. The study was conducted with different material plants of Eucalyptus globulus, of Australian origin, from other sources, open-pollinated families, clones, and families of controlled pollination. Each series tested different vegetal material, except for a number of control codes that were used as reference samples for MLD evaluation. Severity, height at which foliage changes from juvenile to adult, total height, and volume were all measured. There were significant correlations in the average MLD severity of families and provenances obtained from the different trials. ANOVA revealed important differences between subspecies of E. globulus. A correlation was found between the percentage of adult leaf and the severity. There were differences in the impact of MLD between plant material non-selected and selected by its tolerance (p < 0.0001). There was a significant effect on the severity between mature cuttings and families from seed non-selected in their tolerance to MLD. Their tolerance was lower than that achieved from seed selected by its tolerance to MLD. Genetic selection was shown as the best strategy since there are individuals exceptionally tolerant to MLD. Full article
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3426 KiB  
Article
350 Years of Fire-Climate-Human Interactions in a Great Lakes Sandy Outwash Plain
by Richard P. Guyette, Michael C. Stambaugh, Daniel C. Dey, Joseph M. Marschall, Jay Saunders and John Lampereur
Forests 2016, 7(9), 189; https://doi.org/10.3390/f7090189 - 27 Aug 2016
Cited by 25 | Viewed by 7052
Abstract
Throughout much of eastern North America, quantitative records of historical fire regimes and interactions with humans are absent. Annual resolution fire scar histories provide data on fire frequency, extent, and severity, but also can be used to understand fire-climate-human interactions. This study used [...] Read more.
Throughout much of eastern North America, quantitative records of historical fire regimes and interactions with humans are absent. Annual resolution fire scar histories provide data on fire frequency, extent, and severity, but also can be used to understand fire-climate-human interactions. This study used tree-ring dated fire scars from red pines (Pinus resinosa) at four sites in the Northern Sands Ecological Landscapes of Wisconsin to quantify the interactions among fire occurrence and seasonality, drought, and humans. New methods for assessing the influence of human ignitions on fire regimes were developed. A temporal and spatial index of wildland fire was significantly correlated (r = 0.48) with drought indices (Palmer Drought Severity Index, PDSI). Fire intervals varied through time with human activities that included early French Jesuit missions, European trade (fur), diseases, war, and land use. Comparisons of historical fire records suggest that annual climate in this region has a broad influence on the occurrence of fire years in the Great Lakes region. Full article
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2991 KiB  
Article
Analyzing the Efficiency of a Start-Up Cable Yarding Crew in Southern China under New Forest Management Perspectives
by Stephan Hoffmann, Dirk Jaeger, Marcus Lingenfelder and Siegmar Schoenherr
Forests 2016, 7(9), 188; https://doi.org/10.3390/f7090188 - 27 Aug 2016
Cited by 10 | Viewed by 7847
Abstract
This case study analyzed the performance of a start-up cable yarding crew in southern China through operational monitoring by consecutive time studies, long-term log book recordings and efficiency evaluation by stochastic frontier analysis (SFA). The crew, which used a KOLLER K303 H mobile [...] Read more.
This case study analyzed the performance of a start-up cable yarding crew in southern China through operational monitoring by consecutive time studies, long-term log book recordings and efficiency evaluation by stochastic frontier analysis (SFA). The crew, which used a KOLLER K303 H mobile tower yarder, was monitored for two years. During this period, detailed data recordings of 687 yarding cycles of 12 yarding corridors as well as log book recordings of an additional 1122 scheduled system hours (SSH, including all delays) were generated. Mean extraction productivity of the system ranged between 5.23 and 6.40 m3 per productive system hour (PSH0, excluding all delays), mostly depending on slope yarding distance and lateral distance. Corresponding gross-productivity ranged from 1.91 to 2.24 m3/SSH, with an overall mean machine utilization rate of 31%. Unproductive yarding times and delays associated with the relative low utilization rate were mainly caused by lengthy rigging processes, as well as organizational deficiencies and not yet fully developed skill sets of the operating crew. The latter was reflected in a mean efficiency effect frontier value of 0.62 based on evaluation of data sets of individual yarding cycles recorded during detailed assessments, suggesting a mean improvement potential of 38% based on the SFA, translating in a potentially achievable gross-productivity of 2.64 to 3.09 m3/SSH. We conclude that current local operating conditions including insufficient planning, implementation and logistics and in particular, frequent discontinuations of system operations of up to three months all resulting in generally low operation hours per shift and per year, inhibit efficient operations and rapid skill development. These circumstances also inhibit an economic utilization of the equipment. Nevertheless, from a technical perspective, yarding systems have a promising potential in southern China. Full article
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2156 KiB  
Article
Vegetation Mortality within Natural Wildfire Events in the Western Canadian Boreal Forest: What Burns and Why?
by Colin J. Ferster, Bianca N. I. Eskelson, David W. Andison and Valerie M. LeMay
Forests 2016, 7(9), 187; https://doi.org/10.3390/f7090187 - 26 Aug 2016
Cited by 14 | Viewed by 5770
Abstract
Wildfires are a common disturbance event in the Canadian boreal forest. Within event boundaries, the level of vegetation mortality varies greatly. Understanding where surviving vegetation occurs within fire events and how this relates to pre-fire vegetation, topography, and fire weather can inform forest [...] Read more.
Wildfires are a common disturbance event in the Canadian boreal forest. Within event boundaries, the level of vegetation mortality varies greatly. Understanding where surviving vegetation occurs within fire events and how this relates to pre-fire vegetation, topography, and fire weather can inform forest management decisions. We used pre-fire forest inventory data, digital elevation maps, and records of fire weather for 37 naturally-occurring wildfires (1961 to 1982; 30 to 5500 ha) covering a wide range of conditions in the western Canadian boreal forest to investigate these relationships using multinomial logistic models. Overall, vegetation mortality related to a combination of factors representing different spatial scales. Lower vegetation mortality occurred where there was lower fuel continuity and when fires occurred under non-drought conditions. Higher classification accuracy occurred for class extremes of no mortality (i.e., unburned areas within the burn event) and high mortality; partial vegetation mortality classes were harder to distinguish. This research contributes to the knowledge required for natural pattern emulation strategies, and developing responses to climate change. Full article
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2141 KiB  
Article
Spatio-Temporal Configurations of Human-Caused Fires in Spain through Point Patterns
by Sergi Costafreda-Aumedes, Carles Comas and Cristina Vega-Garcia
Forests 2016, 7(9), 185; https://doi.org/10.3390/f7090185 - 26 Aug 2016
Cited by 23 | Viewed by 5921
Abstract
Human-caused wildfires are often regarded as unpredictable, but usually occur in patterns aggregated over space and time. We analysed the spatio-temporal configuration of 7790 anthropogenic wildfires (2007–2013) in nine study areas distributed throughout Peninsular Spain by using the Ripley’s K-function. We also related [...] Read more.
Human-caused wildfires are often regarded as unpredictable, but usually occur in patterns aggregated over space and time. We analysed the spatio-temporal configuration of 7790 anthropogenic wildfires (2007–2013) in nine study areas distributed throughout Peninsular Spain by using the Ripley’s K-function. We also related these aggregation patterns to weather, population density, and landscape structure descriptors of each study area. Our results provide statistical evidence for spatio-temporal structures around a maximum of 4 km and six months. These aggregations lose strength when the spatial and temporal distances increase. At short time lags after a wildfire (<1 month), the probability of another fire occurrence is high at any distance in the range of 0–16 km. When considering larger time lags (up to two years), the probability of fire occurrence is high only at short distances (>3 km). These aggregated patterns vary depending on location in Spain. Wildfires seem to aggregate within fewer days (heat waves) in warm and dry Mediterranean regions than in milder Atlantic areas (bimodal fire season). Wildfires aggregate spatially over shorter distances in diverse, fragmented landscapes with many small and complex patches. Urban interfaces seem to spatially concentrate fire occurrence, while wildland-agriculture interfaces correlate with larger aggregates. Full article
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6522 KiB  
Review
From Litter to Humus in a Norwegian Spruce Forest: Long-Term Studies on the Decomposition of Needles and Cones
by Sigmund Hågvar
Forests 2016, 7(9), 186; https://doi.org/10.3390/f7090186 - 25 Aug 2016
Cited by 9 | Viewed by 5658
Abstract
The aim of this review and synthesis is to illustrate the gradual transformation of needles and cones from litter to humus. Individual needles may follow quite different decomposition pathways, which contributes to a diverse humus structure. In the litter layer (Oi), about 40% [...] Read more.
The aim of this review and synthesis is to illustrate the gradual transformation of needles and cones from litter to humus. Individual needles may follow quite different decomposition pathways, which contributes to a diverse humus structure. In the litter layer (Oi), about 40% of the needles were excavated by special mites that produced slowly decomposable excrements. In the fermentation layer (Oe), needles which happened to be in close contact with fine roots decomposed more rapidly. Cones decomposed slower than needles during the first 3–5 years, so the role of cones in carbon (C) storage may be greater than indicated by their fraction of fresh litter. Over a 13 years period, potassium (K), magnesium (Mg) and phosphorus (P) in cones was released, while the total amount of calcium (Ca), manganese (Mn), iron (Fe) and aluminium (Al) increased strongly. Nitrogen concentration increased but the total nitrogen content remained rather constant. After 13 years, the cones had sunk about 6 cm into the soil and lost 60% of their dry weight but were morphologically intact. A cone monitored for 28 years was fully recognizable and had not yet reached the stable Oa layer. The most inert decomposition products in the Oa layer were fragments of needles and cone scales, microarthropod excrements and chitinous insect remains. Full article
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860 KiB  
Article
Practitioner Perceptions of Wildland Fire Management across South Europe and Latin America
by Domingo M. Molina-Terrén, Adrian Cardil and Leda N. Kobziar
Forests 2016, 7(9), 184; https://doi.org/10.3390/f7090184 - 24 Aug 2016
Cited by 11 | Viewed by 4441
Abstract
Wildfire presents a challenge to natural resource managers the world over, and the intentional setting of fires can be used to alleviate some of the challenges associated with wildfire management. Prescribed burning can be used prior to wildfires to reduce fuel loads and [...] Read more.
Wildfire presents a challenge to natural resource managers the world over, and the intentional setting of fires can be used to alleviate some of the challenges associated with wildfire management. Prescribed burning can be used prior to wildfires to reduce fuel loads and promote ecological integrity in fire-adapted systems, while suppression burning can help firefighters control the direction, extent, and intensity of wildfire behavior under extreme conditions. In both cases, the success of intentional fire use depends on training, knowledge, experience, and institutional and social support. The influence of these factors can significantly impact whether fire use is perceived as positive or negative, increasing or decreasing, and whether managers are supportive of its incorporation into their management planning and decision-making. Perceived impediments to fire use are likely to differ based on location, level of training and experience, and even the social context of fire management specific to different job positions in natural resource management. In order to explore how managers and stakeholders across the world perceive fire use, we surveyed over 700 respondents from 12 countries and three continents. This study represents the largest survey of perceptions on managed fire use ever conducted. Perceptions differed across age categories, job positions, and regions. Countries or regions with larger amounts of wildfire area burned tended to be more supportive of fire use for suppression, while countries with less wildfire had less positive perceptions of fire use for either prescribed or suppression burning. Bureaucracy and social perceptions were identified as impediments to using prescribed fire prior to wildfire occurrence, but neither were identified as impediments to fire use during suppression procedures. Across the countries, fire use in suppression was viewed more positively than prescribed fire use prior to wildfire occurrence. Full article
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2762 KiB  
Review
Ecosystem Services and Disservices of Mangrove Forests: Insights from Historical Colonial Observations
by Daniel A. Friess
Forests 2016, 7(9), 183; https://doi.org/10.3390/f7090183 - 24 Aug 2016
Cited by 58 | Viewed by 13642
Abstract
Ecosystem services are now strongly applied to mangrove forests, though they are not a new way of viewing mangrove-people interactions; the benefits provided by such habitats, and the negative interactions (ecosystem disservices) between mangroves and people have guided perceptions of mangroves for centuries. [...] Read more.
Ecosystem services are now strongly applied to mangrove forests, though they are not a new way of viewing mangrove-people interactions; the benefits provided by such habitats, and the negative interactions (ecosystem disservices) between mangroves and people have guided perceptions of mangroves for centuries. This study quantified the ecosystem services and disservices of mangroves as written by colonial explorers from 1823–1883 through a literature survey of 96 expedition reports and studies. Ecosystem disservices were most commonly discussed (60%), with settlers considering mangroves as reservoirs of diseases such as malaria, with wide-ranging implications, such as the global drainage of wetlands in the 19th–20th centuries. Multiple ecosystem services were discussed, especially provisioning services for export, representing colonial views of new lands as ripe for economic use. Interestingly, regulating services of mangroves such as erosion control and sediment accretion that are a focus of much contemporary research were recognized as early as 1865. This study shows that the ecosystem service paradigm has a long history in mangroves. We should not underestimate mangrove ecosystem disservices, and how contemporary perceptions of mangroves may be influenced by such historical viewpoints. Archival materials provide a rich resource to study human-environment interactions, and how they change through time. Full article
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