Forests2014, 5(12), 3344-3351; doi:10.3390/f5123344 (registering DOI) - published 19 December 2014 Show/Hide Abstract
Abstract: Advanced oak and hickory regeneration is often absent in mature oak-hickory forests in the Central Hardwood Region of the United States. Prescribed fire and thinning, alone and combined, are commonly prescribed silvicultural treatments that are recommended to initiate the regeneration process. This study examined the regeneration response in three mature oak stands following four treatments: (1) thin, (2) burn, (3) thinning and burning, or (4) no treatment (control). Ten years after initial treatment, results indicate that oak and hickory seedlings had greater height and diameter in the thinning and burning treatment compared to the control and that this treatment may help facilitate desirable regeneration in mature oak-hickory forests.
Forests2014, 5(12), 3327-3343; doi:10.3390/f5123327 (registering DOI) - published 19 December 2014 Show/Hide Abstract
Abstract: The Cacheu Mangroves Natural Park (PNTC) was established in the year 2000 with the objective of protecting the coastal forests of Northern Guinea-Bissau, which have been subject to deforestation and are at risk. Concomitantly, the need to find sustainable financial revenues to support forest conservation motivated the development of projects that explore avoidance of deforestation and forest degradation (REDD+) as a potential income possibility. The 886,150 ha of forest in the PNTC include a mosaic of different villages where communities with different cultural and socio-economic habits reside. In addition to the uncontrolled expansion of subsistence agriculture with the associated shortening of fallow periods, forests may have also been subject to degradation from selective logging, fuel wood collection, and charcoal production. To contribute to a forest degradation baseline forest uses for household fuel consumption (wood and charcoal) were surveyed using questionnaires, interviews and focus groups. The data were collected from a representative sample of circa 200 households within a 2 km buffer of the PNTC. These data are analyzed and the results are discussed according to a scenario of ethnic diversity, i.e., a diversity of approaches relating to forest conservation. Even though the results indicate that fuel wood is the main (and almost sole) source of energy for cooking, they also show that the average daily fuel consumption per capita (1.21 kg) is well below the sub-Saharan average and that fuel is obtained from downed dead wood or dead trees. Therefore, it is concluded that reported forest degradation in PNTC cannot be attributed to fuel wood consumption by local populations.
Forests2014, 5(12), 3295-3326; doi:10.3390/f5123295 - published 18 December 2014 Show/Hide Abstract
Abstract: In 2009, the conference of the parties of the United Nations Framework Convention on Climate Change recognized the need to engage communities and indigenous groups into the systems to monitor, report and verify the results of REDD+. Since then, many countries have started to prepare for REDD+ implementation. This article reviews early experiences under development in 11 projects financed by the Alliance Mexico REDD+ located in four Early Action Areas to identify the potential integration of Community Based Monitoring (CBM). The evaluation of the projects is made based on a multi-criteria analysis which considers the potential to produce information relevant for national monitoring systems and the prospects for sustained monitoring practices over time. Results indicate there are challenges to harmonizing monitoring practices and protocols between projects since activities proposed differ greatly from one project to another. Technical specifications for integrating local data into national systems are thus required. The results of these projects can help to identify best practices for planning and implementing REDD+. Findings indicate that in general, resources and capacities to gather, analyse and report information as part of CBM systems are in place in the projects, but usually these reside with non-local experts (i.e., NGOs and Academia); however, there are notable examples where these capacities reside in the communities. If national forest monitoring systems are geared to include information gathered through locally-driven processes REDD+ should promote activities that produce local benefits, but countries would need to build local capacities for managing and monitoring natural resources and would also need to create agreements for sharing and using local data. Otherwise, national systems may need to rely on monitoring practices external to communities, which depend on the continued availability of external financial resources.
Forests2014, 5(12), 3274-3294; doi:10.3390/f5123274 - published 16 December 2014 Show/Hide Abstract
Abstract: The accurate characterization of three-dimensional (3D) root architecture, volume, and biomass is important for a wide variety of applications in forest ecology and to better understand tree and soil stability. Technological advancements have led to increasingly more digitized and automated procedures, which have been used to more accurately and quickly describe the 3D structure of root systems. Terrestrial laser scanners (TLS) have successfully been used to describe aboveground structures of individual trees and stand structure, but have only recently been applied to the 3D characterization of whole root systems. In this study, 13 recently harvested Norway spruce root systems were mechanically pulled from the soil, cleaned, and their volumes were measured by displacement. The root systems were suspended, scanned with TLS from three different angles, and the root surfaces from the co-registered point clouds were modeled with the 3D Quantitative Structure Model to determine root architecture and volume. The modeling procedure facilitated the rapid derivation of root volume, diameters, break point diameters, linear root length, cumulative percentages, and root fraction counts. The modeled root systems underestimated root system volume by 4.4%. The modeling procedure is widely applicable and easily adapted to derive other important topological and volumetric root variables.
Forests2014, 5(12), 3257-3273; doi:10.3390/f5123257 - published 16 December 2014 Show/Hide Abstract
Abstract: Recognition of the importance of forests for local livelihoods, biodiversity and the climate system has spurred a growing interest in understanding the factors that drive forest-cover change. Forest transitions, the change from net deforestation to net reforestation, may follow different pathways depending on a complex interplay of driving forces. However, most studies on forest transitions focus on the national level rather than the local level. Here, case studies from 10 villages in Yunnan, China, are used to clarify the complex interactions among various pathways of forest transitions, derive insights on the underlying drivers that shaped the forest transitions, and determine the importance of changes in drivers over time. The results demonstrate that China’s recent forest transition was caused by a range of interrelated pathways that were mediated by local circumstances. The degradation of forest ecosystem services caused by rampant deforestation and forest degradation created a scarcity of forest products and triggered state-initiated afforestation efforts, particularly in the 1990s, which continue to be important. More recently, economic development concomitant with smallholder intensification spurred reforestation, while the importance of state forest policy declined. The complexity of local land-use changes demonstrates the difficulty of identifying distinct transition pathways and calls for a more diverse approach that recognizes the interdependence of local processes.
Forests2014, 5(12), 3241-3256; doi:10.3390/f5123241 - published 15 December 2014 Show/Hide Abstract
Abstract: Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and Fuels Extension. The wind speeds necessary for crowning (crown-to-crown fire spread) and torching (surface to crown fire spread) were evaluated to test the hypothesis that predicted fire behavior is influenced by the proportion of aspen in the stand. Results showed a strong effect of species composition on crowning, but only under moderate fire weather, where aspen-dominated stands were unlikely to crown or torch. Although rarely observed in actual fires, conifer-dominated stands were likely to crown but not to torch, an example of “hysteresis” in crown fire behavior. Results support the hypothesis that potential crown fire behavior varies across a gradient of aspen dominance and fire weather, where it was likely under extreme and severe fire weather, and unlikely under moderate and high fire weather. Furthermore, the “fire-proof” nature of aspen stands broke down across the gradient of aspen dominance and fire weather.