The Dominant Driving Force of Forest Change in the Yangtze River Basin, China: Climate Variation or Anthropogenic Activities?

Under the combined effect of climate variations and anthropogenic activities, the forest ecosystem in the Yangtze River Basin (YRB) has experienced dramatic changes in recent decades. Quantifying their relative contributions can provide a valuable reference for forest management and ecological sustainability. In this study, we selected net primary productivity (NPP) as an indicator to investigate forest variations. Meanwhile, we established eight scenarios based on the slope coefficients of the potential NPP (PNPP) and actual NPP (ANPP), and human-induced NPP (HNPP) to quantify the contributions of anthropogenic activities and climate variations to forest variations in the YRB from 2000 to 2015. The results revealed that in general, the total forest ANPP increased by 10.42 TgC in the YRB, and forest restoration occurred in 57.25% of the study area during the study period. The forest degradation was mainly observed in the Wujiang River basin, Dongting Lake basin, and Poyang Lake basin. On the whole, the contribution of anthropogenic activities was greater than climate variations on both forest restoration and degradation in the YRB. Their contribution to forest restoration and degradation varied in different tributaries. Among the five forest types, shrubs experienced the most severe degradation during the study period, which should arouse great attention. Ecological restoration programs implemented in YRB have effectively mitigated the adverse effect of climate variations and dominated forest restoration, while rapid urbanization in the mid-lower region has resulted in forest degradation. The forest degradation in Dongting Lake basin and Poyang Lake basin may be ascribed to the absence of the Natural Forest Conservation Program. Therefore, we recommend that the extent of the Natural Forest Conservation Program should expand to cover these two basins. The current research could improve the understanding of the driving mechanism of forest dynamics and promote the effectiveness of ecological restoration programs in the YRB.

A Review of Global Policy Mechanisms Designed for Tropical Forests Conservation and Climate Risks Management

Deforestation and forest degradation of tropical forests are major global concerns due to their ecological, social, and economic roles. In the wake of climate change and its diverse global effects, fragmentation and degradation of tropical forests have jeopardized their ability to support livelihoods and regenerate climate regulating services. Concerted efforts by local, national, and international players, which are primarily scientific, technological, or economic, have borne minimal results in safeguarding these forests from destruction, necessitating a more integrated and inclusive approach. The Rio Earth Summit (1992) brought together world leaders to set targets and priorities on the global sustainability agenda and laid a strong foundation for international policy cooperation in the future. This study employed a systematic review of articles published between 1992 and 2020 to establish how various policy mechanisms have been developed and evolved to bridge forests and climate change discourse in tropical forests while highlighting their strengths and weaknesses. The initial search of peer-reviewed publications and gray literature yielded 2622 records, which were subjected to inclusion and exclusion criteria based on The Preferred Reporting Items for Systematic Review and Meta Analyses guidelines, resulting in a final list of 65 records for in-depth qualitative analysis. The study establishes that the mechanisms in place have contributed mainly to more coordination and incentives to manage climate risks, primarily through tropical forests conservation. However, hurdles such as inadequate participation and involvement of the local and indigenous people, insufficient national and local policy frameworks and bureaucracies around emissions monitoring, measuring, reporting, and verification processes continue to slow tropical forest conservation. Thus, there is a need for more integrated, multilevel, and diverse stakeholder engagement to achieve the set global targets effectively.

Combining Sentinel-1 and Landsat 8 Does Not Improve Classification Accuracy of Tropical Selective Logging

Tropical forests play a key role in the global carbon and hydrological cycles, maintaining biological diversity, slowing climate change, and supporting the global economy and local livelihoods. Yet, rapidly growing populations are driving continued degradation of tropical forests to supply wood products. The United Nations (UN) has developed the Reducing Emissions from Deforestation and Forest Degradation (REDD+) programme to mitigate climate impacts and biodiversity losses through improved forest management. Consistent and reliable systems are still needed to monitor tropical forests at large scales, however, degradation has largely been left out of most REDD+ reporting given the lack of effective monitoring and countries mainly focus on deforestation. Recent advances in combining optical data and Synthetic Aperture Radar (SAR) data have shown promise for improved ability to monitor forest losses, but it remains unclear if similar improvements could be made in detecting and mapping forest degradation. We used detailed selective logging records from three lowland tropical forest regions in the Brazilian Amazon to test the effectiveness of combining Landsat 8 and Sentinel-1 for selective logging detection. We built Random Forest models to classify pixel-based differences in logged and unlogged regions to understand if combining optical and SAR improved the detection capabilities over optical data alone. We found that the classification accuracy of models utilizing optical data from Landsat 8 alone were slightly higher than models that combined Sentinel-1 and Landsat 8. In general, detection of selective logging was high with both optical only and optical-SAR combined models, but our results show that the optical data was dominating the predictive performance and adding SAR data introduced noise, lowering the detection of selective logging. While we have shown limited capabilities with C-band SAR, the anticipated opening of the ALOS-PALSAR archives and the anticipated launch of NISAR and BIOMASS in 2023 should stimulate research investigating similar methods to understand if longer wavelength SAR might improve classification of areas affected by selective logging when combined with optical data.

The Impact of Deforestation, Urbanization, and Changing Land Use Patterns on the Ecology of Mosquito and Tick-Borne Diseases in Central America

Central America is a unique geographical region that connects North and South America, enclosed by the Caribbean Sea to the East, and the Pacific Ocean to the West. This region, encompassing Belize, Costa Rica, Guatemala, El Salvador, Honduras, Panama, and Nicaragua, is highly vulnerable to the emergence or resurgence of mosquito-borne and tick-borne diseases due to a combination of key ecological and socioeconomic determinants acting together, often in a synergistic fashion. Of particular interest are the effects of land use changes, such as deforestation-driven urbanization and forest degradation, on the incidence and prevalence of these diseases, which are not well understood. In recent years, parts of Central America have experienced social and economic improvements; however, the region still faces major challenges in developing effective strategies and significant investments in public health infrastructure to prevent and control these diseases. In this article, we review the current knowledge and potential impacts of deforestation, urbanization, and other land use changes on mosquito-borne and tick-borne disease transmission in Central America and how these anthropogenic drivers could affect the risk for disease emergence and resurgence in the region. These issues are addressed in the context of other interconnected environmental and social challenges.

Negotiating power from the margins: Encountering everyday experiences and contestations to REDD + in Southern Tanzania

This paper provides an account of everyday discursive and material practises deployed by marginalised forest-dependent groups in the course of resisting the implementation of Reduced Emission from Deforestation and forest degradation (REDD + ) and conservation regulations. Available literature have documented extensively that REDD + market-based models across the Global South, and Tanzania in particular, have led to increasing inequality, injustices, and exclusions. Nevertheless, there is little attention to exploring how different social actors that are unequally positioned resist exclusions. The paper explores selected case studies of marginalised forest-dependent groups in Lindi, Southern Tanzania, who creatively work to negotiate unequal power relations through a range of encounters around REDD+. Our analysis shows unequal social, spatial, and environmental ramifications of market-based conservation policies and strategies that have led to different kinds of material and discursive resistance to challenge exclusions. In doing so, it provides critical context-specific realities from the Global South and, specifically, Tanzanian scholarship to focus on both the dynamics of power and resistance in socially differentiated forest-dependent groups affected by envisioned market-based and development model-led conservation regimes.

Acceptance of New Land-Use Activities by Hmong and Khmu Ethnic Groups: A Case Study in Northern Lao People’s Democratic Republic

Reducing emissions from deforestation and forest degradation (REDD+) to address climate change has historically included little evaluation of how heterogeneous local communities respond to REDD+ interventions and new land-use activities. We assessed differences in the acceptance of new land-use activities as a function of livelihoods of the Hmong and Khmu ethnic groups in northern Lao People’s Democratic Republic, where REDD+ was implemented between 2011 and 2018. Our socioeconomic data, collected by a questionnaire-based survey and focal group discussions, showed that the Hmong more effectively incorporated support from REDD+ than the Khmu because the Hmong owned grazing land. Our findings highlight the importance of understanding the capabilities and characteristics of each ethnic group when implementing new land-use activities (i.e., designing and implementing alternative livelihoods) within a target area to ensure distributional equity in heterogeneous communities. Such a consideration should be included in land-use policy and also be a part of the social safeguards in the land-use sector.

The Moisture Content and Absorption Levels of Carbon Dioxide in Binuang Bini (Octomeles sumatrana Miq) Trees For Climate Change Management

Binuang bini (Octomeles sumatrana Miq) is a fast-growing tree with numerous economic benefits, such as the provision of wood for carpentry purposes, building boards, water management, and absorption of carbon dioxide (CO2). Therefore, this tree species has great potential and needs to be included in Reducing Emission from Deforestation and Forest Degradation (REDD)+'s mitigation program to tackle climate change. In its development, REDD+ has made it possible to carry out carbon trading in the world. Therefore, countries capable of performing protective functions and carry out reforestation, afforestation, and restoration, have the opportunity to be involved in world carbon trading. This study aims to determine the moisture content and carbon absorption rate of Binuang bini trees as a first step to regulate the allometric equation using destructive and laboratory analysis. The results show that the water content in the roots, leaves, as well as the base, middle, and tip of the stem were: 73.69%, 68.39%, 65.59%, 61.22%, and 66.26%, respectively. Furthermore, the sample test results indicate a very close relationship between carbon concentration and absorbance in the O. sumatrana tree with a simple linear regression equation: Y = 0.002X + 0.0593 with R2 = 0.9896. Therefore, this regression equation can be used to calculate the carbon concentration sample for the O. sumatrana tree fraction. The carbon content in 3 tree samples with a breast height diameter of 9.24 cm, 10.08 cm, and 11.68 cm was 2,585 kg. 2,913 kg, and 4,654 kg, respectively. In addition, the carbon sequestration for each tree diameter per year is 1.581 kg year-1, 1,782 kg year-1and 2,847 kg year-1, respectively.