A gis-based assessment on the vulnerability and future extent of the tropical forests of the congo basin

This paper examines the vulnerability of the Congo Basin's forests through a GIS platform, taking into consideration the variables of population growth, road density, logging concession, and forest fragmentation. The assessment indicates that the forests will continue to shrink towards the interior over the next 50 years. Current contiguous forests will fragment into three large blocks, including one on the west side of the Congo River and two in the Democratic Republic of Congo, while a large number of small forest patches will retain in the periphery of the large blocks. The study shows that integrated GIS assessment of the driving forces of tropical deforestation can shed light on the future forest distribution and provide a tool to address the broader implications of social and economic development for tropical deforestation.     

长江上游退耕还林与天然林保护的问题与对策

长江上游陡坡耕地退耕还林和天然林禁伐具有长远的生态意义 ,对促进该地区农村经济结构和农业结构调整也有积极作用。但同时给这些地区带来新的挑战 :天然林禁伐区财政收入减少 ,GDP增长速度减慢 ,居民收入降低 ,以木材运输为主体的第三产业萎缩 ,劳动就业压力加大 ;退耕还林区粮食产量减少 ,农民生活受影响。当前 ,在两大工程过程中 ,出现虚报退耕面积和造林成果数字 ,一刀切 ,重视经济林、轻视生态林 ,林种和种植结构雷同 ,林区欠帐无法偿还 ,地方资金不配套 ,退耕后农业不知如何发展等问题。为此 ,笔者建议 :退耕和“天禁”与区域脱贫、社区建设相结合 ;坚持因地制宜、分生态类型区实施 ;坚持实事求是 ,反对浮夸 ;应加强科学规划 ,进行技术攻关和科技集成 ,创立新的农林牧复合种植模式、新的农业经营、管理模式     

Shrinking Tropical Forests, Human Agents of Change, and Conservation Policy

Abstract:  Human agents of landscape transformation in the tropics affect forests differently as the forests decline in size. Five agents of change—road builders, corporate concession holders, community forest managers, park advocates, and urban consumers—have different effects on large forests in remote tropical regions than they do on remnant forests in settled agricultural regions. Because forests vary so much in size across tropical regions, these differences in the effects of agents on forests have important implications for regional conservation efforts. To make these implications explicit, I compared the effects of the five agents in regions with large forests with their effects in regions with small forests. The comparisons indicated that, as forests declined in size, new roads no longer destroyed forests, corporate loggers left the forests, community forest managers became more effective, parks became less feasible as a means of conservation, and urban consumers initiated tree planting. My results suggest that awareness about the changing effects of humans on landscapes with shrinking forests can serve as a useful tool in formulating regionally appropriate policies for conserving tropical forests.     

Land Use,Land-Use Change,Forestry, and Agricultural Activities in the Clean Development Mechanism: Estimates of Greenhouse Gas Offset Potential

Activities involving land use, land-use change,forestry, and agriculture (LUCF) can help reducegreenhouse gas (GHG) concentrations in the atmosphereby increasing biotic carbon storage, by decreasing GHGemissions, and by producing biomass as a substitutefor fossil fuels. Potential activities includereducing rates of deforestation, increasing landdevoted to forest plantations, regenerating secondaryforest, agroforestry, improving the management offorests and agricultural areas; and producing energycrops.Policymakers debating the inclusion of a variety ofLUCF activities in the Clean Development Mechanism(CDM) of the Kyoto Protocol need to consider themagnitude of the carbon contribution these activitiescould make. Existing estimates of the cumulative GHGoffset potential of LUCF activities often take aglobal or regional approach. In contrast, land-usedecisions are usually made at the local level anddepend on many factors including productive capacityof the land, financial considerations of thelandowner, and environmental concerns. Estimates ofGHG offset potential made at a local, or at mostcountry, level that incorporate these factors may belower, as well as more useful for policy analyses,than global or large regional estimates. Whilecountry-level estimates exist for forestry activities,similar estimates utilizing local information need tobe generated for agricultural activities and biofuels,as well as for the cumulative potential of all LUCFactivities in a particular location.     

Increasing food production at the expense of tropical forests

An attempt is made to estimate to what extent it is possible to increase food production by conversion of forest land to agricultural land. To accomplish this two different approaches have been explored. The first one represents the possibility of developing a comprehensive model capable of taking into account the various processes influencing the food production. It is judged that this approach cannot provide a realistic result due to insufficient knowledge of the processes involved, and lack of reliable data. Instead a simple, heuristic method has been applied. The main sources of information used include data representing the soil of the deforested land, the decline of the productivity of the land gained, and the length of time it can be used for agricultural production. Although this method also has its obvious limitations, there are reasons to believe it permits certain conclusions can be safely drawn: (a) even if each year the area of agricultural land is increased by a given amount through removal of forest, there will be no gain of the agricultural production after a few years; and (b) to achieve a constant annual increase of the food production will require that each year the area of forest removal is increased. This revised version was published online in July 2006 with corrections to the Cover Date.     

Untangling the proximate causes and underlying drivers of deforestation and forest degradation in Myanmar

Political transitions often trigger substantial environmental changes. In particular, deforestation can result from the complex interplay among the components of a system—actors, institutions, and existing policies—adapting to new opportunities. A dynamic conceptual map of system components is particularly useful for systems in which multiple actors, each with different worldviews and motivations, may be simultaneously trying to alter different facets of the system, unaware of the impacts on other components. In Myanmar, a global biodiversity hotspot with the largest forest area in mainland Southeast Asia, ongoing political and economic reforms are likely to change the dynamics of deforestation drivers. A fundamental conceptual map of these dynamics is therefore a prerequisite for interventions to reduce deforestation. We used a system‐dynamics approach and causal‐network analysis to determine the proximate causes and underlying drivers of forest loss and degradation in Myanmar from 1995 to 2016 and to articulate the linkages among them. Proximate causes included infrastructure development, timber extraction, and agricultural expansion. These were stimulated primarily by formal agricultural, logging, mining, and hydropower concessions and economic investment and social issues relating to civil war and land tenure. Reform of land laws, the link between natural resource extraction and civil war, and the allocation of agricultural concessions will influence the extent of future forest loss and degradation in Myanmar. The causal‐network analysis identified priority areas for policy interventions, for example, creating a public registry of land‐concession holders to deter corruption in concession allocation. We recommend application of this analytical approach to other countries, particularly those undergoing political transition, to inform policy interventions to reduce forest loss and degradation.     

Considerations about the land use and conversion trends in the savanna environments of Central Brazil under a geomorphological perspective

Assuming that the landscape physiographic characteristics strongly determine the occurrence of land use and land cover types, this study assessed the distribution patterns of natural and converted classes in relation to the major geomorphological units and slope ranges in the central area of continuous savanna formations in Brazil (Cerrado biome), the country’s most important region for cattle ranching and intensive commodity crops. Our results showed that 93% of the agriculture activities are concentrated at slopes of less than 5°, mostly associated to old regional planation surfaces (RPSs). Considering the amount of remnant vegetation and the occupation and land use deterministic trends, we estimated that between 58,041 km² and 79,677 km² of conversions may occur in the near future. If the priority areas for biodiversity conservation are properly enforced and effectively incorporated into the system of fully protected areas and areas of sustainable use, a decrease of approximately 24% in the expected potential deforestation could be achieved.     

Impacts of the deforestation driven by agribusiness on urban population and economic activity in the Dry Chaco of Argentina

Agriculture expansion oriented to global market has changed the relation between population and deforestation in South America. Actually, the population dynamic in an agricultural frontier turned into a consequence of deforestation (rather than the cause). For Dry Chaco of Argentina during the period 1991–2001, we explore the impacts of deforestation over urban population and employment dynamics in small- and medium-size urban centers. We used deforestation maps from remote sensing data and demographic information from the national census. We found a positive relation between population growth and deforestation. Additionally, urban centers in a context of new and active deforestation stages generate more jobs than in a context of advanced stages. Based on our results, we suggest a boom and bust pattern. Agriculture expansion and deforestation generate transient jobs and benefits, but in a long-run perspective, positive impacts are uncertain.     

The archaeology of deforestation in south coastal Turkey

The Rough Cilicia Archaeological Survey Project investigates landscape transformation as a component to its regional survey of ancient Rough Cilicia (south coastal Turkey opposite Cyprus). Rough Cilicia was celebrated during antiquity for pristine cedar forests that stood between 1500 and 1800 m in altitude along the slopes of the Taurus Mountains. Today along the front range of the Taurus Mountains this forest is completely denuded or otherwise replanted with recent growth in the past 80 years. We employ paleoenvironmental analysis of relic cedar forests in the Taurus Mountains to construct a timeline of anthropogenic disturbances associated with population growth over time and thereby assess the sustainability of ancient forestry practices. To obtain these data, the team recovers pollen and carbon samples from geomorphologic trenches excavated in the cedar zone, tree ring data from dendrochronological survey of the existing forest, and archaeological data from remains of ancient highland settlements. Preliminary results indicate that current perspectives about the timing of deforestation in this region are flawed and that the initial deforestation coincided with regional site abandonment and population decline at the end of antiquity.     

Understanding and minimizing environmental impacts of the Belt and Road Initiative

China's Belt and Road Initiative (BRI) sets to create connections and build infrastructure across Eurasia, Asia, and parts of the African continent in its initial phase and is the largest infrastructure project of all time. Any infrastructure project on this scale will necessarily pass through ecofragile regions and key biodiversity areas (KBAs). This creates an imperative to identify possible areas of impact and probable effects on conservation values to facilitate adaptive planning and to mitigate, minimize, or avoid impacts. Using the highest resolution route maps of the BRI available, I overlaid the proposed road and rail routes on KBAs, protected areas, and predicted biodiversity hotspots for over 4138 animal and 7371 plant species. I also assessed the relationship between the proposed route with the distribution of mines across BRI countries and the proportion of deforestation and forest near routes. Infrastructure, especially mining, was clustered near the proposed route; thus, construction and development along the route may increase the size and number of mines. Up to 15% of KBAs were within 1 km of proposed railways. Thus, planned and probable development along the routes may pose a significant risk to biodiversity, especially because the majority of KBAs are unprotected. Many biodiversity hotspots for different taxa were near the route. These hotspots varied between taxa, making systematic management and environmental impact assessments an effective strategy for at least some taxa. A combination of planning and mitigation strategies will likely be necessary to protect the most important areas for biodiversity proximal to development, especially in currently unprotected KBAs and other regions that need protection. A fuller assessment of trade-offs between conservation and other values will be necessary to make good decisions for each project and site being developed, including potentially modifying parts of the route to minimize impacts. Modification or foregoing of infrastructure may be needed if stakeholders consider the conservation costs too high.