Heterogeneity, Succession, and Patchiness as Factors Affecting Deforestation and Carbon Cycling

近年来，许多注意力集中在亚马逊河流域森林砍伐的迅速速度、许多动植物物种的相关灭绝以及对全球气候格局的不利影响。然而，经常被忽视的是，该地区森林在减轻毁林有害影响的时间框架内自然再生的能力。一些科学家估计，在被砍伐后的几年内，多达85%的森林被本土植物重新定居。该项目将包括详细分析自然再生过程和土著人民的作用，因为它们影响亚马逊盆地中部贝罗蒙特附近的新古盆地的森林重新造林。对遥感数据的分析将与实地观测相结合，以便估计清除土地的比率，并跟踪两个特定地点的演替比率。实地分析将评价各种演替森林、土壤类型、斜坡条件、土地利用之间的关系；这些分析将确定不同条件下的再造林率。在两个土壤较肥沃的地点对过去和现在的人类活动进行详细分析，将提供一种手段来评估森林对砍伐的反应，以及鼓励在这类地区而不是在自然恢复速度较慢的地区进行毁林活动的可能性。这个项目将提供宝贵的新资料，了解被砍伐的热带森林地带如何自我再生。对于巴西的亚马逊森林和其他大陆上类似的生物群落，将产生新的见解。该项目还将在方法上作出贡献，提供更多关于如何利用遥感数据监测森林砍伐和再生的知识。由于该项目是与两个巴西机构合作进行的，而且将雇用巴西国民协助完成该项目，因此该项目将有助于发展巴西在这一重要专题和这些有用的新方法方面的科学能力。

Much attention has focused in recent years on rapid rates of deforestation in the Amazon Basin and about related extinctions of many plant and animal species and adverse impacts on global climatic patterns. Frequently overlooked, however, has been the ability of the region's forests to naturally regenerate in time frames that mitigate the detrimental impacts of deforestation. Some scientists estimate that as much as 85 percent of the forests are recolonized by native plants within a few years after clearance. This project will consist of a detailed analysis of the processes of natural regeneration and the roles of native people as they affect reforestation of forests in the Xingu Basin near Belo Monte in the central Amazon Basin. Analyses of remotely sensed data will be combined with field observations in order to estimate rates of cleared land and to track the rates of succession at two specific sites. Field-based analyses will assess the relationships among various successional forests, soil types, slope conditions, land uses; these analyses will determine rates of reforestation under different sets of conditions. Detailed analyses of past and present human activities in two sites with more fertile soils will provide a means for assessing the response of forests to clearance and the potential for encouraging deforestation activities into these types of areas rather than into areas with slower natural rates of recovery. This project will provide valuable new information into the processes by which cleared tropical forest tracts regenerate themselves. New insights will result both with respect to the Amazon forests of Brazil and for similar biomes on other continents. The project also will make methodological contributions, providing greater knowledge of the ways that remotely sensed data can be used to monitor deforestation and regeneration. Because this project is conducted in collaboration with two Brazilian agencies and because Brazilian nationals will be employed to help complete it, the project will help develop Brazilian scientific capabilities with respect to this important topic and these useful new methods.