The Underlying Cause of Tropical Deforestation: Rural Migration and Environmental Degradation in Guatemala

世界各地砍伐森林的主要原因是农业扩张，主要是移民到森林边界的小农场家庭(Houghton 1994；Myers 1994；Geist和Lambdin 2001)。然而，在研究森林开垦和土地利用时，研究人类引起的环境变化的学者几乎只关注边界上的土地利用和退化，而没有考虑为什么定居者家庭一开始就在那里(Carr，2004)。与此同时，几乎所有关于发展中世界移徙的研究都集中在城乡移徙和国际移徙上，它们与砍伐森林只有很小的关系。该项目的目的是调查危地马拉北电的毁林和土地利用/土地覆盖变化(LUCC)，特别是在玛雅生物圈保护区(MBR)，农村外迁的决定因素。虽然家庭决策是审查移民的关键，但家庭并不是在真空中做出这些决定的；地方、地区和国家的背景很重要。因此，私人投资机构提出了一项涉及多种数据来源和方法的研究计划。多尺度数据包括：1)社区和市政一级数据；2)对原社区数千户家庭的调查；3)来自地理信息系统数据层的市政一级数据，这些数据来自遥感陆地卫星TM图像和2003年危地马拉人口和农业普查。研究问题将通过四级分层统计模型的新应用来审查。该模型将被用来确定个人、家庭、社区和市政因素对迁移的相对贡献，并说明空间尺度的重要性。国际和平研究所一直与危地马拉国家统计局和其他主要研究机构的学者开展合作，并将充分利用这些数据集。拟议的研究对1)全球环境变化研究的人的层面作出了新的贡献，2)整合了多尺度空间和调查的定量和定性方法。该项目的学术价值是对人类-环境和空间社会科学研究的新的概念和方法的结合。该项目将加强对农村-边境移民和热带森林砍伐之间联系的了解，热带森林砍伐是世界上最显著的土地覆盖变化形式。PI认为，这是第一次将农业前沿的森林砍伐与一个主要的根本原因联系起来，即从原籍地区迁出。它还率先使用移民原籍地区的调查和空间数据，并使用四级分层随机效应模型审查农村-农村移徙的决定因素。这项研究还通过促进国际合作--包括来自代表性不足群体的合作--产生了更广泛的影响，这些合作将加强危地马拉的人口学教学，制作高质量的学术出版物，并影响政治政策干预，以改善农村贫困和保护中美洲的热带森林。

The primary cause of deforestation worldwide is agricultural expansion, mostly by small-farm families migrating to forest frontiers (Houghton 1994; Myers 1994; Geist and Lambdin 2001). Yet in studying forest clearing and land use, scholars of human-induced environmental change have focused almost exclusively on land use and degradation on the frontier, without considering why settler families end up there in the first place (Carr, 2004). At the same time, virtually all research on migration in the developing world has focused on rural-urban migration and international migration, which are only peripherally related to deforestation. The objective of the project is to investigate the determinants of the rural out-migration that underlies the deforestation and land use/land cover change (LUCC) in Guatemala's Peten, particularly in the Maya Biosphere Reserve (MBR). While household decision-making is key to examining migration, households do not make these decisions in a vacuum; local, regional, and national contexts matter. The PIs therefore propose a research plan that involves multiple data sources and methods. Multiple scale data include proposed: 1) community and municipio-level data; 2) surveys of several thousand households in origin communities; and 3) Municipio-level data from Geographic Information System (GIS) data layers derived from remotely sensed Landsat TM images and from the Guatemalan population and agricultural censuses of 2003. Research questions will be examined through the novel application of a four-level hierarchical statistical model. The model will be used to determine the relative contributions of individual, household, community, and municipio factors to migration, and to illustrate the importance of spatial scale. The PI has enjoyed an ongoing collaboration with scholars at the National Statistics Institute and other major research institutes in Guatemala and will have full access to these data sets The proposed research makes novel contributions to 1) human dimensions of global environmental change research and 2) the integration of multi-scale spatial and survey quantitative and qualitative methods. The intellectual merit of this project is the combination of a novel conceptual and methodological contribution to human-environment and spatial social science research. The project will enhance understanding of linkages between rural-frontier migration and tropical deforestation, the most salient form land cover change in the world. The PIs believe it is the first to link deforestation on the agricultural frontier to a major underlying cause, out-migration from areas of origin. It is also pioneering in using both survey and spatial data in areas of migrant origin, and in examining the determinants of rural-rural migration using a 4-level hierarchical random effects model. The research also makes broader impacts by fostering international collaborations - including those from underrepresented groups - that will strengthen pedagogy on demography in Guatemala, produce quality scholarly publications, and influence polity policy interventions for ameliorating rural poverty and conserving Mesoamerica's tropical forests.