POPULATION AND ENVIRONMENT IN THE U.S. GREAT PLAINS

这个项目的主要目标是长期的多学科研究 中国人口与环境关系的几个方面 美国大平原。这一地区很重要，因为 大平原的草原覆盖了美国的大部分地区， 并受到相当大的环境变化的影响。这项研究 涉及对该区域的人口经验和 环境的变化。该项目的理论基础是 ，并且针对的是递归更改的模型。 人口和环境，其中一个因素的变化 在一个时间段中影响另一个时间段，因此 在……上面。该项目还将检验将土地利用变化视为 空间或文化扩散的过程。 该项目将收集和分析县级土地利用数据 决定及其对人口和环境的影响 一个多世纪以来，为了理解长期的、互动的、 和递归关系。研究人员将测量环境 通过土壤含量和化学成分对种群变化的影响，以及对 通过物种多样性的影响程度较小。他们将测量人口统计数据 通过各种措施应对环境变化的影响， 包括人口密度、移民、社会、职业、种族、年龄 性结构，以及家庭的动态。这一分析将使 使用考虑到空间和时间的统计程序 效果。 这项研究将验证其发现，并开发新的假说。 关于大城市内小样本社区的深入研究 普莱恩斯。这项研究将涉及多种方法：详细 手稿普查、税务记录和报纸的分析；访谈 与农民家庭的联系；以及航拍照片的分析。 该项目的最后阶段将是在这些分析之后进行 建模和模拟演练将首先构建长期 使用世纪土壤模型系统的环境变化模型。然后, 调查人员将综合分析人口统计学和 通过建立人口和社会变化组成部分来实现环境变化 添加到CENTURY模型中，并比较建模结果 演练大平原的历史记录。

This project has as its main goal a multidisciplinary study of long-term aspects of the relationship between population and the environment in the Great Plains of the United States. This region is important because the grasslands of the Great Plains cover a large part of the United States, and are subject to considerable environmental change. This research involves an examination of the demographic experience of the region and of changes in the environment. The theoretical basis of the project draws on many sources, and is directed toward a model of recursive change in population and environment, one in which changes in one of these factors in one time period influence the other in a subsequent time period, and so on. The project will also examine hypotheses that see land use change as a process of spatial or of cultural diffusion. This project will collect and analyze county-level data about land use decisions and their consequences for the population and the environment over more than a century in order to understand long-term, interactive, and recursive relationships. Researchers will measure the environment impact of population change through soil content and chemistry, and to a lesser extent through species diversity. They will measure the demographic impact of the environmental change through a variety of measures, including population density, migration, social, occupational, ethnic, age and sex structures, and the dynamics of families. This analysis will make use of statistical procedures that take into account spatial and temporal effects. The study will validate its findings and develop new hypotheses with in- depth research about a small sample of communities within the Great Plains. This research will involve a variety of methodologies: detailed analysis of manuscript censuses, tax records, and newspapers; interviews with farm families; and analysis of aerial photographs. The final stage of the project will be to follow these analyses with a model-building and simulation exercise that will first build long-term models of environmental change using the CENTURY soil model system. Then, the investigators will integrate the analysis of demographic and environmental change by building a demographic and social change component to add to the CENTURY model, and comparing the results of the modeling exercise with the historical record for the Great Plains.