LTER: Long-Term Ecological Research in Field Crop Ecosystems

9810220 robertson世界范围内的农业活动都是通过生物和化学管理实践相结合的方式进行的。凯洛格生物站（KBS）长期生态研究项目从1987年开始进行研究，重点是验证基于生态相互作用知识的农业管理实践可以有效取代基于化学补贴的管理的假设。测试这一普遍假设的工作集中在美国中西部广泛使用的农田作物生态系统上。KBS研究采用了一系列地点，在这些地点建立了11种不同的种植制度和演替群落，以代表不同程度和类型的生态干扰。在这一系列的站点中，工作假设正在土壤微生物群落、昆虫消费者动态、养分有效性和植物群落动态等一般领域进行测试。最近的工作导致了以生物为基础的农业系统的发展，这些系统可以产生可接受的作物产量。KBS遗址记录了各种分类群的丰富变化，这些分类群似乎对行作物功能和农业系统的生态系统级属性很重要。在田间作物生态系统的关键关系方面，对生态学的一般认识已经取得了进展。除了继续这些努力之外，拟议的工作将在比单个领域更大的尺度上评估农业实践对整个流域生物地球化学过程动态的影响。还将努力纳入社会组成部分，以评价人类决策在农业生态系统中发生的生态过程中发挥关键作用的程度。最后，KBS站点的工作结果将进行区域划分，以便对整个中北部地区的气候与生产力之间的相互作用有一个大致的了解。

9810220RobertsonAgricultural activities worldwide are carried out through a combination of biological and chemical management practices. The Kellogg Biological Station (KBS) Long-Term Ecological Research program has been conducting research since 1987 focusing on testing the hypothesis that agronomic management practices based on knowledge of ecological interactions can effectively replace management based on chemical subsidies. Work to test this general hypothesis is focused on field-crop ecosystems that are used extensively throughout the US Midwest. KBS research employs a series of sites where 11 different cropping systems and successional communities have been established to represent different levels and types of ecological disturbance. Within this series of sites, working hypotheses are being tested in general areas of soil microbial communities, the dynamics of insect consumers, nutrient availability, and plant community dynamics. Recent work has led to development of biologically based agricultural systems that produce acceptable crop yields. The KBS site has documented changes in abundance of various taxa that appear to be important in row-crop function and in ecosystem-level attributes of agricultural systems. General ecological understanding has been advanced in key relationships in field-crop ecosystems. In addition to continuing these efforts, proposed work will evaluate the effects of agricultural practices at scales larger than individual fields on the dynamics of biogeochemical processes in entire watersheds. Efforts will also be developed to incorporate a social component to evaluate the degree to which human decision making plays critical roles in the ecological processes occurring in agricultural ecosystems. Finally, the results of efforts at the KBS site will be regionalized to develop a general understanding of the interactions between climate and productivity across the entire North Central Region.