Collaborative Research: Plant Community Structure Across Resource Gradients from Grassland to Forest

约束模式和系统模式的一般综合 在不同的环境中，生态系统的尺度变化不同。 将通过数学建模来制定制度。 的 搜索将围绕三个目标组织：（1） 综合各种生态系统的现有数据， 由各种LTER位点表示，特别是， 北美大陆的各个地点， 东部的落叶林，通过Konza LTER站点， 高草草原到中原LTER站点的短- 草地草原。 这项工作将侧重于关键的作用， 环境驱动因素（日照，温度，湿度， 营养素和干扰制度）， 生态系统 (2)实施一套完整的计算机化 模拟器是足够普遍的，他们可能是 应用于这个梯度。 (3)测试模型生成的 假设和预测对独立的数据代表 没有参与模型开发的生态系统。 本研究中感兴趣的生态系统水平现象意味着 空间尺度，通常由术语“景观”或 更大的，十年到百年的时间尺度。强调 生态系统类型之间的过渡意味着 至少是区域性的空间尺度， 大陆，在一定程度上。 四个模型已经开发并有很好的记录， 将作为本研究的出发点：（1） 世纪碳和养分动态模型;（2）MAGIC 森林的FORET模型 （4）半干旱草原演替模式 草原 研究的一个主要任务是 在这些模型之间建立适当的接口， 模拟大陆尺度格局的背景 梯度离心 这项研究的意义在于它将帮助我们 建立一个支持比较生态系统的模型库 分析了长期铁路联络网各站点之间的情况， 生态系统理论 该研究还将解决以下问题： 如何在空间和时间的小尺度上进行测量， 外推 无论是理论的发展， 对规模问题的理解对发展至关重要 地球生态系统的可持续管理制度。 Shugart博士和Lauenroth博士是该领域的领导者， 生态模拟 向他们提供的机构支助 是上级的。

A general synthesis of how patterns of constraint and system scaling vary among ecosystems within different environmental regimes will be developed through mathematical modeling. The search will be organized around three objectives: (1) To synthesize existing data from a spectrum of ecosystems as represented by various LTER sites, in particular, the gradient of sites across the North American continent that includes the deciduous forest on the east through the Konza LTER site in the tall-grass prairie to the Central Plains LTER site in the short- grass prairie. This work will focus on the role of key environmental drivers (insolation, temperature, moisture, nutrients, and disturbance regimes) in structuring specific ecosystems. (2) To implement an integrated set of computerized simulators which are sufficiently general that they may be applied across this gradient. (3) To test model-generated hypotheses and predictions against independent data representing ecosystems that were not involved in the model development. The ecosystem-level phenomena of interest in this research imply spatial scales as typically connoted by the term "landscape" or larger, and decadal to centennial time scales. The emphasis on transitions between ecosystem types implies an extension to spatial scales that are at least regional, and ultimately continental, in extent. Four models, which are already developed and well documented, will serve as the starting point for this research: (1) the CENTURY model of carbon and nutrient dynamics; (2) the MAGIC model of soil and water chemistry; (3) the FORET model of forest dynamics; and (4) the STEPPE model of succession in semiarid grasslands. A principal task in the research will bethe development of appropriate interfaces between these models in the context of simulating the pattern in the continental scale gradient. The significance of this research is that it will help us to develop a modeling base in support of comparative ecosystem analysis among sites in the LTER network and the development of ecosystem theory. The research will also address the issue of how measurements made at small scales in space and time can be extrapolated. Both the development of theory and an understanding of issues of scale are essential to the development of sustainable management regimes for the Earth's ecosystems. Drs. Shugart, and Lauenroth are leaders in the field of ecological modeling. The institutional support available to them is superior.