这两个链接是我研究这个问题时使用的来源:“映射关键负载水生生态系统的氮沉降在落基山脉“http://co.water.usgs.gov/publications/non-usgs/Nanus_2012.pdf”的方法估算的关键负载氮和硫沉积对森林生态系统的美国联邦土地”http://www.nrs.fs.fed.us/pubs/gtr/gtr_nrs71.pdf看起来实际上有几种不同的方法可用于计算临界载荷,并根据该方法考虑因素的改变:1。经验(回归)建模:这些都是基于观察生态系统响应(这是跟踪的树叶,地衣,或土壤)和跟踪给定沉积的水平。这通常是在一个面积计算,并应用到其他地方。2。简单的质量平衡模型:估计净亏损或积累的营养基础/系统的养分。这些基本上是稳态模型和测量通常在基阳离子或氮。3所示。动态模型使用质量平衡方法,包含内部反馈。这是两者的结合,通常是使用哪里有丰富的现有数据。包含更多信息的链接,可能会更有帮助。 According to "Wolfe, A.P., Baron, J.S., Cornett, R., 2001. Anthropogenic nitrogen deposition induces rapid change in alpine lakes of the Colorado Front Range (USA). Journal of Paleolimnology 25, 1e7." as cited in the first article I linked, This excess N (caused by exceeding the critical load) can result in acidification and nutrient enrichment, increasing primary productivity in high-elevation lakes and streams, and altering diatom community structures that form the base of the food web – The USFWS Ecoregion classification system was designed by Robert G. Bailey working out of the Rocky Mountain Research Station in Colorado. In his paper, "Identifying Ecoregion Boundaries" found Here: http://www.fs.fed.us/rm/ecoregions/docs/publications/identifying-ecoregion-boundaries.pdf he outlines the rational used for identifying the boundaries, and the 20 different principals he used. They are: 1. The series of ecoregions should express the changing nature of the climate over large areas. 2. Boundaries of ecoregions coincide with certain climatic parameters, 3. , 4. , 5 - 20