SGS-LTER Ecosystem Stress Area - Soil Carbon & Nitrogen in shortgrass steppe on the Central Plains Experimental Range in Nunn, Colorado, USA 1991, ARS Study Number 3

This data package was produced by researchers working on the Shortgrass Steppe Long Term Ecological Research (SGS-LTER) Project, administered at Colorado State University. Long-term datasets and background information (proposals, reports, photographs, etc.) on the SGS-LTER project are contained in a comprehensive project collection within the Digital Collections of Colorado (http://digitool.library.colostate.edu/R/?func=collections&collection_id=3429). The data table and associated metadata document, which is generated in Ecological Metadata Language, may be available through other repositories serving the ecological research community and represent components of the larger SGS-LTER project collection.
Water, nitrogen, and water-plus-nitrogen at levels beyond the range normally experience by shortgrass steppe communities were applied from 1971 through 1975, plant densities were sampled through 1977, and then sampling resumed in 1982, with sampling frequencies changing from annually to every other year. The initial sampling from 1970 to 1974 showed that the water and water plus nitrogen treatments had the strongest effect on plant community structure, both treatments increased biomass, and exotic weed species were noted on the water plus nitrogen treatment. Later sampling from 1982 to 1991 showed a ten-fold increase in exotic weed species on the water plus nitrogen plots as compared to the controls (Milchunas and Lauenroth 1995), a community change that has persisted on this site due to a chronic elevation of soil nitrogen caused by a plant tissue/soil organic matter feedback mechanism (Vinton and Burke 1995). In 1998, Six new treatments were superimposed on the historic study site. The six new treatments were: control, sugar, lignin, sawdust, lignin and sugar, and sawdust and sugar.In 2010, plots will be sampled every 5 years. Our objective in this study is to examine how plant communities change through time and explore implications of these changes for monitoring potentially stressed ecosystems. Additional information and referenced materials can be found: http://hdl.handle.net/10217/83317. Resources in this dataset:Resource Title: Website Pointer to html file. File Name: Web Page, url: https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-sgs&identifier=179 Webpage with information and links to data files for download

本数据包由致力于短草丘陵长期生态研究（SGS-LTER）项目的研究者制作，该项目由科罗拉多州立大学管理。关于SGS-LTER项目的长期数据集及背景信息（提案、报告、照片等）均收录于科罗拉多州数字收藏馆的综合性项目收藏中（http://digitool.library.colostate.edu/R/?func=collections&collection_id=3429）。数据表及相关元数据文档，以生态元数据语言生成，可能通过服务于生态研究社区的其它数据存档机构获取，并代表着SGS-LTER项目整体收藏的一部分。自1971年至1975年，对短草丘陵群落通常未曾经历的水、氮以及水加氮水平进行了施用，植物密度采样持续至1977年，随后于1982年恢复采样，采样频率由每年一次改为每隔一年一次。1970年至1974年的初步采样显示，水和水加氮处理对植物群落结构影响最为显著，两种处理均增加了生物量，并在水加氮处理中记录到了外来杂草物种。1982年至1991年的后续采样表明，与对照相比，水加氮处理地块中外来杂草物种数量增加了十倍（Milchunas和Lauenroth，1995），这种群落变化因植物组织/土壤有机质反馈机制导致的土壤氮素长期升高而在此地持续存在（Vinton和Burke，1995）。1998年，在历史研究站上叠加了六种新的处理方法：对照、糖、木质素、锯末、木质素和糖以及锯末和糖。2010年起，地块将每五年进行一次采样。本研究旨在探究植物群落随时间的变化，并探讨这些变化对监测潜在压力生态系统的影响。更多信息和参考资料请见：http://hdl.handle.net/10217/83317。本数据集包含的资源：资源标题：网站指针至html文件。文件名：网页，url：https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-sgs&identifier=179 包含信息和下载数据文件的链接的网页。