SGS-LTER Standard Production Data: 1983-2008 Annual Aboveground Net Primary Production on the Central Plains Experimental Range, Nunn, Colorado, USA 1983-2008, ARS Study Number 6 (Reformatted to a Darwin Core Archive)

This data package is formatted as a Darwin Core Archive (DwC-A, event core). For more information on Darwin Core see https://www.tdwg.org/standards/dwc/. This Level 2 data package was derived from the Level 1 data package found here: https://pasta.lternet.edu/package/metadata/eml/edi/325/2, which was derived from the Level 0 data package found here: https://pasta.lternet.edu/package/metadata/eml/knb-lter-sgs/700/1. The abstract below was extracted from the Level 0 data package and is included for context: 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. The objective of the long-term ANPP study is to monitor long-term net above ground primary production of the shortgrass steppe community by species. There are 6 sites: ridgetop (ridge), midslope (mid), swale, ESA (replicate 1 not 2), Section 25 (SEC 25), and owl-creek (OC). Each site is located in a different landscape position or soil type on the shortgrass steppe and may be grazed or not. Ridgetop, midslope and swale are grazed and are sampled along a catena. Section 25 is grazed and is located in an upload grassland. ESA is an ungrazed upland grassland an is the control from the Ecosystem Stress Area experiment. Owl Creek is ungrazed and is located in the lowland along the owl creek drainage. There are 3 transects with 5 plots in each transect. Plots in the grazed locations are protected by cages. Because this is a monitoring effort, true replicates across the landscape are not available and it is recommended that the transect be used in calculating mean production at each sampling location. The Shortgrass Steppe Long Term Ecological Research (SGS-LTER) project was funded by National Science Foundation as one of the first sites in the US LTER Network in 1982. This collaborative, interdisciplinary research project was established in the Natural Resource Ecology Lab at Colorado State University by ecosystem scientists who learned novel approaches to study grassland ecosystems during the International Biome Program (IBP) (1968-1974). The SGS-LTER project was built upon the foundation of data and information obtained during IBP, as scientists sought to identify and follow, and often manipulate in experiments, important ecosystem processes over the long-term. The objectives of the SGS-LTER project were to investigate what mechanisms regulate processes in the shortgrass steppe. Research questions focused on how biotic and abiotic components of the ecosystem are coupled, where and when ecosystem components are most vulnerable to perturbations, disseminating information that would be helpful for rangeland management and assessing impacts of climate change. Scientists explored variations in the structure and function of the ecosystem over space and time and sought to understand how these aspects are governed by climate, natural disturbance, biota, physiography, and human use. Scientists at the SGS-LTER integrated long-term monitoring data, designed experimental studies, performed and advanced modeling techniques, and synthesized data to conduct innovative research, education, and outreach. The core SGS-LTER research site was established on the Central Plains Experimental Range (CPER) in Nunn, Colorado, part of the United States Department of Agriculture’s Agricultural Research Service. The research site sits in the rain shadow of the Rocky Mountains at the western edge of the shortgrass steppe of North America. The shortgrass steppe ecosystem evolved with grazing by the American bison, which has now been replaced by cattle. Grazing by domestic livestock is the primary land use of native grassland, which occupies about 60% of the land area of the shortgrass steppe. Short grasses dominate the vegetation community, which have adapted to grazing and less than 400 mm of annual rainfall. The topography is characterized by gently rolling hills, broad ephemeral stream courses and low flat-topped terraces. Aspects of physiography regulate the shortgrass steppe ecosystem, including landscape position, soil age, water holding capacity, soil depth and surface texture which, in turn, determine such properties as soil moisture storage, net primary productivity and the distribution of small mammals such as prairie dogs and pocket gophers. SGS-LTER scientists have expanded their research studies beyond the CPER to identify similar or different patterns in ecosystem structure and function in North American grasslands; across the Great Plains region and along the latitudinal gradient from Wyoming to Mexico. They also conducted cross-site collaborative research and compared their results and tested theories in grasslands located in South America, Asia and Africa. Funding from NSF for the SGS-LTER project ends in 2014, but over thirty years of research has resulted in a scientific team with diverse expertise, which produced over 1200 journal publications, almost 400 book chapters and over 200 theses. Data, products and other information produced from the SGS-LTER are available through the LTER Network Information System, Digital Collections of Colorado at CSU or upon request through [e-mail].本数据包采用达尔文核心档案（Darwin Core Archive, DwC-A，事件核心）格式。有关达尔文核心（Darwin Core）的更多信息，请参阅https://www.tdwg.org/standards/dwc/。本二级数据包源自以下一级数据包：https://pasta.lternet.edu/package/metadata/eml/edi/325/2，而该一级数据包又源自以下零级数据包：https://pasta.lternet.edu/package/metadata/eml/knb-lter-sgs/700/1。以下摘要提取自零级数据包，用于提供背景信息： 本数据包由短草草原长期生态研究（Shortgrass Steppe Long Term Ecological Research, SGS-LTER）项目的研究人员制作，该项目由科罗拉多州立大学管理。有关SGS-LTER项目的长期数据集及背景资料（提案、报告、照片等），可在科罗拉多数字馆藏的综合项目馆藏中获取：http://digitool.library.colostate.edu/R/?func=collections&collection_id=3429。本数据表及采用生态元数据语言（Ecological Metadata Language）生成的关联元数据文档，也可通过其他服务于生态研究社区的仓储获取，它们均属于SGS-LTER综合项目馆藏的组成部分。 本长期地上净初级生产力（Aboveground Net Primary Production, ANPP）研究的目标，是按物种监测短草草原群落的长期地上净初级生产力。本研究共设6个样地：山脊（ridge）、中坡（mid）、洼地（swale）、ESA（重复样地1，非2）、25区（SEC 25）以及猫头鹰溪（owl-creek, OC）。每个样地均位于短草草原的不同景观位置或土壤类型区域，可能采用放牧或禁牧的管理方式。其中，山脊、中坡与洼地为放牧样地，沿链状样带布设；25区为放牧样地，位于补播草原区域；ESA为禁牧高地草原，作为生态系统胁迫区实验的对照样地；猫头鹰溪为禁牧样地，坐落于沿猫头鹰溪流域的低地区域。 每个样地布设3条样带，每条样带包含5个样方。放牧样地的样方设有围栏以排除干扰。由于本研究属于长期监测项目，无法获取跨景观的真实重复样地，因此建议以样带为单位计算每个采样点的平均生产力。 短草草原长期生态研究（SGS-LTER）项目于1982年由美国国家科学基金会资助，是美国长期生态研究（Long Term Ecological Research, LTER）网络首批设立的站点之一。该协作式跨学科研究项目由科罗拉多州立大学自然资源生态实验室的生态系统科学家发起，这些研究者在国际生物群落计划（International Biome Program, IBP，1968-1974）期间掌握了研究草原生态系统的新颖方法。SGS-LTER项目以IBP期间获取的数据与信息为基础搭建而成，研究人员借此识别、追踪（并常通过实验操控）长期尺度下的关键生态系统过程。 SGS-LTER项目的核心目标是探究调控短草草原生态系统过程的机制。研究问题聚焦于：生态系统的生物与非生物组分如何耦合？生态系统组分在何时、何地最易受到扰动？如何为牧场管理提供实用信息？以及如何评估气候变化的影响？研究人员探索了生态系统结构与功能在空间与时间维度上的变异，试图理解这些变异如何受气候、自然干扰、生物群落、地貌以及人类活动的调控。SGS-LTER的研究团队整合长期监测数据、设计实验研究、应用并改进建模技术，并对数据进行综合分析，以开展创新性研究、教育与推广工作。 SGS-LTER的核心研究样地设立于科罗拉多州努恩的中央平原实验牧场（Central Plains Experimental Range, CPER），该牧场隶属于美国农业部农业研究服务局（United States Department of Agriculture’s Agricultural Research Service）。研究样地位于北美短草草原西缘的落基山脉雨影区。短草草原生态系统曾与美洲野牛的放牧活动协同演化，如今该生态位已被家牛取代。家畜放牧是原生草原的主要土地利用方式，原生草原约占短草草原总面积的60%。植被群落以短草为主，这些物种已适应了放牧与年均降水量不足400毫米的环境。该区域地形以缓起伏丘陵、广泛分布的季节性河道以及低平的台地为特征。地貌要素调控着短草草原生态系统，包括景观位置、土壤年龄、持水能力、土层深度与表层质地，这些因素进而决定了土壤水分储存、净初级生产力以及草原犬鼠、囊鼠等小型哺乳动物的分布格局。 SGS-LTER的研究人员已将研究范围拓展至CPER以外，以识别北美草原、大平原区域以及从怀俄明州到墨西哥的纬度梯度上生态系统结构与功能的相似或差异模式。他们还开展了跨区域协作研究，在南美洲、亚洲与非洲的草原中验证其研究结果与理论。美国国家科学基金会对SGS-LTER项目的资助于2014年终止，但三十余年的研究已打造出一支具备多元化专业技能的科研团队，累计发表了超过1200篇期刊论文、近400个图书章节以及200余篇学位论文。SGS-LTER产生的数据、成果及其他信息，可通过LTER网络信息系统、科罗拉多州立大学科罗拉多数字馆藏获取，或通过[e-mail]邮箱申请获取。