NPP GRASSLAND: BRIDGER, U.S.A., 1970-1973

The NPP Database contains documented field measurements of NPP for global terrestrial sites compiled from published literature and other extant data sources. The NPP Database contains biomass dynamics, climate, and site-characteristics data georeferenced to each intensive site. A major goal of the data compilation is to use consistent and standard well-documented methods to estimate NPP from the field data. Other important components of the database include a summary, investigator contact information, and a list of key references for each site. As far as possible, the original principal investigator or his/her successor has been contacted to review the data and documentation. The NPP Database currently contains detailed data for over 60 intensive study sites. A majority of these sites are grasslands, the remainder being tropical forests, boreal forests, and tundra study sites. Some combination of above-ground annual peak live biomass data and/or seasonal biomass dynamics data are available for all sites. Many sites also have data on below-ground biomass and/or turnover. Estimates of net primary productivity are included, where available, for individual sites, and as part of the NPP Summary tables. Climate and soils data are available for all sites in varying degrees of detail. The sites have been grouped according to vegetation maps based upon Bailey ecoregions, Holdridge Life-Zones, Matthews vegetation classes, and Olson World Ecosystem Complexes. Previously compiled multi-site data sets of georeferenced NPP estimates are also provided. NPP estimates are available from a number of different collections, containing more than 1700 sites but with less information available for each individual site as compared to the intensive sites. Records for these sites typically include an NPP value, latitude and longitude, original source of the data, and sometimes information on vegetation type, management, soils, and local climate. More information on the entire Net Primary Productivity Project can be found at the NPP home page, with links to further details on individual study sites or multi-site collections. Users are encouraged to browse these Web pages to find details of original studies, methodologies, and original research contacts. NPP data are available on-line from the ORNL Distributed Active Archive Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, U.S.A. Data Citation: Cite the data sets using the following reference format: Author, P. A., and M. B. Author. Year. Data Set Title. Available on-line from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. For example: Williamson, P., and J. Pitman. 1999. NPP Grassland: Beacon Hill, U.K. 1972-1973. Available on-line from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.

本净初级生产力（Net Primary Productivity，以下简称NPP）数据库收录了来自已发表文献及其他现存数据源的全球陆地样地NPP实地测量记录，所有数据均经过规范化文档整理。该数据库包含各高强度研究样地的生物量动态、气候及样地特征数据，且均已完成地理配准。本次数据汇编的核心目标之一，是采用统一、规范且文档完备的方法，从实地观测数据中估算NPP值。数据库的其他重要组成部分包括各研究样地的汇总信息、研究负责人联系方式以及关键参考文献列表。我们已尽可能联系原始首席研究员或其继任者，对数据及配套文档进行校核确认。

当前，本NPP数据库收录了超过60个高强度研究样地的详细数据。其中多数样地为草地，剩余样地涵盖热带森林、寒温带针叶林（北方森林）及冻原研究样地。所有样地均提供部分组合数据集，包括地上年峰值活体生物量数据及/或季节性生物量动态数据。多数样地还提供地下生物量及/或周转速率相关数据。若有可用数据，各单个样地的NPP估算值将被收录，并作为NPP汇总表的组成部分。所有样地均提供不同详细程度的气候与土壤数据。

本数据库依据基于Bailey生态区、Holdridge生命地带、Matthews植被分类系统以及Olson全球生态系统复合体的植被图对样地进行了分组。数据库同时提供此前已汇编的地理配准NPP估算值多样地数据集。多套不同来源的NPP估算数据集收录了超过1700个样地，但相较于前述高强度研究样地，每个样地可获取的信息相对有限。此类样地的记录通常包含NPP值、经纬度、数据原始来源，部分还包含植被类型、管理方式、土壤及局地气候相关信息。

有关整个净初级生产力项目的更多信息，可访问NPP主页获取，主页内包含各单个研究样地或多样地数据集的详细内容链接。我们鼓励用户浏览此类网页，以获取原始研究、研究方法以及原始研究联系人的相关细节。NPP数据可通过美国田纳西州橡树岭市橡树岭国家实验室（Oak Ridge National Laboratory，简称ORNL）分布式主动存档中心在线获取。

数据引用说明：请按照以下格式引用本数据集：作者, 姓名缩写. 年份. 数据集标题. 可从美国田纳西州橡树岭市橡树岭国家实验室分布式主动存档中心在线获取。示例：Williamson, P., and J. Pitman. 1999. NPP Grassland: Beacon Hill, U.K. 1972-1973. Available on-line from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.