NPP GRASSLAND: TULLGARNSNASET, SWEDEN, 1968-1969

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.

净初级生产力（Net Primary Productivity，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野外实测记录，所有记录均经过规范化文档整理。该数据库为每个密集观测样地配备了地理配准信息，涵盖生物量动态、气候及样地特征三类数据。本次数据汇编的核心目标之一，是采用统一且文档完备的标准化方法，基于野外实测数据估算NPP。
数据库的其他重要组成部分包括样地综述、研究者联系方式，以及各观测样地的关键参考文献列表。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审阅校验。
当前，NPP数据库包含超过60个密集观测样地的详细数据。其中绝大多数为草原样地，其余样地涵盖热带森林、寒温带森林及冻原观测样地。所有样地均提供地上部分年度峰值活生物量数据和/或季节性生物量动态数据的组合信息。多数样地还附有地下生物量及/或周转速率相关数据。
若有可用数据，各观测样地的NPP估算值将被收录，并纳入NPP综述表格中。所有样地均提供不同详细程度的气候与土壤数据。样地已依据基于Bailey生态区、Holdridge生命地带、Matthews植被分类以及Olson全球生态系统复合体的植被地图进行分组归类。
此外，本数据库还提供此前汇编完成的带地理配准信息的多样地NPP估算数据集。现有多套不同数据集提供NPP估算值，涵盖超过1700个样地，但相较于密集观测样地，单个样地可获取的信息相对有限。这类样地的记录通常包含NPP数值、经纬度坐标、数据原始来源，部分还附带植被类型、管理措施、土壤及局地气候相关信息。
关于整个净初级生产力项目的更多信息，可访问NPP官方主页，其中包含各单个观测样地或多样地数据集的详细信息链接。鼓励用户浏览这些网页，以获取原始研究、研究方法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国家实验室分布式主动存档中心（Oak Ridge National Laboratory Distributed Active Archive Center, ORNL）在线获取。
数据引用说明：请采用以下引用格式标注本数据集：作者，P. A.，与M. B. 作者。年份。数据集标题。可从美国田纳西州橡树岭国家实验室分布式主动存档中心在线获取。
例如：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.