Crossett Experimental Forest site, station NADP Station AR02, Warren 2WSW, study of nitrogen from ammonium in precipitation (volume-weighted concentration) in units of milligramsPerLiter on a monthly timescale

The EcoTrends project was established in 2004 by Dr. Debra Peters
(Jornada Basin LTER, USDA-ARS Jornada Experimental Range) and
Dr. Ariel Lugo (Luquillo LTER, USDA-FS Luquillo Experimental Forest)
to support the collection and analysis of long-term ecological datasets.
The project is a large synthesis effort focused on improving the accessibility
and use of long-term data. At present, there are ~50 state and federally funded
research sites that are participating and contributing to the EcoTrends project,
including all 26 Long-Term Ecological Research (LTER) sites and sites funded by
the USDA Agriculture Research Service (ARS), USDA Forest Service,
US Department of Energy, US Geological Survey (USGS) and numerous universities. Data from the EcoTrends project are available through an exploratory web portal
(http://www.ecotrends.info). This web portal enables the continuation of data
compilation and accessibility by users through an interactive web application.
Ongoing data compilation is updated through both manual and automatic
processing as part of the LTER Provenance Aware Synthesis Tracking
Architecture (PASTA). The web portal is a collaboration between the Jornada LTER
and the LTER Network Office. The following dataset from Crossett Experimental Forest (CRO)
contains nitrogen from ammonium in precipitation (volume-weighted concentration) measurements in milligramsPerLiter units
and were aggregated to a monthly timescale.

EcoTrends项目（EcoTrends）由Debra Peters博士（约纳盆地长期生态研究站，美国农业部农业研究服务局约纳实验牧场）与Ariel Lugo博士（卢奎洛长期生态研究站，美国农业部林务局卢奎洛实验林）于2004年创立，旨在支持长期生态数据集的采集与分析工作。
本项目是一项大型综合研究计划，致力于提升长期生态数据的可获取性与复用率。目前共有约50个州级及联邦资助的研究站点参与EcoTrends项目并贡献数据，其中涵盖全部26个长期生态研究（Long-Term Ecological Research, LTER）站点，以及美国农业部农业研究服务局（Agricultural Research Service, ARS）、美国农业部林务局、美国能源部、美国地质调查局（United States Geological Survey, USGS）资助的站点与多所高校。
EcoTrends项目的数据可通过探索性网络门户（http://www.ecotrends.info）获取。该门户依托交互式网络应用程序，支持用户持续开展数据整合与访问操作。作为长期生态研究网络溯源感知综合跟踪架构（Provenance Aware Synthesis Tracking Architecture, PASTA）的组成部分，持续的数据整合工作通过手动与自动两种处理模式进行更新。
该网络门户由约纳LTER站与LTER网络办公室联合开发。本次提供的克罗塞特实验森林（Crossett Experimental Forest, CRO）数据集，包含以毫克每升为单位的降水中铵态氮（体积加权浓度）实测数据，且已聚合至月尺度。