Grazinglands Research Laboratory site, station Oklahoma Division 5, Central, study of Palmer Drought Severity Index in units of dimensionless on a yearly 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 Grazinglands Research Laboratory (GRL)
contains Palmer Drought Severity Index measurements in dimensionless units
and were aggregated to a yearly timescale.

EcoTrends项目由黛布拉·彼得斯博士（约尔纳达盆地长期生态研究站，美国农业部农业研究服务局约尔纳达实验牧场）与阿里尔·卢戈博士（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。
该项目为大型综合研究项目，核心目标是提升长期生态数据的可获取性与利用效率。目前已有约50个由州级与联邦政府资助的研究站点参与并为EcoTrends项目贡献数据，其中包括全部26个长期生态研究（Long-Term Ecological Research, LTER）站点，以及由美国农业部农业研究服务局（ARS）、美国农业部林务局、美国能源部、美国地质调查局（USGS）及众多高校资助的站点。
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Web应用程序，支持用户持续开展数据汇编与获取工作。
作为LTER溯源综合跟踪架构（Provenance Aware Synthesis Tracking Architecture, PASTA）的组成部分，日常数据汇编工作通过手动与自动两种处理方式进行更新。
该网络门户由约尔纳达LTER站与LTER网络办公室联合开发。
牧场研究实验室（Grazinglands Research Laboratory, GRL）提供的以下数据集包含无量纲单位的帕尔默干旱严重指数（Palmer Drought Severity Index）测量值，且已按年时间尺度进行聚合。