Harvard Forest site, station Worcester County, MA (FIPS 25027), study of human population density in units of numberPerKilometerSquared 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 Harvard Forest (HFR)
contains human population density measurements in numberPerKilometerSquared units
and were aggregated to a yearly timescale.

EcoTrends项目由黛布拉·彼得斯博士（乔达纳盆地长期生态研究站，Jornada Basin LTER；美国农业部农业研究局乔达纳试验牧场）与阿里尔·卢戈博士（卢奎洛长期生态研究站，Luquillo LTER；美国农业部林业局卢奎洛试验林）于2004年发起创立，旨在支撑长期生态数据集的采集与分析工作。
该项目是一项大型综合研究计划，核心目标在于提升长期生态数据的可获取性与应用利用率。
目前，已有约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，以及由美国农业部农业研究服务局（Agricultural Research Service, ARS）、美国农业部林业局、美国能源部、美国地质调查局（United States Geological Survey, USGS）及众多高校资助的各类站点。
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，支持用户持续开展数据整合与获取工作。
作为长期生态研究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方式进行更新。
该网络门户由乔达纳LTER站与LTER网络办公室联合共建。
本次提供的哈佛森林（Harvard Forest, HFR）数据集包含以每平方千米人口数为单位的人口密度测量数据，且已按年度时间尺度完成聚合。