Fernow Experimental Forest site, station Compartment 8, subcompartment C, single tree selection harvest in mixed hardwood forest, study of relative frequency of Carya cordiformis (bitternut hickory) in units of percent 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 Fernow Experimental Forest (FER)
contains relative frequency of Carya cordiformis (bitternut hickory) measurements in percent units
and were aggregated to a yearly timescale.

EcoTrends项目由Debra Peters博士（乔纳达盆地长期生态研究站，美国农业部农业研究局（United States Department of Agriculture Agricultural Research Service, USDA-ARS）乔纳达实验牧场）与Ariel Lugo博士（卢奎洛长期生态研究站，美国农业部林业局（United States Department of Agriculture Forest Service, USDA-FS）卢奎洛实验森林）于2004年创立，旨在支撑长期生态数据集的收集与分析工作。该项目为大型综合研究计划，核心目标是提升长期生态数据的可获取性与应用效率。目前共有约50个由州级及联邦政府资助的研究站点参与并为EcoTrends项目贡献数据，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（United States Department of Energy, DOE）、美国地质调查局（United States Geological Survey, USGS）与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，该门户依托交互式网络应用程序，支持用户持续开展数据整合与访问工作。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。该网络门户由乔纳达LTER站与LTER网络办公室联合开发。本次提及的费诺实验森林（Fernow Experimental Forest, FER）数据集，以百分比为单位记录了苦山核桃（Carya cordiformis, bitternut hickory）的相对频度实测数据，并按年度时间尺度完成聚合。