RCCZO -- Flux Tower, Meteorology, Ecosystem model, Nutrient Fluxes -- Data for Partitioned Carbon and Energy Fluxes -- Reynolds Creek Experimental Watershed -- (2014-Ongoing)

Observations of ecosystem processes across gradients provide invaluable information on the effects of potential shifts in the observed gradient. Ongoing observations from a network of four eddy covariance systems are available to quantify water and carbon fluxes along a climate/elevation gradient within a sagebrush ecosystem. The network is part of the Reynolds Creek Critical Zone Observatory located in southwestern Idaho, USA and contributes to ongoing long-term environmental research and monitoring by the USDA Agricultural Research Service at the Reynolds Creek Experimental Watershed. The sites include a Wyoming big sagebrush site, a low sagebrush site, a post-fire mountain big sagebrush site, and a mountain big sagebrush site located at elevations ranging from of 1425 to 2111 m. Climate variation follows the montane elevation gradient; mean annual precipitation at the sites varies from 290 to 795 mm, and mean annual temperature ranges from is 9.1 to 5.4°C. Annual Gross Ecosystem Production (GEP) for the sites averaged 349, 555, and 814 gC/m2, respectively for the first two years of observation. Annual Net Ecosystem Production (NEP) indicated that the Wyoming big sagebrush site at the lowest elevation was nearly carbon-neutral for 2015, while the other sites had a net flux of 110 to 150 gC/m2 to the ecosystem during the first two years.

沿环境梯度开展的生态系统过程观测，可为探明观测梯度内潜在变化所产生的影响提供极具价值的科学依据。目前可获取由4套涡度协方差（eddy covariance）系统组成的观测网络所采集的持续观测数据，用于量化山艾灌丛（sagebrush）生态系统内沿气候/海拔梯度分布的水碳通量。该观测网络隶属于位于美国爱达荷州西南部的雷诺溪关键带观测站（Reynolds Creek Critical Zone Observatory），服务于美国农业部（USDA）农业研究局在雷诺溪实验流域开展的长期环境监测与研究工作。观测站点涵盖海拔范围1425至2111米的4处样地：怀俄明型大蒿灌丛样地、矮生蒿灌丛样地、火烧后山地大蒿灌丛样地以及山地大蒿灌丛样地。区域气候随山地海拔梯度呈现规律性变化：各站点的年平均降水量介于290至795毫米之间，年平均气温则为9.1至5.4摄氏度。观测首两年间，各站点的年生态系统总初级生产力（Gross Ecosystem Production, GEP）均值分别为349、555及814克碳/平方米。年生态系统净初级生产力（Net Ecosystem Production, NEP）数据显示，海拔最低的怀俄明型大蒿灌丛样地在2015年近乎实现碳中性；其余站点在观测首两年内均为生态系统固碳110至150克碳/平方米。