Surface carbon, water and energy fluxes measured by eddy covariance at 3 sites within the Alaska Peatlands Experiment and Bonanza Creek Experimental Forest 2013-2016

These data are simultaneous and continuous measurements of carbon, water and energy fluxes of the terrestrial landscape. These fluxes are major regulatory drivers of the boreal climate system and form key linkages and feedbacks between the land surface, the atmosphere and the oceans. At the APEX project site, within Bonanza Creek Experimental Forest, this monitoring is repeated across a chronosequence of permafrost degradation; the Black Spruce site is an area of stable permafrost with intact black spruce forest (APEX gamma site), the Thermokarst site is an active thermokarst zone with considerable tree mortality (APEX betaSW site), the Fen site is within a stable treeless fen with deep active layer depth (APEX apexcon,low, and ele sites). The main variables being monitored are the instananeous fluxes of CO2, water vapor and surface energy (shortwave, longwave and net radiation), secondary variables included photosynthetically active radiation (PAR), air and soil temperatures, rainfall, snow depth, soil moisture content, wind direction and speed, and average atmospheric concentrations of CO2 and H2O through the year. Our site naming scheme is as follows: 1) gamma = Black Spruce site = YF_2472, 2) betaSW = Thermokarst site= BC_5166, 3) (apexcon+apexele+apexlow) = Fen site = BC_FEN

本数据集为陆地景观碳、水与能量通量的同步连续观测数据。此类通量是北方气候系统的核心调控因子，同时构成了陆地表面、大气与海洋之间的关键连接与反馈环路。
本观测位于博南扎溪实验林（Bonanza Creek Experimental Forest）内的APEX项目站点，围绕多年冻土（permafrost）退化的时间序列样带开展重复监测：其中黑云杉站点为保留完整黑云杉林的稳定多年冻土区（APEX gamma站点）；热喀斯特（thermokarst）站点为存在大量树木死亡的活跃热喀斯特区域（APEX betaSW站点）；沼泽（Fen）站点为活动层深度较深的稳定无树沼泽区，对应APEX apexcon、low及ele站点。
本次监测的核心观测变量为CO₂、水汽与地表能量（短波辐射、长波辐射与净辐射）的瞬时通量；次要变量包括光合有效辐射（Photosynthetically Active Radiation, PAR）、气温与土壤温度、降雨量、积雪深度、土壤含水量、风向与风速，以及全年大气中CO₂与H₂O的平均浓度。
本站点命名规则如下：1) gamma对应黑云杉站点，编号为YF_2472；2) betaSW对应热喀斯特站点，编号为BC_5166；3) (apexcon+apexele+apexlow)对应沼泽站点，编号为BC_FEN。