The impact of drying and warming on ecosystem carbon balance: Measured growing season CO2 flux data from the DryPEHR project, Healy AK, 2011

This drying and warming experiment addresses the following questions: 1) Does ecosystem drying, warming and permafrost thaw cause a net release or uptake of C from the ecosystem to the atmosphere?, 2) Does the decomposition of old C that comprises the bulk of the soil C pool influence ecosystem C loss? 3) How do drying and warmign affect plant communities and ecosystem properties? We are answering these questions using a combined warming and drying experiment (DryPEHR), which is situated with the Carbon in Permafrost Experimental Heating Research (CiPEHR) project and located in an upland tundra field site near Healy, Alaska in the foothills of the Alaska Range. Warming treatment here refers to growing season air temperature warming (~1C) using open top chambers (OTC) combined with soil 'warming' using snow fences during the snow covered months. Drying is achieve using an automated pumping system that lowers the water table in the dry plots. Soil warming began in 2008; OTCs and drying in 2011. This data set includes measured values of CO2 fluxes during the growing season.

本干湿增温实验旨在解答如下科学问题：1）生态系统的干旱化、增温与永久冻土融化，是否会引发生态系统向大气的碳净排放或碳净吸收？2）占土壤碳库主体的老碳分解过程，是否会对生态系统碳损失产生影响？3）干旱化与增温会如何作用于植物群落与生态系统属性？本研究依托永久冻土碳实验加热研究（Carbon in Permafrost Experimental Heating Research, CiPEHR）项目，搭建了干湿增温实验平台（DryPEHR），实验点位设于阿拉斯加山脉山麓、阿拉斯加州希利镇附近的高地苔原场地。本实验的增温处理方案为：生长季采用开顶箱（open top chambers, OTC）实现空气温度增温（增幅约1℃），积雪期则通过雪堤实现土壤增温。干旱化处理通过自动抽水系统降低干旱样地的地下水位。土壤增温实验始于2008年，开顶箱安装与干旱化处理则于2011年启动。本数据集包含生长季期间测定的二氧化碳通量实测数据。