Eight Mile Lake Research Watershed, Thaw Gradient: half-hourly soil moisture 2010-2025

In this larger study, we are asking the question: Is old carbon that comprises the bulk of the soil organic matter pool released in response to thawing of permafrost? We are answering this question by using a combination of field and laboratory experiments to measure radiocarbon isotope ratios in soil organic matter, soil respiration, and dissolved organic carbon, in tundra ecosystems. The objective of these proposed measurements is to develop a mechanistic understanding of the SOM sources contributing to C losses following permafrost thawing. We are making these measurements at an established tundra field site near Healy, Alaska in the foothills of the Alaska Range. Field measurements center on a natural experiment where permafrost has been observed to warm and thaw over the past several decades. This area represents a gradient of sites each with a different degree of change due to permafrost thawing. As such, this area is unique for addressing questions at the time and spatial scales relevant for change in arctic ecosystems. This data set includes soil moisture intergrate over a 20cm soil profile at different locations within gradient of sites described.

在本大型研究中，我们提出的核心科学问题为：占土壤有机质（Soil Organic Matter, SOM）库主体的古老碳，是否会因永久冻土融化而被释放？本研究通过结合野外与室内实验，测定苔原生态系统中土壤有机质、土壤呼吸与溶解性有机碳的放射性碳同位素比值，以此解答上述问题。本研究拟开展的这些测定工作，旨在建立对永久冻土融化后碳损失所涉及的SOM来源的机制性认知。本研究的测定工作将在阿拉斯加山脉山麓、阿拉斯加州希利（Healy）附近一处已建成的苔原野外站点开展。野外测定以一项天然实验为核心：该区域内永久冻土在过去数十年间持续增温并发生融化。该区域包含一系列梯度样地，每个样地均对应永久冻土融化引发的不同程度的生态变化。正因如此，该区域具备独特优势，可用于解答与北极生态系统变化相关的时间与空间尺度层面的科学问题。本数据集包含上述梯度样地内不同点位的20厘米土壤剖面整合湿度数据。