Surface soil moisture across an experimental burn severity gradient in far northeastern Siberia, 2012-2017

Fire severity is increasing across the boreal forest biome as climate warms, and initial post-fire impacts on tree demographic processes and soil conditions could be an important determinant of long-term forest structure and carbon dynamics. To examine soil burn severity impacts on volumetric soil moisture, we conducted experimental burns in summer 2012 that created a gradient of residual post-fire soil organic layer (SOL) depth within a mature, sparse-canopy Cajander larch (Larix cajanderi Mayr.) forest in the Eastern Siberian Arctic. Immediately post-burn and every growing season until 2017, we measured surface (~5-cm depth) soil moisture across the severity gradient.

随着气候变暖，北方森林生物群系（boreal forest biome）内的火烧严重度持续升高；火烧初期对树木种群动态过程与土壤状况的影响，可作为决定森林长期结构与碳动态的关键因素。为探究土壤火烧严重度对土壤体积含水量（volumetric soil moisture）的影响，我们于2012年夏季在北极圈西伯利亚东部一处成熟、林冠稀疏的卡氏落叶松（Larix cajanderi Mayr.）林内开展控制性火烧试验，构建了火烧后残留土壤有机层（soil organic layer, SOL）深度梯度。我们在火烧后即刻以及2017年前的每个生长季，沿该火烧严重度梯度测定了地表（约5厘米深度）的土壤含水量。