Key Laboratory of Forest Ecology and Environment, China's State Forestry Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China; International Joint Research Laboratory for Global Change Ecology, State Key Laboratory of Cotton Biology, College of Life Sciences, Henan University, Kaifeng, Henan 475004, China.
Key Laboratory of Forest Ecology and Environment, China's State Forestry Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China.
Sci Total Environ. 2017 Jan 1;574:1448-1455. doi: 10.1016/j.scitotenv.2016.08.116. Epub 2016 Sep 29.
Fine root dynamics play a critical role in regulating carbon (C) cycling in terrestrial ecosystems. Examining responses of fine root biomass and its decomposition to altered precipitation pattern and climate warming is crucial to understand terrestrial C dynamics and its feedback to climate change. Fine root biomass and its decomposition rate were investigated in a warm temperate oak forest through a field manipulation experiment with throughfall reduction and soil warming conducted. Throughfall reduction significantly interacted with soil warming in affecting fine root biomass and its decomposition. Throughfall reduction substantially increased fine root biomass and its decomposition in unheated plots, but negative effects occurred in warmed plots. Soil warming significantly enhanced fine root biomass and its decomposition under ambient precipitation, but the opposite effects exhibited under throughfall reduction. Different responses in fine root biomass among different treatments could be largely attributed to soil total nitrogen (N), while fine root decomposition rate was more depended on microbial biomass C and N. Our observations indicate that decreased precipitation may offset the positive effect of soil warming on fine root biomass and decomposition.
细根动态在调节陆地生态系统的碳（C）循环中起着关键作用。研究细根生物量及其分解对改变的降水模式和气候变暖的响应，对于理解陆地 C 动态及其对气候变化的反馈至关重要。本研究通过野外削减穿透雨和土壤增温的实验，研究了暖温带栎林的细根生物量及其分解。削减穿透雨与土壤增温显著相互作用，影响细根生物量及其分解。削减穿透雨显著增加了未加热样地的细根生物量及其分解，但在加热样地则产生了负面影响。土壤增温显著增强了背景降水下的细根生物量及其分解，但在削减穿透雨下则表现出相反的效应。不同处理间细根生物量的不同响应主要归因于土壤全氮（N），而细根分解速率则更依赖于微生物生物量 C 和 N。我们的观测结果表明，降水减少可能会抵消土壤增温对细根生物量和分解的积极影响。
