Effects of experimental warming on heterotrophic soil respiration in a cultivated Andisol in Japan

为了研究增温对亚洲季风气候下土壤有机碳（Rh）分解和土壤性质的影响，设计了大田土壤增温试验。在寒冷季节（冬季至初夏），加热样地土壤温度每升高2℃，相对于未加热样地，Rh升高幅度约为2-13%。而在暖季（夏~秋），土壤升温导致加热样地的Rh降低，比对照样地低10 ~ 18%。研究结果表明，升温2℃可能通过对土壤水分状况的影响，对暖、冷季节土壤有机质分解产生显著不同的影响，强调了在气候变暖情景下，在模型中考虑温度与水分相互作用对土壤碳动态预测的重要性。

In order to study the effects of warming on the decomposition of soil organic carbon (Rh) under Asia monsoon climate and soil properties, we designed a field soil warming experiment for a cultivated Andisol. Raising the soil temperature by 2℃ in the heated plots appeared to increase Rh during the cool seasons (winter to early summer) by approximately 2-13% compared to the non-heated control plots. In contrast, during the warm seasons (summer to Autumn), soil warming induced the decreased Rh in the heated plots, about 10-18% lower relative to the control plots. Our results suggest that 2℃ temperature raise can have drastically different impact on soil organic matter decomposition between warm and cold season most likely through its effect on soil moisture regime, highlighting the importance of accounting for temperature vs. moisture interaction in the models when predicting soil carbon dynamic under climate warming scenario.