College of Environment and Planning, Liaocheng University, Liaocheng 252059, Shandong, China.
CAS Key Laboratory of Coastal Environmental Processes and Ecological Restoration, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences (CAS), Yantai 264003, Shandong, China.
Ying Yong Sheng Tai Xue Bao. 2021 Feb;32(2):581-590. doi: 10.13287/j.1001-9332.202102.033.
Studying the effects of rainfall regimes such as rainfall amount and timing on soil carbon mineralization is of great importance for our understanding the mechanisms underlying the stability and accumulation of soil carbon in coastal salt marshes. In this study, we examined the responses of soil carbon mineralization (CO and CH fluxes) from undisturbed soil columns to rainfall events in different seasons (dry and wet seasons) with filed experiments in a primary region in the Yellow River Delta salt-marsh wetland, which is far away from the coast and not affected by tides. The results showed that rainfall amount and timing had a significant interaction in affecting soil CO flux rates. During the dry season, large rainfall events significantly reduced soil CO flux rates but had no significant effect in the wet season, which might be closely related to the significant increase in soil water content and salinity. Rainfall amount, rainfall timing and their interactions had no significant effect on soil CH efflux rates. Rainfall timing and rainfall amount did not affect CH/CO. CH/CO increased with increasing soil water content and salinity. Soil water content and soil salinity showed similar increases to increasing rainfall amount. Our results suggested that the changing rainfall regime under climate change in the future would have a great impact on soil carbon mineralization and carbon sink function by regulating soil water and salt migration in this region.
研究降雨量（如降雨量和时间）等降雨模式对土壤碳矿化的影响，对于理解沿海盐沼土壤碳稳定和积累的机制非常重要。在本研究中，我们通过野外实验，在远离海岸且不受潮汐影响的黄河三角洲盐沼湿地的一个主要区域，研究了不同季节（旱季和雨季）降雨事件对原状土柱土壤碳矿化（CO 和 CH 通量）的响应。结果表明，降雨量和时间在影响土壤 CO 通量速率方面具有显著的交互作用。在旱季，大量降雨事件显著降低了土壤 CO 通量速率，但在雨季没有显著影响，这可能与土壤含水量和盐分的显著增加密切相关。降雨量、降雨时间及其相互作用对土壤 CH 排放速率没有显著影响。降雨时间和降雨量对 CH/CO 没有影响。CH/CO 随着土壤含水量和盐分的增加而增加。土壤含水量和土壤盐分的增加与降雨量的增加相似。我们的研究结果表明，未来气候变化下不断变化的降雨模式将通过调节该地区的土壤水盐运移，对土壤碳矿化和碳汇功能产生重大影响。
