湿地挺水植物凋落物立枯分解研究进展

Research advances in standing litter decomposition of emergent macrophyte in wetlands

在许多湿地生态系统中,挺水植物立枯常组成凋落物总量的主要部分,其分解过程研究对于正确评价湿地生态系统的碳收支状况具有重要意义。对立枯分解过程与传统研究中凋落物分解过程的差异,分解过程中的CO2排放,立枯分解的研究方法,以及分解过程的影响因素进行了综述。一般认为,湿地挺水植物立枯与传统研究中凋落物所处环境的差异造成了分解过程的差异,其分解过程中产生CO2是湿地温室气体排放的重要途径;凋落袋和红外气体分析仪是湿地挺水植物立枯分解研究的主要方法;真菌组成了立枯体上微生物的大部分,对于立枯分解具有重要作用;环境因子(温度、水分等)和"基质质量"是影响挺水植物立枯分解过程的重要因素。在全球变化背景下,气候变化因子会直接或间接影响凋落物立枯分解过程,引起对气候变化的反馈,因此,在全球范围内开展气候变化对于湿地生态系统挺水植物立枯分解影响的研究具有重要的意义,必将成为凋落物研究的一个重要方向。

Standing litter is usually a primary component of litter mass, and its decomposition play a key role in carbon budget in most of wetland ecosystems. In the present study, we reviewed the differences of decomposition processes between litterfall and standing litter, CO2 emission from standing litter of the emergent macrophyte in wetland ecosystems, and research methods and the factors influencing decomposition of standing litter. The differences of ambient environment result in discrepancies of decomposition process between litterfall and standing litter, and CO2 release during standing litter decomposition is an important component of greenhouse gas emission in the wetland ecosystem. Litter bag and infrared gas analyzer are frequently used when studying decomposition of standing litter. Fungi occupy the most of microorganism associated with standing litter decomposition. Environmental factors （e.g. moisture and temperature） and litter quality all control the decomposition rate of standing litter. Considering global climate change, changes in climate factors would make directly or indirectly impacts on standing litter decomposition that then give a feedback effect on global climate change. Therefore, it will become an important topic that the influences of climate change on standing litter decomposition of emergent macrophyte in wetland ecosystems.