草地枯落物分解研究进展及展望

草地枯落物是草地生态系统中生物组分枯死后所有有机物质的总称,是草地生态系统重要的组成部分,是除冠层外,大气与矿质土壤层、植物根系层进行物质与能量交换的另一介质,在生态学中起着不可替代的作用。随着西部大开发战略和退耕还林还草工程的实施,大型家畜等草食性动物退出草地生态系统后,枯落物成为草地生态系统物质和能量循环的重要调节枢纽。近年来,随着全球应对气候变化、节能减排和低碳经济所面临的压力,作为全球碳循环的重要组成部分,草地枯落物的研究被越来越多的学者所重视。文章在综述国内外大量文献的基础上,对草地枯落物的概念进行了比较分析,对其进行了准确定义;归纳出了尼龙网袋法、室内分解培养法、现量估算法和同位素法等多种草地枯落物分解方法,并就枯落物分解过程中经常采用的分解率概算模型、时间衰减模型、影响因子关系模型等进行了比较分析,总结出枯落物的分解是由淋溶、自然粉碎和代谢等3个主要作用,碎屑食物链、腐食食物链等2种不同的食物链共同组成的复杂过程。开展长期定位监测、形成统一的研究方法,探索枯落物分解过程中碳循环微观机理,以及影响因子之间的交互作用是未来草地枯落物研究工作的重点。

Research progress and the prospect of grassland litters decomposition

The grassland litters refers to floorboard of all organic matters in ecosystem of grassland after withering.Except for Plant Canopy,it is the important components of grassland ecosystem,and the medium to exchange of energy and matter between the atmosphere and Mineral soil,Plant root layer.This part is the unique researching target in the ecology.Along with the implement of develop-the-west strategy and grain for green project,after the heavy livestock such as Herbivore leaved the grassland,the litters of the grassland has gradually become the important pivot adjustment of the grassland-ecosystem.In recent years,Along with the global climate change,to developing Energy-saving-and-emission-reduction and Low-Carbon-Economy,as the important part of Global carbon cycle,more and more scholars pay attention to research of the grassland litters.Based on the review of the literature at home and abroad,the paper researched and accurately definite the conception of grassland litters by comparative analysis,and concluded the methods of Nylon net bags,Indoor decomposition cultivating,present litter accumulation and isotope analysis and so on,and comparative analyzing the often using model in the researching of the litters decomposition process includes the Decomposition rate estimate model,Time attenuation model,Influence factors relation model etc.finally,the paper gained the litters decomposition is a complicated process,consisted of three important process including leaching,spontaneous disintegration,metabolism,and detritus-food-chain,detrital-food-chain two different chain.The paper suggests that launching the Long-term monitoring and forming the Unified study method,especially exploring Carbon circulation mechanism in decomposition,and the interaction of factors.All these will be the researching key point in the future.