乌梁素海芦苇枯落物分解动态及营养元素释放研究  

On the decomposition dynamics and nutrient release of Phragmites australis litter in Wuliangsu Lake

作　　者：魏江明[1] 王立新[1,2] 刘东伟[1] 刘华民[3] 清华[1] 王炜[3] 梁存柱[2,3] 

机构地区：[1]内蒙古大学环境与资源学院,呼和浩特010021 [2]中美生态能源及可持续性科学内蒙古研究中心,呼和浩特010021 [3]内蒙古大学生命科学学院,呼和浩特010021

出　　处：《安全与环境学报》2016年第5期364-370,共7页Journal of Safety and Environment

基　　金：国家自然科学基金项目(31560146);国家科技支撑计划项目(2011BAC02B03);内蒙古应用研发项目(20110522)

摘　　要：乌梁素海是内蒙古高原干旱区最典型的浅水草型湖泊,湖滨带芦苇分布广袤,其收割方式是在冬季湖泊结冰后将冰面上芦苇收割,冰面下芦苇则留存在水中,而水下部分的分解是造成湖泊生物淤积的重要原因,且分解过程中营养元素的释放亦加剧了湖泊富营养化。通过分解袋法研究了湖泊水面下芦苇枯落物的分解动态及营养元素的释放过程,并探讨了芦苇枯落物分解的影响因素。结果表明:1)芦苇枯落物分解270 d后质量残留率为52.44%,分解速率常数为0.002 68 d^(-1),其分解50%需要0.83 a,分解95%需要3.19 a;2)芦苇枯落物分解过程中,N元素的分解状态呈现释放-分解-再释放的规律,P元素和C元素均处于持续释放的分解状态;3)芦苇枯落物分解期间,分解速率和营养元素含量动态受枯落物自身质量和环境因子共同影响,且环境因子(温度、溶解氧、pH值)与芦苇枯落物分解速率及元素释放动态相关性显著。研究表明,芦苇枯落物分解释放大量营养物质,对湖泊富营养化有一定的贡献,要进一步加强芦苇植物的收割以减轻植物腐烂分解对湖泊造成的二次污染,减少生物淤积作用。This paper intends to bring about an estimate of the decomposition rate and the nutrient dynamics of Phragmites australis litters with a discussion of the influential factors via the litterbags technique in Wuliangsu Lake,one of the most typical shallow lakes in the arid zone in Inner Mongolia plateau. As is known,the common reed,Phragmites australis（ Cav.） Trin. ex Steudel has been widely scattering along the banks and open shallow water areas of the said lake surroundings,which is usually harvested in the early winter days when the ice has been formed on the lake surface. Nevertheless,there still remain lots of reed litters scattering under the lake-water surface when the reed is harvested,thus resulting in the problem of litter deposition and nutrients release into the water column and sediments,which is likely to speed up the eutrophication of the reeds. The detailed results of our study can be found as follows：（ 1） The decomposed litter tends to be quickly disappearing with only 52. 44% of the dry mass remaining till the end of our experiment,which may last as long as a period of 270 d at a decomposing speed of 0. 002 68d（-1）. And,correspondingly,0. 83 of a year is needed for a decomposition rate of 50% of the dry mass decomposition,whereas3. 19 a is needed for a decomposition rate of 95%. And,（ 2） a conclusion that has been proposed by the authors of the paper is that,in the process of decomposition,N in the litter is supposed to be the dynamics characteristics of the release-accumulation-release process,while P and C are supposed to be a release state in the process of the decomposition.（ 3） In the process of decomposition,the decomposition rate and the nutritional content are supposed to change simultaneously due to the effects of the quality of the litter and the environmental factors,too,such as the water temperature,the dissolved oxygen and pH value. And,thus,it can be concluded that the decomposition of Phragmites australis litter provides a short-term sink for the available nutr

关 键 词：环境科学技术基础学科 枯落物分解 N元素 P元素 生物淤积 乌梁素海 芦苇 

分 类 号：X171.1[环境科学与工程—环境科学]