树叶凋落物在受酸性矿山废水污染溪流中的分解  

The breakdown of leaf litter in a stream impacted by acid mine drainage

作　　者：童晓立[1] 颜玲[1] 赵颖[2] 林初夏[1] 韩翠香[1] 刘若思[1] 刘丽娟[1] 

机构地区：[1]华南农业大学资源环境学院,广州510642 [2]华南农业大学理学院,广州510642

出　　处：《生态学报》2006年第12期4033-4038,共6页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(30170121和30270279);教育部留学归国人员科研启动基金资助项目;教育部科学技术研究重点资助项目(205111);广东省科技厅社会发展计划资助项目(2005A30402006)~~

摘　　要：为了解华南地区酸性矿山废水对溪流中树叶分解的影响，在广东省大宝山矿区附近的1条受酸性矿山废水污染（pH值为2．7—3．4且富含多种重金属元素）的3级溪流中，利用2种孔径（5ram的网袋和0．1ram的布袋）的分解网袋对2种树叶（人面子和蒲桃）进行了为期101d的树叶分解研究。结果表明，人面子树叶网袋和布袋中的树叶干重剩余率分别为39％和48％，而蒲桃树叶网袋和布袋中的干重剩余率仍保持较高的水平，分别为61％和70％。根据指数衰减模型计算出树叶分解的半衰期，人面子树叶在网袋和布袋中的分解半衰期分别为57d和69d，而蒲桃树叶则分别为14-4d和217d。蒲桃树叶的分解速率明显比人面子树叶慢。在网袋中定殖的底栖动物主要是集食者，其中优势类群为摇蚊幼虫，占底栖动物个体总数的99％。摇蚊种群在网袋中的数量波动对2种树叶分解速率的影响并不明显。结果表明，受酸性矿山废水的影响，底栖动物群落的多样性大为减少。同时由于各种金属氧化物在树叶表面的不断沉淀，使树叶处于缺氧状态，抑制了微生物的活动，导致树叶分解速率大为降低。To investigate the effect of acid mine drainage on organic matter processing, we measured leaf breakdown in a thirdorder stream in South China. We used leaves of Dracontomelon duperreanum （Anacardiaceae） and Syzygium jambos （Myrtaceae） allocated into coarse （5mm） and fine （0. lmm） mesh bags. The stream was polluted by acid mine drainage with low pH （2.7 - 3.4） and heavy metal-rich water drained from the Dahaoshan Mine of Guangdong, China. After 101 days in the stream, 39% （coarse-mesh hags） to 48% （fine-mesh bags） of D. duperreanum initial mass still remained in the stream, whereas for S. jambos the values were 61% （coarse-mesh bag） and 70% （fine-mesh hag）. The time required for a 50% loss of leaf litter, based on the exponential model, were 57 days （coarse-mesh hag） and 69 days （fine-mesh hag） for D. duperreanurn, and 144 days （coarse-mesh bag） and 217 days （fine-mesh hag） for S. jambos, respectively. The decomposition rate of D. duperreanum leaves was significantly faster than that of S. jambos. Macroinvertebrates colonizing the coarse-mesh hags consisted mainly of collector-gatherers, of which Chironomidae larvae were numerically dominant in and accounted for more than 99% of the total maeroinvertebrate individuals. The number of chironomids in the bags fluctuated along time, but no relationship was observed between number of chironomids and mass losses, which suggests that the contribution of chironomids to the breakdown of leaf litter was thus unimportant. Our results suggest that the macroinvertebrate biodiversity can be seriously reduced in the stream impacted by acid mine drainage and the decomposition rate of leaf litter in the stream can be slower, mainly as a result of inhibition of microbial activity due to hypoxia with the deposition of metal oxides on leaf surface.

关 键 词：华南地区 酸性矿山废水 树叶分解 底栖动物 

分 类 号：X522[环境科学与工程—环境工程]