Department of Environmental Science, University of Kashmir, Srinagar, Jammu and Kashmir, India,
Environ Sci Pollut Res Int. 2014 Apr;21(8):5653-9. doi: 10.1007/s11356-013-2470-7. Epub 2014 Jan 15.
The aim of the study was to estimate the impact of mechanical deweeding on the community structure of phytophilous macroinvertebrates. The eutrophic lake selected for the study was Dal Lake in the Kashmir Himalayas. The dissolved nutrient concentration was found to be highest in August and September, i.e., nitrates-nitrogen (513 μg l(-l)) and total phosphorus (685 μg l(-l)). During the period of investigation, a total of 22 macroinvertebrate taxa were recorded which belonged to phylum Arthropoda, Mollusca, and Annelida. The samples were collected with the help of a composite Gerking frame box and grappler. Mechanical deweeding had a profound impact on the population density of phylum Mollusca and Arthropoda followed by Annelida. However, family Tubificidae was not influenced by deweeding, as the harvester only trimmed the vegetation, and these organisms were recorded in the sediment of the lake. On average, the reference site had higher density of macroinvertebrates as compared to deweeded areas. The abundance of macroinvertebrates decreased from 200 ind. (individuals) m(-2) in the reference site to 51 ind. m(-2) in the deweeded site as a result of weed removal. Species richness and composition of major macroinvertebrates in harvested and unharvested areas of the lake were also dissimilar as portrayed by biotic indices vis-à-vis Shannon diversity index, evenness index, and Simpson index.
本研究旨在评估机械除草对喜湿大型无脊椎动物群落结构的影响。选择克什米尔喜马拉雅山的达尔湖作为研究对象，该富营养化湖泊的溶解养分浓度在 8 月和 9 月最高，硝酸盐氮（513μg l(-1)）和总磷（685μg l(-1)）。在调查期间，共记录了 22 种大型无脊椎动物类群，属于节肢动物门、软体动物门和环节动物门。使用复合 Gerking 框架箱和抓斗收集样本。机械除草对门软体动物和节肢动物的种群密度有深远影响，随后是环节动物。然而，收割器只修剪了植被，对 Tubificidae 科没有影响，这些生物在湖中沉积物中被记录。平均而言，参考点的大型无脊椎动物密度高于除草区。由于除草，参考点的大型无脊椎动物丰度从 200 个个体 m(-2) 减少到除草区的 51 个个体 m(-2)。生物指数表明，与香农多样性指数、均匀度指数和辛普森指数相比，收获区和未收获区的大型无脊椎动物的物种丰富度和组成也不同。
