摘要
在富营养水体生态修复工程实践中,较高的沉水植被盖度或充分的生物量是水体从浊水态转变为清水态的关键。利用贝类改善水体光照条件、促进沉水植被扩张与恢复是其技术途径之一。根据太湖河蚬的自然丰度,设计了4组河蚬密度处理(对照组、低密度组、中密度组、高密度组)的野外受控实验,研究河蚬对沉水植物苦草生长的影响。结果表明:苦草的相对生长率和块茎数随河蚬密度的增加而显著升高,低、中、高密度组的苦草相对生长率分别比对照组升高了29.1%、41.5%和69.3%,块茎数分别增加了53.0%、88.3%和141.0%;此外,河蚬还显著增加了苦草的根叶比,与对照组相比,中、高密度组的苦草根叶比升高了43.9%和71.6%,而低密度组与对照组没有显著差异;河蚬一方面通过滤食作用显著降低了水体营养盐水平和浮游藻类浓度,促进底栖藻生长,改善了水体光照条件,改变了苦草生长的分配策略,导致较高的块茎数和根叶比;另一方面通过生物沉降作用,增加了沉积物和植物叶片中的N、P含量,降低叶片C∶N和C∶P,促进了植物的生长和繁殖。因此,淡水贝类有利于富营养水体沉水植被恢复。
In the ecological restoration engineering of eutrophic water body,high coverage or biomass of submerged vegetation is the key to shift water body from turbid to clear.Filter-feeding bivalves are always used to improve the light condition of water body and to promote the expansion and restoration of submerged vegetation.We conducted a controlled experiment to investigate the effects of different densities(control,low,medium,and high) of Corbicula fluminea on the growth of the submerged macrophytes Vallisneria natans.Compared with the control,the relative growth rate of V.natans in the low,medium and high density treatments increased significantly by 29.1%,41.5% and 69.3%,respectively,while the abundance of tubers increased by 53.0%,88.3% and 141.0%.Moreover,the root: leaf ratios of V.natans in the medium and high density treatments were 43.9% and 71.6% higher than that in the control,but no significant difference between the low density and the control.C.fluminea can filter-feed on phytoplankton and suspended materials,promote the growth of benthic algae,improve light conditions,change plant biomass allocation,resulting in a higher root: leaf ratio.Moreover,by biodeposition,C.fluminea can increase N and P concentrations in sediments and leaves,decrease C ∶ N and C ∶ P in leaves,and consequently enhance plant growth.Thus,the presence of the bivalve C.fluminea could facilitate the restoration of submerged macrophytes in shallow eutrophic lakes.
作者
谷娇
韩燕青
何虎
戴燕燕
张鹏飞
李宽意
GU Jiao;HAN Yan-qing;HE Hu;DAI Yan-yan;ZHANG Peng-fei;LI Kuan-yi(Institute of Geography Science,Taiyuan Normal University,Jinzhong 030619,Shanxi,China;Nanjing Institute of Geography&Limnology,Chinese Academy of Sciences,State Key Laboratory of Lake Science and Environment,Nanjing 210008,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2021年第5期1512-1520,共9页
Chinese Journal of Ecology
基金
国家自然科学基金项目(31930074,31770509和32001154)
中国科学院区域STS重点项目(KFJ-STS-QYZD-156)资助。
关键词
富营养水体
河蚬
沉水植物
生态修复
eutrophic water
Corbicula fluminea
submerged macrophyte
ecological restoration
