摘要
消落带是影响水库生态环境安全的关键区域。利用生物调查方法,对三峡库区典型缓坡型消落带草本植被的自然恢复情况进行了初步研究。结果表明：（1）研究区植被主要为一年生和多年生草本植物,共有29种,其中空心莲子草、狗牙根、稗草、苍耳、狗尾草、鬼针草和马唐是消落带的优势种类,且空心莲子草和狗牙根是消落带成陆初期的建群种。消落带植物群落多呈斑块状集中分布,沿145~175 m高程梯度从下往上大致可分为4条植物带：空心莲子草-狗牙根带、稗草带、苍耳-马唐-狗尾草带和一年生杂草带。（2）淹水后消落带草本植物群落在没有人为干预的情况下可自然恢复,只是群落结构趋于简单,植物物种多样性显著降低。（3）植物群落的物种多样性、地上生物量和盖度均沿水位梯度带从下往上呈先增后减的抛物线状变化,即消落带下部〈消落带上部〈消落带中部。三者的变化趋势有着高度的相关性,并且都与淹水时间呈负相关。（4）沿水位梯度带植物群落的均匀度指数差异不显著,其他物种多样性指数以及地上生物量差异显著。
Water-level fluctuation zone is the critical area which influences ecological services of reservior.Restoration of natural herbaceous vegetation in the gentle slope water-level fluctuation zone in the Three Gorges Reservior was investigated by ecological methods.The main plant types in study area were annual herbs and perennial herbs.There were 29 species of herbaceous plants,among which,Alternanthera philoxeroides（Mart.）Girseb.,Cynodon dactylon（Linn.）Pers.,Xanthium sibiricum Patrin.,Echinochloa crusgalli（L.）Beauv,Setaria viridis（L.）Beauv.,Bidens bipinnata L.and Digitaria sanguinalis（Linn.）Scop.were the dominant.Alternanthera philoxeroides（Mart.） Girseb.and Cynodon dactylon（Linn.）Pers.were constructive species.Plant communities in water-level fluctuation zone were all patchiness.There were roughly four plant distribution zones,ie,Alternanthera philoxeroides（Mart.） Girseb.and Cynodon dactylon（Linn.） Pers zone,Echinochloa crusgalli（L.）Beauv zone,Xanthium sibiricum Patrin.and Digitaria sanguinalis（Linn.） Scop-Setaria viridis（L.）Beauv.zone.Annual weeds zone were from 145 m to 175 m altitude.Plant communities in water-level fluctuation zone could restore after flooding in the absence of human intervention,but the community structure tended to be simple and species diversity decreased significantly.Species diversity,the biomass and coverage along with water-leverl zone first increased,then decreased,and showed a single-peak pattern,ie,the lower partthe upper partthe middle part.There were a high correlation between the three,and they all negatively correlated with the length of flooding time.The differences of species diversity indices and biomass between water-level zone were remarkable,except for evenness index.
出处
《长江流域资源与环境》
CAS
CSSCI
CSCD
北大核心
2011年第5期603-610,共8页
Resources and Environment in the Yangtze Basin
基金
国家"水体污染控制与治理"科技重大专项课题(2009ZX07104-002)
中国科学院西部行动计划项目(KZCX2-XB2-07)资助
关键词
三峡库区
消落带
物种多样性
植被恢复
Three Gorges Reservoir area
water-level fluctuation zone
species diversity
vegetation restoration
