生态恢复对退化河岸植物群落的作用——以重庆九龙外滩河岸带生态恢复为例

Effects of Ecological Restoration on Degraded Riparian Plant Communities:Take Jiulongwaitan in Chongqing as an Example

河岸带是陆地生态系统与水生生态系统之间的过渡地带,受人类干扰的威胁较大。长江是流经重庆都市区的主要河流,主城区两江四岸部分河岸硬化,河岸生态功能退化或丧失,生物多样性降低。本文以重庆主城区九龙外滩的河岸带为研究区域,通过调查,采用Ward最小方差法对植物群落类型进行划分,比较了生态恢复区域和自然区域的植物群落特征及优势种植物沿海拔高程的分布格局。结果表明:调查共记录维管植物23科60属72种,其中菊科、禾本科等为优势科;河岸带共分为6种群落类型,牛鞭草+狗牙根群落出现频率最高;物种丰富度、Shannon-Wiener多样性、Pielou均匀度指数表现为恢复区>自然区。合理的生态恢复措施可以有效地重建河岸带植物群落,提高河岸植物多样性。

Riparian bank is the transitional zones between terrestrial and aquatic ecosystems.The Yangtze River,flowing through the urban area of Chongqing,has experienced serious river channelization,riparian hardening and other anthropogenic activities.These disturbances result in degradation of ecological function and reduction of biodiversity in riparian ecosystems.Elaborate attempts are underway to restore riparian ecosystems.The Ward’minimum variance method was used to classify plant community types through plot survey in the riparian of Jiulongwaitan in Chongqing.We analyzed the distribution pattern of dominant species along altitude and within plant communities in restored and natural riparian zones.The survey recorded a total of 72 vascular plant species from 60 genera and 23 families.Compositae and Gramineae were dominant families.The riparian zone was divided into 6 community types.The occurrence frequency of Form.Hemarthria altissima+Cynodon dactylon was the highest.Species richness,Shannon-Wiener diversity index and Pielou index were in the order of:restored area>natural area.These results indicated that practicable restoration measures could effectively reconstruct the plant communities and improve the plant diversity in the riparian zones.