嘉兴市石臼漾水源生态湿地运行过程中植物多样性研究

Diversity of Plant in Jiaxing Shijiuyang Ecological Wetland for Drinking Water During Operation

浙江省嘉兴市石臼漾水源生态湿地是目前全国最大的水源保护湿地之一.为了解已实际运行2.5 a的石臼漾水源生态湿地植被现状,于2010年10～11月,采用样地法和样方法对湿地植被进行了系统调查,以期为水源生态湿地植被管理提供理论支持.对群落的物种组成、多样性变化以及生物质生产量进行了分析.共采集到湿地植物70种,隶属于28科62属.其中湿生26种,中生植物20种,挺水植物14种,沉水植物4种,漂浮植物6种.与运行初期相比,湿地植物种类显著增加,由原先15种增加至70种.采用Simpson指数和Shannon-Wiener指数作为物种多样性指标,分析了湿地湖岸带植物群落物种多样性的空间分布特点,结果显示东升路以南湿地湖岸带区域植物物种多样性(Simpson指数为0.468 3,Shannon-Wiener指数为0.835 2)高于北郊河以西湿地湖岸带区域(Simpson指数为0.357 6,Shannon-Wiener指数为0.660 4).对湿地植被的数量特征进行了分析,结果表明东升路以南湿地根孔区植物长势好于北郊河以西区域,而北郊河以西区域湖岸带植被更加丰富.根孔生态净化区植被平均生物量(干重)约为1.73 kg.m-2,植被总面积约为9.12×104 m2,估算总生物量(干重)约为157.8 t;湖岸带区域植被平均生物量(干重)约为0.83 kg.m-2,植被总面积约为3.75×104 m2,估算总生物量(干重)约为31.1 t.

The Shijiuyang ecological wetland for drinking water of Jiaxing City,Zhejiang Province is one of the biggest constructed wetlands for water resource protection in China.To ensure a deep understanding of the present status of the wetland vegetation of Shijiuyang ecological wetland which has been run for 2.5 years and provide support for the vegetation management of ecological wetland,systematic investigation was carried out by using plot method and quadrat method in October to November,2010.The species composition,dynamics of plant diversity and the biomass production during operation were analyzed.Altogether 70 species belonging to 28 families and 62 genera were recorded.Among them,there were 26 wetland plants,20 mesophytes,14 emergent,4 submerged,6 floating ones.Compared with the preliminary stage,the species numbers of wetland plants increased significantly from 15 species to 70 species.The spatial pattern of riparian species diversity was examined by adopting the Simpson index and Shannon-Wiener index as species diversity indices.The results showed that the riparian species diversity was higher in the west of the Beijiaohe river（Simpson index=0.468 3,Shannon-Wiener index=0.835 2） than that in the south of the Dongsheng Road（Simpson index=0.357 6,Shannon-Wiener index=0.660 4）.The analyses of quantitative characteristics of wetland vegetation showed that the plants in the root-channel purification zone in the south of the Dongsheng Road grew better than those in the west of the Beijiaohe river.With regard to the riparian vegetation,the riparian plants in the west of the Beijiaohe river were more abundant.The mean biomass production（dry weight） in the root-channel purification zone was 1.73 kg·m-2 and the total area was 9.12×104 m2,so the total biomass production was estimated to be 157.8 t.In the same way,the mean riparian vegetation biomass production（dry weight） was 0.83 kg·m-2 and the total vegetation area was 3.75×104 m2,so the total riparian vegetation biomass production（dry weight） was estimated as 31.1 t.