宁夏哈巴湖国家级自然保护区湿地植物群落特征与生态需水量

Plant community features and ecological water demands of wetlands for the Ningxia Habahu National Nature Reserve

为了探究干旱半干旱区湿地的植物群落特征以及生态需水量,在宁夏哈巴湖国家级自然保护区内,以4个主要湿地(哈巴湖、花马湖、八子洼和南海子湿地)为研究对象,调查湿地内的植物种类、数量、生物量等指标,计算植物群落的物种多样性指数.同时,计算4个湿地的植物需水量、栖息地需水量和补给地下水需水量,得到湿地的总生态需水量.结果表明,不同湿地的植物种类组成差异较大,哈巴湖湿地的优势植物为苜蓿、沙打旺和芦苇,花马湖湿地的优势植物为芦苇、赖草和披针叶黄华,八子洼和南海子湿地的优势植物为细枝盐爪爪.调查样地距湖边距离不同,植物组成也不相同,越靠近湖边,植物优势种的优势度越大,越呈集群分布. 4个湿地的植物多样性相对贫乏,从湖边趋远,物种多样性不断增大.在湿地的生态需水量中,4个湿地的植物需水量所占比例较大,而栖息地需水量和补给地下水需水量所占比例较小. 4个湿地的总生态需水量的最小值为1 205.3×10~4 m^3,这是维持宁夏哈巴湖自然保护区生态系统功能的最小需水量;总生态需水量的最大值为4 772.1×10~4 m^3,这是维持湿地最佳状态的需水量.

To explore the plant community features and ecological water demands of wetland in arid and semi-arid areas,four wetlands(Habahu,Huamahu,Baziwa and Nanhaizi)of the Ningxia Habahu National Nature Reserve were adopted as the research objects,the plant species,quantity,biomass,etc in wetland were investigated,and the species diversity of plant community was calculated.Meanwhile,the plant water demands,water demands for habitats and water demands for recharge groundwater of four wetlands were calculated to obtain the total water demands for ecological environment.The results of plant community investigation showed that there were obvious differences in plant species among the four wetlands.In Habahu wetland,the dominant species were Medicago sativa,Astragalus adsurgens and Phragmites communis;In Huamahu wetland,the dominant species were Aneurolepidium dasystachys,Phragmites communis and Thermopsis lanceolate;In Baziwa and Nanhaizi wetlands,the dominant species was Kalidium gracile.The plant compositions were different with the different distance from the edge of the lake,the nearer the distance is from the lake,the more advantage the dominant species has,and the more clumped distribution is.The plant species diversities were in relative shortage,and the species diversities increased gradually with the increase of distance from the edge of the lake.In total ecological water demands of the four wetlands,the percentage of plant water demands was the largest,and the percentages of water demands for habitats as well as the water demands for recharge groundwater were relatively lower.The minimum total ecological water demand of four wetlands is 1 205.3×10^4 m^3,which is the minimum water demands to maintain the ecosystem function of the Ningxia Habahu National Nature Reserve.The maximum total ecological water demand is 4 772.1×10^4 m^3,which is the water demand to maintain the optimal condition of the Reserve.