拉鲁湿地水生植物群落多样性与水环境因子的关系

Relationship Between Diversity of Aquatic Plant Communities and Water Environmental Factors in Lhalu Wetland

植物的多样性对湿地生态系统的完整性和稳定性具有重要的意义.以拉鲁湿地为研究对象,采用野外调查、现场监测与室内分析相结合,重点分析了拉鲁湿地不同区域植物多样性的变化及其与水环境因子之间的关系.结果表明拉鲁湿地出现18种水生植物,各区域Margalef物种丰富度指数为M(中西部)>W(西部)>E(东部)>N(北部)>S(南部);物种丰富度由大到小排序为W(11)、M(11)>N(8)>E(7)>S(6);Shannon-Wiener指数依次排序为M(1.9)>W(1.89)>S(1.63)>E(1.26)>N(1.18);Simpson指数依次排序为N(0.44)>E(0.34)>M(0.24)>S(0.21)>W(0.18);Pielou指数依次排序为S(0.91)>M(0.79)>W(0.78)>E(0.65)>N(0.56).RDA分析表明,拉鲁湿地水生植物多样性受溶解氧、pH、水温、总氮、浊度等水环境因子的影响.拉鲁湿地以金鱼藻、杉叶藻、水蓼、水葱、菖蒲和灯芯草等为优势种,呈现由非耐污种演替为耐污种趋势.

Plant diversity plays an important role in the integrity and stability of wetland ecosystems.Lhalu Wetland is the highest wetland in the world and is the largest urban natural swamp in China.It plays an important role in ecological balance,increasing air humidity,improving the urban climate,and purifying the water environment in Lhasa.The changes in plant diversity in different areas of the Lhalu Wetland and its relationship with water environmental factors were analyzed via field investigation,field monitoring,and indoor analysis.Results showed that 18 species of aquatic plants were found in the Lhalu Wetland.The Margalef species richness index was in the order M(Middle west)>W(West)>E(East)>N(North)>S(South).Index of species richness ranked of W(11),M(11)>N(8)>E(7)>S(6).Index of ShannonWiener followed that of M(1.9)>W(1.89)>S(1.63)>E(1.26)>N(1.18).Index of Simpson ranked of N(0.44)>E(0.34)>M(0.24)>S(0.21)>W(0.18).The order of Pielou index was that of S(0.91)>M(0.79)>W(0.78)>E(0.65)>N(0.56).Redundancy analysis showed that the diversity of aquatic plants in the Lhalu Wetland was affected by dissolved oxygen,pH,water temperature,total nitrogen,and turbidity.The dominant species in the Lhalu Wetland are CeratopHyllum demersum L.,Hippuris vulgaris,Polygonum hydropiper,Softstem bulrush,Acorus calamus,and Juncus effusus,which show a trend of non-pollution-resistant species succession to pollution-resistant species.