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

Abstract

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.