The distribution patterns and changes of aquatic plant communities in Napahai Wetland in northwestern Yunnan Plateau,China

Using 3S technology and plant community research methodology,a study on the distribution patterns of and changes to the aquatic plant communities in the high plateau Napahai wetland over the past 24a produced the following results: compared with the aquatic plant communities 24a before,the types and numbers of aquatic plant communities changed,and pollution-tolerant,nutrient-loving plant communities such as Com.Scirpus tabernaemontani,Com.Zizania caduciflora, Com.Myriophyllum spicatum,and Com.Azolla imbricata flourished while primary aquatic plant communities shrank or disappeared.Over the past 24a,the number of aquatic communities has increased from 9 to 12,with two new emergent plant communities and one new floating-leaved plant community.The increase in emergent plant communities was most marked.From east to west and from south to north,there was a pattern of successively distributed floating-leaved plant communities, emergent plant communities and submerged plant communities.With the succession of communities from submerged plant communities to floating-leaved plant communities,and floating-leaved plant communities to emergent plant communities,the composition of communities became complicated,and the number of accompanying species increased while the occurrence of dominant plant species decreased.The current distribution area of emergent plant communities,528.42hm~2,is the largest; submerged plant communities cover 362.50hm~2;and the distribution area of floating-leaf plant communities is the smallest,covering 70.23hm~2.The distribution pattern and change in Napahai wetland's aquatic plant communities is a reaction to the change in the wetland environment.This research showed that human disturbances have led to an inward movement of the wetland shoreline,a decrease in water quality and a reduction in wetland habitat.