Quantitative Ecology Of Wetland Vegetation In The Upper Reaches Of Qinhe River In Shanxi

To take the wetland vegetation in the upper reaches of the Qinhe River as research object.The system sampling method was used to set up 7 plot in the study area according to the elevation gradient.In each plot,6 samples band were set at different distances from the river,take 10 1m × 1m herbaceous plots for ecological investigation on each samples band,based on the area of wetland vegetation flora on feature analysis,and the interspecies relationship between the dominant species of wetland plants was analyzed to study ecological niche of wetland plants.It aims to provide scientific basis for the protection of natural wetland resources and ecological environment in the upper reaches of the Qinhe River.The results of the study are as follows:(1)The characteristics of the wetland vegetation flora:After investigating flora composition and its geographical composition for the species on the wetlands in the upper reaches of the Qinhe River,the results showed that there were 30 families,86 genera and 118 species of seed plants on the wetlands,of which there were 4 families,21 genera and 27 species of monocotyledonous plants(monocotyledons)and there were 26 families,65 genera and 91 species of dicotyledonous plants(dicotyledons).The analysis methods of TWINSPAN combining with DCA were used to classify the wetland plants in the upper reaches of the Qinhe River into 12 associations;and 420 sample plots and 40 species were sequenced by DCA to indicate the distribution pattern of the plant associations and the relationship between them and environmental factors(mainly refer to moisture factor and altitude).(2)The characteristics of species diversity of wetland vegetation:After studying the diversity of ? species in the plant communities,it was found that the influence of the moisture factor became larger,species diversity and richness also decreased and the evenness(uniformity)didn't change significantly as the altitude slowly decreased.Individual numbers and important values were used to measure species evenness and species diversity,for which overall trends were similar,while the species diversity acquired based on important values was more accurate.It was concluded that the degree of flooding decreased,species differences became larger,species similarity became lower,and species changed significantly from sample plot No.1 to sample plot No.7 with the increase of altitude by studying the diversity of plant ?.Compared with the results acquired based on the Bray-Curtis indexes of individual numbers,the results acquired based on the Bray-Curtis indexes of important values were more accurate.(3)The relationship between the advantages of wetland vegetation:The functional groups of wetland plants in the upper reaches of the Qin River can be divided using the interspecies relationships and water conditions of the dominant species,which could be divided into functional groups of aquatic plants,functional groups of wet plants,functional groups of mesophytes,and functional groups of mesoxerophytes.It was found that the species correlation between herbaceous plants on the wetlands in the upper reaches of the Qin River was relatively weak,which was due to the larger differences in the ecological environment of the selected sampling sites.(4)The ecological niche of wetland vegetation:The Levins index and Shannon-Wiener index were used to measure the ecological niche breadth of40 dominant species on the wetlands in the upper reaches of the Qinhe River.The results reflected the capability of herbaceous plants being adapt to the environment and their competitiveness,and reflected the status of each plant species in the plant community.The plants such as setaria viridis,commelina diffusa,polypogon fugax,artemisia apiacea,euphorbia pekinensis and viola prionantha were all generalized species(generalists),occupying a wider range of ecological niche,and meanwhile it was shown that the ecological characteristics on the wetlands in the upper reaches of the Qinhe River were not similar and the coexistence relationship was inconspicuous.