| Wetlands belong to the junction of land and water and have high research value.Subalpine swampy meadows are wet with perennial or seasonal stagnant water,which is suitable for the survival of wet-loving wild animals,and has a wide water area,rich plant resources and important ecological functions.In this study,the subalpine swamp meadow wetland in Xundian Black-necked Crane Provincial Nature Reserve,Yunnan Province was taken as the research object,and the characteristics and diversity of wetland vegetation community,soil physical and chemical properties,soil enzyme activity and soil microbial community were investigated in March,June,September and December,2021,respectively,the vegetation-soil characteristics and changing rules of Xundian wetland in different seasons,and enrich the basic data of vegetation and soil research in subalpine swamp meadow wetland.It has important guiding significance for in-depth study of wetland ecosystem and wetland protection and maintenance of biodiversity.The main research results are as follows:(1)There ara 23 families,55 genera and 68 species of vegetation in Xundian Black-necked Crane Provincial Nature Resrve.Among them,Gramineae plants account for 16.8% of the total apecies,followed by Asteraceae with 13.24%.There are10 single genera and 1 species(that is,1 family in 1 genus and 1 species),accounting for 14.7% of the total number of species.(2)The vegetation coverage of Xundian Black-necked Crane Provincial Nature Reserve varies from 79.67% to 93.50%,and the plants are short as a whole.The average height of the community is 9.78 cm in September,and it is 3.30～3.89 cm in other seasons.Vegetation community height,coverage,density and grass yield all showed the trend of September > December > June > March.(3)Shannon-Wiener index and Margalef index of the vegetation community in Xundian Black-necked Crane Provincial Nature Reserve were the highest in September,Simpson index and Menhinick index showed a trend of March >September > June > December,while the average value of Pielou index in four growth months was between 0.83 and 0.86,with no obvious change.(4)Soil urease activity in Xundian Black-necked Crane Provincial Nature Reserve showed a trend of June > December > September >March.Sucrase activity was March > June > September > December.The activities of catalase and protease were the highest in March.The activity of acid phosphatase was the lowest in March.(5)The variation range of soil p H in Xundian Black-necked Crane Provincial Nature Reserve is 3.66～5.02,which is acidic soil.Soil organic matter,organic carbon,total phosphorus,total potassium,p H and water content were the highest in December.The contents of total nitrogen and available potassium were the highest in March.The content of soil organic matter and organic carbon showed a trend of December > September > March > June.The total phosphorus content showed a trend of March > September > December > June.The available phosphorus content showed a trend of December > June > March > September.The total potassium content showed a trend of December > March > June > September.The trend of available potassium content is March > June > September > December.Soil total phosphorus leaching is serious,and soil nutrients are generally low.(6)The number of soil microorganisms in Xundian Black-necked Crane Provincial Nature Reserve showed the trend of bacteria > actinomycetes > fungi.The number of bacteria showed a trend of June > September > December > March.The number of fungi and actinomycetes showed a trend of September > June >December > March.There was no significant difference in microbial diversity(7)index,among which Simpson index,Shannon-Wiener index and Pielou index were the highest in September and December.Margalef index and Menhinick index reached their highest values in June.(8)The height and density of plant community in Xundian Black-necked Crane Provincial Nature Reserve are positively correlated with soil water content and organic matter.Soil total phosphorus is positively correlated with Simpson index,Pielou index and Menhinick index of vegetation.There is a significant positive correlation between soil enzyme activity and soil organic matter.Soil water content is positively correlated with the activities of sucrase,catalase and protease.There was a significant possitive correlation between the number of soil mircoorganisms,fungi and bacteria and the coverage of vegetation community coversge;Soil microbial Shannon-Wieren index was positively correlated with vegetation community density,negatively correlated with soil invertase,and positively correlated with acid phosphatase activity.Organic matter and total phosphorus are the key factors limiting the growth and development of plants in nature reserves,and grass yield is very important to the characteristics of vegetation community and soil enzyme activity. |
