Water Pattern And Species Diversity Conservation In The Process Of Vegetation Restoration In Mao Lan Karst

Biodiversity is an important material basis for human survival and development,and its rapid loss has hindered the sustainable development of the current society.Due to the increasing destruction of the ecological environment,the rate of extinction of species is accelerating,and the species diversity is seriously threatened.Especially in the Karst area,the ecology is fragile,and it is difficult to recover after the destruction of biological diversity.The forest vegetation in Karst forest in Maolan Karst region as the representative of the non zone,its distribution,native strong,compared with the same latitudes in normal forest landscape,higher species richness and heterogeneity.In the Karst area,the habitat is complex,the heterogeneity is high,the temporary drought is frequent,the water deficit is widespread,but still maintains the high species diversity.In this paper,the water pattern and species diversity of Karst community were studied,and the distribution pattern of soil water and species diversity in Karst were studied.The main conclusions are as follows:(1)The microhabitat types in Karst are complex and diverse,with abundant numbers and strong random distribution,and the number of rocky and stony habitats is dominant.(2)There were significant differences among species in different succession stages,and different plant species showed different substitution rates in succession.The variation of species substitution was most severe in the Shrub Stage and shrub stage,and the number of species increased and lost were 161 and 81,respectively.Alternative variation showed by woody plants,especially in shrub species,shrub stage,shrub and grass to forest to the top stage,the number of species increased respectively 132 and 109,the number of species lost respectively for 32,23.The change in the level of the top community,the farther away from the community,the greater the difference between species,the more the number of species increased and lost;vertical variation in the low altitude of the species substitution between species is higher than the high altitude.(3)The similarity of species in different succession stage,horizontal transect and vertical transect were the highest among the two adjacent stages(community),and the farther the community succession(or distance),the lower the species similarity.The similarity between different succession was shrub and Shrub Stage(0.463).At the same stage,there was little difference in the species similarity coefficient between the three habitats,but the value was higher than that in each stage.(4)The water content of the soil in different succession stages,and the water content of the stone ditch,the stone surface and the soil surface were the highest in the top stage,respectively,were 42.43%?51.67%?35.81%?39.82%.The standard deviation of soil water content in different succession stages was 4.41%~ 17.80%,the variation coefficient was 16.64%~ 61.14%,that is,moderate variation.At the same stage,the difference of soil water content between the three habitats was not obvious.The coefficient of variation of soil water content was 3.345%~20.300%,which was weak variation to moderate intensity variation.The coefficient of variation of soil water content was 2.74%~16.76%,that is,weak variation to moderate intensity variation.(5)The Simpson index(D),Shannon-Wiener index(H)and Pielou evenness(E)in different succession stages were the same,and the former was decreased firstly and then increased.Among them,the Simpson index(D),Shannon-Wiener index(H)were in the top stage(0.93,3.32),the smallest in the grass stage(0.59,1.30);Pielou(E)on evenness of rocky desertification stage(0.68),(0.30)the smallest grass stage.There was little difference in species diversity between different levels,and species richness,Simpson index(D)and species composition were consistent.With the increase of altitude,the species diversity of vertical transect increased first and then decreased.(6)The interpretation of the species distribution of the environmental factors,such as elevation,slope,slope direction and soil moisture content was 35.83%,of which,the contribution rate of soil water content was 5.19%().Slope and soil water content had a significant effect on the distribution of species,and the coefficient of soil water content was 0.9008.There was positive correlation between soil water content and species diversity coefficient in different succession stages,horizontal transect and vertical transect,but there was no significant difference between them.