Diversity And Calcium Utilization Of Terrestrial Mollusca Under Karst Landform In Guizhou

Terrestrial mollusca are an important type of wildlife resource,as well as an important part of biodiversity,with their wide range,wide distribution range and large population.They play an significant role in the conversion of substances,the change of soil composition and structure,and the maintenance of natural ecological balance.Although the survey of terrestrial mollusca has been carried out in some nature reserves in Guizhou,Yunnan and other places,it is limited to basic research on their species diversity and distribution.At present,no studies have been seen on the association between karst landforms and terrestrial mollusc.Based on the existing data of terrestrial mollusca samples in Guizhou Province,combined with field collection and surveys,the species composition and fauna distribution of terrestrial mollusca in Guizhou Province were systematically sorted out.The resource characteristics of terrestrial mollusca in Guizhou are preliminarily studied,and the diversity of terrestrial mollusca and their calcium utilization under the karst landform of Guizhou are discussed.We took random terrestrial mollusca samples in forests,shrublands and bamboo forests in non-karst areas of Landing Mountain and karst areas of Guibei Mountain.And then random sampling is carried out by ves(Visual Encounter Surveys)method.We analyzed the correlation between terrestrial mollusca species distribution and calcium content in different habitats within the collection site,and further explored the effects of different geologies on terrestrial mollusca species diversity by quantifying the species diversity index.In order to provide an significant reference for the study of calcium circulation in karst areas,as well as provide scientific support for species protection,habitat protection and karst rock desertification control.The main results are as follows:(1)There are 316 species and subspecies of terrestrial mollusca in Guizhou Province(including 13 undefined species)which belong to 2 subclass,4 orders,20 families,76 genera.The faunal analysis results show that the composition of the terrestrial mollusca fauna in Guizhou Province is mainly in the southwest region of the Eastern Ocean Boundary,followed by the South China region,and there are a small number of Palearctic species.There are 263 species distributed in the Eastern Ocean,accounting for about 83.23% of the total number of species;There are 13 species distributed in the Palearctic realm,accounting for about 4.11% of the total number of species;There are 16 species distributed across the Palearctic boundary of the East Ocean,accounting for about 5.06% of the total number of species;There are 11 widely distributed species,accounting for about3.48% of the total number of species,and 13 undetermined species,accounting for about 4.11% of the total number of species.(2)From the perspective of geographical distribution,the terrestrial mollusca in central region of Guizhou are the most abundant,with 17 families,54 genera,170 species;The second distribution area of terrestrial mollusca is in the sub-subtropical humid areas in southern Guizhou and the sub-subtropical areas in southwestern Guizhou,with 18 families,56 genera,152 species and 17 families,57 genera,150 species;There are only 10 families,18 genera,27 species in the eastern area of Guizhou.(3)From the perspective of the diversity of terrestrial mollusca in different geologies,terrestrial mollusca in the Landing Mountain and Guibei Mountain areas showed obvious differences in species number,Chanel index,Simpson index,Pielou uniformity index,and species richness.The number and species richness of terrestrial mollusca species in Guibei Back Mountain are also significantly higher than those in Landing Mountain.In summary,the species of terrestrial mollusca in Landing Mountain are rich but low in diversity,and the species in Guibei Mountain are sparse but highly diverse.(4)From the correlation between soil factors and terrestrial mollusca,the calcium content of soil and terrestrial mollusca in Guibei Mountain was significantly higher than that in Landing Mountain.Our results showed that there was no correlation between calcium content of terrestrial mollusca and soil organic matter content(P=0.8540).The soils of Guibei Mountain and Landing Mountain were alkaline and there was no obvious difference,and the p H value in alkaline soils has a very weak effect on calcium content of terrestrial mollusca.There is a close relationship between terrestrial mollusca and soil sample calcium content,and the calcium ion content of terrestrial mollusca increases with the increase of calcium ion content in soil.