Guangxi Zhiwu (Mar 2023)
Relationships among species diversity and soil enzyme activities and nutrient contents in tiankeng forests, Guangxi
Abstract
In order to study, the distribution characteristics and internal links of soil enzyme activities, nutrient content and woody plant diversity in negative topographic habitats of tiankeng, the tiankeng forests of the Dashiwei tiankeng group in Guangxi were selected as the object, and the relationship between species diversity and soil factors of woody plants was explored by correlation analysis and redundancy analysis methods, based on the community diversity survey and soil habitat survey along the inner area-top area-outer area of tiankeng. The results were as follows: (1) There were 21 species, 31 genera and 20 families of woody plants in the inside area of tiankeng, 91 species, 58 genera and 58 families of woody plants in the top area of tiankeng, and 47 species, 30 genera and 30 families of woody plants in the outside area of tiankeng. The Margalef index and Patrick index in the inside areas of tiankeng were significantly lower than those in the top and outside areas of tiankeng, indicating that the individuals of species increased, but the species distribution was steady. (2) The total soil nitrogen content in the outside areas of tiankeng was significantly higher than those in the top and outside areas of tiankeng. The soil total magnesium content, soil phosphorus content and soil available phosphorus content in the inside area of tiankeng were significantly higher than those in the top and outside area of tiankeng. The soil alkaline phosphatase content and soil urease activities in the outside area of tiankeng were significantly higher than those in the top and inside area of tiankeng. The soil phosphorus content in the tiankeng was higher, but the soil enzyme activities were lower. (3) The species diversity was strongly correlated with soil nutrients and soil enzyme activities. In conclusion, it can be seen that the habitats of the tiankeng have a great influence on the species diversity, soil enzyme activity and soil nutrient content distribution characteristics, and the soil available phosphorus content, soil alkaline phosphatase activity, soil moisture content, soil urease activity, soil total magnesium content and soil total phosphorus content are the key factors affecting the species diversity of woody plants in the tiankeng forest. The results provide a theoretical basis for the protection and reconstruction of plant resources in karst areas.
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