Guangxi Zhiwu (Mar 2023)
Relationship between aboveground biomass and environmental factors of typical karst secondary forest in Tianlong Mountain, central Guizhou
Abstract
In order to explore the relationship between the aboveground biomass of karst secondary forest land and environmental factors, we took the typical secondary forest sample of karst Tianlong Mountain in Puding County, Central Guizhou as the research object, adopted the aboveground biomass model of single species and different diameter groups to calculate the biomass of dominant species and community, used the spatial distribution map to describe the spatial distribution of environmental factors and aboveground biomass of community, and used the correlation test (Pearson) General linear model (GLM) and redundancy analysis (RDA) to discuss the relationship between community, life form, species aboveground biomass and environmental factors. The results were as follows: (1) The total aboveground biomass of karst secondary forest group was 106.94 t·hm-2, and the aboveground biomass of dominant species accounted for 91.77% of the whole sample plot. The aboveground biomass of evergreen plants was higher than that of deciduous plants. The aboveground biomass of Lithocarpus confinis and Platycarya strobilacea accounted for the highest proportion in the community, 34.23% and 34.37% respectively. (2) The spatial distribution of rock exposure rate showed obvious upper and lower gradient difference, the upper slope was significantly greater than the lower slope, and the spatial distribution of slope and soil thickness was discontinuous and had no obvious law. (3) There was a significant positive correlation between aboveground biomass and soil thickness, and their spatial distribution tended to be consistent. Soil thickness was the main influencing factor of aboveground biomass of the community, and the influence of rock exposure rate and slope on aboveground biomass of the community was low. (4) For different life forms, the influence of rock exposure rate on aboveground biomass was the highest, and the influence of soil thickness and slope on evergreen plants was greater than that of defoliation. (5) For different species, the correlation between environmental factors and aboveground biomass was complex. Most species were positively correlated with soil thickness. Platycarya strobilacea and Zanthoxylum dimorphophyllum var. spinifolium were positively correlated with rock exposure rate and slope respectively. In conclusion, the vegetation restoration of secondary forest in the study area is slow, and soil thickness is the main influencing factor of aboveground biomass of the community. However, for different life forms and species, the response of aboveground biomass to the environment will be affected by biological factors such as life form differences, species habitat preferences and interspecific relationships.
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