ASSESSMENT OF PLANT DIVERSITY IN HEAVY METALPOLLUTED AREAS OF THE XIKUANGSHAN MINING REGION, HUNAN PROVINCE

. Taking plant communities in heavy metal-polluted areas as the research subject, this study analyzed the species composition, diversity, and dominant species differences in plant communities within the Xikuangshan heavy metal-polluted area using the typical sampling method. The results indicated that in the heavy metal-polluted area, Gramineae and Compositae were the dominant families, comprising 8 genera and 9 species, and 8 genera and 11 species, respectively. Herbaceous plants dominated the plant communities in the heavy metal-polluted area, accounting for 70.77% of the total. The number of plant families in lightly, moderately, and heavily polluted areas significantly decreased with increasing pollution levels, and monotypic families and monospecific genera became increasingly scarce. The 54 genera of seed plants in the area could be classified into 11 distribution types, with the pantropical and cosmopolitan distribution types containing the largest number of genera, accounting for 42.59% and 24.07%, respectively, indicating distinct tropical characteristics. The Margalef richness index, Shannon-Wiener diversity index, and Pielou evenness index of plant communities in lightly, moderately, and heavily polluted areas showed no significant differences with in creasing pollution levels. The β -diversity results revealed a certain negative correlation between the degree of heavy metal pollution and plant community species similarity; the greater the change in pollution level, the lower the community similarity. The findings of this study provide a theoretical basis for formulating science-based restoration and protection strategies in the region.