Biodiv Sci ›› 2022, Vol. 30 ›› Issue (11): 22025.

• Original Papers:Plant Diversity •

### Effects of environmental factors on quantitative characteristics of woody plant sexual system in Maolan karst forest

Moxu Wu1,2, Mingtai An1,2,*(), Li Tian1,2, Feng Liu1,2

1. 1. College of Forestry, Guizhou University, Guiyang 550025
2. Research Center for Biodiversity and Nature Conservation, Guizhou University, Guiyang 550025
• Received:2022-01-13 Accepted:2022-06-23 Online:2022-11-20 Published:2022-09-29
• Contact: Mingtai An

Abstract:

Aims: Plant sexual systems play an important role in community regeneration, adaptability and future development. The purpose of this study is to clarify the quantitative characteristics of karst forest sexual systems and its relationship with environmental factors.

Methods: In this study, the adjacent grid method was used to establish 11 vertical plots from the foot to the top of Baixian Mountain in Maolan and 21 horizontal plots from the middle of the mountain, along the same contour line. The quantitative characteristics of woody plant sexual systems with DBH greater than 1 cm in the sample plots were characterized and analyzed. An independent sample t test was used to analyze in the number and sexual system of plants in the sample plots. Redundancy analysis (RDA) was conducted to explore the correlation between quantitative characteristics of sexual systems and environmental factors.

Results: In the sample plots, there were 14,622 woody plants of 286 species. These species are composed of 156 hermaphroditic (54.5%), 57 monoecious (20.0%) and 73 dioecious (25.5%) species. Vertical sample plots located at higher altitude had a significantly greater number of monoecious species and significantly lower proportion of bisexual species. While sample plots located on the mountain slope had a lower diversity of plant sexual systems. In the horizontal sample plots, there were no obvious patterns observed among the number of individual of plants, species proportion and sexual system diversity index of hermaphrodite plants, monoecious plants and dioecious plants. Independent sample t test showed that there were significant differences in the number of plants and the species proportion between the vertical sample plot and the horizontal sample plots (P < 0.05), but no significant differences were observed in the number of plants nor the proportion between dioecious and hermaphrodite species. RDA showed that environmental factors influence the quantitative characteristics of different sexual systems. Altitude had an extremely significant (P < 0.01) effect and slope position was significant as well (P < 0.05).

Conclusion: The woody plant sexual systems in Maolan karst forest are different from other areas in aspects of richness, diversity, and complexity. Most species populations of woody plant are small and their quantitative distribution characteristics may be the result of adaptation to the heterogeneity of karst habitats.