Abstract: Aims Lianas are a crucial component of tropical forest ecosystems. The prevalence of lianas can significantly restrict tree growth and biomass accumulation. However, the extent of liana prevalence among forest trees and the underlying factors contributing to this pattern remain insufficiently understood. This study investigates the effects of environmental factors and tree diameter variation on liana prevalence across different tropical forest types in Xishuangbanna. Methods The study utilized 21 one-hectare forest dynamic plots in Xishuangbanna to examine liana prevalence by analyzing the role of environmental factors associated with liana prevalence, conducting cross-comparisons of liana prevalence across tree diameter classes and forest types, and exploring the trend of liana prevalence with respect to tree diameter at breast height (DBH). Important findings The liana prevalence was highest in tropical seasonal moist forests (TSMF) (27.8% ± 9.2%), followed by tropical rainforests (TRF) (25.2% ± 10.6%), and lowest in tropical lowland evergreen broad-leaved forests (TLEBF) (12.5% ± 10.7%). The primary environmental factors influencing liana prevalence included Climate Principal Component 1, which had positive loadings for temperature-related variables such as the minimum temperature of the coldest month, the mean temperature of the coldest quarter, and the mean temperature of the driest quarter; Soil Principal Component 2, which was negatively associated with nutrient factors like total carbon concentration, total nitrogen concentration, and hydrolyzable nitrogen concentration; and Soil Principal Component 3, which was primarily loaded with total potassium concentration. In all forest types, liana prevalence increased with tree diameter at breast height (DBH). Castanopsis indica exhibited liana prevalence of 54.3% in TRF and 40.6% in TLEBF, while Markhamia stipulata showed liana prevalence of 38.2% in TLEBF and 55.6% in TSMF. Additionally, Mallotus barbatus and Mallotus philippensis exhibited liana prevalence of 43.9% and 75.8%, respectively, in TRF and TSMF. This study examined the variation patterns of liana prevalence in the tropical forests of Xishuangbanna in relation to environmental factors and tree diameter. It provided new scientific insights into the relationships among liana prevalence, vegetation types, and environmental factors in tropical forests, contributing to the sustainable management and conservation of these ecosystems in the context of global change.

Key words: Liana prevalence, Tropical forests, Environmental gradients, Tree diameter gradients