Differential adaptation of lianas and trees in wet and dry forests revealed by trait correlation networks

Abstract

The single functional differentiation of lianas and trees has been explored at both local and regional scales. Traits are not independent of each other, and the differentiation and integration of the multiple traits of lianas and trees under contrasting environments remain unclear. We used trait correlation networks to distinguish the topological relationships of multiple traits of lianas and trees in dry versus wet forests. We evaluated 17 plant traits of 16 liana and 16 tree species. Compared with trees, the trait networks of lianas were more modularized in both wet and dry forests, indicating that these fluctuating environments were less influential on lianas compared to trees. In the wet forest, economic traits showed higher connectedness in lianas whereas hydraulic traits were more connected in trees. Thus, it was cost-effective for plants to increase the connectivity of specific key traits when resource conditions were poor. The number and composition of trait modules varied with life form and environmental conditions, with alternative designs being common for plants to cope with their local environments. This study revealed plant adaptations can be improved through greater variation in trait correlations, providing new insights on why lianas are more abundant and diverse in highly seasonal forests.