Light‐demanding tree species are more susceptible to lianas than shade‐tolerant tree species in a subtropical secondary forest

Abstract

1. Tree-tree competition has been widely studied as a mechanism responsible for maintaining forest plant species diversity. Other common plant types, such as lianas, may influence tree species competition. Previous studies reported the negative effects of lianas on trees; however, variation in susceptibility to lianas among tree species and the species-specificity of liana species for tree hosts remain unclear. If lianas have species-specific interactions with trees, based either on tree or liana species identity, then lianas may influence tree-tree interactions by altering tree species-specific competitiveness.2. We surveyed 5676 lianas (DBH ≥ 0.5 cm) and 61,538 trees (DBH ≥ 1 cm) in a 12ha subtropical secondary forest plot to assess liana-tree interactions. We tested variation among the 20 most common tree species in their susceptibility to lianas, including whether light-demanding and shade-tolerant tree species differed. We quantified liana-tree network structure and evaluated the specificity between the 20 most common tree species and the 15 most common liana species. We expected that: (1) tree species would vary in their susceptibility to lianas, and the extent of this variation would be predicted by tree shade-tolerance; and (2) liana species would have distinct species-specific interactions with host trees.3. Tree species differed greatly in their susceptibility to lianas, with some tree species accumulating many more lianas than others. Light-demanding tree species particularly had greater susceptibility to lianas than shade-tolerant tree species.Both the liana-tree network structure and the interaction intensity between the 15 liana species and 20 tree species showed distinct specialization of liana-tree interactions.4. Synthesis. Variation in trees species' susceptibility to lianas implies that lianas may alter tree species-specific competitive abilities by disproportionately affecting some tree species more than others. In contrast to studies in neotropical forests, light-demanding tree species were more susceptible to lianas than shade-tolerant | 1657