Lianas reduce tree height across the tropics

Abstract Lianas are a defining component of tropical forests. Yet their influence on tree architecture, particularly height—a fundamental dimension of forest structure—remains unresolved, with only fragmentary and localised evidence. In this study, we quantify the effect of liana infestation on tree height using a pantropical dataset of 50,473 individual tree height and liana occupancy observations across 66 sites, by fitting hierarchical allometric tree height models. We show that liana-hosting trees are consistently shorter than individuals of the same stem diameter that do not bear lianas. Further, tree height suppression scaled with liana occupancy, with heavily infested trees (>50% occupancy) being suppressed about twice as much as moderately infested trees. We further reveal that the magnitude of liana-induced tree height suppression increases with temperatures and rainfall seasonality. Our results indicate that liana-induced tree height suppression is likely to intensify pantropically under climate change.