Climate and soil mediate the effects of liana density on forest dynamics

Abstract

Forest community dynamics is a topic of great interest in times when the global carbon budget is a widespread concern due to climate change. Among its effects, longer periods of drought and liana proliferation, coupled with land use change, may endanger tropical forest carbon sinks. Here, in a 10.3 ha sampling of six Atlantic semideciduous forests, we investigated the effects of liana crown occupancy and large-stemmed lianas, as well as their interactions with climate and soil, on forest dynamics. We expected that harsh environmental conditions would enhance the negative effects of lianas on forest productivity. Our hypothesis was corroborated by the findings that the positive effect of lianas on tree mortality increases under drier conditions, as well as their negative effect on tree recruitment. In addition, liana crown occupancy was the best predictor of net aboveground woody biomass productivity, which decreases as liana crown occupancy increases. Our study provides additional evidence of indirect climate change impacts on the tropical forest carbon sink by increasing the negative effects of liana crown occupancy on tree biomass productivity.