Climbing mechanisms as a central trait to understand the ecology of
lianas -- a global synthesis.
Abstract
Lianas are a distinctive component of tropical forests and their
increase in abundance may have profound ramifications for forest
composition and ecosystem functioning. However, so far, the current view
considers lianas as a single, functional plant type and, therefore,
ignores the life history differences among species resulting from their
climbing mechanisms. Here, we integrate data from the main functional
traits used to characterize plant form and function with global
abundance data to reveal that lianas consistently have differences
associated with their main climbing mechanisms. Overall, lianas with
active climbing were characterized by an acquisitive strategy, showing
higher specific leaf area, foliar nitrogen and slightly higher
(marginally significant) maximum photosynthetic rates compared to lianas
with passive climbing. Using structural equation modeling, we show that
across the tropics the abundance of lianas with active climbing is
mainly determined by forest structure (stem size distribution). Our
study shows that active and passive climbing lianas clearly diverge in
their functional traits and factors affecting their distribution. We
conclude that a shift in the current view, where lianas are considered a
single, functional plant type, is urgently needed to increase our
predictability of their effects on tropical forests in the future.