Tropical forests are essential components of the earth system and play a critical role for land-surface feedbacks to climate change. These forests are currently experiencing large-scale structural changes of which the most apparent may be the increase in liana abundance and biomass. The first study that documented liana proliferation in the Neotropics (1) was initially debated but later confirmed by multiple other studies (2). The consensus on liana proliferation led to speculations that this phenomenon could potentially have large impacts on the carbon cycle of tropical forests. But experimental proof for such speculations was lacking until recently.