Differential effects of lianas on population growth rates of tropical forest trees

Background/Question/Methods

Lianas are increasing in relative importance throughout the neotropics. Lianas dramatically reduce tree performance along all ontological stages. However, no previous study has examined to what extent lianas alter tree population growth rates and community composition. Here we tested whether lianas have stronger negative effects on the population growth rates of some tree species than on others, which is a prerequisite to lianas altering tree community composition and tree species diversity. We utilize an exceptionally large and long-term dataset from Barro Colorado Island in Panama and construct integral projection models for 33 tropical forest species. With these we quantify the net negative effects of liana infestation on tree population growth rates.

Results/Conclusions

Our results show that tree species have different degrees of tolerance to lianas, with fast-growing species being especially more sensitive to liana infestation.  This demonstrates that lianas can have a strong differential effect on tree species and that ongoing increases in liana abundance may cause shifts in the functional composition of tropical tree communities.