Prevalence and climatic correlates of caulifory in tropical forests

Background/Question/Methods

Caulifory is a condition found in trees and woody vines where the reproductive structures are borne on the trunk or main branches. Cauliflory is widespread in tropical forests but rare in temperate regions. Cauliflory is interpreted as a strategy for plant species to present their flowers and fruits to understory pollinators and dispersers. We used tree data from large tropical forest census plots in the Center for Tropical Forest Science network to investigate the prevalence of cauliflory among free standing trees of dbh>=1.0 cm. We investigated correlations between the level of cauliflory in the plot trees and various environmental variables.

Results/Conclusions

The number of cauliflorous taxa and their abundance varied among sites. The 50-ha plot in Cameroon comprised 38 cauliflorous species in 18 genera and 13 families, accounting for 22% of the total number of stems, while the Barro Colorado Island Plot in Panama had two cauliforous species in two genera and two families, accounting for only 0.6% of the total stems. All but three of the cauliforous species were treelets or understory trees, indicating that cauliflory in tropical forests is predominantly a condition of tree species that complete their life cycle in the forest understory. We compare these results to those from 11 other sites across a range of climatic variables in tropical forests.