When early successional species were excluded, the relationship among functional characters was more closely related to season of leaf production and light availability than to leaf longevity. Variation in functional characters across seasons and light environments was more continuous than discrete for each species. This project has been funded by NSF grants to S. Mulkey and S. J. Wright. Additional funding is being sought to expand this work with the new canopy crane in wet forest on the Atlantic side of the Isthmus of Panama. These unique life forms are rooted in the soil, but are parasitic on canopy trees for their access to sunlight and support.
Lianas compete for light with their host trees and displace the foliage of the host tree.
Despite their importance, lianas have received little study in tropical forests due to their inaccessibility in the uppermost canopy. Outstanding among the many questions that remain unexamined for lianas is their mechanism of water transport. Central to Avalos' dissertation are experiments to assess the degree of physiological flexibility shown by these remarkable plants, which traverse the entire range of light availability on their way to the top of the canopy.