Tree plantations are used in the tropics for economic and ecological restoration purposes. Until recently, however, a large majority of plantations used non-native fast-growing tree species such as Tectona grandis, Acacia mangium, and Eucalyptus sp. As part of a new effort led by the Smithsonian Tropical Research Institute and Yale School of Forestry in Panama, 75 native and non-native tree species are being evaluated for their potential to re-establish tree cover on degraded pasture land. In this study we evaluated above-ground biomass partitioning of 21 native and 2 non-native tree species that were planted in two locations that differed in their average annual precipitation. These sites received approximately 2225 (wet site) and 1100 (dry site) mm rain yr-1. Total dry biomass was assessed using subsamples of leaves, branches and trunk biomass. Crown morphological traits were investigated, and included live crown ratio, photosynthetic/non-photosynthetic biomass and crown length/diameter.

Results/Conclusions There were no clear universal crown morphological traits that explained high biomass growth among tree species. However, all fast-growing species had a high life crown ratio and crown length/diameter ratio suggesting that light capture mechanisms are necessary traits for fast-growth. Moreover, some crown morphological differences found among tree species were related to size and not to site. Atchinson transformation was applied to eliminate this effect of size on crown traits. Transformed data showed significant differences for some crown traits between sites for a few species. Many native tree species showed good reforestation potential for timber production, restoration and on-farm systems.