The consistency and ecological importance of life history trade-offs in tropical trees and lianas.
Gilbert, Benjamin*,1, Wright, S. Joseph2, Kitajima, Kaoru3, Muller-Landau, Helene4, Hernandez, Andres2, 1 University of British Columbia, Vancouver, BC, Canada2 Smithsonian Tropical Research Institute, Panama City, Panama3 University of Florida, Gainesville4 University of Minnesota, Twin Cities
ABSTRACT- Life-history trade-offs in growth and survival were quantified for 58 species of woody seedlings and augmented with existing data on tree saplings (10 mm < dbh < 39 mm) from Barro Colorado Island (BCI), Panama. We evaluated the general applicability of a rapid growth to low survival trade-off across two functional groups (lianas and trees) and for two life stages (seedlings and saplings, for trees only). A species' relative position on the trade-off gradient was correlated to two other traits in trees --wood density and fecundity-- and was likewise correlated to species' gap preferences. Lianas showed trade-offs similar to trees, with these groups demonstrating broadly overlapping ranges in survival and relative height growth as seedlings. Trees were tested for ontogenetic shifts in life history trade-offs; only two out of 15 species demonstrated shifts in their growth and survival trade-off patterns between seedling and sapling life stages. The relative positions of tree species on the trade-off gradient were correlated to their abundances in this community. In the case of the two species showing ontogenetic shifts, abundances were more strongly correlated to seedling trade-offs than sapling trade-offs. Our results indicate that life-history trade-offs are applicable across functional groups (lianas and trees), are mainly consistent across life-stages (within trees), and likely play an important role in determining plant species composition in forests.′
Key words: life history, lianas, trade-offs, tropical forests
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