Biomass allocation and shade tolerance in tree species of the Atlantic Forest

Light availability is an important factor determining plant morphology and niche occupation in tropical forests. In this study, we tested whether seedlings that differ in shade tolerance also differ in the way they partition their resources among stems and leaves. The morphology of the first pair of leaves (eophylls), cotyledons, stems, and seeds of 14 species (five shade tolerant and nine gap dependent) from the Atlantic Rainforest (Brazil) were analyzed. Significant differences were observed in the patterns of biomass allocation between the two ecological groups; shade-tolerant species invested more in total biomass, cotyledons, and leaves, whereas gap-dependent species allocated more biomass to stems and vertical growth. In conclusion, shade-tolerant and gap-dependent species invest more in photosynthesis and vertical growth, respectively. Apparently, these characteristics specific to each group are not related to the life history of the species studied but to the strategies developed to the environment in which they were inserted.