Leaf herbivory and monodominance in a Cerrado–Amazonia transitional forest, Mato Grosso, Brazil.

Monodominant tropical forests occur on several continents, including the Brazilian Amazon. In this study, we tested the hypothesis that seedling escape from leaf herbivory contributes to the maintenance of the monodominantBrosimum rubescensforest. The study was undertaken both in a monodominant forest ofB. rubescensand in an adjacent seasonal forest in the transitional zone between the Cerrado and the Amazonian forest biomes. Percentage of leaf area damaged and herbivory rates were evaluated on young and mature leaves of seedlings ofBrosimum rubescens,Protium pilosissimumandTetragastris altissimain the understory and in the gap between the monodominant and seasonal forests. Little evidence of any significant relationship between leaf herbivory and seedling density indicates that the monodominant species does not follow the hypothesized pattern of an intensive herbivore attack in areas of higher seedling density. The escape ofBrosimum rubescensfrom herbivore pressure under conditions of high seedling density may be part of a set of conditions that determine the maintenance of this monodominant forest. [ABSTRACT FROM AUTHOR]