Allometry of Caryocar brasiliense (Caryocaraceae) in differents physiognomies of the Parque Estadual da Serra de Caldas Novas, GO, Brazil

Abstract

The relationship between size and shape in trees is important for understanding adaptive differences of species. Variations in these characteristics reflect the environmental conditions they are exposed to, being a response to the particular stress experienced by these individuals. Within this context, the present study aimed to analyze the allometric relation of two populations of Caryocar brasiliense Camb, present in two different physiognomies (cerradão and cerrado stricto sensu) of the Parque Estadual da Serra de Caldas Novas (PESCAN), located in the State of Goiás. Within each researched environment 30 individuals of C. brasiliense with diameter larger or equal to 15 cm from 30 cm up ground were sampled. The diameter from 30 cm up ground (DAS30), the breast height diameter (DAP), total height and shaft height was recorded to each individual. For the correct analysis of this data, different models of regression were set. We found that the relation DAP/ DAS between the two environments were distinct, revealing a variation in the shape of the stem between the two environments. In the cerrado s.s. the trees presented a more conic shape, whilst in the cerradão, a more cylindrical stem was observed. Trees of C. brasiliense in the cerradão presented larger total height and shaft height than those of the cerrado s.s. due to, among other reasons, the competition for light in the environment. The occurrence of taller individuals suggests a larger investment in the vertical growth as a way of escape from the adverse conditions of the environment. The fact that individuals of Caryocar brasiliense adjust themselves to distinct allometric models, within each environment, suggests that the ecological factors may have a restrictive role in the allometry of this species.