Plasticidade morfofisiológica em Banisteriopsis argyrophylla (A. Juss) B. Gates: uma liana de comum ocorrência em Florestas Estacionais Semideciduais

Abstract

Lianas are frequently found in high light environments such as gaps, forest edges and fragmented environments. The species Banisteriopsis argyrophylla, common in semideciduous tropical forests (FES), was identified on the edges of an environmental fragment in the city of Uberlândia - MG. The individuals of the species had leaves exposed to the full sunlight and to the shaded environment. Thus, the morphophysiological plasticity of this species was evaluated by analyzing leaves exposed to the sun and leaves in the shade. Physiological and morphological measurements were performed, as well as measures on the anatomical characteristics in leaves of five individuals of B. argyrophylla. The leaves of the sun presented higher values in almost all the evaluated measures, which the net CO2 assimilation rate (ACO2) and the transpiration rate (E) obtained higher values in relation to the shade leaves. However, stomatal conductance (gs) did not differ significantly between the two leaf types. Regarding the morphological characteristics, the mesophyll thickness, the palisade parenchyma thickness and the spongy parenchyma thickness were superior in sun leaves when compared to shade leaves, while the adaxial epidermis thickness and abaxial epidermis thickness did not differed. The physiological traits demonstrated greater plasticity than morphological traits, indicating the B. argyrophylla species presents greater physiological plasticity in relation to the morphological plasticity.