Atributos ecofisiológicos de Erythroxylum pauferrense Plowman (Erythroxylaceae)

Abstract

The effects of seasonality may provide peculiar conditions in sub-forest species, since these have limitations on the availability of light. Based on this, a study was carried out to verify and evaluate the gas exchange of Erythroxylum pauferrense, a species of endemic sub-forest located in the northeastern region of Brazil. This work was divided in two chapters: I) The first one has the objective of evaluating the gas exchange of the species E. pauferrense in relation to the seasonal variation (dry and rainy period). In a remnant of the Atlantic Forest, 10 individuals of the species were selected. Irradiance, relative chlorophyll terrors, soil moisture, and physiological parameters such as photosynthetic rates, internal carbon, transpiration, stomatal conductance and leaf temperature were also verified , All these attributes were evaluated in rainy and dry periods. It was observed that there was no significant difference in attributes during the periods evaluated except for stomatal conductance, transpiration and leaf temperature. II) In the following chapter the objective of this work was to evaluate 12 allometric equations to estimate the leaf area using the leaf blade measures and to verify which of these would be the best to estimate the leaf area of the E. pauferrense species. In order to perform this research, 600 leaves were collected and twelve theoretical models were tested using combinations of length and width dimension variables and respective leaf area values. Among the models that best estimate the leaf area of Erythroxylum pauferrense were the equations of the linear model and power since, the models showed normality in the distribution of the errors, the two equations prove to be good models for the estimation of leaf area of the species Erythroxylum pauferrense. Therefore, these studies provided important information regarding the physiological mechanisms and contributed to promising studies of the species, besides providing subsidies for the knowledge of the species at the local level, and could thus contribute to the use of degraded areas recovery and to the increase Of floristic diversity.