Ecofisiofiologia de cinco espécies da mata atlântica de diferentes grupos funcionais sob condições distintas de luminosidade em unidade de restauração ecológica

Abstract

Ecological restoration actions are carried out when the environment has its resilience compromised in function of a degrading action. By incorporating concepts and theories from other sciences, the Ecology of Restoration aims to provide the restored environment with self-perpetuating conditions, for which one of the critical aspects is the selection of suitable species to compose these projects, since the success restoration is linked to their performance and capacity to field conditions. know the plant responses to environmental variations then becomes essential. In this sense, it constitutes as the objective of this work, to evaluate the responses of different conditions of luminosity in the development of five species of different functional groups, based on successional groups. For this purpose, pioneer species of filling lines were studied, Dictyoloma vandellianum and Schinus terebinthifolius, and non-pioneer species from diversity lines, Spondias mombin, Astronium fraxinifolium, Caesalpinea echinata. Gas exchanges, chlorophyll a fluorescence, contents of of pigments and relative growth rates, for the five species under shading conditions partial (SO) and full sun (PS). The species showed different behaviors among themselves, and in function of the treatments, so that there was an increase in the rates of net carbon assimilation, under higher radiation levels. The species responded with photosynthesis rates consistent with the successional groups to which they belong. Only Schinus terebinthifolius, a pioneer species, presented influence of the environment on the contents of chlorophyll a, b, and total, indicating the strategy of the species to adapt to environments with less availability of light. Astronium fraxinifolium and Dictyoloma vandellianum, showed a higher concentration of carotenoids under full sun conditions. there was not concentration pattern of pigments relative to the functional groups to which the species belong. To the species did not differ among themselves, and depending on the treatments for the fluorescence variables of the chlorophyll a, indicating mechanisms of prevention, against excesses of luminosity and thus, damages to the photosynthetic machinery. The species responded in growth rates in height and diameter, as expected for diversity and fill lines, so fill species exhibited greater increments in both conditions, in relation to species diversity, photo proven by contracting growth of Caesalpinea echinata, climax species and Schinus terebinthifolius pioneer species. The largest increments were verified in all species when they developed in the partially shaded condition, which denotes characteristics inherent to the non-pioneer species, with better development under shading conditions, and possible rapid growth strategy of Dictyoloma vandellianum and Schinus terebinthifolius aiming escape of this condition.