Morphological and physiological adjustments of Brazilwood (Caesalpinia echinata Lam.) to direct solar radiation

Abstract

ABSTRACTThis study aimed to characterize the alarm and resistance phases of stress of Caesalpinia echinata under intense irradiance in order to better define its position on forest succession. The alarm phase was identified by rapid reduction in the maximum quantum yield of PSII primary photochemical reactions (φP0 = F V /F M ) and Performance Index (PI ABS ) followed by total leaf abscission in the first week of exposure to direct sunlight. The new leaves grown showed recovery of chlorophyll a parameters, in…