Aspectos anatômicos e fisiológicos de folhas de mimosa scabrella de áreas com diferentes graus de sucessão

Abstract

This study aims to evaluate the influence of light conditions at different stages of succession in leaves of Mimosa scabrella Benthan planted in Iraí's water reservoir margins, State of Paraná, Brazil. We evaluated leaf morphology (area, dry weight, specific area), anatomy (cuticle thickness, adaxial epidermis, palisade parenchyma, parenchyma spongy, adaxial epidermis and total thickness), physiology (photosynthesis rate, stomatal conductance, transpiration) and plant growth (height, diameter) and survival up to age of 18 months. Plants of Mimosa scabrella of natural regeneration showed greater leaf specific area than those of planted individuals. Significant differences were found on thickness of the adaxial epidermis and palisade parenchyma. The adaxial epidermis was higher in regenerating area, whereas the palisade parenchyma was higher in open field. Plants of open field presented higher values of transpiration and stomatal conductance. Concerning height and diameter growth, plants of both areas showed no significant differences. Survival was considered unsatisfactory for both areas, but was slightly higher in regenerating area. According to M. scabrella behavior in natural conditions, the results suggest that this species must be implanted in greater densities.