Morphological variation of Laguncularia racemosa (L.) C. F. Gaertn. (Combretaceae) in mangrove areas and in transition areas between mangrove and restinga forest

Abstract

Adaptive responses to the interaction of abiotic factors that operate at different spatial and temporal scales may reflect on the distribution of species, due to their interaction with the environment. This study aimed to check differences in the structure of individuals between populations of Laguncularia racemosa (L.) C. F. Gaertn. (Combretaceae) distributed in mangrove areas and in transition areas between mangrove and restinga forest, using leaf morphological characteristics and plant architecture. Environmental variables were analyzed, such as soil nutrients and salinity level. The transition area showed lower salinity of pore water and soil pH, probably due to the high levels of aluminum. Laguncularia racemosa individuals in the mangrove area had larger leaves than the population in the transition area, with larger leaf area, specific leaf area, and leaf density, and smaller leaf volume. In mangrove, L. racemosa individuals had higher height and basal trunk diameter and lower canopy density and percentage of leaves subject to herbivory, but a higher number of senescent leaves. Such results may be related to the contrasting environmental conditions and significant differences in water salinity and soil nutrients.