Estratégias ecológicas e atributos funcionais de espécies lenhosas de floresta de restinga.

Abstract

The ecological performance of a species in a given ecosystem is related to its functional traits, that is, its morphophysiological characteristics which gives them the ability to grow, colonize, survive and reproduce in an environment. In resource-poor environments with adverse environmental conditions, such as the restinga, the plants present ecological strategies to optimize the acquisition and use of resources. In view of this the CSR theory points out three main types of ecological strategies in plants: competitors ("C"); tolerant stresses ("S") and ruderals ("R"). The objective of this work was to evaluate: i) which are the functional traits most associated with the plants ecological strategies; ii) what are the CSR strategies used by dominant species in restinga environments; iii) do the functional traits or percentage of CSR strategies explain species abundance? The study was carried out in a restinga forest on the island of Algodoal, Maracanã, Pará. In order to answer these questions, we evaluated three sets of functional traits in nine (9) abundant species in the studied arca: leaf traits (specific leaf arca - SLA, leaf dry mass content - LDMC e succulence - SUC); stem traits (wood density - WD, xylem vessel arca- VA and vulnerability index - VI); and physiological (turgor loss point - TTLP, modulus of elasticity - C and leaf capacitance - CFT). We tested if there were correlations between the analyzed attributes and if there were species groups based on their functional traits. We also calculated the relative proportions of CSR strategies using the StrateFy tool. The species of restinga forest, according to the CSR model, are highly stress tolerant (S / CS), some species are also competing (CS) and present different sets of attributes that influence their performance. In that, there is a variation firom species with traits that guarantee a high environmental resistance, showing traits related to structural defenses (high LDMC and WD), to species that invest in attributes that guarantee higher capacity of water storage (high SUC and C). Furthermore, there are species with a tendency to acquisitive strategies (high VA and SLA). The percentage of CSR did not explain the species abundance in restinga. Our results showed that despite the convergency in CSR strategies, there are a diversity of traits that give stress tolerance and competitive hability.