Spatial distribution by Canistropsis microps (E. Morren ex Mez) Leme (Bromeliaceae: Bromelioideae) in the Atlantic rain forest in Ilha Grande, Southeastern Brazil

Af Nunes-Freitas,Cfd Rocha

doi:10.1590/s1519-69842007000300011

Abstract

Canistropsis microps (Bromeliaceae: Bromelioideae) is an endemic species of Atlantic rain forest areas in Rio de Janeiro State, which are very abundant in not very disturbed forests in Ilha Grande, on the southern coast of the State. In this study, we analyzed the vertical and horizontal distribution patterns of the species in an area of rain forest with little evidence of disturbance at Vila Dois Rios, Ilha Grande, relating the patterns to sunlight in the microhabitat. We also identified the types of substrate used by the species and the rate of asexual reproduction. Canistropsis microps had high densities (estimated at 84,425 rosettes/ha), and has an aggregated distribution (Id = 2.86). About 80% of the rosettes were generated by clonal growth, whereas less than 20% were produced from seedlings. Most of the rosettes were found on straight tree trunks (DBH > 50 cm). There was a significant inverse correlation between the incidence of sunlight in the habitat and the abundance of individuals. Rosettes were found up to a maximum height of 9.5 m, but most occured between 1.5 and 5.5 m, where light varied from 25 to 50 micromol x s(-1) x m(-2). We conclude that vertical and horizontal distribution patterns in C. microps may be partially explained by the occurrence of appropriate substrate, an intensity of sunlight favorable to the development of the species and to a high rate of vegetative reproduction.

Highlights

The success of a plant species in the colonization of a habitat and in the occupation of a substratum type, resulting in the configuration of a certain pattern of space distribution, can be explained by the interaction of a group of factors, both intrinsic and extrinsic to the species
We investigated the spatial distribution of Canistropsis microps, vertically and horizontally, relating its frequency of occurrence with light in the forest habitat
In a study comparing the populations of different bromeliad species in the same area, Almeida et al (1998) found that C. microps was the bromeliad species with the highest density, which is corroborated by our data

Summary

Introduction

The success of a plant species in the colonization of a habitat and in the occupation of a substratum type, resulting in the configuration of a certain pattern of space distribution, can be explained by the interaction of a group of factors, both intrinsic and extrinsic to the species. The type of reproduction, the capacity and form of dispersion (Silvertown, 1987), the metabolic capacities of the species (Martin, 1994) and the life form (Benzing, 1980) can be mentioned. The combined action of extrinsic and intrinsic factors, or the interaction among some of them, determines the success of the establishment of a given plant species

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Conclusion