Rare canopy species in communities within the Atlantic Coastal Forest in Rio de Janeiro State, Brazil

Abstract

Rare species are one of the principal components of the species richness and diversity encountered in Dense Ombrophilous Tropical Forests. This study sought to analyze the rare canopy species within the Atlantic Coastal Forest in Rio de Janeiro State, Brazil. Six diVerent communities were examined: Dense Ombrophilous alluvial Forest; Dense sub-montane Ombrophilous Forest; Dense Montane Ombrophilous in Serra do Mar and Serra da Mantiqueira. In each area the vegetation was sampled within forty 10 £ 25 m plots alternately distributed along a linear transect. All trees with DBH (1.3 m above ground level) ¸5 cm were sampled. The canopy was characterized using the allometric relationship between diameter and height, and included all trees with BDH ¸10 cm and height ¸10 m. A total of 64 families, 206 genera, and 542 species were sampled, of which 297 (54.8%) represented rare species (less than one individual per hectare). The percentage of rare species varied from 34 to 50% in each of the diVerent communities sampled. A majority of these rare trees belonged to the Rosidae, and a smaller proportion to the Dilleniidae. It was concluded that there was no apparent pattern to rarity among families, that rarity was probably derived from a number of processes (such as gap formation), and that a great majority of the rare species sampled were consistently rare. This indicates that the restricted geographic distribution and high degree of endemism of many arboreal taxa justiWes the conservation of even small fragments of Atlantic Forest.

Tree changes in a mature rainforest with high diversity and endemism on the Brazilian coast

“…This role of less abundant species in community dynamics has been confirmed by other studies (Ayyappan and Parthasarathy 2004;Werneck and Franceschinelli 2004;Guedes-Bruni et al 2009). …”

Evidence for conservation and sustainable use in a fragment of the Atlantic forest in southeastern Brazil by a traditional human group

“…It may be an indicative for conservation, because the low density or even rarity must not necessarily prevent a plant species to be taken for human use, what may endanger them. Some plant species of rare occurrence in Atlantic Rain Forest inventories, with a single individual per hectare, may represent more than 50% of the sampled taxa, which contributes to the high diversity indexes of these forests ([Guedes-Bruni et al 2009]). This rarity pattern must be taken into account before drawing conclusions about the eventual results from the management by local people.…”

Using leaf δ13C and photosynthetic parameters to understand acclimation to irradiance and leaf age effects during tropical forest regeneration

“…We evaluated photosynthetic performance and leaf δ 13 C in young and mature leaves in the three most abundant species (Evaristo et al, 2011), along an irradiance gradient in managed parcels of Brazilian Atlantic forest. The Atlantic forest of Brazil contains one of the most biodiverse and highly endemic floras in the world (Guedes-Bruni et al, 2009;Murray-Smith et al, 2009;Mutke and Barthlott, 2005). Originally occupying 150 million ha, today the Brazilian Atlantic forest has been reduced to 12 to 15% of its original extent (Ribeiro et al, 2009), 30 to 40% of which is secondary forests in early or medium stages of succession, combined with small fragments (< 50 ha) and few large fragments (Morellato and Haddad, 2000).…”