Heterogeneidade altitudinal na Floresta Atlântica setentrional: um estudo de caso no sul da Bahia, Brasil

Abstract

ABSTRACT(Altitudinal heterogeneity in northern Atlantic Forest: a case study in southeastern Bahia, Brazil) Th e Atlantic Forest has a heterogeneity that is still largely unappreciated, especially that associated with altitudinal factors; this has rarely been examined in the northern extension of this biome. Th e study investigated the occurrence of variation in fl oristic composition, diversity, and vegetation structure at two altitudes in a remnant area of forest in southern Bahia state. A total of 0.5 ha of vegetation was sampled in fi ve separate plots established in a wet forest in the RPPN Serra Bonita, Bahia, Brazil. A total of 354 species belonging to 68 families were found, with Myrtaceae, Fabaceae, Rubiaceae and Lauraceae being the richest taxa. Th e two altitudinal sites showed signifi cant diff erences in density, basal area and structure. Th ere were notable changes in forest structure with increasing altitude, refl ected in higher densities of the understory and a reduction in species richness. Serra Bonita had high species diversity that was similar to other areas in Bahia, but higher than found in the Atlantic Forests of southeastern Brazil. Th e forest sections sampled were well preserved, as indicated by the abundance of woody vines, elevated basal area, and lack of evidence of signifi cant logging activities. Th e variation detected between the areas suggests the existence of abrupt structural modifi cations infl uenced not by edaphic factors but by rainfall diff erences, temperature variations, and by local barriers determined by the steep topography.

Toward a better understanding of the subtropical Atlantic Forest in the state of Santa Catarina, Brazil: tree sampling accuracy, species richness and frequency of rare species

“…In addition, various studies have indicated that the number of tree species per sample unit increases when the amount and frequency of rainfall are greater (as they are in rain forests) and decreases in proportion to the duration of the dry season (Gentry 1988;Nimer 1990;Clinebell II et al 1995;Pitman et al 2002;EPAGRI 2008). Together with shorter dry seasons, the high environmental heterogeneity generated by the hilly landscape (in the Serra Geral and Serra do Mar mountain ranges) might contribute to the high species richness in the areas of rain forest, where each elevation harbors a particular set of species (Martinelli 2007;Rocha & Amorim 2012). The results of the rarefaction procedure, used in order to deal with the variation in sample size, confirmed that species richness was higher in the rain forest than in the other forest types.…”

Epiphytic angiosperms in a mountain forest in southern Bahia, Brazil

“…Southern Bahia is considered an area of great biological importance, with elevated levels of richness and endemism in its arboreal component (Mori et al 1983, Thomas et al 1998, Martini et al 2007, Thomas et al 2009, Rocha & Amorim 2012, although surveys of humid montane forests have been scarce, especially those focusing on terrestrial and epiphytic herbs , Matos et al 2010. The recently created Serra das Lontras National Park comprises a vast remnant of montane Atlantic Forest in southern Bahia (Save Brasil et al 2009).…”

Sapindaceae em remanescentes de florestas montanas no sul da Bahia, Brasil

“…1). Descrições mais detalhadas sobre as áreas de estudo, incluindo dados climáticos e de relevo foram apresentados em Amorim et al (2009), Rocha & Amorim (2012), Liuth et al (2013), Coelho & Amorim (2014) e Leitman et al (2014).…”

“…Levantamentos recentes no sul da Bahia (e.g., Amorim et al 2009;Rocha & Amorim 2012;Coelho & Amorim 2014;Leitman et al 2014) investigaram aspectos florísticos e ecológicos de florestas montanas em diferentes áreas, revelando uma flora muito diversa, com elevado número de espécies novas e conexões fitogeográficas anteriormente desconhecidas com a flora da Região Sudeste (detalhes em Amorim et al 2009). Esses estudos concentraram-se em três fragmentos de floresta em regiões montanhosas e que possuem a vegetação relativamente preservada, principalmente nos pontos de altitude mais elevada.…”