Habitat loss effects on spatial distribution of non-vascular epiphytes in a Brazilian Atlantic forest

Abstract

The vertical distribution of the richness, abundance, and composition of epiphytic bryophytes was studied in a matrix of fragmented habitats in the Brazilian Atlantic rainforest of the Murici Ecological Station (9°11 0 05 00 -9°16 0 48 00 S, 35°45 0 20 00 -35°55 0 12 00 W), northeastern Brazil. The aim was to compare the horizontal (between sites) and vertical (between phorophyte heights) turnover to test a hypothesis based on niche width vulnerability. There was a highly significant decreasing of richness accompanying the loss of habitat, and the most conserved fragment housed a total richness more than 10 times higher than the less conserved fragment. Epiphytes failed to colonize lower trunks (2.1-10 m) and higher zones in most of the non-conserved fragments; they were restricted to the base (0-2 m) and displayed a clear altered floristic composition. The species with restricted ecological amplitudes such as sun and shade tolerant taxa were more negatively affected by habitat loss than generalists. Although the mean richness of generalists decreased in non conserved fragments, the proportional contribution of this guild increased, proving that these taxa are the ones which persist in disturbed sites. The forest fragments capable of harboring rich epiphyte flora in the area studied are over 300 ha in size, which is far from being a common size among Brazilian Atlantic rainforest fragments. Hence, our results highlight the need of conserving the few large remnants in this ecosystem.

Richness, geographic distribution and ecological aspects of the fern community within the Murici Ecological Station in the state of Alagoas, Brazil

“…These aspects, which have been widely discussed in the literature, are corroborated by our study, because, during our field work, we observed that forest interiors had a higher diversity of environments, such as streams, brooks, ravines and hillsides, than did the forest edges. Similar observations were reported by Silva & Pôrto (2009) and Alvarenga et al (2010), who studied the behavior of the community of bryophytes in the Murici Ecological Station. In addition, the forest interior has the capacity to retain more humidity and, as reported in the literature , environments with higher water availability are more easily colonized by ferns.…”

Aspectos brioflorísticos e fitogeográficos de duas formações costeiras de Floresta Atlântica da Serra do Mar, Ubatuba/SP, Brasil

“…Foi realizada também uma distinção da forma de vida tapete taloso, compreendendo as hepáticas talosas (que não apresentam diferenciação entre filídios e caulídios). Quanto à tolerância à luz do sol, as briófitas foram classificadas em: generalistas, típicas de sol e típicas de sombra, baseando-se em dados da literatura (Gradstein et al 2001, Gradstein & Costa 2003, Alvarenga et al 2010, Silva & Pôrto 2010, em experiência de campo e na consulta a especialistas. Para analisar a relação entre a riqueza de espécies típicas de sol e o índice de abertura do dossel, foi realizada uma Regressão Linear Simples no programa BioEstat 5.0 (Ayres et al 2007).…”

Bryophyte communities of restingas in Northeastern Brazil and their similarity to those of other restingas in the country

“…Due to their structural and physiological characteristics, bryophytes respond more significantly to microenvironmental than to macroenvironmental variables (e.g. Alvarenga et al 2010), and so it is reasonable to consider the importance of microenvironmental variables in the distribution of these plants in restingas.…”

“…Samples were identified with the aid of literature such as Frahm (1991), Reese (1993), Sharp et al (1994), Buck (1998), Lemos-Michel (2001), Gradstein & Costa (2003) and Bordin & Yano (2013 Gradstein (1992), Pócs & Tóthmérész (1997), Gradstein et al (2001), Reiner-Drehwald (2000), Alvarenga et al (2010) and Oliveira et al (2011): for life-form in relation to desiccation tolerance (exigent, intermediate and tolerant) according to Gimingham & Birse (1957) and Glime (2013); and for habitat type (corticolous, epixylic and terrestrial).…”