Structure, Function and Floristic Relationships of Plant Communities in Stressful Habitats Marginal to the Brazilian Atlantic Rainforest

Abstract

The Brazilian Atlantic rainforest consists of a typical tropical rainforest on mountain slopes, and stands out as a biodiversity hotspot for its high species richness and high level of species endemism. This forest is bordered by plant communities with lower species diversity, due mostly to more extreme environmental conditions than those found in the mesic rainforest. Between the mountain slopes and the sea, the coastal plains have swamp forests, dry semi-deciduous forests and open thicket vegetation on marine sand deposits. At the other extreme, on top of the mountains (>2000 m a.s.l.), the rainforest is substituted by high altitude fields and open thicket vegetation on rocky outcrops. Thus, the plant communities that are marginal to the rainforest are subjected either to flooding, drought, oceanicity or cold winter temperatures. It was found that positive interactions among plants play an important role in the structuring and functioning of a swamp forest, a coastal sandy vegetation and a cold, high altitude vegetation in the state of Rio de Janeiro. Moreover, only a few species seem to adopt this positive role and, therefore, the functioning of these entire systems may rely on them. Curiously, these nurse plants are often epiphytes in the rainforest, and at the study sites are typically terrestrial. Many exhibit crassulacean acid metabolism. Conservation initiatives must treat the Atlantic coastal vegetation as a complex rather than a rainforest alone.

Phenotypic plasticity and local adaptation favor range expansion of a Neotropical palm

“…(2011) and hereafter refer to this subtype of Lowland Rainforest as Restinga Forests. Restinga Forests lack endemic woody species and are marginal habitats predominantly formed by repeated colonization events from neighboring Rainforests distributed across the Atlantic mountain range (Marques et al., 2011; Scarano, 2002). …”

Riqueza, estrutura e interações edáficas em um gradiente de restinga do Parque Estadual do Acaraí, Estado de Santa Catarina, Brasil

“…Estão submetidas à condições ambientais extremas, caracterizadas por altas temperaturas, ventos constantes, elevada salinidade e deficiência em nutrientes (Scarano et al 2001, Scarano 2002. Variações fisionômicas são observadas desde a região pós-praia até as áreas mais interiores da planície costeira (Veloso et al 1991, Oliveira-Filho & Carvalho 1993.…”

Composição florística e estrutura do componente arbóreo de uma área transicional de Floresta Atlântica no sul da Bahia, Brasil

“…Gradientes de composição florística na Floresta Atlântica são evidentes quando associados a diferenças fisionômicas em larga escala (Scarano 2002), tornando-se mais sutis em menor escala, quando aspectos topográficos locais passam a ser mais determinantes (i.e. Martins et al 2003).…”