Spatial variation in the structure and floristic composition of "restinga" vegetation in southeastern Brazil

Abstract

-(Spatial variation in the structure and floristic composition of "restinga" vegetation in southeastern Brazil). We examined large-scale spatial variation of structural parameters and floristic composition in open Clusia scrub, a vegetation type of the Brazilian "restingas" (sandy coastal plain vegetation). This vegetation is organized in islands separated by sandy stretches with sparse herbaceous vegetation. We located 12 sample areas on three consecutive beach ridges, lying parallel to the coastline and at different distances from the ocean, in close proximity to two lagoons (Cabiúnas and Comprida). Each sample area was divided into three strips. We used the line intercept method to sample all woody plants ³ 50 cm tall. We used nested ANOVA to verify structural variation between different sampling scales. TWINSPAN analysis was performed to examine the variation in floristic composition between areas. The overall diversity index was 3.07. Six species are repeatedly dominant throughout the entire sampling area. There was homogeneity in relation to diversity and species richness between beach ridges but not within beach ridges. Floristic composition and structural parameters did not vary in relation to distance from the sea but floristic composition did vary as a function of proximity to Cabiúnas or Comprida lagoon. Differences in plant cover between sample areas may be related to the paleoformation of this sandy coastal plain.Key words -phytosociology, plant community, sampling scale, sandy coastal plain RESUMO -(Variação espacial na estrutura e composição florística de uma vegetação de restinga no Sudeste brasileiro). A variação em ampla escala espacial para parâmetros estruturais e composição florística foi examinada para uma formação aberta de Clusia, um tipo vegetacional das restingas brasileiras. Esta vegetação é organizada em moitas separadas por areia com esparsa vegetação herbácea. Foram levantadas 12 áreas amostrais em três cordões arenosos paralelos, às margens de duas lagoas costeiras (Cabiúnas e Comprida). Estes cordões estavam dispostos a diferentes distâncias do mar. Cada área amostral foi dividida em três faixas. Usamos o método de intercepto de linha para amostrar todas as plantas lenhosas ³ 50 cm de altura. Foi empregada ANOVA hierárquica para verificar a variação estrutural em diferentes escalas amostrais, e análise de TWINSPAN para examinar a variação na composição florística entre áreas. A diversidade total da área (H') foi de 3,07. Apenas poucas espécies foram repetidamente dominantes ao longo de toda a área amostral. Houve homogeneidade em relação à diversidade e riqueza de espécies entre cordões arenosos, mas não dentro destes cordões. Composição florística e parâmetros estruturais não variaram em relação à distância do mar, mas a composição florística variou em função da lagoa que margeava. As diferenças observadas na cobertura vegetal podem estar relacionadas com a história geológica desta área de restinga.

Pollen grains in quaternary sediments from the Campos Basin, state of Rio de Janeiro, Brazil: Core BU-91-GL-05

“…Phytosociological data for northern Rio de Janeiro (Assumpção & Nascimento 2000; Costa & Dias 2001;Moreno et al 2003;Pessoa & Oliveira 2006;Pimentel et al 2007;Silva & Nascimento 2001) suggest that the region encompasses the so-called tabuleiro forests (coastal lowland forests on Tertiary deposits) in the lowlands and xeromorphic (restinga) vegetation in the coastal areas.…”

“…To make those associations, we consulted floristic studies undertaken in montane and submontane areas (Kurtz & Araujo 2000;Moreno et al 2003;Pessoa & Oliveira 2006); dense lowland forest and semideciduous forest (Silva & Nascimento 2001;Kurtz et al 2009); restinga (Costa & Dias 2001;Pimentel et al 2007); and herbaceous and hygrophytic coastal vegetation ecosystems (IBGE 1992;Costa & Dias 2001;Bove et al 2003).…”

“…The pollen grains described are also related to the shrub-arboreal component in Coastal Woodlands National Park, near Lake Comprida and Lake Cabiúnas, along the northern coast of Rio de Janeiro. Pimentel et al (2007) analyzed the taxa richness and diversity among beaches, dunes and Clusia-dominated formations. The taxa found were: Croton, Garcinia, Heteropteris, Ilex, Inga, Meliaceae, Tribe Vernonieae (Vernonia) and Myrtaceae.…”

Bryophyte and pteridophyte spores and other palynomorphs in quaternary marine sediments from Campos Basin, southeastern Brazil: Core BU-91-GL-05

“…Phytosociological studies conducted in the region (Assumpção & Nascimento 2000;Silva & Nascimento 2001;Moreno et al 2003;Pimentel et al 2007) identified deciduous forests on top of Tertiary coastal plateaus, and a xerophytic type of vegetation (restinga) near the shore. The restinga vegetation is strongly influenced by the sea, and presents several grades of physiognomy (i.e., from herbaceous to shrubby woodlands).…”

Carbon and nitrogen stock and fluxes in coastal Atlantic Forest of southeast Brazil: potential impacts of climate change on biogeochemical functioning

“…Depending on the functional diversity variation among coexisting species, a more efficient use of resources is expected, as at the same time decreasing interspecific competition, which overall may increase ecosystem productivity (Scherer-Lorenzen et al, 2007). On the other hand, many tropical vegetation types have few species that attain high dominance at the community level, mainly in terms of biomass, in contrast to many subordinate or rare species (Hubbell, 2001;Macía and Svenning, 2005;Pimentel et al, 2007). Thus, one may expect that the higher abundance of a few species will be the main driver of community structure that modulate the magnitude of fluxes of energy and matter in ecosystems (Grime, 1998;Dangles and Malmqvist, 2004).…”