Tree population and community dynamics in a Brazilian tropical semideciduous forest
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Data
2005-06-01
Autores
Appolinário, Vivette
Oliveira Filho, Ary T.
Guilherme, Frederico A.G. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Botânica de São Paulo
Resumo
A dinâmica da comunidade arbórea e de 30 populações das espécies constituintes foi investigada em uma área de floresta tropical semidecídua situada na margem do Rio Grande, em Bom Sucesso (MG), com base em inventários conduzidos em 1990 e 1997 em três parcelas de 0,18 ha. O objetivo principal foi verificar se variações na dinâmica estariam relacionadas à topografia e aos efeitos de uma inundação catastrófica ocorrida em 1992. Foram obtidas taxas de mortalidade e recrutamento de árvores e taxas de ganho e perda de área basal em dois sítios topográficos: baixo (inundado) e alto (não-inundado). Trajetórias de crescimento médio e acelerado foram obtidas para cada espécie. Registrou-se, para ambos os sítios topográficos, que as taxas de mortalidade superaram as de recrutamento, as taxas de ganho superaram as de perda de aérea basal e as distribuições de tamanho mudaram no período devido ao declínio na proporção de árvores menores. Tais mudanças se relacionaram, possivelmente, ao incremento do suprimento de água subterrânea registrado depois da inundação de 1992, bem como a um processo de sucessão primária que vinha ocorrendo há cerca de 250 anos em uma área de mineração de ouro abandonada. Possíveis efeitos da inundação apareceram na maior proporção de árvores mortas nos sítios inundados e nas taxas de crescimento mais aceleradas nos sítios não-inundados. Espécies de diferentes guildas de regeneração mostraram tendências particulares com respeito às suas mudanças demográficas e padrões de crescimento em diâmetro.
The dynamics of the tree community and 30 tree populations were examined in an area of tropical semideciduous forest located on the margin of the Rio Grande, SE Brazil, based on surveys done in 1990 and 1997 in three 0.18 ha plots. The main purpose was to assess whether variations in dynamics were related to topography and the effects of a catastrophic flood in 1992. Rates of mortality and recruitment of trees and gain and loss of basal area in two topographic sites, lower (flooded) and upper (non-flooded), were obtained. Projected trajectories of mean and accelerated growth in diameter were obtained for each species. In both topographic sites, mortality rates surpassed recruitment rates, gain rates of basal area surpassed loss rates, and size distributions changed, with declining proportions of smaller trees. These overall changes were possibly related to increased underground water supply after the 1992 flood as well as to a c. 250-year-old process of primary succession on abandoned gold mines. Possible effects of the 1992 flood showed up in the higher proportions of dead trees in the flooded sites and faster growth rates in the flood-free sites. Species of different regeneration guilds showed particular trends with respect to their demographic changes and diameter growth patterns. Nevertheless, patterns of population dynamics differed between topographic sites for only two species.
The dynamics of the tree community and 30 tree populations were examined in an area of tropical semideciduous forest located on the margin of the Rio Grande, SE Brazil, based on surveys done in 1990 and 1997 in three 0.18 ha plots. The main purpose was to assess whether variations in dynamics were related to topography and the effects of a catastrophic flood in 1992. Rates of mortality and recruitment of trees and gain and loss of basal area in two topographic sites, lower (flooded) and upper (non-flooded), were obtained. Projected trajectories of mean and accelerated growth in diameter were obtained for each species. In both topographic sites, mortality rates surpassed recruitment rates, gain rates of basal area surpassed loss rates, and size distributions changed, with declining proportions of smaller trees. These overall changes were possibly related to increased underground water supply after the 1992 flood as well as to a c. 250-year-old process of primary succession on abandoned gold mines. Possible effects of the 1992 flood showed up in the higher proportions of dead trees in the flooded sites and faster growth rates in the flood-free sites. Species of different regeneration guilds showed particular trends with respect to their demographic changes and diameter growth patterns. Nevertheless, patterns of population dynamics differed between topographic sites for only two species.
Descrição
Palavras-chave
crescimento de árvores, dinâmica de comunidades arbóreas, dinâmica florestal, dinâmica de populações arbóreas, floresta tropical semidecídua, forest dynamics, tree community dynamics, tree growth, tree population dynamics, tropical semideciduous forest
Como citar
Brazilian Journal of Botany. Sociedade Botânica de São Paulo, v. 28, n. 2, p. 347-360, 2005.