Regeneração de espécies arbóreas em floresta impactada

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

22/06/2011

RESUMO

This study aimed to investigate aspects of population ecology of six tree species in two areas with different historical preservation: Mata São Francisco State Park (MSFSP), Santa Mariana-Cornelio Procópio, PR, Brazil (23º 15 S and 50º 45 W, central point of fragment), who suffered exploration anthropogenic, and Mata dos Godoy State Park (MGSP) (23º 27 S and 51º 15 W, central point of fragment), with no history of disturbance. Studies of allometric relationships, height structure and spatial pattern were performed on shade-intolerant species (Astronium graveolens Jacq., Croton floribundus Spreng., Gallesia integrifolia (Spreng.) Harms) and shade-tolerant species (Chrysophyllum gonocarpum (Mart. &Eichler ex Miq.) Engl., Euterpe edulis Mart. and Holocalyx balansae Micheli) in both fragments. Sixty plots of 100 m2 (10 m x 10 m) were allocated, being 30 contiguous plots in each fragment, with similar physiognomy. All individuals of six species were marked, assessed for total height, diameter. The canopy cover was measured with densiometer to verify a possible difference in luminosity between areas, through the t test. The analysis of covariance (ANCOVA) was used to test for possible differences in allometric relationships of height-diameter of species between areas. The height structure of each species between areas was compared by the Kolmogorov-Smirnov test. The spatial distribution of species in each area was evaluated by the spatial autocorrelation coefficient Moran (I). The analysis of t test revealed differences in canopy cover between areas, suggesting a higher luminosity in MSFSP. All populations had high r2 values (between 0.83 and 0.96), indicating low variation in individuals form. The “b” values (slope of regression) indicated that the populations of MSFSP have a larger investment in diameter for to the same height than individuals of MGSP, possibly related to higher luminosity and less competition for light in MSFSP. In the same area, there wasn’t difference in growth pattern between functional groups, suggesting the diameter-height growth pattern reflect growth strategies in response to different light conditions. Differences were observed in the distribution of individuals by height classes between areas for all species, demonstrating the impacts of anthropogenic exploitation on population structure in the studied species. All populations had a random spatial pattern, except H. balansae in MSFSP and E. edulis in MGSP, which showed an aggregate distribution. The study showed evidences of regeneration of study species due establishment of shade-tolerant species in MSFSP and coexistence of functional groups in both fragments. The populational aspects studied showed some of effects of anthropogenic exploration on populations.

ASSUNTO(S)

vegetação - regeneração (botânica) reflorestamento floresta - restauração botânica vegetation regeneration (botany) restoration of forests

ACESSO AO ARTIGO

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