Estrutura e dinamica de populações de especies arbustivo-arboreas da vertentes norte e sul do morro da Boavista, maciço da Tijuca-RJ

AUTOR(ES)
DATA DE PUBLICAÇÃO

1993

RESUMO

The structural and dynamic differences between North and South slopes of Morro da Boavista (22° 57 9" S. and 43° 18 3" W. Gr.), in Tijuca Mountain, Rio de Janeiro tree communities were studied. The Tijuca Montain range runs in a Northeast-Southeast direction, and most of the slopes are either North- facing or South- facing. This orientation causes gradients of sunlight and moisture which define different floristic composition and structure in both slopes. The vegetation in South area is in early secondary successional stage and in North is in late secondary successional stage. The instability of physical environment in North slope comes from lower moistures and greater variations in temperature, light, declivity, erosion and polution rates. The high environmental heterogenety may be responsible for the floristic, structural and dynamic differences between North and South plant populations. Measurements of the seedlings and saplings diameter and heights were for the ten more abundant species of each area for two years. The mortality and growth were accompanied. It was analized the seedling and sapling seed bank and the soil fertility. The mortality rate of seedlings and saplings was greater in North (13,1%) than South slope (7,9%). The highest density in seedling and sapling banks was presented by Myrcia rostrata in North and Eugenia prasina in South. The North area seed bank presented 325 seeds in a 0,36 m2 area and South 120 seeds in 0,36 m2. Finally we can consider that it is occurring different dynamics successional processes in both slopes. The changes seem to be consequence of the heterogeneity of physical environment of the areas which generate different structural patterns in North and South slopes of Morro da Boavista, RJ

ASSUNTO(S)

comunidades vegetais arbustos - rio de janeiro (rj)

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