EFEITO DAS ATIVIDADES ANTRÓPICAS NA COBERTURA VEGETAL NA RESERVA FLORESTAL DE MECUBÚRI, MOÇAMBIQUE

O estudo foi realizado na Reserva Florestal de Mecubúri, em Moçambiquee, visando avaliar os efeitos das atividades antrópicas sobre a cobertura florestal. Áreas de queimada, agrícola e de exploração florestal foram comparadas com uma área controle em termos de composição e fitossociologia. Em cada área, foram estabelecidas, de maneira sistemática, parcelas quadrangulares de 20 x 20 m, distantes 20 m uma da outra, sendo realizado o levantamento da vegetação adulta e da regeneração. Foram determinados índices de similaridade, diversidade e riqueza. Os resultados indicaram existir dissimilaridade entre as áreas, sendo que as espécies Julbernardia globiflora, Diplorhynchus condylocarpon, Brachystegia utilis, Millettia stuhlmannii, Afzelia quanzensis, Burkea africana e Cussonia arborea destacaram-se em termos de abundância, frequência, dominância, Índice de Valor de Importância (IVI) e regeneração. O maior número de árvores por hectare foi encontrado na área de controle e o menor número foi encontrado na área agrícola. Com base no índice de dispersão de Morisita, a maior parte das espécies distribui-se de forma aleatória e agrupada. A distribuição diamétrica das árvores seguiu o padrão de J-invertido, característico de florestas naturais. As práticas de queimadas, agricultura e exploração florestal contribuem na redução da cobertura florestal na Reserva Florestal de Mecubúri. Palavras-chave: fitossociologia; conservação; desmatamento. The effect of anthropic activities on forest coverage in the Mecubúri Forest Reserve, Mozambique ABSTRACT: The study was carried out in the Mecubúri Forest Reserve, Mozambique, with the purpose of evaluating the effects of human activities on the forest cover. Burning, agricultural and logging areas were compared with a control area in terms of composition and phytosociology. In each area were systematically established 20 x 20 m quadrangular plots, 20 m apart from each other, in which were carried out the survey of adult vegetation and regeneration. The similarity, diversity and richness indices were determined. The results showed that there is dissimilarity between the areas and the species Julbernardia globiflora, Diplorhynchus condylocarpon, Brachystegia utilis, Millettia stuhlmannii, Afzelia quanzensis, Burkea africana e Cussonia arborea stood out in terms of abundance, frequency, dominance, Importance Value Index (IVI) and regeneration. The largest number of trees per hectare was found in the control area, and the smallest number was found in the agricultural area. Based on the Morisita dispersion index, most species have random and clustered distribution. The diametric structure of the trees followed the inverted-j, typical of natural forests. Burning, agriculture and logging contribute to the reduction of forest cover in the Mecubúri Forest Reserve. Keywords: phytosociology; conservation; deforestation.

Effect of Seed Size ofAfzelia quanzensison Germination and Seedling Growth

Afzelia quanzensisWelw is a valuable timber producing tree species in Africa. A study was conducted to evaluate the influence of seed size on seed germination and seedlings quality ofAfzelia quanzensis. Seed was categorized into three groups in regard to their length, small (<1.5 cm), medium (≥ 1.5 ≤ 2.5 cm), and large (>2.5 cm). The treatments were completely randomized into four replications. Germination percentage was not significantly(P>0.05)different between the treatments, although large seeds had the highest germination percentage of 94.9%. There were significant(P<0.05)differences in seedling height and root collar diameter among the different seed sizes, with large seeds having the highest seedlings height and largest root collar diameter. This was attributed to differences in the food reserves. Survival of transplants from shoot dieback was significantly(P<0.05)different such that seedlings from large seed attained the highest survival of 92%. It is therefore recommended that, for production of high quality transplants in the nursery, large seeds should be used.