Comunidade de lianas e sua associação com arvores em uma floresta estacional semidecidual

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Lianas are soil-germinating plants, perennially rooted and which need support to reach the canopy. They are characteristically from the rain forests, where they contribute with near 25% of vegetal diversity. Lianas compete with trees for nutrients and light, influencing growth and mortality rates of its host tree. Although lianas begin their life on the ground, many of them colonize vicinity trees through the forest canopy, ?tying? themselves to the others, and may cause the fall of many trees. Due to their abundance and impact over other trees, it is important to know the factors governing distribution and dynamics of the lianas in order to better understand the rain forest and to develop sustainable strategies. Thus, the aims of this study were: (1) to assess the richness and abundance of lianas, and (2) to establish the relation of lianas with the characteristics of the hosts and the structure of the forest. The research was carried out in a fragment of a Semideciduous Stational Forest with 435.73 ha, at the Paulo de Faria Ecological Station. The sampling consisted of 100 plots of 10 x 10 m (1 ha), allotted in an area of 4 ha. Lianas with a diameter ³ 1 cm and trees ³ 3 cm rooted in the plots were measured in DBH (diameter at breast height ?1.30m) e identified. In the study area, 1427 individuals were sampled from 45 species of lianas, belonging to 14 families, the richest ones being Bignoniaceae (14 species), Sapindaceae (nine) e Malpighiaceae (six), and the more abundant Bignoniaceae, Sapindaceae e Apocynaceae, adding up to 80% of the sampled individuals. The liana richness was approximately equal to half (ratio 0.51) the tree richness (87 species). Average density of lianas and trees was similar, around 1400 individuals/ha. Melloa quadrivalvis (Bignoniaceae) was the most common species in the study area. From the total number of the sampled liana individuals, 57.6% presented diameters between 1- 2.5 cm, corresponding to 95% of the total sampled richness. Only 26 individuals presented diameter higher than 10 cm. From the 1419 trees with diameter ³ 3 cm, 53% carried at least one liana, with the higher rate of infestation (79%) occurred in the individuals with diameters >10 cm. Species less infested than the expectation were Inga marginata, Piper amalago, Trichia catigua e T. claussenii. One species, Machaerium paraguariense, was more infested than the expectation. In general, results did not support the hypothesis of species-specificity between lianas and trees, since the richness and diversity of liana species increased with the infestation rate. Climbing mechanism did not influence the number of trees climbed by each liana, although we have found positive association between wrinkled bark and tendrils. Considering the individual characteristics of the host, trees with larger diameters showed higher density of lianas. In relation to the vicinity characteristics, the plots with higher rate of big trees (DBH >30 cm) showed significant negative relation with the density of lianas. The relation was positive in plots with higher rate of trees with small crown (£ 3 m). Thus, our study showed the association between tree and vicinity characteristics with infestation and density of lianas

ASSUNTO(S)

climbing plants vines plantas florestais forest plants rain forests florestas tropicais trepadeira

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