Estudo de liquens corticícolas foliosos em um mosaico de vegetação no sul do Brasil / lichens;forest;Araucaria angustifolia

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Lichens are important epiphytic components of forests, however anthropogenic alterations of forest habitats could lead to substantial modifications in the diversity and species spatial distribution of lichens. This work investigates how species composition, richness, abundance, diversity and vertical distribution of lichens in tree trunks could be modified when native forest is replaced by forest monocultures. The lichen community was studied in the National Forest of São Francisco de Paula, southern Brazil, in three replicates of the following vegetation types: native Araucaria forest, and plantations of Araucaria, Pinus and Eucalyptus, 12 areas in total. In each area, ten host-trees were randomly chosen, with a total of 120 host-trees sampled in the four habitats. In each host tree, lichens were surveyed from 30 to 150 cm in trunk height. There were 113 lichen species registered, 78 in the survey and 35 in an additional non systematic survey. Five new species to science were encountered, eight new citation for Brazil and eight new occurrences for the Rio Grande do Sul state. The conversion of native forests to forest monocultures altered the richness, abundance, diversity and vertical distribution of lichens. The largest number of shade tolerant species was registered in the Araucaria forest and the largest number of light demanding species was registered in the plantations of exotic forest species. Araucaria plantations have shown the highest richness and diversity values, and have differed in species composition in relation to the other habitats. This pattern could be related to the dominance of Araucaria angustifolia in these areas, because this species is an excellent host-tree due to its bark characteristics. This pattern could also be explained by the high light incidence in the Araucaria plantations, which could favor the establishment of lichens characteristic from the native forest canopy. In conclusion, the conversion of native Araucaria forests to forest monocultures could lead to the loss of species typical from shaded and moist environments. However, light demanding species were able to establish in forest monocultures. The use of native species such as Araucaria angustifolia in forest monocultures instead of exotic tree species would lead to the preservation of a higher lichen diversity in the landscape.

ASSUNTO(S)

florestas nativas araucária angustifolia botanica liquens corticícolas foliosos

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