Abstract

BRAVO-MONASTERIO, Pablo; SAN MARTIN, José  and  BAEZA-H., Gabriela. Distribution, abundance and phenology of Orchids in a deciduous endemic forest from central Chile. Polibotánica [online]. 2012, n.33, pp.117-129. ISSN 1405-2768.

In the central Chile Mediterranean area and in three fragments of Nothofagus glauca (Nothofagaceae) forest, an endemic and deciduous tree, the associated orchid flora under cover, edge and outside of the three fragments were studied. The microhabitat, demography, distribution model, and phenology were evaluated. The thermal regime is relatively homogenous and the luminance radiation diminishes as expected from the outside to the interior of the forest as well as litter of the floor whose thickness is increased in the same sequence of the luminance gradient. The orchid species are Gavilea venosa, endemic, G. odoratissima and Codonorchis lessonii, all perennial geophytes with strategy of survival by underground roots, where the two first develop multiflowers stem with yellow flowers and last the monofloral one with a white color flower. In the forest they fulfill the vital cycle agreeing. The vegetative activity begins with succulent basal leaves formation with the exception of C. lessonii that forms the verticiladas in an escape floral. The flowering coincides with the warm spring station and end after the drought of summer leaves. The size of the populations of the species is different being higher in C. lessonii followed from G. venosa and the minor in G. odoratissima. The spatial model distribution is grouped secreting itself in the microsites in monospecific groups. Clear G. venosa tends to occupy the edge and of the forest, C. lessonii in the edge and interior and G. odoratissima under cover. The orchidology diversity is valid for the studied site in his area of distribution on the 35°32' S.

Keywords : orchidologic flora; endemic; native; plant population.

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