DISTRIBUCIÓN, ABUNDANCIA Y FENOLOGÍA DE ORQUÍDEAS EN UN BOSQUE CADUCIFOLIO ENDÉMICO DE CHILE CENTRAL

Abstract

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.