Werner et al. 2005 (Article) Ecuador

Diversity of Vascular Epiphytes on isolated remnant Trees In the Montane Forest Belt of Southern Ecuador

Author(s):—F.A. Werner, J. Homeier & S.R. Gradstein

Publication:—Ecotropica 11: 21–40. (2005)

Abstract:—We studied the diversity of vascular epiphytes on isolated remnant trees of pastures in southern Ecuador. The objective of this study was to document the importance of remnant trees for the survival of vascular epiphytes following forest clearance. Twenty-one canopy trees (15 remnant trees, 6 forest trees) were divided into five zones following Johansson (1974) and climbed with the single rope technique. Recorded parameters include floristic composition, species richness, abundance, and spatial distribution of epiphytes. Bromeliaceae, Orchidaceae, Piperaceae and Polypodiaceae were relatively well represented on remnant trees in terms of species richness and abundance, whereas other families such as Dryopteridaceae, Ericaceae, Grammitidaceae or Hymenophyllaceae were poorly represented or absent. Diversity, species richness, and abundance of epiphytes were significantly lower on remnant trees compared with forest trees. Impoverishment was greatest on the stem base and in the outer crown, and least in the inner crown of the host trees. We postulate that microclimatic changes and increased drought stress following the isolation of the remnant trees resulted in lowered rates of establishment and survival of vascular epiphytes.

Keywords:—deforestation, diversity, Ecuador, epiphytes, remnant trees, spatial distribution, tropical montane forest, tropical pastures.