Impact of deforestation and forest regrowth on vascular epiphyte diversity in the Andes of Bolivia

Abstract

Species richness of vascular epiphytes in mature sub-montane and montane forests is compared that in adjacent 15-year old fallow forests at two sites in the Andes of Bolivia. These forests rank among the richest worldwide in terms of epiphyte diversity. Approximately 500 species (25 families, 110 genera) were recorded in total, whereas 0.33 ha of moist montane forest had up to 175 species. Fallows had 60–70% fewer epiphyte species than did mature forest, but species reductions varied considerably among different groups of epiphytes. Species richness of orchids, bromeliads, and grammitid and filmy ferns was much lower in fallows than in mature forest but was not reduced for hemi-epiphytic aroids, nor for polypodioid and asplenioid ferns. The reduced epiphyte diversity in fallows is explained by structural characteristics of the fallow trees, including the lack of dense epiphytic moss mats, and by the drier micro-climate in the fallows.