Spatial Distribution and Abundance of Epiphytes along a Gradient of Human Disturbance in an Interandean Dry Valley, Ecuador

摘要

We studied the effects of different disturbance regimes on abundance and within-tree distribution of dry-forest epiphytes at the Bosque Protector Jerusalén in northern Ecuador. Epiphytes on 100 trees of Acacia macracantha were sampled in closed mixedand pure acacia forest stands, forest edge, semi-closed secondary woodland, and isolated trees in pastures. Vascular epiphytes were sampled for entire host trees and macrolichens and bryophytes for inner tree crowns. The number of vascular epiphyte species did not differ significantly between crown zones but their cover decreased significantly from middle to inner and outer crown. Vascular epiphytes attained greatest and bryophytes lowest cover values on isolated trees. Covers of bryophytes and vascular plants were correlated with canopy integrity, suggesting that microclimate was a strong predictor of epiphyte abundance. The high abundance of atmospheric bromeliads in the studied disturbed, perarid habitats is suggestive of their effective adaptationto the use of dew.