Werner, F.A. & Gradstein, S.R. (2009): <b>Diversity of dry forest epiphytes along a gradient of human disturbance in the tropical Andes</b>. <i>Journal of Vegetation Science</i> <b>20</b>(1), 59-68.
Resource Description
Title:
Diversity of dry forest epiphytes along a gradient of human disturbance in the tropical Andes
FOR816dw ID:
278
Publication Date:
2009-08-14
License and Usage Rights:
Copyright International Association of Vegetation Science
Resource Owner(s):
Individual:
Florian A. Werner
Contact:
email:
florianwerner <at> yahoo.com
AG Funktionelle Ökologie
Institut für Biologie und Umweltwissenschaften
Universität Oldenburg
Postfach (P.O. box) 2503
D-26111 Oldenburg
Individual:
S. Robbert Gradstein
Contact:
email:
sgradst <at> uni-goettingen.de
Untere Karspüle 2
Department of Plant Systematics
Georg August University Göttingen
Albrecht von Haller Institute of Plant Sciences
37073 Goettingen
Germany
Abstract:
Question: Disturbance effects on dry forest epiphytes are poorly known. How are epiphytic assemblages affected by different degrees of human disturbance, and what are the driving forces?<br/>
Location: An inter-Andean dry forest landscape at 2300 m elevation in northern Ecuador.<br/>
Methods: We sampled epiphytic bryophytes and vascular plants on 100 trees of Acacia macracantha in five habitats: closed-canopy mixed and pure acacia forest (old secondary), forest edge, young semi-closed secondary woodland, and isolated trees in grassland.<br/>
Results: Total species richness in forest edge habitats and on isolated trees was significantly lower than in closed forest types. Species density of vascular epiphytes (species per tree) did not differ significantly between habitat types. Species density of bryophytes, in contrast, was significantly lower in edge habitat and on isolated trees than in closed forest. Forest edge showed greater impoverishment than semi-closed woodland and similar floristic affinity to isolated trees and to closed forest types. Assemblages<br/>
were significantly nested; habitat types with major disturbance held only subsets of the closed forest assemblages, indicating a gradual reduction in niche availability. Distance to forest had no effect on species density of epiphytes on isolated trees, but species density was closely correlated with crown closure, a measure of canopy integrity.<br/>
Main conclusions: Microclimatic changes but not dispersal constraints were key determinants of epiphyte assemblages following disturbance. Epiphytic cryptogams are sensitive indicators of microclimate and human disturbance in montane dry forests. The substantial impoverishment of edge habitat underlines the need for fragmentation studies on epiphytes elsewhere in the Tropics.
Literature type specific fields:
ARTICLE
Journal:
Journal of Vegetation Science
Volume:
20
Issue:
1
Page Range:
59-68
Publisher:
Opulus Press
Metadata Provider:
Individual:
S. Robbert Gradstein
Contact:
email:
sgradst <at> uni-goettingen.de
Untere Karspüle 2
Department of Plant Systematics
Georg August University Göttingen
Albrecht von Haller Institute of Plant Sciences
37073 Goettingen
Germany
