Recolonisation of natural landslides in tropical mountain forests of Southern Ecuador

Abstract

AbstractThe regeneration of the vegetation of natural landslides was studied at Estación Científica San Francisco (ECSF) in a tropical mountain forest area of Southern Ecuador, north of Podocarpus National Park. The study focused on the process of regeneration on natural landslides and the vegetation change along an altitudinal gradient using space‐for‐time substitution. The most important plant families present on the landslides during the first stages of succession are Gleicheniaceae (Pteridophyta), Melastomataceae, Ericaceae and Orchidaceae. Species of the genus Sticherus (Gleicheniaceae) are dominant, and species composition varies with altitude and soil conditions. Colonisation of landslides is not homogeneous. Zones with bare ground, sparsely vegetated patches and densely covered areas may be present within the same slide. This small scale spatial heterogeneity is often created by local ongoing sliding processes and different distances towards undisturbed areas. Therefore, the duration of the successional process is highly variable. The initial stage of the succession is a community of non vascular plants interspersed with scattered individuals of vascular plants. By means of runner‐shoots they form vegetation patches which start growing into each other. The second stage is dominated by Gleicheniaceae (species composition varying in altitude and soil chemistry). In the third stage, bushes and trees colonise, sheltered by the ferns, and a secondary forest develops with pioneer species that are not found in the primary forest vegetation. The common phenomenon of the natural landslides leads to an increase in structural and species diversity on a regional scale. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)