Journal of Tropical Ecology



Density and diversity of lianas along a chronosequence in a central Panamanian lowland forest


Saara J.  Dewalt a1c1, Stefan A.  Schnitzer a2 and Julie S.  Denslow a3p1
a1 Department of Biological Sciences, 202 Life Sciences Building, Louisiana State University, Baton Rouge, LA 70803
a2 Department of Biological Sciences, University of Pittsburgh, A234 Langley Hall, Pittsburgh, PA 15260
a3 Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803

Abstract

The abundance and diversity of lianas were examined along a tropical forest chronosequence at the Barro Colorado Nature Monument, Panama. Lianas [greater-than-or-equal]0.5 cm diameter were sampled along transects in two replicated stands in secondary (20, 40, 70 and 100 y after abandonment) and old-growth (>500 y) forests. Ordination of stands based on relative abundance, but not presence-absence, showed a significant separation of stands by age. Lianas were significantly more abundant and diverse (Fisher's α) in younger forests (20 and 40 y) than in older forests (70 and 100 y, and old-growth). The decline in liana abundance with stand age was offset by increased mean basal area per individual, resulting in a relatively constant total basal area and estimated biomass across stand age. The proportions of tendril climbers decreased and stem twiners increased over stand age. Decline in liana abundance and changes in liana composition may be related to changes in support and light availability. Although lianas are recognized as playing an important role in the early secondary sucession of many tropical forests, these results have shown that their important contribution to total basal area and biomass can continue as the forest matures, even as the numbers of established lianas declines.

(Accepted June 23 1999)


Key Words: Barro Colorado Nature Monument; climbing mechanisms; lianas; ordination; Panama; species diversity; sucession.

Correspondence:
c1 E-mail: sdewalt@unix1.sncc.lsu.edu
p1 Institute of Pacific Islands Forestry, USDA Forest Service, 23 E. Kawili Street, Hilo, HI 96720