Journal of Tropical Ecology



The epiphyte vegetation of the palm Socratea exorrhiza - correlations with tree size, tree age and bryophyte cover


Gerhard Zotz a1a2c1 and Birgit Vollrath a1
a1 Botanisches Institut der Universität Basel, Schönbeinstrasse 6, CH-4056 Basel, Switzerland
a2 Smithsonian Tropical Research Institute, Apdo 2072, Balboa, Panama

Abstract

We conducted a survey of the epiphyte flora growing on the stilt palm Socratea exorrhiza in a primary lowland rain forest in Panama by means of a canopy crane. For each palm in a 0.9-ha plot, we determined diameter at breast height, tree height, per cent bryophyte cover and the number, identity and attachment site of all vascular epiphytes. The 118 palm trees hosted a total of 701 epiphytes and hemi-epiphytes, belonging to 66 species. Trees were estimated to be c. 20 y old before colonization with vascular epiphytes began. Epiphyte species were highly clumped and segregated along the vertical axis of the trunk. Sequential colonization led to an increased number of species and individuals as the tree grows. Epiphytes were associated with bryophyte patches much more than expected by chance, but no species seemed to depend upon them for establishment. The influence of tree size, age and bryophyte cover on the composition of the epiphyte community are discussed.

(Accepted January 6 2002)


Key Words: Araceae; Bromeliaceae; canopy dynamics; diversity; ferns; hemi-epiphytes; moss; Orchidaceae; vascular epiphytes.

Correspondence:
c1 Address for correspondence: Botanisches Institut der Universität Basel, Schönbeinstrasse 6, CH-4056 Basel, Switzerland. Email: gerhard.zotz@unibas.ch