Journal of Tropical Ecology



Post-dispersal removal of seeds of pioneer species from five Panamanian forests


D. A. Fornara a1c1 and J. W. Dalling a2
a1 Dipartimento di Biologia, Sezione Botanica Ambientale e Applicata, Università Statale di Milano, via Celoria 26, Milano, Italy
a2 Department of Plant Biology, University of Illinois, 265 Morrill Hall, 505 S Goodwin Avenue, Urbana IL 61801, USA

Article author query
fornara da   [PubMed][Google Scholar] 
dalling jw   [PubMed][Google Scholar] 

Abstract

Variation among forests in environmental and biotic conditions may strongly influence seed fate with important consequences for the abundance and distribution of plant species. Here we examine the post-dispersal seed removal rates of six pioneer species (Cecropia peltata, Miconia argentea, Luehea seemannii, Trema micrantha, Apeiba aspera and Jacaranda copaia) from the soil surface at five sites in Panama varying in elevation (0–1100 m) and seasonality (0–4 mo dry season). We compared removal rates of washed seeds placed in vertebrate exclosures, invertebrate exclosures, and unprotected controls in January and June. Overall, removal rates of unprotected seeds were similar among sites. Almost all seed removal could be attributed to litter ants in two subfamilies (Myrmicinae and Ponerinae). Little or no removal was recorded from invertebrate exclosures while vertebrate exclosures had no effect on removal either in lowland and montane forests. Seed removal rates were high for four animal-dispersed species (mean 45% removed over 2 d), whereas two wind-dispersed species were largely untouched (mean 2% removed). These results indicate that seed dispersal characteristics, rather than site characteristics, may be the strongest determinant of the post-dispersal seed fate of pioneers.

(Accepted April 5 2004)


Key Words: environmental gradient; litter ants; seed dispersal; seed removal.

Correspondence:
c1 Corresponding author, at Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa. Email: dfornara@zoology.up.ac.za