Hostname: page-component-848d4c4894-8kt4b Total loading time: 0 Render date: 2024-07-03T20:42:50.426Z Has data issue: false hasContentIssue false

Seed germination, seedling growth and habitat partitioning in two morphotypes of the tropical pioneer tree Trema micrantha in a seasonal forest in Panama

Published online by Cambridge University Press:  10 January 2003

Katia Silvera
Affiliation:
Departamento de Botánica, Universidad de Panamá, República de Panamá Smithsonian Tropical Research Institute, Apartado 2072, Balboa, República de Panamá Present address: Department of Botany, University of Florida, 220 Bartram Hall, P.O. Box 118526, Gainesville, FL 32611-8526, USA. Email: silvera@flmnh.ufl.edu
John B. Skillman
Affiliation:
Smithsonian Tropical Research Institute, Apartado 2072, Balboa, República de Panamá Department of Biology, California State University, San Bernardino, CA 92407, USA
J. W. Dalling
Affiliation:
Smithsonian Tropical Research Institute, Apartado 2072, Balboa, República de Panamá Department of Plant Biology, University of Illinois, Urbana, IL 61801, USA

Abstract

We examined the distribution, germination, growth and photosynthetic characteristics of two co-existing morphotypes of the pioneer tree Trema micrantha at the Barro Colorado Nature Monument (BCNM), Panama. Morphotypes differed significantly in distribution and in seed characteristics. A ‘large’-seeded morphotype (endocarp mass=3.83 mg) was associated with treefall gaps in the forest interior, whereas a ‘small’-seeded morphotype (endocarp mass=1.38 mg) was found predominantly on landslides on the margins of Lake Gatun. Seeds of the small-seeded morphotype germinated faster than seeds of the large-seeded morphotype, with seedlings of the small-seeded morphotype showing both a higher Unit Leaf Rate (ULR) and a lower Specific Leaf Area (SLA). Differences in photosynthetic rates reflected differences in SLA; the small-seeded morphotype had a higher rate on a leaf area basis, while the large-seeded morphotype had a higher rate on a leaf mass basis. Although allocation patterns between morphotypes varied in a way consistent with known interspecific differences between ‘sun’ and ‘shade’ plants, relative growth rates (RGR) of the morphotypes were similar across different light conditions suggesting that factors other than light, such as water uptake efficiency, soil nutrient requirements, and perhaps seed dispersal characters may explain the habitat partitioning of morphotypes.

Type
Research Article
Copyright
2003 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)