Temperate and Tropical Podocarps: How Ecologically Alike Are They?
- Autores: David A. Coomes, Peter J. Bellingham
- Localización: Smithsonian Contributions to Botany, ISSN 0081-024X, Nº. 95, 2011 (Ejemplar dedicado a: Ecology of the Podocarpaceae in Tropical Forests), págs. 119-140
- Idioma: inglés
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Resumen
With few exceptions, podocarps are specialists of nutrient-poor soils within temperate and tropical rainforests. They are locally abundant in some tropical mountains, especially near the tree line, and in the lowland tropics most are confined to heathlands and impoverished habitats, although some can persist in forest understories. The ecology of tropical podocarps is not well understood, so here we draw on literature from temperate regions to help characterize their niches. Temperate podocarps are effective at capturing and retaining nutrients at the expense of competitors. They are universally slow growing, but this is not necessarily an encumbrance on poor soils because competition for light is relatively weak. Temperate podocarps are often outcompeted on richer soils because several factors stack against them: they are ill equipped to compete with angiosperms in the race to occupy canopy gaps, there may be few sites for their establishment on the forest floors, and continuous regeneration by podocarps is seldom found in the forest understory because their growth is severely hampered by shading. We suggest that competition excludes imbricate-leaved podocarps from most lowland tropical forests, whereas broad-leaved species with anastomosing veins (Nageia and some Podocarpus) are so shade tolerant that they regenerate beneath closed canopies.
