Understorey Patterns in Mixed Evergreen-Deciduous Nothofagus Forests in Chile

Abstract

SUMMARY (1) Mixed evergreen-deciduous Nothofagus forests in south-central Chile, western Patagonia and Magellanic Chile were studied to determine the influence of the tree dominants on the distribution and dominance of plants in the understorey. (2) In mixed stands of Nothofagus dombeyi-N. pumilio and N. betuloides-N. pumilio near the timberline in south-central Chile, the understorey dominant Chusquea tenuiflora, a bamboo, is more abundant and taller beneath the evergreen trees. Most of the other common species are more abundant and larger under the deciduous N. pumilio. (3) Spring snow-melt is earlier beneath the evergreen Nothofagus spp., resulting in a longer vegetative period in comparison to sites beneath the deciduous trees. During summer, light levels are also greater beneath the evergreen trees. Both these habitat differences favour the tall, rapidly-growing bamboos, which, in turn, retard the establishment and growth of herbs, shrubs and tree seedlings beneath the evergreen species.