Abstract

Forested wetlands have hydroperiods that range from permanent to seasonal, constituting an important environmental factor that directly influences the biological activity. This study evaluated how hydrologic dynamics affect the structure of arboreal vegetation in the forested wetlands of southern Chile. These wetlands are dominated by species of the myrtle family and the present study considers structural (diameter, total height, crown base height, crown projection) and community (richness, abundance) variables for 596 adult trees distributed in six wetlands. The wetlands studied herein have hydroperiods lasting three, six, or twelve months. Our results demonstrate that these periods have physiological and community effects, with tree species exposed to permanent flooding exhibiting lower total heights and greater crown base heights (p50.001) and tree and bush species showing less vegetative species richness (r21/40.85; p50.05) as compared to individuals of the same species from seasonal wetlands (512 months flooding). The magnitude of the effect of the hydroperiod on the community structure and organization of arboreal vegetation was directly related to the length of the flood or drought periods. © 2012 Taylor & Francis.