CONICET | Buscador de Institutos y Recursos Humanos

p { margin-bottom: 0.25cm; line-height: 120%; }Wind is one of themost important disturbances affecting the temperate mountain forestsof southern Patagonia. Wind blowdown history has been studied inNothofagus pumilio forests in the southern island of Tierra delFuego, and recent interest have been put on wind blowdowns leading towave regeneration incontinental forests; yet, little is known about the history (dates oforigin) of this disturbance at a regional scale. We undertook aretrospective study to reconstruct and date wind blowdown events infive continental valleys of Santa Cruz, Argentina to reconstruct theblowdown history of N. pumilio forests. We used vegetation transectsalong the disturbed patches and adjacent undisturbed forests to i)reconstruct forest structure and dynamics, and ii) date mortality andgrowth releases events, andthus date the occurrence of windstorms; intense sampling along theedge allowed us to describe mortality and growth patterns in theresidual trees after the windstorms. The occurrence ofwind blowdown events was highly variable in the sampled valleys, andthus the resulting forest structure of the blowdown patches. Theforests exhibited numerous growth release events depicting pastmultiple disturbance events and the frequency and magnitude varied ateach valley. We determined a total of sixteen blowdown events, andthe number of events per valley varied from two to six. Three eventswere recorded in more than one valley. Pre-blowdown structure of theforests and wind intensity might have determined disturbancefrequency and severity, leading to diverse post-blowdown structuresand blowdown history. This study represents the first reconstructionof wind blowdown history leading to wave regeneration in continentaland mountain N. pumilio forests in southern Patagonia.