Disturbance history and dynamics of an old-growth Nothofagus forest in southern Patagonia

MARIANO AMOROSO; PAULA BLAZINA

Mendoza

Conferencia; Third American Dendrochronology Conference-Ameridendro; 2016

IANIGLA, TREE RING SOCIETY

The identification of disturbance events using disturbance chronologies has become a valuable tool in reconstructing disturbance history in temperate forests worldwide; yet, its usefulness has not been tested in the temperate forests of Patagonia. Knowledge on the different disturbance regimes and their effect on the structure and dynamics of the oldgrowth forests in the southern Patagonia area of Argentina is scarce. We reconstructed the forest dynamics and disturbance history of an old-growth N. pumilio forests in the Toro River Valley, Santa Cruz, Argentina using dendroecological techniques. Since a variation in the disturbance regimes was expected with changing altitude, we sampled at different altitudes. We found distinct differences in forest structure, dynamics and disturbance history with changes in the altitude. The disturbance chronologies provided robust evidence that forests in the study area have been subjected to multiple disturbance events over the last 270 years. Yet, recognizing the agent of disturbance could be difficult in these montane forests and further studies are required. Moreover, disturbances might have varied from frequent, moderate to highseverity events to less frequent and more severe events. This study represents the first of its kind for the temperate forests of Patagonia.