INVESTIGADORES
MARCOTTI eugenia
congresos y reuniones científicas
Título:
Extreme droughts in northern Patagonia affect resilience in Austrocedrus chilensis forests
Autor/es:
MARCOTTI, EUGENIA; AMOROSO, MARIANO M.; RODRÍGUEZ CATÓN, MILAGROS; VEGA, LETICIA; SRUR, ANA M.; VILLALBA, RICARDO
Reunión:
Congreso; Fall Meeting 2019; 2019
Resumen:
The increase in drought frequency forecasted in southern South America will induce forest declines in the Patagonian Andes. To assess the impact of major droughts on the radial growth of the Austrocedrus chilensis, we analyze different indices of growth resilience between living and dead trees along a precipitation gradient in northern Patagonia, Argentina. We hypothesize that A. chilensis in semi-arid sites shows a great capacity of resistance to droughts, but less recovery capacity after droughts than trees in the humid forests. Additionally, we assume that dead trees have lower resilience indexes than living trees. The study area is located in the Nahuel Huapi National Park, along a 60-km transect encompassing the West-East precipitation gradient (form 2000 mm to 500 mm total annual) due to the orographic effect of the Andes Cordillera. We sampled at nine plots of dead trees and nine plots of living trees in mixed, compact and open forests. We quantify the extreme droughts using six monthly precipitation CRUTS v4 temperature records. Based on basal area increment before, during and after ten extreme droughts, we quantified resistance, recovery and resilience indices. The total resistance and relative resilience were low (index1) along a gradient for all trees. Differences among forest configuration were only significant for the total resistance (mixed>open>compact forest). Considering the living and dead trees, the temporal evolution of the resilience indices were different for particular droughts. Although all trees showed high recovery indices after droughts, the resistance and relative resilience responses to droughts suggest major limitations in A. chilensis growth. It is important to consider the characteristics of droughts, since the duration and severity of the events affect the recovery of the specie and consequently their conservation.