Abstract

Natural ecosystems at the extreme species distribution are vulnerable to changes and can provide useful insight on management and conservation strategies to counteract effects of recent climate change. Patagonia has unique features: (i) extreme climate and closeness to Antarctica, (ii) relative intact ecosystems, but (iii) few long-term forest studies conducted there. The objective was to determine changes in diversity, forest structure and ecosystem processes and relate them with climate variables and indexes (e.g. El Nino Southern Oscillation, ENSO; Southern Annular Mode, SAM) in the short- medium-term (last 5-20 years). We employed longterm data and experimental plots into managed and unmanaged Nothofagus forests, remote sensing and climate indexes. We found evidences of impact of extreme climate events on: (i) crown dieback in natural forests resulting in changing site quality; (ii) tree mortality rates in managed forests (e.g. thinnings) where summer drought and primary productivity net explain most of the tree losses; (iii) seed production can changed due to ENSO (e.g. La Niña increased the seeding) or SAM (increased seeding with negative values of SAM), (iv) daily regeneration growth is related to rainfall events determining survival along the season; and (v) biodiversity indicators (birds and understory) related to net primary productivity and climatic events. Besides an evaluation of the effectiveness of current management and conservation strategies, our monitoring permitted to suggest new ones to increase the resilience of the natural forests to climate change.