The Mediterranean region in central Chile is experiencing a significant decrease in precipitation due to climate change and the dynamics of the El Niño Southern Oscillation (ENSO). Droughts have increased in recent decades, with the most severe and longest drought of the last millennium occurring since 2010 in central Chile. The impact of ongoing water scarcity is leading to significant drought-related declines in tree growth and forest dieback in the Mediterranean region. A deep understanding of how tree species respond to climate is crucial to accurately predict how forests will respond to climate change. We examined the growth responses to climate of three endemic and threatened tree species of the Mediterranean forests of central Chile, Nothofagus macrocarpa, Cryptocarya alba and Persea lingue, in a protected area. We observed that the growth of all three species was highly dependent on water availability and ENSO, and that the evergreen species C. alba and P. lingue increased their sensitivity to hydroclimate more than the deciduous species N. macrocarpa. These relationships were consistent across much of southern South America, highlighting the dependence of these species on water availability at large geographic scales. We found that there is a relationship between local water availability and ENSO that has intensified temporally and expanded geographically in recent decades. The xerophyllous species C. alba showed greater resistance and increasing resilience to severe droughts, while P. lingue and N. macrocarpa showed greater growth decline during droughts, possibly due to their preference for wetter environments. Our results highlight the crucial role of ENSO-driven water availability and drought in limiting tree growth and threatening the conservation of Mediterranean forests in central Chile.

Laurel forests are quite relevant for biodiversity conservation and are among the island ecosystems most severely damaged by human activities. In the past, Canary laurel forests have been greatly altered by logging, livestock and agriculture. The remains of laurel forests are currently protected in the Canary Islands (Spain). However, we miss basic information needed for their restoration and adaptive management, such as tree longevity, growth potential and responsiveness to natural and anthropogenic disturbances. Using dendrochronological methods, we studied how forest dynamic is related to land-use change and windstorms in two well-preserved laurel forests on Tenerife Island. Wood cores were collected from over 80 trees per stand at three stands per forest. We used ring-width series to estimate tree ages and calculate annual basal area increments (BAI), cumulative diameter increases, and changes indicative of released and suppressed growth. Twelve tree species were found in all stands, with Laurus novocanariensis, Ilex canariensis and Morella faya being the most common species. Although some individuals were over 100 years old, 61.8%–88.9% of the trees per stand established between 1940 and 1970, coinciding with a post-war period of land abandonment, rural exodus and the onset of a tourism economy. Some trees have shown growth rates larger than 1 ​cm diameter per year and most species have had increasing BAI trends over the past decades. Strong growth releases occurred after windstorms at both sites, but the effects of windstorms were site-dependent, with the 1958 storm affecting mainly the eastern tip of the island (Anaga massif) and the 1991 storm the western tip (Teno massif). Given the great ability of laurel forest trees to establish after land use cessation and to increase growth after local disturbances such as windstorms, passive restoration may be sufficient to regenerate this habitat in currently degraded areas.