Oak Competition Dominates Interspecific Interactions in Growth and Water-Use Efficiency in a Mixed Pine–Oak Mediterranean Forest

In the Mediterranean, mixed forests of Aleppo pine and holm oak are widespread. Generally considered a transition stage in succession towards climax communities, niche segregation may also contribute to prevalence these communities. So far, there is increasing evidence hydrological segregation, with two species showing complementary water use seasonal growth patterns. However, it remains unknown whether interspecific interactions affect response climate mid-term (decadal) water-use efficiency pines oaks stands. Here, we combined tree-ring chronologies, built on different competition classes within stand, spatially explicit assessment individual wood carbon isotope discrimination (?13C), as proxy intrinsic efficiency, compared results previously reported uptake We found that modulated oaks, whereas was insensitive competition. On other hand, density affected only growth, both species. conclude presence had negligible or even positive effects but neighbor limited their ability recover after drought. Conversely, experienced greater drought stress under competition, pines.