RESEARCH ARTICLE Stand Competition Determines How Different Tree Species Will Cope with a Warming Climate

Plant-plant interactions influence how forests cope with climate and contribute to modulate species response to future climate scenarios. We analysed the functional relationships be-tween growth, climate and competition for Pinus sylvestris,Quercus pyrenaica andQuercus faginea to investigate how stand competition modifies forest sensitivity to climate and simu-lated how annual growth rates of these species with different drought tolerance would change throughout the 21st century. Dendroecological data from stands subjected to thin-ning were modelled using a novel multiplicative nonlinear approach to overcome biases re-lated to the general assumption of a linear relationship between covariates and to better mimic the biological relationships involved. Growth always decreased exponentially with in-creasing competition, which explained more growth variability than climate inQ. faginea and P. sylvestris. The effect of precipitation was asymptotic in all cases, while the relation-ship between growth and temperature reached an optimum after which growth declined with warmer temperatures. Our growth projections indicate that the less drought-tolerant P. sylvestris would be more negatively affected by climate change than the studied sub-Medi