Functional diversity enhances silver fir growth resilience to an extreme drought

It is expected that extreme climate events such as droughts will increase both in severity and intensity as a consequence of forecasted climate change. Complementarity among tree species in resource acquisition strategy may reduce interspecific competition and increase the occurrence of facilitative interactions, resulting in an improved tree growth and resilience to extreme climatic events. However, the response of individual trees growing in more functionally diverse stands to extreme events is still under debate. We investigate the growth response of silver fir (Abies alba) to an extreme drought event which occurred in 1985-1986 in the central Spanish Pyrenees, and how the growth and resilience of trees relate to their neighbourhood functional diversity, stand heterogeneity, and to intraspecific and interspecific competition. Dendroecological methods were used to reconstruct radial growth. We recorded all tree species living around each sampled tree and calculated indices of intra- a...