Impacts of recurrent dry and wet years alter long-term tree growth trajectories

Climate extremes, such as abnormally dry and wet conditions, generate abrupt shifts in tree growth, a situation which is expected to increase under predicted climate conditions. Thus, it is crucial to understand factors determining short- and long-term tree performance in response to higher frequency and intensity of climate extremes.

We evaluated how three successive droughts and wet years influenced short- and long -term growth of six dominant Iberian tree species. Within species variation in growth response to repeated dry and wet years was evaluated as a function of individual traits related to resource and water use (diameter at breast height (DBH), wood density (WD) and specific leaf area (SLA)) and tree-to-tree competition across climatically contrasted populations. Furthermore, we assessed how short-term accumulated impacts of the repeated dry and wet years influenced long-term growth performance.

All species showed strong short-term growth decreases and enhancements due t...