Cold-induced forest dieback of rear-edge tree populations

Although extreme climatic events such as drought are known to modify forest dynamics by triggering tree dieback, the impact of extreme cold events, especially at the low-latitude margin (‘rear edge’) of species distributional ranges, has received little attention.

Camarero et al. quantify how an extreme cold event in 2001 in Spain affected growth, needle loss and mortality of Scots pine (Pinus sylvestris) and compare it with the predictions of a species distribution model (SDM). For trees already stressed by a preceding dry summer and autumn, the record minimum temperatures caused dieback and large-scale mortality. The SDM, which predicts distribution mainly on the basis of responses to maximum and minimum monthly temperatures, failed to model this, leading to the conclusion that distribution modelling techniques such as SDM must incorporate climatic extremes in order to avoid biased predictions based solely on warmer climatic scenarios.

This article appears in the special issue Plants and Climate Change.