This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: In 2020, our research published in New Phytologist showed how the height growth of Aleppo pine populations responded to climate gradients across the Mediterranean, and how these populations were expected to respond under future climate change based on decades of common-garden experiments. Since then, multiple studies on Pinus halepensis have documented diverse and often rapid growth and survival responses to recent climatic extremes.
Instead of conducting a traditional systematic review, we evaluated these new findings against our original projections developed six years earlier, testing explicit hypotheses in a new review published in Forest Ecology and Management. Our review reveals that several climate impacts originally predicted for midcentury are already occurring, highlighting an accelerated vulnerability of Mediterranean Aleppo pine forests. The tested hypotheses were that climate change would reshape the growth of Pinus halepensis in predictable ways.
Coastal forests would be more vulnerable than inland ones, dry sites more sensitive than wet sites, and range-edge populations more exposed than core regions. The result is a clear and consistent pattern: Across the Mediterranean, Aleppo pine forests are already experiencing the climate-driven growth declines that were originally forecast for midcentury. Several recent tree-ring studies confirm that coastal Aleppo pine populations are losing growth faster than inland ones.
In Algeria, growth declines between 2013 and 2023 were significantly stronger in coastal forests than in continental montane sites. Similar patterns were observed in Italy, where coastal forests showed steeper reductions in earlywood growth and greater sensitivity to drought. These findings match the 2020 projections, which predicted mild to moderate declines in coastal regions and relative stability inland.
What is striking is not the direction of change, but its timing—declines expected decades from now are already visible. The study also highlights rapid changes at the edges of the species' distribution. In southern Spain, new species-distribution models show that range-edge populations are losing suitable habitat far earlier than expected.
In Israel, natural regeneration at the hyperarid Yatir Forest has nearly collapsed, with almost no seedlings surviving beyond their first year. This mirrors earlier observations from provenance trials, where survival at Yatir was already low, but the new field evidence suggests that regeneration failure is accelerating. Across Greece, Spain and Israel, dry sites show the strongest declines.
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