Physiological and phenological adjustments in water and carbon fluxes of Aleppo pine forests under contrasting climates in the Eastern Mediterranean.

This article focuses on a two-year comparative ecophysiological study of Aleppo pine (Pinus halepensis Mill.) forests in two Eastern Mediterranean sites—Sani, Greece (mild climate), and Yatir, Israel (extreme semi-arid climate)—to assess their physiological responses and ecosystem CO2 and water vapor fluxes under contrasting environmental conditions. Using eddy covariance measurements and generalized additive models (GAMs), the study found that soil water content (SWC) was the primary factor influencing seasonal carbon and water flux patterns, with vapor pressure deficit and temperature having milder effects. Despite significant differences in climate and seasonal flux timing, the two forests exhibited similar physiological responses during optimal periods, indicating strong phenotypic plasticity that may enable Aleppo pine to adjust to increasing drought and warming without requiring genetic adaptation. These findings suggest that Aleppo pine forests have the capacity to maintain carbon sequestration and ecosystem functioning under projected Mediterranean climate change, although site-specific water limitations strongly affect annual carbon and water fluxes.