Climate Differently Impacts the Growth of Coexisting Trees and Shrubs under Semi-Arid Mediterranean Conditions

Background and Objectives—Coexisting tree shrub species will have to withstand more arid conditions as temperatures keep rising in the Mediterranean Basin. However, we still lack reliable assessments on how climate drought affect radial growth of at intra- interannual time scales under semi-arid conditions. Materials Methods—We investigated responses four co-occurring gymnosperms inhabiting sites northeastern Spain: two (Aleppo pine, Pinus halepensis Mill.; Spanish juniper, Juniperus thurifera L.) shrubs (Phoenicean phoenicea L.; Ephedra nebrodensis Tineo ex Guss.). First, quantified intra-annual radial-growth rates by periodically sampling wood samples during one growing season. Second, climate–growth relationships an scale with different soil water availability using dendrochronology. Third, simulated temperature moisture forward, process-based Vaganov?Shashkin (VS-Lite) model disentangle main climatic drivers growth. Results—The all peaked spring early summer (May–June). The pine junipers grew after dry summer, i.e., they showed a bimodal pattern. Prior wet winter leading high before cambium reactivation enhanced P. sites, whereas both depended spring–summer moisture. VS-Lite identified these influences species. Conclusions—Our approach (i) revealed contrasting dynamics co-existing (ii) provided novel insights function habits similar drought-prone regions.