2025/12/19 by I. Aranda, D. Sánchez-Gómez, F.J. Cano +8 · 1 voice
Agricultural and Biological Sciences · Environmental Science · #Plant responses to elevated CO2 #Plant Water Relations and Carbon Dynamics #Plant responses to water stress
paper · doi:10.1016/j.plaphy.2025.110958
openalex created_date 2025/12/19 · openalex publication_date 2025/12/19 · openalex updated_date 2026/08/01
The wild olive ( Olea europaea L.) is one of the most iconic Mediterranean forest tree species and the ancestor of many cultivated olive varieties. In this study, twelve wild olive genotypes from three distinct subspecies (subsp. europaea , subsp. guanchica , and subsp. maroccana ) were grown under ambient ([CO 2 ] amb ) and enriched CO 2 atmospheres ([CO 2 ] enr ), subject to two watering regimes (WW – Well-watered / WS – Water-stressed). We measured water use at leaf and whole-plant levels, along with growth traits, leaf gas exchange, and leaf isotopic carbon (δ 13 C) and nitrogen composition (δ 15 N), to differentiate functional strategies among genotypes in response to CO 2 and soil water availability. Growth under [CO 2 ] enr lessened water stress effects by increasing water use efficiency (WUE). The improved WUE came from reduced water consumption at both leaf and plant levels under [CO 2 ] enr , although sensitivities to soil water content varied among genotypes. Growth-related traits responded more to water stress than to CO 2 . Patterns of N 15 isotopic composition (δ 15 N) and total leaf nitrogen content on a mass and area basis (N mass and N area ) varied among genotypes in response to atmospheric CO 2 and water stress. A negative relationship between δ 13 C and δ 15 N indicates a complex interaction between carbon and nitrogen metabolisms under the influence of water availability and CO 2 supply. Our study shows that (1) the response of wild olive to atmospheric CO 2 enrichment is strongly influenced by resource availability, especially water, and (2) it is necessary to consider genotype- and subspecies-specific responses when predicting vegetation response in a CO 2 -enriched world.