Low acclimation potential compromises the performance of water-stressed pine saplings under Mediterranean xeric conditions Juan Ovejero, Raquel Castro Gutiérrez, Jorge Querejeta Mercader, José Ignacio Afforestation Irrigation Physiological plasticity Reforestation Resource-use strategies We are grateful to the Centro Nacional de Recursos Genéticos Forestales “El Serranillo” (MITECO) for cultivating the plants during the nursery stage. Moreover, we want to thank two anonymous reviewers for improving the manuscript with their comments. This study was supported by the projects RESISTE ( P18-RT-1927 ) of the Consejería de Transformación Económica, Industria, Conocimiento y Universidades from the Junta de Andalucía, and PID2019-107382RB-I00 of Ministerio de Ciencia e Innovación from Gobierno de España. Funding for open access charge: Universidad de Granada / CBUA . Predicted hotter and drier climatic conditions in the Mediterranean Basin will probably hamper current afforestations and reforestations by negatively influencing tree performance. Understanding how saplings can adjust their physiology to shortages in water availability is essential to predict early-stage success of forest ecological restoration. Pines are common target species used in afforestations and reforestations; however, the capacity of their saplings for physiological plasticity to promote drought tolerance remains largely unexplored. In this study, we evaluated the demographical and resource-use consequences of short-term irrigation among four pine species (Pinus halepensis, Pinus pinea, Pinus nigra and Pinus sylvestris) growing under water-limiting conditions in a common garden experiment. Summer irrigation increased the survival rate of those pines that were suffering from hydric stress under the xeric conditions of the common garden (i.e. P. pinea, P. nigra and P. sylvestris). Moreover, short-term water supplementation slightly enhanced aboveground biomass production across species. However, leaf isotopic composition and nutrient concentrations did not change after summer irrigation. Independently of water supplementation, P. halepensis was the best adapted species to water scarcity and showed the best physiological and growth performance. By contrast, P. pinea, P. nigra and P. sylvestris saplings exhibited drought-induced reductions in stomatal conductance and low water-use efficiency, nutrient deficiency, and severe N:P and N:K stoichiometric imbalances, leading to impaired growth. We conclude that the lack of physiological plasticity of water-stressed pine saplings to withstand the impacts of climate aridification will likely cause severe impairment of their nutrient status, growth and survival, with dire implications for the successful establishment of Mediterranean afforestation and reforestation programs. 2022-04-21T08:48:26Z 2022-04-21T08:48:26Z 2022-07-20 info:eu-repo/semantics/article R. Juan-Ovejero et al. Low acclimation potential compromises the performance of water-stressed pine saplings under Mediterranean xeric conditions. Science of the Total Environment 831 (2022) 154797. [https://doi.org/10.1016/j.scitotenv.2022.154797] http://hdl.handle.net/10481/74428 10.1016/j.scitotenv.2022.154797 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ info:eu-repo/semantics/openAccess Atribución-NoComercial-SinDerivadas 3.0 España Elsevier B.V.