title: Plasticity in dendroclimatic response across the distribution range of Aleppo pine (Pinus halepensis).
abstract: We investigated the variability of the climate-growth relationship of Aleppo pine across its distribution range in the Mediterranean Basin. We constructed a network of tree-ring index chronologies from 63 sites across the region. Correlation function analysis identified the relationships of tree-ring index to climate factors for each site. We also estimated the dominant climatic gradients of the region using principal component analysis of monthly, seasonal, and annual mean temperature and total precipitation from 1,068 climatic gridpoints. Variation in ring width index was primarily related to precipitation and secondarily to temperature. However, we found that the dendroclimatic relationship depended on the position of the site along the climatic gradient. In the southern part of the distribution range, where temperature was generally higher and precipitation lower than the regional average, reduced growth was also associated with warm and dry conditions. In the northern part, where the average temperature was lower and the precipitation more abundant than the regional average, reduced growth was associated with cool conditions. Thus, our study highlights the substantial plasticity of Aleppo pine in response to different climatic conditions. These results do not resolve the source of response variability as being due to either genetic variation in provenance, to phenotypic plasticity, or a combination of factors. However, as current growth responses to inter-annual climate variability vary spatially across existing climate gradients, future climate-growth relationships will also likely be determined by differential adaptation and/or acclimation responses to spatial climatic variation. The contribution of local adaptation and/or phenotypic plasticity across populations to the persistence of species under global warming could be decisive for prediction of climate change impacts across populations. In this sense, a more complex forest dynamics modeling approach that includes the contribution of genetic variation and phenotypic plasticity can improve the reliability of the ecological inferences derived from the climate-growth relationships.
authors.affiliation: Departamento de Geografía y Ordenación del Territorio, Universidad de Zaragoza, Zaragoza, Spain ; Instituto de Investigación en Ciencias Ambientales (IUCA), Universidad de Zaragoza, Zaragoza, Spain.
authors.forename: Martin
authors.initials: M
authors.lastname: de Luis
authors.affiliation: Department of Wood Science and Technology, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Katarina
authors.initials: K
authors.lastname: Čufar
authors.affiliation: DendrologyLab (DAFNE), Università Degli Studi della Tuscia, Viterbo, Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Di Filippo
authors.affiliation: Departamento de Geografía y Ordenación del Territorio, Universidad de Zaragoza, Zaragoza, Spain ; Instituto de Investigación en Ciencias Ambientales (IUCA), Universidad de Zaragoza, Zaragoza, Spain.
authors.forename: Klemen
authors.initials: K
authors.lastname: Novak
authors.affiliation: Department of Forestry and Natural Environment Management, Technological Education Institute of Lamia, Karpenissi, Greece.
authors.forename: Andreas
authors.initials: A
authors.lastname: Papadopoulos
authors.affiliation: DendrologyLab (DAFNE), Università Degli Studi della Tuscia, Viterbo, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Piovesan
authors.affiliation: Laboratoire d'Etude des Ressources Forèt-Bois (LERFoB), Centre INRA de Nancy, Champenoux, France.
authors.forename: Cyrille B K
authors.initials: CB
authors.lastname: Rathgeber
authors.affiliation: Departamento de Ecología, Universidad de Alicante, San Vicente del Raspeig, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Raventós
authors.affiliation: Departamento de Geografía y Ordenación del Territorio, Universidad de Zaragoza, Zaragoza, Spain ; Instituto de Investigación en Ciencias Ambientales (IUCA), Universidad de Zaragoza, Zaragoza, Spain.
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Saz
authors.affiliation: Northern Research Station, USDA Forest Service, Durham, North Carolina, United States of America.
authors.forename: Kevin T
authors.initials: KT
authors.lastname: Smith
mesh_terms: D000064:Acclimatization / Q000235:genetics / Q000502:physiology; D002980:Climate; D057231:Climate Change; D014644:Genetic Variation; D057232:Global Warming; D019083:Mediterranean Region; D008954:Models, Biological; D028223:Pinus / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D025341:Principal Component Analysis; D011891:Rain; D013696:Temperature