-• The effect of climatic variables (temperature and precipitation) on radial growth of the Mediterranean Maritime pine (Pinus pinaster Ait.) was studied using dendrochronological techniques in the Iberian Peninsula.• Ten tree-ring width chronologies, along the central distribution area of the species, were built. Chronology variability was analysed using Principal Component Analysis (PCA) for the period 1952-2005.• The first principal component (PC1) explained 56% of tree-growth variability. Tree-growth association with climate was analysed at regional and local scales using correlation coefficient and bootstrapped response functions.• Radial growth at both scales was positively correlated with rainfall during and prior to the growing season at all sites, and with summer rainfall before the growing season at five sites. Mean temperature effect changed according to the sampling site, from non-significant at the highest sites to significant (positive relationship in winter) at the lowest sites. Growth season temperature also had a negative effect.• The Kalman filter was applied to estimate changing association between growth and climate over-time. Results suggested a change in association, initiated in the 80s, from non-significant to significant ( * p < 0.05) at six of the sampling sites.• Pinus pinaster is an accurate species for analysing tree-growth association with climate and for studying plant behaviour under global change conditions. dendroclimatology / Mediterranean Maritime pine / tree-ring / response function / Kalman filter Résumé -L'influence des variables climatiques sur la croissance radiale de Pinus pinaster Ait. dans les forêts de l' Espagne centrale.• L'influence des variables climatiques (températures et précipitations) sur la croissance radiale du pin maritime (Pinus pinaster Ait.) a été étudiée en utilisant des techniques dendrochronologiques dans la péninsule Ibérique.• Dix chronologies de largeur de cerne ont été établies tout au long de la zone centrale de distribution de l'espèce. La variabilité des chronologies a été étudiée par une Analyse en Composantes Principales (PCA) pour la période 1952-2005.• La première composante principale (PC1) a expliqué 56 % de la variabilité de la croissance des arbres. L'association entre la croissance des arbres et le climat a été analysée à l'échelle locale et régionale en utilisant un coefficient de corrélation et une méthode de rééchantillonnage.• La croissance radiale à ces deux échelles a montré une corrélation positive avec les précipitations survenues pendant et avant la saison de croissance dans tous les sites et avec les précipitations estivales survenues avant la saison de croissance dans cinq sites. L'effet de la température moyenne a varié en fonction de l'altitude des sites, en étant non significatif dans les sites les plus élevés et positivement significatif en hiver dans les sites les plus bas. La température de la saison de croissance a également eu un effet négatif.• On a appliqué le filtre de Kalman pour estimer les variations ...

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Copyright Thinning has a positive effect on growth dynamics and growth-climate relationships in Aleppo pine (Pinus halepensis) trees of different crown classes

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The associations between tree-ring width and climatic variables, the tree age effect on climate-growth relationship and the drought index impact on radial growth of Scots pine (Pinus sylvestris L.) were studied in Mediterranean environments in the Iberian Peninsula. Dendrochronological techniques were applied to construct six tree-ring width chronologies for P. sylvestris. The association between tree growth and climate was analysed with correlation coefficients and bootstrapped response functions. Drought index (DRI) was used to detect the effects of aridity. Tree-ring width was positively correlated with rainfall in the growing season but this association stated earlier at the lowest altitudinal sites. The effects of temperature varied according to the site. The response to climatic variables depended on the age of the trees: more of the variability was explained by climatic variables in young stands than in old stands. The significant association between radial growth and DRI suggests that drought is a determining factor in the radial growth of P. sylvestris. Climate forecast scenarios show an increase in rainfall irregularity in the Mediterranean region so the differential tree response to rainfall at different elevations can be used to predict tree growth for determining silvicultural treatments.

Intraannual features or anomalies in the tree rings of woody species may provided useful information for ecological and climatological studies. The frequency of intraannual density fluctuations (IADFs), differences in IADFs according to the cambial age, changes in IADFs in the last century, and relationships of IADFs to radial growth and climate were analyzed in five stands of Pinus pinaster subsp. mesogeensis (Fieschi & Gaussen) Silba in east-central Spain. Standard dendrochronological techniques were used. Two cores were extracted 1.30 m above ground level from 15 dominant and codominant trees at each sampling site. The data were analyzed by analysis of variance, Pearson’s correlation, and logistic regression. Results showed that (i) the mean frequency of IADFs was higher in younger than older trees; (ii) the frequency of IADFs increased from the 1940s to the present; (iii) radial growth was negatively correlated with the presence of IADFs; and (iv) density fluctuations may be predicted by using a logistic model, with monthly rainfall and temperature as independent variables. Studies of intraannual features or anomalies in radial growth may be useful for ecological and climatological applications under forecasted climate change scenarios.

RESEARCH ARTICLEOPEN ACCESS (Lavorel et al., 1998). Mediterranean forests are the most important ecological infrastructure of the region, providing goods and services and acting as a key for resilience and adaptability. AbstractBackground: The Mediterranean basin has experienced an increase in the mean annual temperature, a decrease in the mean annual precipitation, and an increase in the frequency of severe drought periods during the second half of the 20 th century. However, winter and spring precipitation has increased and summer precipitation has decreased in the western Mediterranean region.Aim of the study: The objectives of the present study were: i) to compare changes in climate-growth relationships over time for Pinus halepensis, P. pinaster and P. sylvestris in Spain ii) to quantify the presence of intra-annual density fluctuations (IADFs) on the three species, and iii) to define the associated climatic variables.Area of study: 26 sampling sites (8 P. halepensis sites, 8 P. pinaster sites and 10 P. sylvestris sites) were selected in their distribution area in Spain.Main results: Precipitation is the main factor influencing growth and IADF occurrence in the three species. Wet periods during previous winter and spring induced higher growth rates on P. halepensis and P. pinaster, while P. sylvestris was mostly influenced by summer precipitation. However, the influence of these climatic variables on the growth of these species changed over the studied period. The increase of winter and spring precipitation combined with increasingly harsh summer climatic conditions in the second half of the 20 th century may have enhanced the importance of precipitation at the beginning of the growing season on the growth of species subject to higher summer drought stress (P. halepensis and P. pinaster) and increased IADF occurrence.Research highlights: Besides reflecting changes in the environmental conditions during the growing season, the inclusion of IADF detection in chronologies adds new information to ring-width chronologies, thereby improving its quality.Key words: Aleppo pine; maritime pine; scots pine; dendroclimatology, IADFs. Abbreviations used: IADF: Intra-annual density fluctuation; AIC: Akaike information criterion; ROC: Receiver operating characteristic.Citation: Olivar, J., Bogino, S., Spiecker, H., Bravo, F. (2015). Changes in climate-growth relationships and IADF formation over time of pine species (Pinus halepensis, P. pinaster and P. sylvestris) in Mediterranean environments. Forest Systems, Volume 24, Issue 1, e-010, 9 pages. http://dx

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