Comparative relationships between rainfall and radial growth assessed by dendrochronology in Pinus pinea and Pinus pinaster from high Tiétar river valley (Avila, Spain).

PATÓN, D., GALAVIS, M., VENEGAS, F., ROIG, F.A.

Carmona, Sevilla

Workshop; First MedCLIVAR Workshop on Reconstruction of Past Mediterranean Climate; 2006

European Science Fundation and others

The response to climate of tree-ring chronologies developed from Pinuspinea (L.) and Pinus pinaster (Aiton Cast.) are discussed here. Although, bothspecies growth at similar environments, results indicate different response inrelation to a decrease amount in rainfall. This could be related to differentphysiological behavior to drought effects. Both species were introduced in TiétarRiver Valley in 1274, during the reign Fernando IV who give political privileges tothe villages of the area for its economical returns to kingdom based in forestexploitation. At present our dendrochronological register cover the last 98 yearsshowing a severe decrease in radial growth, especially in P.pinaster, the mostextended species in the area. We observed the incidence of the first cases ofgeneralized insect damage in the area in the last 30 years. Very probably a severedecrease of rainfall cause an acute water deficit (detected in radial growth) andconsequently an stress that can increase vulnerability to insect damage andtherefore cause the observed mortality, specially in P.pinaster. Similar processeshas been studied in Pinus genus from other Mediterranean areas.