Tree ring research on conifers in the Alps
Dendroecology, dendroclimatology and climatic studies

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Rolland C. (1993). Fonctionnement hydrique et croissance du Sapin (Abies alba Mill.) dans les Alpes françaises. Dynamique des flux de sève, écophysiologie et dendroécologie. Thèse de Doctorat, Juin 1993, Université Joseph Fourier, Grenoble, France, 180 p.
  • TITLE   Water relations and growth of the White Fir (Abies alba Mill.) in the French Alps. Sap flow measurements, ecophysiology and dendroecology.
  • LANGUAGE French
  • SUBJECT Ecology, Tree growth, Response to climate, Sap flow, Soil / Plant / Atmosphere, Climate
  • SPECIES Abies alba Mill.
  • SITES Briançonnais, South-East of France, Alps.

  • Water relationships and growth of the White Fir (Abies alba Mill.) were studied in field conditions in three forests on North facing slopes with contrasting climates. These forests are located in the external Alps in Chartreuse, where the climate is mild, rainy and humid, in the intermediate Alps in Oisans, and in the internal Alps in Briançonnais, where the climate is particularly dry. The number of stomata was shown to vary according to the area. Next, the Soil-Plant-Atmosphere continuum was studied using soil water potential measurements at different depths, leaf water potential measurements on several trees and continuous recording of microclimatical factors such as temperature, relative humidity, solar radiation and wind speed. The air vapour deficit and potential evapotranspiration were then computed. Leaf water potential was measured hourly during the day and weekly during the growing season. Furthermore, a continuous recording of sap speed in four trunks was carried out using a thermal method in the two most contrasting forests. Sap speed and climate relationships were analysed daily and seasonally, before calculating a mathematical model for sap speed and leaf potential. Finally, a dendroecological study was carried out on the Fir in Briançon using a large amount of core samples, to analyse the influence of age on basal area growth, and to study the spatial variations of productivity. The influences of both altitude and slope on the relationships between tree-rings and climate were analysed using ring-widths measurements, and using also the number and sizes of wood cells.
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