Analysis of edaphic and ecophysiological parameters in relation to nutrient levels and growth of Pinus pinaster in acidic soils

Abstract

The main aim of this doctoral research was to improve the understanding of the relationships between the ecophysiological and edaphic parameters that determine the growth of Pinus pinaster and its ability to adapt to different environments. The relationships between soil properties, foliar nutrients and growth were studied in plots of Pinus pinaster established in soil over different types of bedrock. Good adaptation of Pinus pinaster was observed in soils developed over biotitic schist, granitic rocks, gneiss and migmatites, in which growth of the species was highest. Foliar Ca and K, soil depth and average annual temperature explained around 52% of the variability in site index. Needle length, width and thickness were closely related to climate conditions, year of formation and also foliar concentrations of N and Mg. Foliage biomass and leaf area index were negatively correlated with needle age and positively correlated with site index and foliar nutrients. In the soil over biotitic schist, the concentrations of oxalate and pyrophosphate Al were higher than in other soils and tended to form highly stable organic–aluminium complexes. The toxicity indices considered indicated a higher risk of Al toxicity in the plots developed over slate and mica schist, but no risk of Al toxicity in the plots on biotitic schist.