Effects of site related environmental stresses on radial growth of Scots pine stands Pinus sylvestris (L.)

Dendrochronological and multivariate techniques were used to assess the influence of climate and site-specific factors on radial growth (tree ring-width) of stunted Scots pine trees Pinus sylvestris (L.). Tree growth within the study area (750 m a.s.l.) is strikingly restricted due to the inherent low nutrient content and retarded soil development of dolomite parent material and low water holding capacity of the predominantly shallow, stony soils. The climate-tree-growth relationship of eight scattered populations belonging to the same phytosociological community, a Spring Heath-Pine wood (Erico-Pinetum typicum), was investigated. Arrangement of sites was in relation to a "moisture gradient" defined in terms of a physiographic series from hollows to open south-facing slopes, i.e. from slightly moist to the most xeric sites. Though the overall climate response at the various habitats is similar, principal component analysis resulted in clustering of habitats according to topographic features (slope magnitude, slope aspect, soil depth, vegetation cover). This study shows that at the limit of tree growth, small scale variation of edaphic conditions exert a major influence on susceptibility of trees to environmental stresses.