SPATIAL HETEROGENEITY AND RELATIONSHIPS OF MINERAL SOIL PROPERTIES INA BOREAL PINUS-SYLVESTRIS STAND

The spatial variation of physical and chemical properties of mineral s oil was studied in the surface layer of a glaciofluvial marginal-inter lobate complex in a Pinus sylvestris (L.) stand in eastern Finland. An area of one hectare was sampled (n = 107) from a depth of 10-15 cm in the mineral soil. Particle size distribution of the samples was measu red. The fine grain fraction (<0.06 mm) was analyzed for mineral nutri ents, specific surface area, pH, organic matter and air-dry moisture. In the factor analysis the variables were grouped into three factors d escribing soil texture, mineralogical composition and secondary soil p rocesses. The variation within the area in mineral nutrient contents w as near threefold (Mg 2.7-7.3, K 0.5-1.4, Ca 0.13-0.29 g Kg-1). Averag e Mg/Ca ratio was 28.3, Mg/K ratio 5.7 and K/Ca ratio 4.9. The proport ion of fine sand described best the sorting process, and it was negati vely correlated with variables determined from the silt and clay fract ion. The proportion of fine sand varied from 7% to 46% within the area . The semivariogram analysis suggested that variables describing soil texture and mineralogy were autocorrelated within 15 m distance betwee n sampling points.