Spatial heterogeneity and relationships of mineral soil properties in a boreal Pinus sylvestris stand

The spatial variation of physical and chemical properties of mineral soil was studied in the surface layer of a glaciofluvial marginal‐interlobate 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 measured. The fine grain fraction (<0.06 mm) was analyzed for mineral nutrients, specific surface area, pH, organic matter and air‐dry moisture. In the factor analysis the variables were grouped into three factors describing soil texture, mineralogical composition and secondary soil processes. The variation within the area in mineral nutrient contents was near threefold (Mg 2.7–7.3, K 0.5–1.4, Ca 0.13–0.29 g Kg‐1). Average Mg/Ca ratio was 28.3, Mg/K ratio 5.7 and K/Ca ratio 4.9. The proportion of fine sand described best the sorting process, and it was negatively correlated with variables determined from the silt and clay fraction. 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 between sampling points.