The physico-chemical parameters and catalase activity of the soils in the range of phytogenic fields of Korean pine plus trees at Verkhneussuriysky forest station

The variability of physico-chemical parameters and enzymatic activity in the surface horizons of brown soil (Cambisols) in the range of phytogenous fields (PF) of Korean pine plus trees of different size and age, growing on the territory of the Verkhneussuriysky forest Station, were investigated. The soil samples were taken inside PF within sectors in the direction: north-south; according to the scheme: I – near-trunk part (30 cm from the trunk); II – middle part (middle of the crown projection); III – the edge of the crown projection. The higher-level (Corg) parameters (28.4%) were under Korean pine with the bigger stem diameter (61 cm) and age (240 years). In the range of PF of Korean pine plus trees (200-210 years old, with stem diameters of 40 cm and size of crown 12.5 x 5.2 m) the middle Corg. factor was 22.5-23.8%. The higher pH average parameters determined under these trees too. The middle (Corg) parameters in the north sectors of PF trees were higher (26.3%) than in south (23.5%). The major trend of decreasing pH value in the edge parts of the PF investigated trees compared with the near-trunk parts.