The Long Term Influence of Different Tree Species on some Physical and Chemical Properties of a Stagnic Haplic Luvisol from Tinca Forest District, U.P. II Sititelec

Abstract

The main objective of this work is studying the evolution of some physical-chemical properties of a stagnic haplic luvisol under the long-term influence of the forest vegetation, respective 43 year old red oak (Quercus rubra) forest and 77 year old sessile oak (Quercus petraea). In order to reach the proposed objective, on the stagnic haplic luvisol from U.P. II Sititelec were opened two soil profiles, until the depth of 0.5 m, one in the 139 A parcel, occupied by red oak tree and the other one in the 130 parcel, occupied by sessile oak on a distance of approximately 1500 m between the profiles. The folic unhydromorf O horizons, present on the surface of analyzed soil profiles, has under the sessile oak a content of 39.38% humus and 22.84% of organic carbon while under red oak 22.92 % and 13.29 %. The big humus quantity from the folic horizon O and it reaction more acid under sessile oak than under red oak influences the evolution of the superior part of the soil profiles. The modification of chemical properties of stagnic haplic luvisol under red oak and sessile oak produced in the last 43 years had influenced the modification of physical characteristics of soil. The differences between the clay content of the two profiles of analyzed soil indicates the fact that this increase on the profile under sessile oak in comparison with the profile under red oak, with values between 12.0 % at surface o profile and 7.5 % on the first clay accumulation horizon Btw1. The established logarithmic equation, distinct significant, demonstrates that the increase of the clay percent is inverse proportional with the logarithm of humus content (%) and soil reaction (pH). The increasing tendency of clay percent from the profile under red oak in comparison with the profile under sessile oak can be due to the increasing aggression of environment, as a result of small humus content and increasing tendency of acidity that determines an increasing intensity of soil physical disintegration and decomposition.