Leś. Pr. Bad., 2009, Vol. 70 (3): 297-302.

Wpływ więźby sadzenia na wybrane cechy składu chemicznego wierzchniej warstwy gleby w 30-letnim drzewostanie sosnowym
The effect of planting density on chemical properties of the top soil layer in a 30-year-old pine stand

Wojciech Gil
Intytut Badawczy Leśnictwa, Zakład Hodowli Lasu, Sękocin Stary ul. Braci Leśnej 3, 05–090 Raszyn; Fax +48 022 7150300; e-mail: W.Gil@ibles.waw.pl

Abstract. The purpose of this study was to establish the relationship between the initial density of trees and selected elements of chemical composition of the top soil layer in a 30-year-old pine stand.
The studies were conducted on the permanent study plot located in the territory of the Parciaki Forest District, Bramura Forest Subdistrict, compartment 149. The experiment was carried out in three variants (in three replications): A – 15,625 trees/ha (spacing 0.8×0.8 m), B – 10,000 trees/ha (spacing 1×1 m), C – 6,945 trees/ha (spacing 1.2×1.2 m). 41 soil samples were collected from each plot according to the set plan. The analysis comprised soil pH, total carbon and sulphur content, concentrations of nitrate, potash, magnesium and phosphorus ions. The initial density was confirmed to have had a significant impact on the chemical composition of the top soil layer. At a lower tree density, the concentrations of nitrate, sulphur, nitrogen and general carbon ions in the soil were higher and the pH value – lower. The content of the analysed elements in the mineral layer of forest soil in the fresh coniferous forest habitat varied even on relatively small study plots. The largest differences (variation coefficients over 100%) were in the case of nitrate ions and the smallest – in the case of pH.

Key words: initial density, spacing, Scots pine, soil chemical properties, variability of forest soil.