%0 Research article
%T Spatial distribution of fine roots at ploughed Norway spruce forest sites
%A Tanskanen, Niina
%A Ilvesniemi, Hannu
%D 2007
%J Silva Fennica
%V 41
%N 1
%R doi:10.14214/sf.306
%U https://silvafennica.fi/article/306
%X We examined the spatial distribution of fine roots at two forest sites  that were ploughed 20 (site K1) and 33 years (site K2) before sampling  and planted with Norway spruce (Picea abies (L.) Karst.) seedlings. Soil  core samples were taken from the tilt and beneath the tilt, the furrow  and the intermediate undisturbed soil to a depth of 0.4 m for fine root  biomass, length and necromass determinations. Norway spruce fine roots  were found throughout the ploughed forest sites. The fine roots were,  however, unevenly distributed: the fine root biomass was highest in the  tilt (624 and 452 g m<sup>–2</sup> at sites K1 and K2, respectively) and lowest in the undisturbed soil at site K1 (79 g m<sup>–2</sup>) and in the furrow at site K2 (145 g m<sup>–2</sup>). The estimated average fine root biomass at the ploughed forest sites (268 and 248 g m<sup>–2</sup> at sites K1 and K2, respectively) was, however, similar to those  presented in other studies concerning sites that had not been ploughed.  In the tilt, a substantial proportion of the fine roots was in the  inverted mineral soil horizons and in the new organic horizon above the  tilt. Consistent with the fine root biomass findings, the Norway spruce  necromass was highest in the tilt but the vertical distribution of the  dead roots was different: the necromass was highest in the buried O<sub>BT</sub> horizon. The results of this study suggest that at the ploughed forest  sites, a substantial part of Norway spruce nutrient and water uptake  occured in the tilt during the first 20 or 33 years after plantation.