Spatial distribution of fine roots at ploughed Norway spruce forest sites

Abstract

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 -2 at sites K1 and K2, respectively) and lowest in the undisturbed soil at site K1 (79 g m -2 ) and in the furrow at site K2 (145 g m -2 ). The estimated average fine root biomass at the ploughed forest sites (268 and 248 g m -2 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 BT 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.

Soil hydrological properties and conditions, site preparation, and the long-term performance of planted Scots pine (<em>Pinus sylvestris</em> L.) on upland forest sites in Finnish Lapland

“…Rusanen (1986) found that 80% of the pine roots in ridges were located in the mineral soil under the ridges, and that the horizontal distribution of Scots pine roots was relatively even on ploughed areas, including also the intermediate areas. However, Tanskanen and Ilvesniemi (2007) recently showed that the fine root biomass of planted Norway spruce in southern Finland was the highest in the ridges and the lowest in the intact intermediate areas and furrows, 20-33 years after site preparation.…”

Long-term effects on soil-water nitrogen and pH of clearcutting and simulated disc trenching of previously nitrogen-fertilised pine plots

“…The distribution of fineroot biomass in two Norway spruce (Picea abies (L.) Karst.) stands 20 or 33 years after planting suggested significant uptake of nutrients and water from tilts created by ploughing (Tanskanen and Ilvesniemi 2007). Effects of previous N fertilisation may still be present in the upper soil at the time of site preparation (Nohrstedt 1990).…”

Deep soil ploughing for afforestation: a review of potential impacts on soil and vegetation

“…For example, higher fine-root biomass was found in nitrogen-deficient soils, and fertilisation reduced specific root length (Finér et al 2007, Ostonen et al 2007b). In previously ploughed forest soil, it is reasonable to assess the spatial distribution of fine roots in the soil to elucidate soil properties and possible changes in these properties and to assess the long-term uptake of plant nutrients and water (Tanskanen and Ilvesniemi 2007). The distribution of fine roots in ploughed forest sites has shown that SOM, produced by root exudates and fine root turnover, is distributed unevenly in the profile, thus altering the properties of the inverted soil.…”

“…• Easier seedbed preparation / planting of tree seedlings (Russell 2009); • Can be applied to a variety of climatic / soil conditions (Hansen et al 2007, Schneider et al 2017, Hussein et al 2019); • Deeper soil mixing is important for long-term responses (Tanskanen and Ilvesniemi 2007, Baumhardt et al 2008, Alcántara et al 2016); • Successful treatment for sandy topsoil of arable land in dry season (Schneider et al 2017).…”