Abstract

In the study reported here we examined the short-term effects (1-3 years) of slash retention (SR) and the long-term effects (13-15 years) of wood-ash application (A) on fine roots and mycorrhizae in a 40-year-old Norway spruce forest in southwest Sweden. Soil cores were used to obtain estimates of the biomass (g m(-2)) of roots in three diameter classes (< 0.5, 0.5-1 and 1-2 mm), root length density (RLD), specific root length (SRL) and mycorrhizal root tip density (RTD). Fine root (< 1 mm) length production and mortality, and mycelium production, were estimated using minirhizotron and mesh bag techniques, respectively. Compared with the control plots (C), the biomass of fine roots in diameter classes < 0.5 mm and 0.5-1 mm was significantly higher in A plots, but lower in SR plots. In addition, RLD was significantly lower in the humus layer of SR plots than in the humus layers of C and A plots, but not in the other layers. None of the treatments affected the SRL. In all soil layers, the SR treatment resulted in significant reductions in the number of ectomycorrhizal root tips, and the mycelia production of fungi in mesh bags, relative to the C treatment, but the C and A treatments induced no significant changes in these variables. Fine root length production in the C, A and SR plots amounted to 94, 87 and 70 turn tube(-1) during the 2003 growing season, respectively. Fine root mortality in treated plots did not change over the course of the study. We suggest that leaving logging residues on fertile sites may result in nitrogen mineralisation, which may in turn induce reductions in root biomass, and both root and mycelium production, and consequently affect nutrient uptake and the accumulation of organic carbon in soil derived from roots and mycorrhizae. (C) 2008 Elsevier B.V. All rights reserved.

Keywords

fine roots; mortality; mycelium; production; slash retention; soil cores; minirhizotrons; wood ash

Published in

Forest Ecology and Management
2008, Volume: 255, number: 7, pages: 2109-2117
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Majdi, Hooshang

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Johansson, Ulf

  • Unit for Field-based Forest Research, Swedish University of Agricultural Sciences
    

• Nylund, Jan-Erik

  • Department of Forest Products, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use
Forest Science


Publication identifier

DOI: https://doi.org/10.1016/j.foreco.2007.12.017

Permanent link to this page (URI)

https://res.slu.se/id/publ/17904