Nitrogen mineralization and phenol accumulation along a fire chronosequence in northern Sweden

Tom Miles

Nitrogen mineralization and phenol accumulation along a fire chronosequence in northern Sweden
T. DeLuca, M.-C. Nilsson, O. Zackrisson , Oecologia, October 2002

Abstract

Scots pine (Pinus sylvestris L.) forests of northern Sweden are often considered to be N limited. This limitation may have been exacerbated by the elimination of wildfire as a natural disturbance factor in these boreal forests. Phenolic inhibition of N mineralization and nitrification (due to litter and exudates of ericaceous shrubs) has been proposed as a mechanism for N limitation of these forests, but this hypothesis remains largely untested. N mineralization rates, nitrification rates, and sorption of free phenolic compounds were assessed along a fire-induced chronosequence in northern Sweden. A total of 34 forest stands varying in age since the last fire were identified and characterized. Overstorey and understorey vegetative composition and depth of humus were analysed in replicated plots at all 34 sites. Eight of the forest stands aged 3-352 years since the last fire were selected for intensive investigation in which ten replicate ionic resin capsules (used to assess net N mineralization and nitrification) and non-ionic carbonaceous resin capsules (used to assess free phenolic compounds) were installed at the interface of humus and mineral soil. A highly significant correlation was observed between site age and net sorption of inorganic N to resin capsules. Net accumulation of NH4+ and NO3- on resin capsules followed a linear decrease (R2=0.61, P

Keywords
Boreal forest, Succession, Charcoal, Nitrogen transformations

Publisher Springer Berlin / Heidelberg
ISSN 0029-8549 (Print) 1432-1939 (Online)
Issue Volume 133, Number 2 / October, 2002
Category Ecosystems Ecology
DOI 10.1007/s00442-002-1025-2
Pages 206-214
Subject Collection Biomedical and Life Sciences
SpringerLink Date Thursday, February 19, 2004