Abstract

The critical load concept is used to establish the deposition levels which ecosystems can tolerate without significant harmful effects. Here we summarize work within the Swedish research program Abatement Strategies for Transboundary Air Pollution (ASTA) assessing the critical load of N for boreal forests. Results from both field experiments in an area with low background N deposition in northern Sweden, and from a large-scale monitoring study, show that important vegetational changes start to take place when adding low N doses and that recovery of the vegetation after ceasing N input is a very slow process. The data presented indicate that changes in key ecosystem components occur even at a lower rate of N input than the present recommended empirical critical load for boreal forest understorey vegetation of 10-15 kg N ha(-1) yr(-1). Based on the data presented, we suggest that the critical load should be lowered to 6 kg N ha(-1) yr(-1)

Published in

AMBIO: A Journal of the Human Environment
2005, Volume: 34, number: 1, pages: 20-24
Publisher: ROYAL SWEDISH ACAD SCIENCES

SLU Authors

• Nordin, Annika

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Witzell, Johanna

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Näsholm, Torgny

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Publication identifier

DOI: https://doi.org/10.1639/0044-7447(2005)034[0020:NDATBO]2.0.CO;2

Permanent link to this page (URI)

https://res.slu.se/id/publ/6989