Variation in nitrogen deposition and available soil nitrogen in a forest–grassland ecotone in Canada

  • Regional variation in nitrogen (N) deposition increases plant productivity and decreases species diversity, but landscape- or local-scale influences on N deposition are less well-known. Using ion-exchange resin, we measured variation of N deposition and soil N availability within Elk Island National Park in the ecotone between grassland and boreal forest in western Canada. The park receives regionally high amounts of atmospheric N deposition (22 kg ha⁻¹ yr⁻¹). N deposition was on average higher ton clayrich luvisols than on brunisols, and areas burned 1 – 15 years previously received more atmospheric N than unburned sites. We suggest that the effects of previous fires and soil type on deposition rate act through differences in canopy structure. The magnitude of these effects varied with the presence of ungulate grazers (bison, moose, elk) and vegetation type (forest, shrubland, grassland). Available soil N (ammonium and nitrate) was higher in burned than unburned sites in the absence of grazing, suggesting an effect of deposition. On Regional variation in nitrogen (N) deposition increases plant productivity and decreases species diversity, but landscape- or local-scale influences on N deposition are less well-known. Using ion-exchange resin, we measured variation of N deposition and soil N availability within Elk Island National Park in the ecotone between grassland and boreal forest in western Canada. The park receives regionally high amounts of atmospheric N deposition (22 kg ha⁻¹ yr⁻¹). N deposition was on average higher ton clayrich luvisols than on brunisols, and areas burned 1 – 15 years previously received more atmospheric N than unburned sites. We suggest that the effects of previous fires and soil type on deposition rate act through differences in canopy structure. The magnitude of these effects varied with the presence of ungulate grazers (bison, moose, elk) and vegetation type (forest, shrubland, grassland). Available soil N (ammonium and nitrate) was higher in burned than unburned sites in the absence of grazing, suggesting an effect of deposition. On grazed sites, differences between fire treatments were small, presumably because the removal of biomass by grazers reduced the effect of fire. Aspen invades native grassland in this region, and our results suggest that fire without grazing might reinforce the expansion of forest into grassland facilitated by N deposition.show moreshow less

Download full text files

Export metadata

  • Export Bibtex
  • Export RIS
  • Export XML

Additional Services

Share in Twitter Search Google Scholar
Metadaten
Author:Martin Köchy, Scott D. Wilson
URN:urn:nbn:de:kobv:517-opus-5768
Document Type:Postprint
Language:English
Date of Publication (online):2005/09/02
Year of Completion:2004
Publishing Institution:Universität Potsdam
Release Date:2005/09/02
Tag:Canada; aspen parkland; fire; forest invasion; grazing; shrubland; soil type; subboreal; vegetation type
Source:LANDSCAPE ECOLOGY 20 (2): 191-202 FEB 2005
RVK - Regensburg Classification:RT 40525
Organizational units:Mathematisch-Naturwissenschaftliche Fakultät / Institut für Biochemie und Biologie
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften
Notes extern:First published in:
LANDSCAPE ECOLOGY 20 (2): 191-202 FEB 2005
DOI: 10.1007/s10980-004-2264-x