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Nitrogen and phosphorus dynamics across an elevational gradient in a Swedish subarctic tundra

Sundqvist, Maja (2011). Nitrogen and phosphorus dynamics across an elevational gradient in a Swedish subarctic tundra. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2011:83
ISBN 978-91-576-7627-6
[Doctoral thesis]

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Rising temperatures associated with global climate change are likely to drive major shifts in plant and soil properties as well as plant-soil linkages that govern key ecosystem processes in subarctic tundra. However, the tundra landscape is not homogenous, but instead consists of a mosaic of vegetation types which differ greatly in vegetation characteristics and soil fertility. Two types of vegetation commonly co-occur across broad areas of the Fennoscandian subarctic tundra, i.e., heath vegetation dominated by slow-growing dwarf-shrubs and present on N-poor acidic soils, and meadow vegetation, dominated by herbaceous species and present in shallow depressions on more fertile soils. Temperature declines predictably with elevation, and therefore gradients of elevation are powerful natural experiments for studying the effects of long-term changes in temperature on ecosystem properties and processes. This thesis uses an elevational gradient to understand how temperature influences nitrogen (N) and phosphorus (P) dynamics, and how this is associated with shifts in plant and soil microbial properties, for both tundra heath and meadow vegetation. The overall results of this thesis showed that increasing elevation led to an increase in plant limitation of P relative to N, and a general decline in soil P availability but had highly variable effects of soil N availability. Such variation in soil N and P responses to elevation were often associated with the specific characteristics of the plant species that dominated at the different elevations. Importantly, the effect of elevation on aboveground and belowground characteristics differed greatly between tundra heath and meadow vegetation, leading to vastly different responses of litter decomposability, soil microbial properties, soil nutrient cycling, and ultimately N and P availability to elevation among these two vegetation types. In total these findings highlight how shifts in elevation and associated changes in abiotic factors such as temperature not only have contrasting effects on the availability of N and P, but also have fundamentally different influences on N and P cycling for two functionally contrasting vegetation types that co-occur in the same tundra landscape.

Authors/Creators:Sundqvist, Maja
Title:Nitrogen and phosphorus dynamics across an elevational gradient in a Swedish subarctic tundra
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :September 2011
Number of Pages:54
ISundqvist, M.K., Giesler, R., Graae, B.J., Wallander, H., Fogelberg, E., & Wardle, D.A. (2011). Interactive effects of vegetation type and elevation on aboveground and belowground properties in a subarctic tundra. Oikos 120, 128-142.
IISundqvist, M.K., Giesler, R. & Wardle, D.A. Within- and across-species responses of plant traits and litter decomposition to elevation across contrasting vegetation types in a subarctic tundra. Submitted manuscript.
IIISundqvist, M.K., Olofsson, E., Giesler, R., Gundale, M.J. & Wardle, D.A. Plant polyphenolics across an elevational gradient: does subarctic vegetation support plant polyphenolic allocation theory? Manuscript.
IVSundqvist, M.K., Wardle, D.A., Vincent, A. & Giesler, R. Contrasting nitrogen and phosphorus dynamics across an elevational gradient for subarctic tundra heath and meadow vegetation. Manuscript.
Place of Publication:Umeå
Publisher:Institutionen för skogens ekologi och skötsel, Sveriges lantbruksuniversitet
ISBN for printed version:978-91-576-7627-6
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:P Natural resources > P35 Soil fertility
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Ecology
Agrovoc terms:nitrogen, phosphorus, soil fertility, microbial properties, phenolic compounds, tundra, sweden
Keywords:plant functional leaf traits, litter quality, phenolic compounds, decomposition, mineralization, immobilization, fungal:bacterial ratio
Permanent URL:
ID Code:8331
Department:(S) > Dept. of Forest Ecology and Management
Deposited By: PhD studen Maja K Sundqvist
Deposited On:26 Sep 2011 04:49
Metadata Last Modified:02 Dec 2014 10:47

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