Plant and Soil

, Volume 330, Issue 1–2, pp 407–421

Soil nitrogen cycling rates in low arctic shrub tundra are enhanced by litter feedbacks

  • Kate M. Buckeridge
  • Erik Zufelt
  • Haiyan Chu
  • Paul Grogan
Regular Article

DOI: 10.1007/s11104-009-0214-8

Cite this article as:
Buckeridge, K.M., Zufelt, E., Chu, H. et al. Plant Soil (2010) 330: 407. doi:10.1007/s11104-009-0214-8

Abstract

Shrub growth has increased across the Arctic in recent decades and is strongly limited by soil nitrogen (N) availability. In order to understand the role of N in controlling shrub growth, we compared N-cycling in tall birch (Betula glandulosa) and surrounding dwarf birch hummock vegetation on similar soils in a Canadian low arctic site. Stable isotope tracer analysis revealed N pools and cycling rates were ∼3 times larger and faster in the tall birch ecosystem in the late growing season, just prior to leaf senescence. Gross NH4+-N production rates in these ecosystems correlated positively with larger pools and production rates of dissolved soil C and N, higher quality litter inputs and lower soil C. Analyses of the soil microbial community in both ecosystems indicated similar fungal dominance (epifluorescence microscopy) and similar compositions of the principal fungal or bacterial phylotypes (denaturing gradient gel electrophoresis). Together, these results strongly suggest that vegetation feedbacks associated with larger inputs of higher quality litter promote rapid soil N-cycling and enhanced shrub growth in tall birch tundra. We conclude that these litter-related feedbacks during summer may be as important as snow-shrub feedbacks in maintaining and promoting differences in shrub growth across the arctic landscape.

Keywords

15Nitrogen Gross N mineralization Arctic tundra Litter Soil microbial community Betula 

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Kate M. Buckeridge
    • 1
  • Erik Zufelt
    • 1
    • 2
  • Haiyan Chu
    • 1
    • 3
  • Paul Grogan
    • 1
  1. 1.Department of BiologyQueen’s UniversityKingstonCanada
  2. 2.Department of Life SciencesQueen’s UniversityKingstonCanada
  3. 3.State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil ScienceChinese Academy of SciencesNanjingChina

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