loading page

Warming, permafrost thawing and nitrogen availability are drivers of increasing plant growth and species richness on the Tibetan Plateau
  • +5
  • Hanbo Yun,
  • Qing Zhu,
  • Jing Tang,
  • Wenxin Zhang,
  • Deliang Chen,
  • Philippe Ciais,
  • Qingbai Wu,
  • Bo Elberling
Hanbo Yun
University of Copenhagen

Corresponding Author:[email protected]

Author Profile
Qing Zhu
Lawrence Berkeley National Lab
Author Profile
Jing Tang
University of Copenhagen
Author Profile
Wenxin Zhang
Lund University
Author Profile
Deliang Chen
University of Gothenburg
Author Profile
Philippe Ciais
Laboratory for Climate Sciences and the Environment (LSCE)
Author Profile
Qingbai Wu
State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences
Author Profile
Bo Elberling
University of Copenhagen
Author Profile

Abstract

Permafrost-affected ecosystems are prone to warming and thawing, which can increase the availability of subsurface nitrogen (N) with consequences for otherwise N-limited tundra vegetation. Here, we show that the upper permafrost of the Tibetan Plateau is subject to thawing and that the upper permafrost zone is rich in ammonium. Furthermore, a five-year 15N tracer experiment showed that long-rooted plant species were able to utilize 15N-labeled N at the permafrost table and far below the main root zone. A 20 years survey is used here to document that long-rooted plant species had a competitive advantage at sites subject to warming and that both plant composition and growth were significantly correlated with permafrost thawing and changes in nitrogen availability. Our experiment documents a clear feedback mechanism of climate warming, which releases plant–available N favoring long-rooted plants and explains important changes in plant composition and growth across sites on the Tibetan Plateau.