Research Highlights

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Observations in Tundra Imply Needed Improvements in Land Models

December 11, 2014

Objective

We describe an observational and modeling meta-analysis to benchmark land models and identify needed improvements. We applied the method to the Community Land Model (CLM) with two versions of belowground biogeochemistry (CN and Century).

Research

  • We extracted benchmark metrics (e.g., belowground respiration, soil organic matter content) from 53 manipulation experiment studies across 17 high-latitude ecosystems.
  • We calculated a response ratio of a metric relative to the control.
  • We performed complimentary CLM4.5 simulations and analyzed discrepancies.

Carbon cycle responses to warming from two versions of CLM (orange and red) are compared to observations (blue).
Carbon cycle responses to warming from two versions of CLM (orange and red) are compared to observations (blue). CLM performed poorly against many of these observations.

Impacts

  • We identified poor representation of microbial activity, above- and belowground coupling, and nutrient cycling as the primary reasons for the discrepancies.
  • Identifying deficiencies in the model structure can motivate future experiments and focus model development efforts.

Bouskill, Nicholas J., William J. Riley, and Jinyun Tang. December 11, 2014. “Meta-analysis of High-latitude Nitrogen-addition and Warming Studies Implies Ecological Mechanisms Overlooked by Land Models.” Biogeosci., 11(23):6969–6983. doi:10.5194/bg-11-6969-2014.

Observations in Tundra Imply Needed Improvements in Land Models
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