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Northern Research Station
One Gifford Pinchot Drive
Madison, WI 53726
(608) 231-9318
(608) 231-9544 TTY/TDD

Clean Air and Water

Modeling: Optimal Co-allocation

Research Issue

Forest production varies from site to site, depending in part on the availability and uptake of nitrogen. Understanding how nitrogen affects productivity is key to precise forecasting of productivity, but our understanding is incomplete.

Our Research

We are approaching the issue of forecasting productivity from a simple Darwinian argument: nature selects for trees that tend to optimize their use of limited resources. In the aggregate, such trees tend to maximize net forest production through the optimal co-allocation of carbon and nitrogen to leaves, fine roots, and wood, as constrained by the stand-level carbon and nitrogen balances.    

Expected Outcomes

  • Steady state and dynamic versions of an optimization model of the co-allocation of carbon and nitrogen in closed forest stands. 
  • New theory for modeling forest production.

Dewar RC;  Franklin O; Mäkelä A; McMurtrie RE; Valentine HT. Optimal plant function explains responses to rising atmospheric carbon dioxide and nitrogen deposition. In prep.

Research Results

Mäkelä A; Valentine HT; Helmisaari H.-S. 2008. Optimal co-allocation of carbon and nitrogen in a closed forest stand at steady state. New Phytologist. 180: 114-123.

Research Participants

Principal Investigator

  • H.T. Valentine, US Forest Service- Northern Research Station Research Forester
  • Annikki Mäkelä, University of Helsinki, Helsinki, Finland

Research Partners

  • Helja-Sisko Helmisaari, Finnish Forest Research Institute, Vantaa, Finland
  • Roderick C. Dewar, INRA, d'Ornon, France
  • Oskar Franklin, IIASA, Laxenburg, Austria
  • Ross E. McMurtrie, University of New South Wales, Sydney, Australia


Last Modified: 06/04/2009