Modeling forest stand dynamics from optimal balances of carbon and nitrogen
Article first published online: 28 MAR 2012
No claim to original US government works. New Phytologist © 2012 New Phytologist Trust
Volume 194, Issue 4, pages 961–971, June 2012
How to Cite
Valentine, H. T. and Mäkelä, A. (2012), Modeling forest stand dynamics from optimal balances of carbon and nitrogen. New Phytologist, 194: 961–971. doi: 10.1111/j.1469-8137.2012.04123.x
- Issue published online: 2 MAY 2012
- Article first published online: 28 MAR 2012
- Received: 25 November 2011, Accepted: 14 February 2012
- carbon (C);
- growth model;
- pipe model;
- stand dynamics
- •We formulate a dynamic evolutionary optimization problem to predict the optimal pattern by which carbon (C) and nitrogen (N) are co-allocated to fine-root, leaf, and wood production, with the objective of maximizing height growth rate, year by year, in an even-aged stand.
- •Height growth is maximized with respect to two adaptive traits, leaf N concentration and the ratio of fine-root mass to sapwood cross-sectional area. Constraints on the optimization include pipe-model structure, the C cost of N acquisition, and agreement between the C and N balances. The latter is determined by two models of height growth rate, one derived from the C balance and the other from the N balance; agreement is defined by identical growth rates.
- •Predicted time-courses of maximized height growth rate accord with general observations. Across an N gradient, higher N availability leads to greater N utilization and net primary productivity, larger trees, and greater stocks of leaf and live wood biomass, with declining gains as a result of saturation effects at high N availability. Fine-root biomass is greatest at intermediate N availability.
- •Predicted leaf and fine-root stocks agree with data from coniferous stands across Finland. Optimal C-allocation patterns agree with published observations and model analyses.