Edinburgh Forestry Model
About the EFM
The Edinburgh Forest Model is a dynamic, process-based model of carbon (C), nitrogen (N) and water in cool temperate forests. It simulates tree growth (evergreen or deciduous) with growth responses to the environment (e.g. light, temperature, day length, rainfall, humidity, wind, atmospheric N deposition, CO2) and also to management (e.g. fertilizer input, plantations or “natural forests” with possible self-thinning and regeneration). It incorporates a soil submodel with mineral and organic matter pools, and also a plant/soil water submodel of the physics and biology of water movement. A list of the possibilities and processes covered by EFM is included at the start of the “source program/text – efm.csl”; this is highly annotated and hopefully adequately explanatory. Although there is as yet no complete description of the EFM, much of it is based on an earlier developed pasture model (Thornley, 1998. Grassland Dynamics: an ecosystem simulation model, CAB International). More recent developments are described in various papers. (Thornley JHM, Cannell MGR. 2004. Long-term effects of fire frequency on carbon storage and productivity of boreal forests: a modeling study. Tree Physiology 24: 765-773. Cannell MGR, Thornley JHM. 2003. Ecosystem productivity is independent of some soil properties at equilibrium. Plant and Soil 257: 193-204. Thornley JHM, Cannell MGR. 2000. Managing forests for wood yield and carbon storage: a theoretical study. Tree Physiology 20: 477‑485. Thornley JHM. 1999. Modelling stem height and diameter growth in plants. Annals of Botany 84: 195-205. Thornley JHM, Cannell MGR. 2000. Modelling the components of plant respiration: representation and realism. Annals of Botany 85: 55-67.) A recent and ongoing development is the addition of an aphid submodel (the green spruce aphid).
The model tracks the rates of inputs and outputs of both the C, N and water, and their effects on the state variables (e.g. C, N and water pools in the trees and soil) on a time scale from diurnal, to centuries. Responses to changes in environment or management can be studied in the short-term, when the responses are transient, or longer term, as the responses move toward sustainable, dynamic steady states.
Access to the EFM program/code
The source code for the Edinburgh Forestry Model is available for educational and research purposes. Please see Technical details, before downloading from the menu.