My research project

I am using the simplified process-based model 3-PG which I integrated fully using a close loop with the equally simplified soil organic mater model ICBM/2N to produce a full ecosystem model that I call 3-PGN (3-PG Nitrogen). The new model maintains all the major features of both models however a new way for estimation of the fertility rating of a site was introduced based on the nutritional status produced by the nitrogen pools of ICBM/2N. The model was parameterised for commercial plantations of Scots pine with data from spatially distributed stands across Scotland using a modern Bayesian approached based on Monte Carlo simulations. I used the model to investigate the major eco-physiological principals behind the differences of Scots pine productivity and to investigate the carbon budget under current management proposed by normal yield tables. I am also using 3-PGN with its spatial version which I customised from the existing C++ source code. Spatially distributed data of temperature, precipitation, incoming solar radiation, frost days and soil texture are the main inputs of the model to produce maps of current and future timber and carbon productivity in order to investigate the effect of site conditions.

The figures below illustrate the first maps produced by 3-PGN spatial and show the development of Scots pine stem biomass (tDM ha^-1) for the year 2000, 2025 and 2050.

The results of the model shown a clear pattern in productivity between east-west. Stem growth is greater on the east coastal line of Scotland where soils are in their majority sandy with deep water tables whereas the western coast and the central mountain region of Caingorms are clearly not suitable for growth. The clip of stem biomass developement produced by model results supports the above outcome.

The project was partially funded by the Greek State Scholarship Foundation (IKY) and Forest Research UK.

If you are interested to learn more about the model or to have access to either excel, C++ or Simile version of the model please do not hesitate to contact me at G.Xenakis@sms.ed.ac.uk.