GROWFOR

 Forest Planning Models

Reliably constructed growth models that permit forecasting of growth and yield are important for the successful management of forest plantations.

Irish dynamic yield models are being developed for the most important commercial species. This necessitates the models being used through a computer programme rather than from yield tables, as is the practice with static yield models. The key advantage of dynamic yield models is the flexibility and accuracy that they give to forest managers. Models can be applied to actual plantation characteristics rather than trying to align the plantation to a set management regime outlined in a yield table. 

Interactive forest planning model software has been developed to allow growers to input variables related to various scenarios or operations and project the anticipated outcomes of such activities.

Following the successful launch last year of the Irish Sitka spruce dynamic yield model, the system - now referred to as GROWFOR - has been updated, with a number of new features added:

• in addition to Sitka spruce, four new species: Douglas fir, lodgepole pine, Norway spruce and Scots pine, are now included,
• net present value for different stands and management options can be calculated automatically,
• yield class as well as site index can be displayed if required,
• current annual increment and mean annual increment have been included in the stand projections screen.

This phase of modelling work, funded jointly by Coillte and COFORD since 2001, is now at an end, and is a significant milestone in Irish forest research, as it brings to fruition work which started over four decades ago - when the first crop structure field trials and permanent sample plots were established by the Research Branch of the Forestry Division - a good example of how the benefits of long term research can accrue, where there are clear objectives set out at the beginning of the work.

The models underlying GROWFOR were derived by Dr Lance Broad, with the collaboration Ted Lynch of Coillte. PTR Limited developed the user interface and carried out field validation of the models.

The models and manuals are available from COFORD, and workshops can be arranged to instruct users on their use. 

WORKSHOP

These are full day workshops incorporating a short outdoor field exercise in the morning and a classroom session in the afternoon. There are limited spaces available at these events.