Windthrow

The Windthrow Model was developed by Dr Áine Ní Dhubháin, School of Biology and Environmental Science, University College Dublin in conjunction with Jonathon Walshe (UCD), Michael Bulfin (Teagasc), Dr Michael Keane (Coillte) and Paul Mills (Compass Infomatics).

Users of the model should note the following:

• The model predicts the probability of windthrow occurring in a stand. A probability of 50% indicates that in 50% of all stands with similar site characteristics, windthrow (i.e. > 3% of stems windthrown) will have occurred by the specified top height.

• The model was developed based on pure Sitka spruce stands with a top height range of 2 to 30 m. The model should be applied to similar stands.

• The model is unable to predict windthrow risk in the southwest of Ireland (i.e. Miller's windzone A, see map on opening page of model). Users may wish, however, to use the prediction for the adjoining windzone B, but should be aware that the risk of windthrow is likely to be less in windzone B than in A.

• The model provides estimates of windthrow risk. The precision of these estimates is also provided through the confidence limits option. The degree of confidence is 95%. Thus if the confidence limit option indicates that the results can range from 20 to 30%, this implies that one can be 95% confident that the true risk of windthrow in the stand in question lies between 20 and 30%.

PLEASE NOTE: The software was updated on 17 August 2010. If you have downloaded a previous version, please remove the programme before installing the revised version. 

Windthrow_105setup (11,127Kb) (updated 17 August 2010)