Coillte Bioclass

Coillte first mapped biodiversity areas during 2001-2005. A preliminary review of Coillte’s forest inventory, along with the extensive knowledge of Coillte’s foresters, revealed the location of potential biodiversity areas within a broad range of site types.

Ecologists surveyed the potential biodiversity areas, and assessed their habitat value, based on standard scientific principles. Additional biodiversity areas were subsequently identified by forest managers – mostly, these are riparian buffer zones.

The outcome of this work was that 90,000 hectares (about 20% of the estate), in more than 2,300 sites, were identified and mapped as biodiversity areas.

In recent years, we invested in the development of BioClass, which is a new system for recording and mapping biodiversity areas. The reasons for developing BioClass were to help staff to better understand our biodiversity resource, to make decisions and prioritise resources.


The concept of BioClass is based on the “yield class” system used by foresters in inventory. Yield classes combine a range of information, such as soil type and tree species, to describe the productivity of a forest stand. BioClass combines a range of information to describe the ecological value of a site.

Based on a review of the scientific literature on biodiversity in Irish forests, we have defined a series of natural values and biodiversity features which indicate the biodiversity value of the forest. Based on the presence of these natural values or features, a forest can be assigned to one of four BioClass ranks. These range from BioClass 1, the areas of highest ecological value, to BioClass 4, areas that currently have moderate value, or have low value at present, but with potential to develop into habitat of high ecological value.


We also developed a BioClass scoring system for open habitats. There are large areas of open habitat on the Coillte estate and this assessment system ensures that the best of them are properly recognised as biodiversity areas.

Leave a Reply