Deer Impacts on Montane Habitats

Forest Enterprise Scotland (FES) manages the national forest estate on behalf of the Scottish Government.

The Glen Affric area is one of their flagship sites for nature conservation, holding one of the most extensive remnant native pinewoods in the country. It is also the subject of a large restoration project, whereby commercial trees planted in the 1950’s-1970’s are being removed to allow native woodland to re-colonise.

In the first phase of work we undertook an extensive deer population assessment, focusing on mapping out the areas of high and low deer occupancy. The methods we used were those we developed in the late 1990’s and now published as research.

We also undertook intensive assessments to ascertain the degree to which deer impacts on key habitats occurred in line with occupancy. The habitats included woodland and open range, with technical methods being developed by SCL to deal with both situations.

In the second phase, which is ongoing, we have been re-visiting the sites to monitor them and ascertain the degree of change that has occurred in the intervening period during which deer culls were increased in an attempt to reducing browsing pressure of native trees and dwarf shrubs.

The current program of work also a range of more detailed habitat-impact assessments, including an exercise to map the distribution of Heather on a key area of the site and also to erect a suite of high altitude experimental enclosures on part of the site to quantify in the long-term the effects of deer grazing.  This is a very interesting part of the project, partly because of the logistical and physical difficultly of getting the equipment in place (at up to 900m) but also because habitats at this altitude have so rarely been studied in this very detailed and rigorous way.