Question reference: S6W-25649
- Asked by: Rhoda Grant, MSP for Highlands and Islands, Scottish Labour
- Date lodged: 21 February 2024
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Current status: Answered by Lorna Slater on 4 March 2024
Question
To ask the Scottish Government what data it has regarding any impact of deer numbers in Scotland on the natural regeneration of trees and scrub; what its position is on what the optimal number of deer per hectare on unfarmed land is that would achieve sustained natural regeneration of tree cover, and how any such optimal number of deer per hectare compares with current numbers of deer per hectare on unfarmed land in Scotland.
Answer
The natural regeneration of trees, scrub and associated ground vegetation across most parts of Scotland will be potentially vulnerable to deer (and other herbivore) impacts, such as browsing, fraying and trampling (as will young, planted trees and shrubs). When considering the impact of deer on our natural environment we look at a variety of evidence as well as advice from NatureScot. The data available for the impacts of deer numbers on natural regeneration is limited and may be combined with data for planted trees.
On Scotland’s National Forests and Land alone, which makes up almost 10% of Scotland, around 150 million young trees, naturally regenerated and planted, can be vulnerable to deer damage impacts at any one time. This includes native woodland, productive woodland (broadleaved and soft conifer tree species), and the expansion of natural regeneration onto open ground. The number and area of young trees and scrub vulnerable to deer damage impacts across the whole of Scotland will be significantly higher.
In terms of national data and evidence, recent statistics on Woodland Ecological condition produced by Forest Research shows that herbivore damage, which includes wild deer, is widespread with almost 50% of woodland area in unfavourable condition as a result of grazing.
Alongside that report, a 2013 a study on the National Forest Estate found that 15-20% of young trees had been damaged by deer. Then in 2014 the first Native Woodland Survey of Scotland assessed around 311,000 hectares of Scottish woodland, found that deer were present in over 70%, and that over 30% of that area had high or very high browsing impacts which were considered too high for the woodlands to survive by natural regeneration.
While there is no one-size-fits-all approach to deer densities and our focus is on evidence of impacts when considering the best approach, the Deer Working Group recommended a target of 10 red deer per square kilometre in open hill, red deer range. We accepted that recommendation, and recognise that there are some areas of Scotland where that target is already being met. However, there are also areas of Scotland where deer populations, all four species, may be in excess of 20 deer per square kilometre and will be causing significant damage. We also recognise that in areas where there is to be natural regeneration, a density of 10 deer per square kilometre is still too high. The successful establishment and sustained management of natural regeneration can require low to very low deer densities of 1-5 deer per square kilometre, and for many woodland and open ground habitats may need to be sustained at densities as low as 2-3 deer per square kilometre.