Foreign trees more a threat than grazing
Scotland's native woods will miss Biodiversity targets for 2020 unless urgent action is taken to address non-native tree species in the country's forests.
That is the lesson of new analysis claiming a multi-million pound study into Scotland’s native woods down-played the threat of non-native trees, focusing chiefly on deer damage.
The Native Woodland Survey of Scotland, undertaken by Forestry Commission Scotland and heavily analysed by Scottish Natural Heritage (SNH), was hailed as Scotland’s most authoritative stock-take of native forests.
It concluded 54 per cent were in unsatisfactory condition, the principal cause being ‘excessive browsing and grazing’, mainly by deer, which impacted 33 per cent of the total.
The announcement led to environmental groups angrily rounding on sporting estates for keeping deer numbers high for deerstalking, damaging the environment as a result.
Environment Minister Roseanna Cunningham will now decide in 2017 whether tougher laws are required to force deer managers to meet strict cull plans, with 2020 Biodiversity targets pivotal.
However, new analysis, published in the Scottish Forestry journal, claims thousands of hectares of ancient woodlands, classed unsatisfactory due to exotic tree planting, were omitted from the survey, despite being assessed.
Had 39,000 hectares of Planted Ancient Woodland Sites (PAWS) been included in the final draft, the percentage of woods impacted by non-native trees would have outnumbered those damaged by deer and livestock.
That has led to the Scottish Gamekeepers Association to call for an end to ‘tunnel vision’, claiming all factors affecting woodland condition should be considered – not just deer.
The author of the new analysis, Victor Clements, also an Executive Member of the Association of Deer Management Groups, noticed discrepancies whilst preparing deer plans and had his figures independently verified.
Writing in the latest edition of Scottish Forestry magazine, he says: “An initial draft revealed an important sub-set of our native woodlands were not actually included in the main report though available for mapping purposes.
“When the PAWS area is added, it becomes apparent the greatest threat (to native woodlands) in terms of area, is actually non-native tree species, not herbivore impacts, although the order of magnitude is broadly the same.
“This means the narrative surrounding the launch of the report is not actually correct.
“Herbivore impacts are not the most significant issue affecting native woodlands at all, although their effects are not denied in many cases. A more appropriate narrative would be that we have a number of issues impacting on native woodlands in Scotland, with non-native species and herbivore impacts being the most important, in almost equal measure.”
Adding the excluded woodlands to the survey would have meant the area impacted by exotic trees would have been 117,342 hectares compared to 112,383 grazed by sheep and deer.
Scottish Gamekeepers Association Chairman Alex Hogg said: “Even without the omitted 39,000 hectares, non-native trees impact 77,000 hectares of native woodland in Scotland. This won’t go away because it is one of the key criteria determining whether woodlands are satisfactory or not.
“If native woodlands are to meet 2020 Biodiversity targets, focusing on one issue, deer, won’t work in isolation. Something has to be done about the amount of exotic species such as Sitka Spruce and other conifers on these sites, although this seems to be of little concern.
“At some point, a wider view has to be taken addressing all issues in the round.”