NON-NATIVE trees are a bigger threat to biodiversity than deer, a new report claims.

The Scottish Gamekeepers Association (SGA) is calling for an end to “tunnel vision” on the country’s wild areas, claiming the country will miss biodiversity targets unless urgent action is taken to address the proliferation of imported species in woodland.

However, Forestry Commission Scotland has questioned the claim, which is based on new analysis of data from a “stock take” of forests.

The SGA claims the multi-million pound study downplayed the extent of the problem to focus on deer damage, skewing both strategy and public opinion.

The Native Woodland Survey of Scotland, undertaken by Forestry Commission Scotland and analysed by Scottish Natural Heritage (SNH), 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.

However, new analysis published in the Scottish Forestry journal claims thousands of hectares of ancient woodlands classed unsatisfactory due to the planting of exotic tree species such as Sitka spruce, lodgepole pine and hybrid larch were omitted from the survey after the assessment.

It says that if the 39,000 hectares of Planted Ancient Woodland Sites (PAWS) had been included in the final draft, the percentage of forestry impacted by imported species (117,340 hectares) would have outnumbered that damaged by deer and sheep (112,380ha).

SGA chairman Alex Hogg said: “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.”

According to estimates, there are more than 750,000 deer in Scotland, including native red and roe deer and smaller numbers of Sika and fallow deer, as well as about 2.5 million breeding ewes on the land roamed by the game species, the majority of which is in the Highlands.

Environment Minister Roseanna Cunningham will this year rule on whether tougher laws should be brought in to force deer managers to meet strict cull plans, with 2020 biodiversity targets pivotal.

The author of the new analysis, Victor Clements, an executive member of the Association of Deer Management Groups, claims to have uncovered discrepancies in the forest audit while preparing deer plans.

Writing in the latest edition of Scottish Forestry magazine, he said: “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.”

Forestry Commission Scotland, said: “We are always interested in new analysis of woodland data.

“This is an interesting new report, which analyses herbivore impacts in a new way, combining information from Deer Management Groups and the Native Woodland Survey of Scotland [NWSS].

“The PAWS referred to in the new report are sites which have been woodland for a long time, regardless of whether they are native or not.

“Therefore the data for ‘nearly native’ and PAWS sites was included as supplementary information within the NWSS, because these sites can be of greater ecological interest than new plantations.

“However, it would be incorrect, as suggested in the postscript of the report, to use this data to amend the findings of the NWSS.”