RSPB Scotland to blow up trees in aid of conservation.
Abernethy trees
- There are several million trees in Abernethy forest. This trial plans to blow up 10.
- Dead wood also provides nursery sites for the germination of plants, protection from grazing damage, shelter and mobility for birds and mammals, a store of nutrients that can be cycled through the ecosystem, and a store of carbon.
- The explosive charges will be placed in pre-drilled holes (for maximum compression) and will create only a moderate blast - about the sound of a shot gun report.
- The project has been scheduled outside of the breeding season.
- In a review of nationally rare and scarce non-avian species at Abernethy (Amphlett 2000), of 795 species occurring within the whole reserve, 601 were recorded from the existing forest zone, and 379 from woodland. From the available information it is not possible to say what proportion are reliant on deadwood, but in some taxonomic groups it is very high. For example, of 69 nationally rare and scarce lichens in woodland, >90% are restricted to dead wood (exposed lignum).
Trees in one of Scotland’s oldest and scarcest forests are to be blown up in an unusual conservation effort. 10 mature Caledonian pines on the RSPB’s Abernethy nature reserve are to have their crowns removed with explosives to increase the amount of dead wood in the forest. This apparent act of destruction should actually improve and replenish the woodland’s rare wildlife habitats by providing a home for countless invertebrates, fungi, mosses, lichens, birds and even small mammals.
The explosive charges will expose raw wood with ragged, torn and splintered edges, in much the same way as a storm, avalanche-damage or lightning strike. When trees die, their biological function within the forest ecosystem is far from over, and they continue to play a crucially important role in maintaining the health and productivity of the woodland ecosystem.
As they gradually decay, they become nature reserves in their own right, remaining upright for perhaps another century and teeming with life. In a natural forest ecosystem free of human interference, between 20 – 30% of the existing trees will be either dead or dying. However, much of the remaining ancient and semi-natural woodlands in Scotland have been highly modified over several millennia, and this natural dynamic is either absent or much reduced.
The aim of the project at Abernethy is to blow the crowns off 10 trees aged between 100 - 200 years old, and restore the natural balance of dead and live trees to something approaching this equilibrium. Unlike the clean, chainsaw cuts of many modern forestry techniques, detonating the trees will expose a far greater surface area of the wood. This then allows all the pathogens, bacteria and microbes that accelerate the decay process a much faster start.
Desmond Dugan, Site Manager for the Forest Lodge section of Abernethy, said. ‘Dead wood habitats, particularly large volume deadwood, are in short supply at Abernethy forest. To enhance this important habitat component, RSPB plan to harvest much less timber than previously and to leave most of the timber to recycle into the forest.
‘It may seem ironic but dead wood is a key driving element of our forest ecosystem. The biological function and output of these great Caledonian Scots pine trees is often greater during and after death than when the trees were alive.’
He added: ‘The exploded trees will be carefully monitored by our ecology colleagues to measure the effectiveness of this novel management. Explosives may seem extreme but the effect will be no less catastrophic than a wind snapped, lightning struck or avalanched tree. Whatever the outcome, the project will surely go with a bang!’
Some 16 species of birds use these dead trees at Abernethy. Woodpeckers drill nesting holes that are readily colonised by tree-nesting swifts, crested tits, redstarts or flycatchers. Often there is great competition to secure these scarce cosy ‘houses’, and such is the demand for this valuable real estate that nesting birds are often evicted by pine martens or by larger or more dominant birds such as goosanders, goldeneye ducks or tawny owls.
In winter, these holes and cavities are much favoured by hibernating bats and butterflies. When eventually these dead trees fall to the to the ground, the softer moist fallen deadwood is further colonised by a different range of invertebrates, lichens, mosses, bryophytes or fungi. In time, albeit a very long time, the great skeletons are recycled into the forest floor to renew and revitalise the cycle of death, decay and regrowth.
RSPB’s Abernethy reserve is the largest remaining expanse of the once sprawling ancient Caledonian pine forest, containing roughly 3.5million Scots pine (Pinus sylvestris) trees.
