We have had some complaints from our members about the thinning work ongoing at the Linn of Dee and earlier this month, I and a group of our members visited the Linn of Dee area to see for ourselves the results of the ongoing timber harvesting. We are raising these concerns with you as we want to support the very best environmental practices on an estate which our members view as one of Scotland’s crown jewels.

The first site that we visited was just west of the road along the track to the White Bridge. To us, this looked like poor management. Trees had been felled and hauled to the track by horse logging and then just left. Why pay for them to be cut and hauled to the track and then just left? We agree with the general observation that there isn’t enough dead wood in the area but, as you know, this needs to be in the form of standing dead trees and not rotting logs in the mud. Standing dead trees support different lichens, flora and invertebrates than lying logs left to rot. See attached photos.

The second site that we visited was immediately west of the car park. The ruts from felling by machines, see attached photos, are an eyesore. (Refer to Mountain Views issues 71 and 72, for a detailed explanation of damage to the natural podzol soils caused by heavy timber machines). Use of lighter machines coupled with more effective use of brash would prevent this destruction.

We also noted a lot of damage by red deer barking living trees and large quantities of droppings, corresponding with this area being on the “wrong side” of the new deer fence. Given the excellent work which is leading to regeneration on the east side of the fence, we are interested in the Trust’s policy on woodland and deer numbers in this area.

The third site, just east of where the Lui Water crosses the road, shows large piles of logs. These are not a natural feature and should be aged outside the forest, near to the bio-mass boiler. We also noted a lot of ring-barking to kill the trees and hence promote more standing dead wood. Surely the aim should be to allow the trees to compete for light and space and hence derive dead wood in a natural way? Alternatively, is the demand for wood for the bio-mass boiler so large that thinning will now have to be so regular that tree competition will be effectively ended?

The first point you raise relates to the logs left following our horse logging experiment in 2013. I think the first thing to say is that in general I agree with you entirely. It is not ideal that so many logs were left at trackside following this work. You may be aware that using horse loggers was an experimental option, and while the overall results in the woodland were good, the conclusion we came to was that it was not a technique that we could use on an ongoing basis, due to the time and cost implications. When the contract ended, there was still a substantial amount of wood still to be extracted. We then had a dilemma, because to extract that timber would require putting machines into the wood and given that the whole purpose of the experiment was to avoid this, it seemed entirely counterproductive. So, in summary, I agree it is not the best way to create deadwood in a plantation (we have a well established ringbarking programme to do that), in this case it seemed like the lesser of two evils to simply leave the felled timber where it was.

In relation to your second point relating to rutting by harvesting machines, there are several points to make.

1. Adam Watson’s demonstration and explanation of soil podzols in the boreal forest is quite correct and we have no argument with this. However, the damage has already been done in these woodlands. These plantations, along with many other older plantations on the estate were “deep ploughed” prior to planting. Therefore, the soil podzol has already been destroyed. The soil structure is in no way natural and therefore while I agree entirely that rutting is unsightly and should be avoided wherever possible, in fact, it is doing no more damage to the soil than has already been done. The situation would of course be entirely different if we were to put machines into areas of “natural” woodland but we have no intention of doing this.

2. The machines we now use for timber harvesting are not the “monster machines” reported by Adam and others back in 2013. We have sourced a contractor further down Deeside who uses relatively light weight machinery. The damage they cause is therefore significantly less.

3. The photographs you have sent of the rutting all show main access routes to the central timber stacking points. However, when you look at the total area thinned, the impact on the ground is minimal. The ruts themselves will heal, and will provide niches for future regeneration.

4. I do agree with your assessment that greater use of brash matting could be made on some of these access routes and we will certainly discuss this with our contractor before we undertake harvesting in 2017 and beyond.

A more general note on our thinning and biomass plant. We have always been quite clear that our thinning programme should never be driven by the need for timber to fuel the biomass boiler. We are simply using the by-product of conservation management activity to fuel the buildings. For interest, we have substantial quantities of timber from one of our neighbours over the past 2 years as they were carrying out thinning works anyway.

Whether or not it is right to thin plantation woodlands is a matter of opinion. There are some ecologists who believe we should simply have clear felled all the plantations in order to let nature take over. You seem to be suggesting we should leave them alone and let natural processes thin them. The third approach is to intervene to accelerate the natural process. While intervention is something we would generally try and avoid, you have to remember that there is nothing natural about a plantation. However, we can take steps to improve the woodland habitat and improve the landscape impact of plantations. This is the route we have chosen to follow.

You make a point about leaving timber stacks in the woodland rather than moving them to a more suitable location closer to the biomass boiler. In short I agree with you on this point (and work has already started on this).

So the point about deer numbers on the wrong side of the deer fence was answered by the NTS, but as you are all aware, this is a complicated story. The original deer management plan had to be modified after the report produced by the Independent Review Group. We objected at that time and still consider that NTS were asked to do the wrong thing. Suffice to say, there is some excellent regeneration ongoing on other areas of the estate.