Rangers at the National Trust for Scotland's Mar Lodge Estate have issued a plea for responsible behaviour after it was reported that live trees have been felled for fuel by bothy users at both Bob Scot's and the Hutchison Hut in two separate incidents at the weekend.

At Bob Scot's in Glen Derry the tree was a 30-foot birch, while up in Coire Etchachan members of the public cut down a much smaller - though no less important - scots pine. The estate has been undertaking woodland regeneration in the area for many years.

"Aside from the fact that living wood simply doesn't burn well, any loss of young trees in a woodland recovering from centuries of decline is keenly felt" said the ranger team in a post on social media today.

"This is especially the case in Coire Etchachan where tree growth, at more than 700m altitude, can be painfully slow. It has taken decades for the trees around the Hutchison to reach their modest size, and every single one of them is invaluable as a seed source to help the montane woodland in that wild place recover. But even lower down, at Derry Lodge, where the woodland regeneration is faster and more dense, deciduous trees like birch are still scarce in relation to pine, and therefore every seed-bearing birch is precious."

While cutting live trees to burn is both very stupid and obviously worse than scavenging dead wood to feed the bothy stove, the rangers point out that even this should be avoided.

"Dead logs, branches and sticks are a vital component of the woodland ecosystem, recycling nutrients into the ground but also supporting 40% of all woodland species. 2000 invertebrate species, including 700 beetle species, depend entirely upon deadwood to survive" the estate rangers said.

"It might sound like an overreaction on our part, asking visitors not to burn deadwood scavenged from the estate in the bothies. But as with so many things in the outdoors these days, where your own personal impact on a given day can seem small or insignificant by itself, remember it's never just you who is visiting. Today it's just you, but tomorrow it will be someone else. The day after that, someone else. And so it goes on, seven days a week, 52 weeks a year.

"Our impact on places is cumulative. The result, in the most popular places, is a woodland floor completely stripped bare of deadwood. The only time you will see any is in the weeks and months following a storm. However, just months later, most of that will have gone up a bothy chimney."

The Mountain Bothies association have added their voice to the calls for more responsible behaviour. MBA Chairman, Simon Birch (no relation), said:

"This is very disappointing news. We work closely with estate staff in caring for the Cairngorm bothies, and our volunteers are very appreciative of the work Mar Lodge staff have done in tree regeneration in this area. Bothies can only work where people treat not just the bothy but also the area around with respect - and that's built into the Bothy Code which we expect users to abide by. Selfish acts like this can endanger the future use of a bothy."

While the NTS is supportive of bothies on its land, and recognises the importance of getting people outdoors, they ask visitors to help take care of the area, and abide by the bothy code. While the code simply says to use fuel 'sparingly', at Mar Lodge the rangers go one step further and say that if bothy users want to have a fire they should bring all fuel from home.

"Please also note that while it is okay to bring fuel for bothy stoves, it is not okay to do so for campfires or firebowls, as these are not permitted in woodland or peaty areas, both of which cover the majority of Mar Lodge Estate" they say.

"If you're intending to use the bothy stove, bring your own fuel from home and, if the opportunity arises, pass on your knowledge and experience on this matter to fellow bothy users who might be unaware of the Bothy Code or the woodland restoration work we're undertaking.

"If you need to report irresponsible behaviour during or after a visit to any of the bothies, you can contact the ranger service on 01339 720164 or email [email protected], and we will follow it up."

The weekend's vandalism has been reported to Police Scotland.