Pictures show changes at Scotland's largest nature reserve after 30 years of National Trust Scotland ownership

Sprawling across 30,000 hectares of the Cairngorms National Park lies one of Scotland’s most remarkable estates.

Mar Lodge Estate is home to an astonishing mosaic of Scottish landscape, from heather-covered moorland, Caledonian pine forest, some 15 munros and the Quoich wetlands.

Golden and sea eagles can be seen soaring above the peaks, while waders are often heard echoing up the glen.

This year marks 30 years since the estate came under the ownership of National Trust for Scotland (NTS), following a then-anonymous £4.5 million donation from Ann Marie Salvesen of the Christian Salvesen shipping and distribution dynasty.

Since 1995, the landscape has undergone significant changes, with ownership shifting conservation efforts for a sporting estate to conservation work for trees and forested areas by reducing deer numbers.

Shaila Rao, who has worked as the estate’s ecologist for the last two decades, tells The Scotsman how and why some of the landscape has changed under NTS.

What’s been the biggest change at Mar Lodge under NTS ownership?

“The main driver of change has been reduced deer numbers and it has influenced a few things.

“It’s influenced natural regeneration. Previously deer were suppressing any growth of young trees, but also browsing some back.

“We have also started to see other vegetation flourish, like tall herb communities. The taller flowering plants that had become confined to higher altitude ledges because that’s the only place they could survive in the past we’re now seeing them grow in other places.

“The place has really come to life. Because there’s lower grazing pressure, you get other things like improved small mammal population numbers which some of the raptors benefit from as well.”

What have the challenges been?

“When we embarked on a deer reduction plan, that was quite controversial in this part of the world - particularly the north east with many big sporting estates. So there was quite a lot of opposition from neighbours and the local community.

“There were a lot of things for NTS to contend with with regards to opposition to what we were doing. It became quite a difficult environment to work in so changes were slower than they could have happened. Other places since, for example Glen Feshie [owned by Danish billionaire Anders Polvsen], managed to achieve the reduction much faster and they achieved a response much quicker. For NTS, however, it was a slower burn for various reasons. But when we hit the mark, the changes started to come.

“This type of land management was in its infancy at the time, so it was a bit of an unknown as to how successful it was going to be and how difficult it was going to be to reduce deer numbers.

“Once we got the deer population right down, there’s a three to four year lag before you start to see the trees coming. So that’s why it’s probably about 2010 when we started to see things start to change.”

What are the aims of the estate?

“There were a set of management principles agreed at the time of acquisition after Ann Marie Salveson left the money for the Trust to buy the lodge through the Easter Charitable Trust. The key ones were that Mar Lodge was managed for conservation, open to public access and that it continued to run as a Highland sporting estate.

“On one part of it, about a third, we’ve completely reduced the deer population to help the trees. We do peatland restoration and woodland creation which is fenced and slightly different to natural regeneration.

“There’s no sport that happens there and the woodland is encouraging natural processes and ecological restoration.

“But on the west part of the estate, where there’s very little existing woodland and no seed source for natural regeneration, we have a different approach. We have reduced the deer population there, but not so much so that we can shoot up to 100 sporting stags a year with guests, which maintains the sporting principle. We also do shoot walked up grouse to fulfil that agreement. But we do not do muirburn anymore [the controlled burning of heather].

With Mar Lodge encouraging trees and natural regeneration, what’s your view on the argument that trees have died out naturally?

“My personal view point, and one shared by many other conservationists, is that climate and people have had a role to play in the loss of woodland in Scotland, and I think those influences have been different in different parts of Scotland.

“But I think the east, particularly the Cairngorms, and particularly Mar Lodge, the history shows people have had a huge hand in the woodland decline - be that grazing animals, preventing natural regeneration, both livestock and deer, felling of trees for timber and to open up grazing land. There’s documentary evidence of all those things happening.

“We know at Mar Lodge there were mesolithic people living here, and it’s hard to believe they didn’t have an impact on the woodland. My feeling for Mar Lodge, and particularly the Cairngorms, is if you protect an area from deer, trees will grow.

“We then have the silly debate about what the deer populations were like - no one really knows. What we know for sure is that at Mar Lodge we’ve done nothing else except reduce the deer population, and we have 2,000 hectares of natural regeneration coming from existing woodland. To me that indicates this wants to be a wooded habitat here.

“If you look at what’s gone on in Scotland and how we’ve managed the land, there’s been a lot of taking off the land, with nothing going back on.

“When I walk around Mar Lodge now where there’s been regeneration, I look at a small birch tree and you see how many leaves fall off that in autumn and go back in the soil to improve the soil. You can see that Scotland has just become very degraded and depleted because of the way we’ve managed the land.”

There’s a strong focus on deer management for trees growing - what about the heather moorland habitat?

“People sometimes, particularly the sporting community, talk about moorland like it’s a dying habitat.

“Mar Lodge is 30,000 hectares. There’s 1,000 hectares of pine woodland left. We now have 2,000 hectares of regeneration. So, as it stands, we have 3,000 hectares of woodland and 27,000 hectares of open moorland. There’s a long way to go before heather moorland will be at risk.”

What’s your view on tree planting and natural regeneration?

“I think natural regeneration is far preferable to planting trees because they grow where is suitable. When seeds shed, they only grow where the ground is suitable.

“Whereas when you choose to plant trees you’re actively making that decision and we’re not very good at that a lot of the time. It’s often not that successful, and you end up with trees where they shouldn’t really be.

“You also get a natural distribution of trees. Whereas when you plant, no matter how you do that, inevitably it will look like you’ve planted it.

“Also the way the grant system is set up here - a lot of people are doing this through the Forestry Grant Scheme (FGS) which can mean you’re trying to plant all your trees in one year. Inevitably they all grow up one age. Whereas if you look at natural regeneration, trees are recruiting, every year, a few more years, so you end up with an age distribution of woodland.

“What the FGS should do is give say 30 years to plant your trees and have a gap in planting.

“The timescales we are working on with the policy are nothing like what the timescales are for natural woodland.

“It’s madness really.”