Controls on deer numbers have led to woodland regeneration around the Cairngorms’ green lochan, according to Forestry and Land Scotland (FLS).
An Lochan Uaine, south of Aviemore, is one of the area’s best-known lochs because of its emerald colour.
FLS said deer culls had allowed woods in the Ryvoan Pass, which overlooks the lochan, to flourish.
The public agency said photographs taken in 1984 and the present day showed the scale of recovery.
An Lochan Uaine – meaning the Green Lochan – gets its colour from the Sun reflecting minerals in rocks in and around the lochan.
According to folklore, the colour is the result of fairies washing their clothes in the small loch at night.
An Lochan Uaine lies within an area of surviving ancient Caledonian Forest.
FLS said a photograph taken in 1984 by a forester, George Dey, and an image taken by one of its ecology interns, Rossina Parvanova, showed how well the woodland had expanded.
Woodland restoration has been ongoing since the early 1990s and has involved increased deer management and removal of non-native trees.
Tom Cameron, an FLS area wildlife manager, said: “In the 1984 photo, you can see the trees were sparse with limited regeneration and vegetation growth.
“That was down to deer trampling and grazing on vegetation and new shoots.”
He added: “Ryvoan Pass has regenerated itself incredibly well in the absence of deer.
“You can see the Caledonian pine has expanded back up the hillside, accompanied by the associated native broadleaf species such as willow, rowan and birch.
“We haven’t added or planted anything here – nature did this all by herself once we increased deer management efforts.”