It is being carried out in phases to reduce disruption and allow wildlife to adapt.
Peatland restoration officer George Hemstock said the work was designed to balance environmental goals with species protection.
"To minimise disturbance to reptiles, work is being carried out in phases over three years, allowing animals time to move safely across the site.
"Key refuge areas such as dry, south-facing bog edges where reptiles hibernate are being retained and protected throughout operations."
Longbridge Muir covers about 1,255 acres (508 ha) and forms one of the largest surviving remnants of the historic Lochar Moss peatland complex near Dumfries.
The site is protected as a Site of Special Scientific Interest and is recognised for its internationally important raised bog habitat, which supports a range of wildlife including adders and common lizards.
Forestry and Land Scotland has also confirmed the presence of slow worms in the wider restoration area, although reptile population numbers are not known.
The site is part of the wider Solway Mosses North Special Area of Conservation, which covers almost 1,600 acres (649 ha) and is regarded as one of the most significant lowland raised bog systems in Europe.
