These remnants have adapted genetically to different Scottish environments, and as such, are globally unique; their ecological characteristics form an unbroken, 9000-year chain of natural evolution with a distinct variety of soils, vegetation, and animals.

The largest remnants are in Strathspey and Strath Dee on highly acidic, freely drained glacial deposits that are of little value for cultivation and domestic stock.

The native pinewoods that formed this westernmost outpost of the taiga of post-glacial Europe are estimated to have covered 15,000 km2 (3,700,000 acres) as a vast wilderness of Scots pine, birch, rowan, aspen, juniper, oak and a few other hardy species.

The forest is also the retreat of another character named Lailoken from the Vita Kentigerni, who also fled into the woods in a fit of madness and who may be the original model for Myrddin Wyllt.

Another figure from the same story, Cyledyr Wyllt hints at a close relationship of the forest being a retreat for people who suffered from a special kind of madness or gwyllt (Irish geilt).

In line 994 to 996 of the story, it is briefly explained, "a Chyledyr Wyllt y uab, a llad Nwython a oruc a diot y gallon, a chymhell yssu callon y dat, ac am hynny yd aeth Kyledyr yg gwyllt."

[16] The agaric fungus Mycena purpureofusca is commonly found in Caledonian pine woods,[17] and it is considered an indicator species for that habitat type.

[19] The charity Trees for Life (Scotland) has been working to conserve the remaining forest, and reforest areas where it has been lost, using fences to prevent deer from eating saplings.

[20][21] In recent years, there has been a growing interest to reintroduce animals which are native to but currently extinct in Great Britain, back into Caledonian pine forests.

[23] Paul Lister plans to release Eurasian lynx, brown bear, grey wolf, elk, wild boar and species already present in Scotland into a huge 200 km2 (49,000-acre) enclosure at his estate, Alladale Wilderness Reserve,[23] although releasing top predators such as wolves and bears has become a difficult proposition with local and national regulations.

In March 2019, as part of the implementation of the Forestry and Land Management (Scotland) Act 2018, the Scottish Government listed 84 sites as Caledonian pinewood in regulations, given below.