Lush pasture at Shebster
As temperatures rose quickly at the start of the Holocene 11,000 years ago, major changes in vegetation occurred. Arctic-alpine species were displaced to higher altitudes in the Northern Highlands. Pioneer trees species, especially juniper and birch, invaded the lower ground. Heather and crowberry formed the understorey. By around 9000 14C yr BP, a more closed woodland had developed, with strong representation of birch. Birch pollen and remains then disappeared around 6200 14C yr BP to be replaced by heather. At Cross Lochs, Sutherland there was a short-lived colonisation by pine around 4250 14C yr but thereafter the landscape became largely treeless. At the coast much more extensive woodlands developed:
“But the most remarkable evidence of ancient woods in Caithness is found in the Bay of Keiss. Between the links and the sand, and running down under the sea, are found the remains of a submarine forest. These are, like peat-moss, entirely composed of decayed wood. The barks of various kinds of trees are quite discernible, and even the seeds of birch and ash are so well preserved as to appear but lately taken from the tree”. New Statistical Account of Wick
On the acid rocks of along the western edge of the plain of Caithness, the vast bogs of the Flow Country have been gradually accumulating peat for the last 11, 000 years.