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Numerous interglacials show expanding NAP [non-arboreal pollen] percentages … This development is interpreted as caused by acid, infertile soil conditions and perhaps increasing rainfall … a postglacial trend of woodland expansion followed by decline, has also happened in the Holocene. In: Schneider SH, Miller JR, Crist E, Boston PJ, editors.

More recently, in a review of the literature for northwest Europe, Svenning (2002) has concluded that “vegetation development during the preceding interglacials … The native woodland resource of Scotland: a review 1993–1998. Edinburgh: Forestry Commission, Technical Paper 12.

suggests that open woodland or even heath vegetation can develop on nutrient-poor soils. Land-use legacies and soil development in semi-natural ecosystems in the marginal uplands of Ireland. Edinburgh: Forestry Commission, Technical Paper 30.

Thereafter there is the phase of forest regression with open conifer-dominated woods, ericaceous heaths, and bogs growing on infertile, humus-rich podsols and peats. Mackey EC, Shaw P, Holbrook J, Shewry MC, Saunders G, Hall J, Ellis NE.

Local extinction of nutrient-demanding mesocratic plants occurs and some protocratic plants expand as a result of decreasing shade.

The area under consideration comprises the uplands and marginal uplands of Scotland, north of the Highland boundary fault.

The paper is a review of the relevant published literature on the history of the vegetation, together with the factors that influence vegetation pattern, in particular soils, competition, herbivores, fires and felling.

If the Holocene is seen as the most recent of a series of interglacial periods, then Iverson (1958) has identified a vegetation cycle that has been broadly similar in Quaternary interglacial periods in north-western Europe.

This interglacial cycle can be summarised as follows (after Birks 1986): in the immediate postglacial period there is a cold, phase where shade intolerant herbs, shrubs and trees immigrate and expand rapidly to form widespread species-rich grasslands, scrub and open woodlands growing on unleached, fertile soils of low humus content.

4% of the landscape of Scotland (Forestry Commission 2003). Miles (1981) has concluded that Scotland’s moorlands were ‘degraded ecosystems’.

The dominant paradigm of recent years is that this open, moorland landscape is largely anthropogenic, brought about by the grazing of domestic stock, and by the burning and felling of the indigenous woodland that would naturally be the climax vegetation up to a climatically determined tree-line of about 600 m (e.g. Research has also concluded that natural factors can cause expansion of blanket peat in the landscape and, hence, by implication, woodland decline, particularly in the north of Scotland (e.g.

Darling 1947; Mc Vean and Ratcliffe 1962; Bennett 1995; Peterken et al. O’Sullivan 1977; Birks 1988a; Bennett 1995; Huntley et al. However, although common in certain areas, peatland is by no means dominant throughout upland Scotland so that peatland expansion cannot be the only reason for woodland decline.

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