Spruce growth rates on drumlin soils.

Abstract

Of the many topographic features left to us by a departing Ice Age, one of the most outstanding is that characterised by the numerous small oval-shaped hills located mainly on the North-Central plains. These hills oalled drumlins (from the Irish druim meaning a mound or rounded hill) also occur in small ·areas in other parts of the country notably around Clew Bay and in Clare, but the great belt of drumlins stretching from southern Donegal and Sligo through Fermanagh, Leitrim, Cavan, Louth, Monaghan, Armagh and Down is one of the hrgest in the world . Drumlins were forrr,ed under moving ice and this is the reason claimed for their long low streamlined shape. Gardiner and Ryan (1969) state that drumlin soils occupy 10.1 % of the Republic, of which 7.8 "/0 are wet mineral or organic soils; only 2.3"/0 are classed as mainly drier mineral soils. The discussion of spruce production on drumlin soils which follows, is confined to the wet mineral soils with particular reference to the Leitrim-W'est Cavan area.