Dawson, Sir J. William (1868) The Geology of Nova Scotia, New Brunswick and Prince Edward Island, or Acadian Geology. Second edition. MacMiIlian & Co., London. 694 + xxvi pp. (First edition 1855.)

William Dawson (b. 1820, d. 7899), the principal of McG/l/ University from 7855 until 7893, and an eminent geologist of international standing, had been born and brought up in Pictou, Nova Scotia, where from an early age he had taken an interest in the geology and natural history of the region. After an education that included a degree from Edinburgh University, in 1854 he completed the manuscript of the first edition of his monumental work ’Acadian Geology', an authoritative guide to the geology of the Maritime colonies, which was to eventually receive three further printings and to reach 700 pages in length. In collecting material for his book Dawson visited Prince Edward island several times and he included a separate chapter on the geology of the island. Not surprisingly, ’Acadian Geology’ is not very much concerned with the then existing vegetation or with recent vegetation phenomena, though in an introductory chapter he does consider the factors, such as land clearance and forest fire, that were acting to bring about changes to the natural forests of the region. Dawson in fact gives a useful description of vegetation succession after fire and forest clearance, even using the verb ’succeed’, and he cites two examples of such succession from Prince Edward Island.

REFERENCE: Eakins, P. R. & Sinnamon, J. (1990) Dawson, Sir John William. Dictionary of Canadian Biography,

XII: 230—37. The forésfs 0’ In their natural state, Nova Scotia and the neighbouring provinces were covered with the Ma””mes' dense woods, extending from the shores to the summits of the hills. In general,

the deciduous or hardwood trees prevail on intervale ground, fertile uplands, and the flanks and summits of slaty and trappean hills; while swamps, the less fertile and

lightest upland soils, and granite hills, are chiefly occupied by coniferous woods. (p. 46]

The woods perish by the axe and by fire, either purposely applied for their destruction or accidental. Forest fires have not been confined to the period of European occupation. The traditions of the Indians tell of extensive conflagrations; [p. 47)

Fire.

Where the forest trees are merely cut down and not burned, the same description of wood is immediately reproduced. If the original wood have been of kinds requiring a fertile soil, such as maple or beech, and if this wood be removed, for example, for firewood, it may happen that the quantity of inorganic matter thus removed from the soil may incapacitate it, at least for a long time, from producing the same description

Succession after of timber. In this case some species requiring a less fertile soil may occupy the

wood—cutting. ground. For this reason, forests of beech growing on light soils, when removed for firewood, are sometimes succeeded by spruce and fir. I have observed instances of this kind, both in Nova Scotia and Prince Edward Island.

in the Mar/times When the trees are burned, without the destruction of the whole of the vegetable soil, ”7 general. the woods are reproduced by a more complicated process, which may occupy a number of years. The original forest may have consisted of white or red pine;

black, white, or hemlock spruce; maple, beech, black or yellow birch, or of other trees of large dimensions, and capable of attaining to a great age. The “second growth" which succeeds these usually consists of poplar, white or poplar birch, wild cherry, balsam fir, scrub pine, alder, and other trees of small stature, and usually of rapid growth, which in good soils, prepare the way for the larger forest trees, and occupy permanently only the less fertile soils. A few examples will show the contrast which

Slime-$9.0” thus appears between the primeval forest and that which succeeds it after fire. [:1 after fire' In Prince Edward Island, fine hardwood forests have been succeeded by spruce and fir. Ipp- 49-51]

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