In reference to this question of reproducing the forest, the most apparent point is the incongruity of uniform cutting regulations to apply to vastly different forest types and market conditions. The same regulations govern the lumbering of the white spruce-aspen type of northern Manitoba and Saskatchewan, the lodgepole pine-Engelmann spruce type of western Alberta, and the wet, dry and coast regional types of the railway belt. Logging in these different types necessarily results in a wide variation of conditions for seed germination and seedling growth, and as each tree species has its own inherent biological requirements, it is evident that uniform logging treatment cannot result beneficially.
The idea of the imposition of a diameter limit, below which trees are not to be felled, is to leave seed trees to prevent the extinction of the merchantable species. The lumberman naturally has no interest in the future forest on land that does not belong to him, and his tendency in logging is to cut all that is marketable with profit. This is ordinary business. The initial improvements, in the shape of buildings and roads necessary to log a certain tract, form a fixed overhead charge, and the more timber taken off the area, the lower is the expense per thousand feet, as far as this item is concerned.
The diameter limit on Dominion berths is 10 inches. In operations a decade ago the market offered no inducement to cut below the limit. But, year by year, with disappearing supplies, the lumbering standards are becoming less fastidious, and in the smaller timber there is a temptation to cut below the legal limit, and conduct what amounts to a clean-cutting operation. Moreover, a stump diameter limit means nothing, since stumps vary in height. The size of tree taken with a 10-inch stump is a matter of how far down in the root swelling, present on all trees, the cut is made. The limit should at least be stated in terms of the diameter at a certain height.
An arbitrary diameter limit very seldom brings about the perpetuation of the desired forest. Unless the stand contains a wide range of sizes, too few trees are left to seed up the area, and, in the case of spruce, the isolated trees are very apt to be wind-thrown. In addition, the trees remaining are not spaced to the best advantage to distribute the seed. Even if the above requirements are accidentally met, as sometimes happens, the openings made by cutting to a rigid limit may or may not be favourable to the growth of the seedlings desired.
As a general statement, the above factors characterize the conditions to be observed on logging operations on Dominion lands. The present lumbering methods result usually in leaving an insufficient number of seed trees, and in consequence the forest is yearly deteriorating. In this connection it is of interest to note that in the leading