Using climatic factors as the basis of forest classification, seven broad regions may be distinguished as follows.*
An annual precipitation of over 50 inches, a mean
Douglas Fir temperature of 45 degrees, with an absence of ex-
Coast Region tremes, a humid atmosphere and long growing season, which characterize the climate of the southern coast and the greater portion of Vancouver Island, produce a coniferous forest which is only equalled for density, rapidity of growth, yield and individual tree development, in the coast regions of Oregon and Washington, where the same climatic conditions prevail.
The typical stand in this region is of even-age origin, dating from a fire, and is made up of varying proportions of Douglas fir, hemlock and cedar, with occasional admixture of spruce, white fir, lovely fir, and white pine. Where this typical stand escapes fire for a period of 400 years, the Douglas fir drops out, and, thereafter, the forest continues as an uneven-aged stand, the blanks being filled by reproduction of hem-lock, cedar and lovely fir. Pure stands of hemlock are of frequent occurrence, and, occasionally, nearly pure stands of cedar are found.
The forest is everywhere very dense, regardless of age, with a very rank undergrowth of shrubs and hemlock seedlings, and a heavy deposit of dead leaves, branches and down trees, all covered with a thick layer of moss. The mature stands bear from 10,000 to 100,000 feet, board measure, per acre, with an average of 20,000 feet.
Commercially, Douglas fir is the most important forest type in British Columbia, furnishing at the present time over 1,000.000,000 board feet annually, or two-thirds of the lumber cut of the province.
Owing to the density of the stand, the great size of the individual trees, the heavy undergrowth, the large amount of dead vegetable material on the ground, the destructiveness of the methods of logging (donkey engines and wire cable being used almost exclusively), and the high standard of merchantability, the amount of debris left on the ground is really stupendous, and the damage to the remaining trees is generally so great as to destroy their further usefulness.
The heavy deposits of debris, besides rendering the conditions extremely unfavourable to re-seeding, constitutes a fire hazard so great that any attempt to use the remnants of the stand as a basis for a second crop would be altogether impracticable. Again, Douglas fir is undoubtedly the most rapidly growing and commercially valuable species, and, unless the debris is removed, this tree will form only a very small proportion of the new stand, hemlock becoming the predominant species.
* For situation of regions see accompanying map.