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216   COMMISSION OF CONSERVATION

hemlock, so that even in the pure stands of fir there are scattered small groups of mature hemlock. At the higher elevations, the hemlock gradually displaces the fir in the forest.

Western cedar is much less common than the hemlock as an associate of the Douglas fir, but in its best situations it more nearly approaches the fir in size; in fact it sometimes surpasses the fir in diameter, but not in height. The largest cedars are found on moist flats along lakes, sea and streams. Cedar, however, like the hemlock, may be found in almost any soil condition, but it apparently does not reach large size on indifferent soils except on the immediate slopes of the shores.

Balsam, Sitka spruce and western white pine, so far as observed, occur only scatteringly in the Douglas fir forests. The balsam is the most common of the three.

One is impressed by the occurrence of a large number of stands of mature fir in which the trees are nearly all of the same age. The stands of medium-sized trees, for example, were prevailingly 315, 170 and 124 years old. In fact, representatives of these age classes were found on every area studied, whether on the island or on the main-land. The uniformity of age, however, was not so pronounced among the largest and oldest trees. The largest tree observed was seven feet in diameter and was 910 years old. Fire scars disclosed the fact that the tree was burned 856 and 335 years ago. The large trees, about six feet in diameter, at Chemainus, were 540 years old. Those near Cowichan lake and Gibson landing were 425 years old, with an average diameter of five feet. In both places they showed fire scars 230 years old. At Powell river they were 356 years old, and averaged four feet in diameter, while at Union bay they were 460 years old and six feet in diameter.

Younger stands, 70 and 100 years old, were also frequent on all of the areas investigated. These are the ages of most of the fir trees left after the logging operations at Shawnigan lake, Chemainus and Union bay, and also of the trees now standing on the logged-over areas on the north side of Burrard inlet, at Gibson landing and Powell river.

Judging by what we know of the method of re-establishing fir forests after the more recent fires, we are fairly safe in assuming that these mature Douglas fir forests were established as the result of fire. Moreover, all the five younger age classes mentioned above correspond with the ages of fire scars on the neighbouring older trees. This point may be made clear by describing the condition of affairs at Powell river, where a careful study of the history of the forest on a square mile was made. The majority of trees logged on the area would be approximately 315 years old if standing to-day. The fire scars on the


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