A Bog Forest

Abstract

In a previous paper (4, I9I7) the writer has described forest succession in Puget Sound sphagnum bogs, and in other papers (4, I9I3; I9I4; I9I9) has listed the trees growing in various sphagnum bogs of the Puget Sound region and Alaska. All of these are comparatively early stages in bog succession. None of them have reached a stage where the forest is dominant. An area of about three acres near Victoria, British Columbia, shows a very late stage where the forest has become the dominant vegetation, and sphagnum is no longer found living. This area was visited in July, 1920, and a more careful study was made during several visits to it at various times in July, I92I. The area is at present bordered on the south by a meadow, on the east and north by Lost Lake, and on the west by the Patricia Bay line of the Canadian National Railway. The forest consists of a pure stand of lodge-pole pine, Pinus contorta. The trees are of good size for this species, many of them being 20 to 30 feet tall and 6 to io inches thick at the base. A few are 12 inches thick. The stand of trees is very dense over nearly all of the area, and many young trees have been killed by the shade of the taller ones. The trunks of these trees are straight and slender. They do not have the scrubby form that this species does on rocky, exposed places, nor the stunted appearance that it has in the early stages of forest succession in Puget Sound bogs. Very few pine seedlings were found, and these only on the border along the west side, where the forest was cleared a few years ago when the railroad was built, and Nature was then allowed to take her course again. Lodge-pole pine is common on this portion of Vancouver Island. It is found around lakes, both in swampy places and on rocky shores, and on the thin soil of rocky hills. It is found practically to the top of Mount Benson, near Nanaimo. Glendenning (i, i9i8) says that it is frequent in bogs and on gravel ridges in the Cowichan district on Vancouver Island. Whitford and Craig (5, i9i8) state that this species is general throughout the province of British Columbia, from the international boundary to the Yukon drainage, being found at an altitude of 5,ooo to 6,ooo feet, and attaining a height of 50 to 75 feet and a diameter of I2 to 24 inches. The undergrowth in the bog forest under consideration consists of a dense thicket of Labrador tea, Ledum qroenlandicum, and salal, Gaultheria shallon.