The Role of Western White Pine in Forest Succession in Northern Idaho

Abstract

The importance of vegetational studies in virgin forests has become more and more obvious during the past few years as a result of the increasing scarcity of primeval areas. The work of Cooper ('13) on Isle Royale, Michigaln; of Nichols ('13) at Colebrook, Connecticut; of Lutz ('30) at Heart's Content, Pennsylvania; of Gates and Nichols ('30) studying an area near Pellston, Michigan; and of Hough ('32) in Pennsylvania, may be said to compose the greatest portion of the meagre literature on this subject. With a view, therefore, to obtaining knowledge of the character of the vegetation of the sub-climax and near-climax forest of the white pine these studies were undertaken. in three virgin communities. Although there have been several general surveys and observational studies made on this subject in the Northern Rocky Mountain region, there is no published work available on the vegetation of specific areas. It is the purpose of this paper, therefore, to present such data. In his more or less extensive observations in the Bitterroot Mountains of northern Idaho, Larsen ('29) notes that after fires, the succession is somewhat as follows: The intolerant and drought-resistant western larch and lodgepole pine represent the first stage. These trees, with an initial stage of subordinate vegetation, prepare the site for the advent of Douglas fir and western white pine, and a second layer of lesser vegetation. This stage in turn paves the way for the climax forest association of western red cedar, western hemlock, and lowland white fir with a typical sparse shrubby and herbaceous vegetation (fig. 1). Accepting these general relationships, the areas investigated ill this study may be placed in the second stage in the case of areas 1 and 2, while area 3 probably belongs to the climax or near-climax stage. In a general way the three areas belong to the white pine type, so termed because of the volume and economic value of PFinls 1mt0onticola, rather than because of the number of trees per acre or its importance in the climax forest. Briefly, this type consists most commonly of western white pine, Pinnas monticola, as the dominant species with other trees subordinate. With age,