598 Part IV. Chapter 4. 
The coniferous trees in the Cascade Mountains of Oregon (see plate XV, page 600), especially 
in the neighborhood of Mount Hood (*marked)?) are *Pinus ponderosa, *P. Lambertiana, *P. 
monticola, *P. albicaulis, *P. Murrayana, *Abies concolor, *A. amabilis, *A, nobilis, A. a 
*Pseudotsuga Douglasii, Libocedrus decurrens, *Chamaecyparis nootkatensis, *Thuja plicata, *Tsuga 
Mertensiana, *Tsuga Pattoniana, *Picea Engelmanni, *Taxus brevifolia, Juniperus ak s, while 
the broad-leaved trees comprise *Quercus californica, Q. Garryana, Arbutus Menziesii, Fraxinus 
reg *Acer macrophyllum, *Alnus oregona, Cercocarpus ledifolius, C. betuloides, *Castanopsis 
Gi schri, Pirus (Malus) rivularis, *Populus tremuloides, P. balsamifera, P. trichocarpa and Sam- 
bucus glauca. The northern limit of Pinus Lambertiana is 44° 47’ latitude on the 
western slopes. The southern limit of Chamaecyparis nootkatensis is Deer Creek a 
tributary of the as River, while Larix occidentalis attains its northern limit at 
44° 08’ north latitude 
The altitudinal distribution of the trees mentioned is shown in the accompanying table. 
West of Cascades. East of Cascades. 
rn a a ie A ER 1,800—6,000 feet 4,000— 7,000 feet 
Varlaineie a 3,000— 5,000 » 4,500—6,000 >» 
> Mongolei Een 5,000—7,500 >» 5,500—6,000 >» 
RE RE EN 6,000—9,300 >» 6,000— 9,300 * 
timber line 
Murrayana. . ac ee 3,000— 8,000 >» 4,200—8,500 > 
Pseudotsuga Dysshikr; a a Re ae 2,500—6,800 » 4,300—7,000 > 
N SER ET ER TE EL 3,000—6,000 » 4,000—7,500 > 
Be ROBENE en ne we eh 5,200— 8,800 >» 6,000— 8,800 > 
ee en EEE RE RE ER 5,880— 7,800 >» 5,880— 7,800 >» 
TSURBSDBRRBREDE tee : 5,200— 6,000 » " 
52, SPELOBIANE De N 6,000—9,200 >» 6,000— 9,200 > 
Close to timber line. 
Libocedrus. deeurrens ..... 1......0% , 2,500—5,000 feet 5,000—6,600 >» 
PRCEN ERSChHHBNE er en a ee 5,800—8,000 > 5,6 000 >? 
‚janigerüs ScGsdentalis hs ce See 1,600— 5,200 » Lowest elevations 
to 6,000 feet. 
Several facies, or types, are recognizable in this forest formation. As 
complete data is lacking for each, only the general details of their composition 
can be given. 
Pinus ponderosa Belt. As to annual precipitation and mean ratio of soil humidity, this 
facies occupies the lowest position. It is the dominant type throughout the upper Klamath Basin, 
but on the western side of the Cascades it is not well developed. It is rarely pure, but Abies 
concolor, Pseudotsuga Douglasii, Libocedrus decurrens, Pinus Lambertiana and P. Murrayana are 
associated with the yellow pine, and an undergrowth of Purshia tridentata, Ceanothus velutinus, 
Arctostaphylos patula and Castanopsis chrysophylla var. minor2). It is more of a southern type 
= forest. Frequently Pinus Murrayana forms almost pure stands, in two aspects; first, in the 
contorta” form of the species found along the edges of marshes, creeks or springy localities; 
a in the “Murrayana” form found as straight slender trees on well drained uplands. 
1) LEIBERG, JOHN B.: Cascade Range forest Reserve, 2ıst Re eport U. S. Geological Survey 
art V. 209—497; LAnGItLe, H. H., PLumMER 
en forest Reserve Oregon, U. S$. Geological Survey, Professional Paper No. 9. Seri ies H. 
restry 6; SUDWORTH, GEORGE B.: Forest Trees of the Pacific Slope. U.S. Forest Service 1908. 
2) Covır LE, F. V.: Forest ehe and Berg grazing in the Cascade Mountains of OregoR. 
U.S. Division of Forestry, Bulletin 15: 8. 
‚F.G. et al. Forest Conditions in the Cascade 
