Sierra Nevadan Distriet. 619 
2. Formations of the higher Sierra. 
Subalpine Forest Belt. This formation, or forest belt, seems at first but a 
thinner upper fringe to the magnificent forest composed of Pinus ponderosa, 
P. Lambertiana and Seguoia gigantea. There is, however, no species of tree 
common to the two belts, or extending much from one into the other. The 
composition of this higher forest belt varies. 
In the northern Sierra Nevada Mountains, it occurs above u feet on the western 
slopes and above 7,300 feet on the eastern and trans-sierran slo ere the Shasta fir 
bies shastensis is the prevailing tree forming fully 83 per cent ur the forest associated 
with Pinus Murrayana (12 per cent), Pinus monticola (3 per cent), mountain hemlock, er Patto- 
niana (= T. Mertensiana, 2 per cent), Pinus albicaulis with Populus trichocarpa, P. tremuloides 
Cercocarpus parvifolius, Castanopsis ehsophyli, Arctostaphylos pungens, while RR cordu- 
latus constitutes the underbrush above 7,000 fee 
This forest in the neigborhood of Lake Tahoe and Yosemite Valley consists essen- 
tially of three conifers: Pinus Murrayana, Abies magnifica, and Pinus ponderosa var. 
Jeffreyi. The other coniferous and u trees form no considerable part of the 
forests, Associated with the species named above are Pinus monticola, Pinus albicaulis, mountain 
hemlock Tsuga Pattoniana, Abies concolor, Juniperus occidentalis, Populus tremuloides, Alnus 
tenuifolia, Prunus emarginata and Acer glabrum. 
On Mount Rose at the western edge of the Nevada Desert above Reno at about 7000 feet 
(2130 m) on this Sierra peak there are forests of Pseudotsuga Douglasii, Pinus ponderosa, Libo- 
cedrus decurrens with such shrubs as Arctostaphylos nevadensis, A. pungens, Castanopsis chryso- 
phylla, Ceanothus prostratus, C. velutinus, Cercocarpus ledifolius and Ribes cereum, together with 
such herbs as Arabis pedicellata, Erysimum asperum, Gilia aggregata, Monardella odoratissima and 
Pentstemon deustus. At the upper limits of Pinus ponderosa 9000 feet (2743 m) on Mount Ros 
is a facies of Pinus Murrayana and, scattered on protected north-facing slopes, Tsuga En 
and in protected canyons Pinus monticola. 
Pinus Murrayana forms the bulk of the subalpine forests near Yosemite Valley. 
As a tree, it is widely distributed between 6,000 and 9,300 feet, while the area of its greatest 
abundance lies between 6,000 and 8,500 feet. On higher ground, it is associated with Pinus 
ponderosa var. Jefireyi, Abies ae Pinus monticola and Tsuga Pattoniana here forming 
50 per cent . the stand. This shows a remarkable edaphie adaptation. It thrives best in 
meadow bottoms, but spreads ee over low rock ridges and stretches of high granite 
plateaus, establishing itself everywhere in crevices and pockets. — The range of Abies magni- 
fica is between 6,000 and 8,500 feet and the prevailing growth lies between 6,500 and 7,500 feet 
where forests of pure growth are frequent on the soil-covered lava rock benches on ci CRSEEN, 
southern and western slopes of the larger mountain peaks and ranges. Pinus mo ee n 
rather rare but widely distributed between 6,500 and 9,400 feet. It appears as scattered indivi- 
duals associated with Abies magnifica, Tsuga Pattoniana or less frequently with Pinus ARHEERERRN 
Tsuga Pattoniana (= T. Mertensiana) is a strietly subalpine tree, zonlmea chiefly to 
northern slopes at elevations between 6,900 an 
these limits and associated with Pinus Murrayana only or with Pinus monticola, P. Murrayana and 
Abies magnifica; while in its highest range it occurs in small groups by itself or interspersed 
with Pinus albica 
Pinus albicaulis grows among broken bare rocks and in beds of disintegrated granite 
elevations between 8,000 and 9,500 feet, forming small patches of stunted and storm-beaten == 
with which except at the upper levels, are rer groups and single trees of mountain hem- 
lock, Pinus monticola and Pinus Murrayana. At the upper limits of its distribution Pinus albi- 
caulis is the only tree and fixes erie As a tree, it grows on eastern, southern and 
