422 C. S. Sargent—The Forests of Central Nevada. 
forest, which follows, both on public and private domain, every 
relation of moisture to forest distribution, especially with refer- 
ence to the multiplication of species, which will be found to 
increase or diminish as the rain-fall is more or less abundant 
and more or less equally distributed. 
In the territory between the 41st and 37th parallels of lati- 
tude, and extending from the eastern base of the Rocky Mts. 
to the foot of the western slope of the Sierra Nevada are three 
distinct belts of arborescent vegetation.* Beginning at the east 
there is: 1. The Rocky Mountain Region including, besides the 
main range, the Uinta and the Wahsatch, and embracing Colo- 
rado and the eastern half of Utah; 2. The Nevada Region, ex- 
tending from the western base of the Wahsatch, to the eastern 
base of the Sierra Nevada, and embracing the western half of 
Utah and the whole of Nevada with the exception of the ex- 
treme northern and southern portions of the State; 3. The Sierra 
Nevada Region. 
_ In the Rocky Mountain Region, to which in spite of its mid- 
continental position considerable moisture is attracted by the 
high peaks which everywhere dominate it, there are twenty-five 
trees and forty-eight shrubs, in all seventy-three species. In 
the Nevada Region, where, owing to its isolated position be- 
tween high mountain ranges, the rain-fall is small and very un- 
equally distributed, the number of species is reduced nearly 
one-half—to thirty-eight; ten trees and twenty-eight shrubs. 
In the Sierra Nevada Region, to which the Pacific contributes 
a large although unequally distributed, snow and rain fall, the 
number of species is increased to eighty-nine; of these thirty- 
five are trees,+ or three and a half times more than occur 
in the adjoining Nevada Region, and a third more than are 
found in the y Mountain Region ; and fifty-four are shrubs, 
or double the number of the Nevada Region. 
he following table shows the arborescent ¢ and frutescent 
species, so far as they are now known, which occur in these three 
Regions. 
__* For the purpose of the present comparison not only all frutescent 
— which may be expected to exceed four feet in height, and therefore as un- 
dergrowth to form an important element in the forest, will be included. 
_ + Pinus monophylla Torr., although it has found a foothold on the eastern 
flank of the Siecra Nevadas, is not included among the trees of this region. This 
species, as well as Artemesia tri hae Berens tape ieoene bag 
y cannot be | ly considered a part of the Flora of the Sierra Nevada. 
: Species which become large enough to be of economic value as timber trees, 
are designated bya *. 
