COVER TYPE AND FIRE CONTROL 5 
extreme flexibility necessary in a control organization designed to 
cope with the problem. Even the individual types, because of site 
differences and effect of previous fires, vary enormously within them- 
selves. Density, height, and age of the timber; degree and direction 
ELEVATION 
IN FEET 
CREST OF 
10,000 SIERRAS 
AST 
———_> 
86,000 
PINYON 
6,000 
4,000 
PLACERVILLE _ 
S222 GRASSLAND : 
WOODLAND YELLOW PINE 
AN 
HAPARRAL DOUGLAS FIR 
ra) WOODLAND 
10 A 30 40 50 60 80 
DISTANCE IN MILES 
FIGURE 3.—Typical cover-type distribution in the north Sierra group of forests, Eldorado 
National Forest 
of slope; amount and character of associated: vegetation; and pres- 
ence or absence of young growth, all vary at times from acre to acre 
and hence affect the spread and severity of fires. With given fuel, 
slope, and soil, the spread of fires also varies greatly from time to 
30 <0 
OISTANCE IN MILES 
13,000 
12,000 
WHITE BARK 
PINE 
11,000 
MOUNTAIN HEMLOCK 
WESTERN WHITE PINE 
WHITE-BARK 
10,000 ene PINE 
JEFFREY 
eA PINE 
MOUNTAIN HEMLOCK 
9.000 
, GIANT 
SEQUOIA 
ie 
4 y ASPEN 
LYALL 
FORK (JUNIPER 
Ue 
oy 
8,000 
cee 
TRANSITION BRUSH 
SUGAR PINE 
INCENSE CEDAR 
Ps = 
ies 
7,000 
LEEVINING 
CREEK 
6,000 
WESTERN YELLOW PINE 
INCENSE CEDAR 
ALTITUDE ~- FEET 
5,000 
Ragu G ati WHITE FIR 
{VERNAL 
FALLS 
SUB-ALPINE —~ 
AiR 
JEFFREY ANE ——> 
WOODLAND 
4,000 
DIGGER PINE 
LIVE OAK 
3.000 
.—~<— CHAPARRAL 
& § 
ao 
°o 
OAK ~ TiWa3 ‘ 
2,000 WOODLAND t+ By & 530" 
GRASS BRUSH 
nN 
oO 
SAN JOAQUIN RIV. 
1,000 MARGINAL WILLOWS 5 
yo’ Grass 
S207 
to) 
SUB-ALPINE ALPINE 
RAINFALL-INCHES 
FicuRE 4.—Profile of the San Joaquin Valley and the Sierra Nevada Mountains, showing the 
BU Dever nate life zones and distribution of cover type in a south Sierra forest, Sierra National 
orest 
time as the moisture content of the fuel and the velocity of the wind 
vary. The behavior of fire in each type is controlled not only by the 
amount and kind of fuel, but also directly by the climatic elements 
of which the type itself is an expression.! 
