CHAPARRAL. 1133 
woodland of oaks. As the rainfall increases with altitude a point is 
reached where timber can grow. This is the lower timber line. Its 
altitude varies with latitude and exposure, but averages about 2,000 
feet. The upper timber line is not determinable, since the moun- 
tains are not of sufficient height. Probably this line would be at 
about 13,000 feet. 
Every school child has drawn maps, making wiggly lines for the 
rivers, which increase in thickness from source to mouth. This 
among map-making nations is the recognized conventional symbol 
for drainage. In the chaparral country, however, the drainage 
ignores all the conventions. More often a stream is largest near its 
source, while the water gradually thins out toward its mouth, and 
disappears entirely without reaching the ocean. The flow is usually 
intermittent, though there may be short stretches of bed where water 
is permanent. 
Citrus fruits, olives, figs, and guavas are grown on the lowlands, 
between the chaparral and the ocean, as far northward as Point 
Conception. North of this point the climate changes, and apple and 
peach orchards are common. There is, however, an isolated region 
near Portersville which has a climate favorable for oranges. It will 
_be seen from the map that chaparral is also present in this locality. 
The climate southward from Point Conception is considered one 
of the finest in the world, comparable with that of Ceylon and 
Jamaica. An unusual climatic feature of the region is called by 
orchardists the “ frostless belt.” This is a narrow subzone, seldom 
more than 200 feet in altitudinal range. In the foothills north of 
Santa Barbara Channel it hes from 700 to 900 feet above the sea, and 
has almost a subtropical climate, although frosts occur both above 
and below it. Southward it is not always so clearly defined, since 
the mountains recede from the shore, and the belt is therefore 
spread out over a broader area on the coastal plain. Near San Diego 
it is certainly lower than farther north, in spite of the fact that it 
would be naturally expected to increase in altitude with the decrease 
of latitude. At Point Loma, a promontory nearly 400 feet high, the 
lower limit of the belt has been defined at 275 feet above the sea. The 
upper lmit has not been determined, since it is above the altitude of 
the Point. On top of the promontory the climate is almost perpetual 
spring, with oranges, figs, and bananas growing there. Below the 
275-foot contour, where ice has formed in winter, apples, quinces, 
pears, and peaches are grown. 
The peculiar climate of coastal southern California prevails up to 
the mountains, and even on some of their slopes. Beyond, in the 
intramontane region, there is a different climate, and in the depressed 
ultramontane region there is a complete change into severe desert 
conditions. 
