PRESENT VEGETATION OE THE SIERRA NEVADA 



233 



It having been stated that remains of fossil plants are abundant in the 

 gravel deposits, one of the first questions to be examined in this connection 

 is : In what way are they distributed ? Are they found in such positions as 

 to indicate an effect produced by difference of altitude or of latitude ? We 

 know that the present vegetation of the Sierra Nevada, as is always the case 

 in mountain ranges of considerable elevation, shows in the most marked 

 degree the effect of change of altitude, and that the element of latitude 

 also plays a part which is especially conspicuous in the distribution of the 

 forest growth of that chain. 



There are at the present epoch four pretty well marked belts of vegetation 

 on the western slope of the Sierra. These belts, however, pass gradually 

 into each other, and are not so defined that lines can be drawn exactly limit- 

 ing their range. Still, in the central portion of the State the succession of 

 the different groups of species as we rise in altitude is very easily recognized. 

 The great predominance of coniferous trees is the most conspicuous feature 

 of the arboreal growth of the Sierra. Even in the lowest belt, — that of the 

 foot-hills, — which extends up to an altitude of between 2,000 and 3,000 feet, 

 the pines are decidedly superior in number to the oaks, the digger-pine (P. 

 Sabiniana) and the black oak ( Q. Sonomensis) being the predominant species. 

 With these two trees are mingled some quite conspicuous shrubs, some of 

 which attain to considerable height. Of these the California buckeye (JEscn- 

 lus Calif ornica), the Manzanita (Arctosiaphglos glaaca), and the Ccanollms are the 

 most striking, as helping to give some variety to what, on the whole, is a 

 decidedly monotonous vegetation. The next succeeding belt, which ranges 

 up to 4,000 or 5,000 feet, is peculiarly the forest zone of the Sierra, distin- 

 guished by the great size and beauty of the individual trees, but still without 

 sufficient variety and intermixture of deciduous foliage to be beautiful as 











well as grand. The pitch pine (P. pontic rasa), the sugar pine (P. Lambertiana), 

 the white cedar (Libocedrus deeurrens), and the Douglas spruce (Abies Dovg- 

 mi%) are the principal trees of this belt, in which also the Big Tree (Sequoia 



# 



OMjantea) belongs, although the latter is quite limited in its range. Above the 

 zone of pines come the firs, Picca grandis and amabilis, with a considerable 

 number of the pine characteristic of high altitudes, the so-called tamarack 

 pme (P. eontorta). This belt of firs ranges, in the Central Sierra, from 7,000 

 to 9,000 feet, P. mon/icola, in many localities, rather usurping the place of the 

 firs at very high elevations, while a variety (as considered by some botanists) 

 °f P. ponderosa,P. Jeffreys is also of somewhat common occurrence. Above 



