FOREST TREES OF THE PACIFIC SLOPE. 145 



Its range the precipitation varies with increase in altitude and for dry and wet years 

 from about 18 to over 60 inches. At high altitudes the snowfall is often very heavy. 

 At Summit, an annual snowfall of nearly 700 inches, equivalent to 70 inches of rain, 

 has been reported. The winters are long but mild, and the flowering and pollination of 

 bigtree take place as early as February or March, although spring does not commence 

 until considerably later. The climate varies little with latitude, because as bigtree ex- 

 tends southward it grows at increasingly higher elevations. 



Tolerance. — Tolerant of but little shade at any stage ; for vigorous growth, abundant 

 overhead light required from the start. Endures more shade during early youth than 

 in old age, when crowns are always in full light. Under dense shade young plants grow 

 very slowly, and have sparse foilage, flat crowns, and a gnarly habit, showing need of 

 light. Such trees, however, often survive for a number of years, recovering slowly with 

 light. General absence of reproduction in all but openings in forest and in open ground 

 adjacent to seed trees shows clearly that light is a most important factor in early life. 

 Kndures considerable side shade; close stands of trees, 20 to 30 years old, often retain- 

 ing branches to ground, while in full light they are kept many more years. 



Reproduction. — An abundant seeder at short intervals, witli specially heavy seed 

 years; some seed usually borne annually in parts of range. Seed of moderately high 

 rate germination, with persistent vitality. Open-grown trees may bear seed sparingly 

 when IS or 20 years old. Seed production in forest, much later; mainly when from 

 150 to 200 years old. Seeds are scattered in late fall and early winter. Lightness of 

 seed permits restocking of open ground for several hundred yards from mother trees. 

 Germination mainly and best on exposed mineral soil ; seedlings rare or wanting on heavy 

 litter, which they can not penetrate. Reproduction generally best on burned areas, where 

 fire has cleared off litter, and exposed mineral soil, or even after light ground fire has 

 left a layer of ashes or charcoal. Heavy stocking, which occurs only under such condi- 

 tions, often amounts to 2,500 seedlings per square rod. Dense snowbrush common on 

 burns does not prevent growth of bigtree seedlings. Usually seeded before the brush 

 comes in, seedlings grow slowly through it. Thrifty sapling stands are frequent over 

 this brush. Seedlings grow rapidly in clearings, under full light, sometimes reaching 

 ti feel in as many years, the greater part of which is attained during the third and fourth 

 years. Such open-mown seedlings begin to branch vigorously from the first year, and 

 assume the characteristic pointed form of rapid growth. 



Redwood. 



Sequoia sempervirens (Lamb. )' Endlicher. 



DISTINGUISHING CHARACTERISTICS. 



The dark cinnamon-brown, grayish tinged trunks of redwoods are more or less 

 buttressed at their bases and, :is a result, are often marked with correspond i 1 1 g 

 rounded ridges and broad hollows. The trunk is full and round higher up, and 

 has a gradual taper throughout. Average large trees are from 190 to 280, some- 

 times 300, feet high, and from 8 to 12 feet or occasionally 12 or 15 feet in diam- 

 eter. Exceptionally large trees are 325 or 350 feet high and 18 or 20 feet in 

 diameter at a height of from 8 to 12 feet above the greatly swelled base. Old 

 trunks tire clear of branches for 50 or GO feet in open stands and for 80 or 100 

 or more feet in dense forests. The crowns of young trees from 10 to 15 inches 

 in diameter are narrowly conical, and extend nearly or quite to the ground. The 

 slender, short lower crown branches droop with a downward curve, while above 

 the middle the branches gradually trend more and more upward. On larger 

 trees in close stands the lower limbs are shaded out, leaving a very short, round- 

 topped or sometimes a flat-topped crown. The few branches on such trees, now 

 long and thick, stand out rigidly from the trunk, drooping slightly — at the top 

 not at all — forming a very open head. Bark of old trunks is from 8 to 10 or 

 even 11' Inches thick at the base of the trees, and it is very deeply and widely 

 furrowed and ridged. The leaves dig. 57) are flat, sharp-pointed, stiff, of 

 unequal lengths (one-third inch to about 1 inch) on the same twig. On side 

 twigs of lower branches and on young saplings the leaves stand out in two 



