Association. Frequently in pure stands, typically open. On 

 better drained soils it associates with red and white spruce, hemlock, 

 balsam, balm of Gilead, aspens, birches, red and sugar maples and 

 willows. 



General. The U.S. Forest Service recommends managing under 

 a clean cutting system, leaving groups of strong seed trees when grown 

 in pure stands. 



LARIX OCCIDENTALS, Nutt. 

 Western Larch. Tamarack. 



Size. Average size of mature timber 90 to 100 ft. by 13 in. In 

 northern Idaho it reaches its best development, 200 by 4 ft. 



Growth. Larch is a rather slow but persistent grower. In its 

 optimum its best development in height growth occurs between 10th 

 and 30th years, and its best diameter growth between 20th and 50th 

 years. Height growth culminates at about 60 years, and diameter growth 

 at about 90 to 100 years. A study of 43 trees at Summit Lake, B.C., 

 showed growths of 5 inches in 29 years, 8 inches in 52 years, and 10 inches 

 in 82 years. 



Root System. Deep heart roots. 



Bole. Straight, small taper, clear one-half to two-thirds in forest. 



Crown. Narrow crown, short and conical in the forest, but often 

 reaching nearly to the ground in the open. 



Tolerance. Very intolerant throughout its life, and is more light 

 demanding than yellow pine. More tolerant on moist than on dry soils. 



Wood. Like Douglas fir, strong, hard and stiff; 46 pounds. 



Reproduction. Seed production variable but normally prolific 

 at intervals of one to several years after 40 to 50 years old. Cones open 

 in August and in dry weather shed seeds readily. Seeds winged and 

 light; germination percent relatively low as compared with its associates; 

 vitality high. Abundant moisture required for germination. Exposed 

 mineral soil the most suitable seed bed. 



Range. Rather limited; southwestern British Columbia, valley 

 of the Columbia River, northwestern Montana, northern Idaho, Wash- 

 ington, and northern Oregon. High valleys and mountain slopes from 

 2000 to 7000 feet. Optimum in northern Idaho and Montana. 



Climate. Wide range of temperature, -30 to 100 Fahr., and an 

 annual precipitation of from 20 to 30 inches, with a moderately heavy 

 snowfall. Rains frequent in spring and fall, but the summers are hot 

 and dry. 



Soil. Rather exacting in its soil moisture requirements, but will 

 grow on dry mountain slopes. 



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