FOREST CONDITIONS 



IN THE 



ROCKY MOUNTAINS FOREST RESERVE 



GENERAL SILVICTJLTITRAL CONDITIONS. 

 MATURE STANDS. 



SITES AXD TYPES. 



Mature stands in the Rocky Mountains forest reserve occur in irregular and 

 usually isolated areas, where, for one reason or another, they have escaped the fires 

 that swept over the remainder of the region. This is well shown on the map of the 

 forest contiguous to the boundary, which accompanies the report of the survey of 

 the boundary (Bulletin 18 Forestry Branch). In the unmapped area to the west, 

 larger areas of mature timber occur than those shown on the map, but the general 

 condition is much the same. Xot more than twenty -five per cent of the area of the 

 reserve is covered with mature timber, the rest of the forest being second-growth, 

 mostly under fifty years of age and too small to be sawn into lumber, and only 

 occasionally large enough for mine timber or cordwood. The mature stands contain 

 mostly densely grown trees of merchantable size, and yield 5,000 to 20,000 feet board 

 measure per acre. 



Three species comprise the greatest part of the timber, and only these need be 

 considered in planning for future crops. Lodgepole pine forms about sixty per cent 

 of the stands, Engelmann spruce thirty-five per cent and Douglas fir five per cent. 

 About fifty per cent of the forest consists of mixed stands of these three species. 

 Of the approximately pure stands, sixty per cent are pine and forty per cent spruce. 

 There are no sites, however, where one tree is found uniformly to the exclusion of 

 the other, and most stands will have at least scattered individuals of second species. 

 A classification of the forest area into three sites would typically show spruce or, 

 under certain conditions. Douglas fir predominating on Site I, and pine on Site 111, 

 with a mixed type or a mixture of small pure stands of spruce and pine on Site II. 



Site I includes the smooth slopes on the border of the prairie, which have com- 

 paratively deep, well-drained soil; and in the mountains it comprehends the bottoms 

 of the valleys and the lower, gentler slopes. 



On soils of the first class are often found small stands of well developed Douglas 

 fir. Formerly, more or less extensive stands of this type were in existence, but as 

 this site, on account of its location adjacent to grass-land, has been most exposed 

 to. and most over-run by fires, the stands have been reduced in extent. The type 

 now consists mainly of restricted patches on which the trees are considerably dam- 

 aged by fire and where the density has been materially decreased or a park-like stand 

 formed. These Douglas fir stands show the maximum development of individual 

 tree? in the region, but on account of their present restricted area, they are not 

 relatively of great commercial importance. On account of the well-drained soil, 

 and in some cases by reason of the occurrence of recent fires, the ground-cover is 

 light except where grass has gained a firm foothold, which is usually the case where 

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