Management of Lodgepole Pine 179 



suppression, thinnings increase the rate of growth of the trees 

 left, the species is sufficiently windfirm under reasonable condi- 

 tions, the market demands much large size material and is able to 

 absorb considerable material of small size. 



In the fall of 1910, mindful of the points just mentioned, a sys- 

 tem was given a trial, which with a few modifications developed 

 into the plan now in effect. The present rules for handling Lodge- 

 pole stands on the Deerlodge Forest, approved in the summer of 

 1913, provide, first of all, for the classification of the stands on 

 the basis of their age and with reference to the average size of 

 the trees, which, of course, depends upon the density of the stand, 

 into "over-mature,"' "mature," and "immature," the last named 

 being further subdivided into "converter pole" and "lagging pole" 

 stands. The different situations are also classified as to wind 

 exposure into "safe," "medium," and "great" exposures. 



"Over-mature" stands are those over 160 years old and in 

 which from 35 to 60 per cent of the trees are 10 inches or over in 

 diameter. Here a clean cutting is made including all trees 7 

 inches and over in diameter, merchantable under the terms of the 

 contract, with the object of harvesting a crop which is at, or 

 approaching, a standstill and replacing it with vigorously growing 

 reproduction. No attention is paid to windfall which may take 

 place among the small trees left, for it is better to lose a number 

 of them than to leave on the ground a sufficient number of the 

 larger trees to protect the smaller from windthrow. Reproduc- 

 tion is amply provided for by the groups of seedlings and poles 

 already started in the openings, by seed from the trees left stand- 

 ing, and by seed from cones knocked from the tops of the trees 

 removed. 



"Mature" stands, from 120 to 160 years in age, while contain- 

 ing from 25 to 40 per cent of trees over 10 inches in diameter, 

 consist mainly of trees of smaller sizes which still, for the most 

 part, have fairly thrifty crowns. These stands are cut in accord- 

 ance with the selection system, using a flexible ten-inch diameter 

 limit. Here it is the aim to cut the larger trees and to reserve the 

 smaller ones for further growth. Reproduction is not an object, 

 but it will be secured in the frequent small openings, resulting 

 from cutting groups of larger trees, and also in other places 

 where the stand is opened sufficiently. Constant attention is paid 



