FORESTS OF ROCKY MOUNTAIN-: FOREST RESERVE 45 



The second system is the selection system; and this, if followed, must be prac- 

 tised conservatively on account of the danger from wind-fall. On an average, thirty 

 per cent of the merchantable stand should be left, but the exact amount will vary in 

 different stands, depending mainly on the range of diameters. That will also be an 

 important factor in deciding between this system and a strip system, the latter being 

 chosen where the trees are more uniform in size throughout the stand. The selection 

 system must be operated by marking each tree to be cut. These will comprise the 

 larger trees of the stand, but no definite limit should be set, and one of the chief 

 aims of the marker should be to leave a uniform stand on the ground, rather than to 

 remove all the trees above a certain size. The advantage of the system would be 

 that, while reproduction was taking place on the ground, there would be trees left 

 that would occupy a portion of the growing space without materially retarding repro- 

 duction or the development of the seedlings, and the older trees would, on account 

 of increased light afforded them, grow at a rapid rate. Many of them, also, would 

 grow from a size so small that harvesting them would yield a small proportion of 

 the total volume of the tree as lumber of poor quality into a size which would give 

 fairly good lumber with less proportionate waste. The spruce seedlings would thus 

 be given an opportunity of passing through the period of slow growth without 

 exclusively occupying the area and having it for that period comparatively unpro- 

 ductive from the standpoint of volume growth. Also, the shade afforded by the tree? 

 left would keep the seed-bed moister. but on the clear-cut strips, the concentrated 

 logging would expose more mineral soil and aid seeding in that way. 



PURE PINE STANDS. 



Most of these that are now being cut are even-aged, with few relatively small 

 trees. This makes a system of clear-cutting advisable, since there are few trees 

 which can, because of their small size, be left economically, and the stimulated 

 growth of the trees left would be small after the stand was opened up, as pine in 

 dense stands has a small crown and slight power of recovery. 



The best method of clear-cutting is in strips, which should be 100 ft. to 250 ft. 

 wide with 100 ft. to 150 ft. left uncut in between, the exact widths depending on the 

 proportion of timber that it is desired to remove at the first cut, and on the danger 

 from wind-fall. The strips do not need to be laid out mathematically, but should 

 be distributed according to variations in the size of the timber and according to 

 topography. The smaller and more elevated trees should be left, the latter because 

 of the better distribution of seeds from high points. This method provides a full 

 supply of light for germination and development of the pine seedlings, and gives a 

 maximum preparation of the seed-bed. The distribution of seed over the cleared 

 area should also be satisfactory, if the distances given are adhered to. The second 

 cut should not be made until the young growth on the first-cut strips is old enough 

 to seed back, which would be at least twenty-five years. That means that the two 

 logging operations by which the timber would be removed would be entirely distinct 

 as far as practical business considerations are concerned. 



The splendid and often too abundant reproduction of pine after forest fires 

 suggests using that instrument to secure reproduction on clear-cut areas, where, after 

 the logs had been removed, the brush might be burned broadcast. The idea is attrac- 

 tive and will probably eventually prove of practical utility, but at present practical 

 considerations prevent its use being recommended, at least until greater experience 

 in burning brush is gained. Forest fires occur only under drouthy conditions, and 

 to set fire to brush under the same conditions would be very dangerous. Under con- 

 ditions moist enough to make the measure comparatively safe, practical difficulty 

 would probably be experienced in getting the ground uniformly burnt over, and the 

 expense would be proportionately great. Moreover, the chance of successful repro- 



