222 REPOET OF THE COMMISSIONER OF AGRICULTURE. 



The degree of thinning depends also a great deal on the species 

 forming the forest. In another place I have pointed out the import- 

 ance of the classification of the * different species with reference to 

 their relation to light and shade, as shade-enduring and light-need- 

 ing. This classification has some bearing on the degree of interluca- 

 tion. Those kinds which for their development require a larger 

 amount of light would naturally show in a dense growth a greater 

 amount of subdued stems, and consequently a stronger interlucation 

 would be indicated. On the other hand, these very species are the 

 ones which are least capable of preserving favorable soil conditions, 

 because their naturally thin foliage not only does little toward the in- 

 crease of the layer of humus, but does not efficiently exclude the rays 

 of the sun, especially as they have the tendency with increasing age 

 to thin out still more their leafage. They are, therefore, the most 

 difficult to manage, and the continuity of their crowns must be most 

 carefully preserved. 



The time when the first thinning should take place is generally de- 

 termined by the possibility of marketing the extracted material at a 

 price which will cover at least the expense of the operation. This 

 IS, however, not always possible, and the consideration of the increase 

 in value of the remaining growth, or rather of the detriment to the 

 same by omission of timely thinning, may then be conclusive. 



On good soil and on mild exposures interlucation may take place 

 earliest, because here the growth is rankest and a difference in the 

 development of the different stems is soonest noticeable. Light-need- 

 ing and quicker-growing kinds show similar conditions to those grown 

 on good soil, and here, therefore, early thinnings are desirable. In 

 these cases the thinnings have also to be repeated oftenest, especially 

 during the period of prevalent height accretion. Absolute rules as to 

 the time for interlucations and their periodical repetition evidently 

 cannot be given; the peculiar conditions of each individual case alone 

 can determine this. The golden rule, however, is: early, often, moder- 

 ately. The right time for the beginning of tiiese regular and periodical 

 interlucations is generally considered to have arrived when the natural 

 thinning out mentioned before commences and shows the need of the 

 operation. This occurs generally when the crojD has attained the size 

 of hop poles. At this stage the well-marked difference in size of the 

 suppressed trees will point them out as having to fall, and there 

 will not be much risk of making any gross mistakes. Until the trees 

 have attained their full height the thinning should remain moderate. 

 From this time forward it will prove expedient to open out the stock 

 more freely, without ever going so far as to thin severely. 



OTHER METHODS OF MANAGEMENT. 



The methods of management briefly outlined above are the princi- 

 pal ones and serve as the basis of all others, which are mostly modi- 

 fications of these. Methods are also practised by which a combina- 

 tion of agricultural use of the soil with forestry takes place. While 

 in these there is much that seems attractive, they can be considered 

 only in the same light as combination tools, which are generally de- 

 fective at one end or both — the poor man's tool — a poverty-stricken 

 practice, to which our rich and broad lands need not yet be subjected. 

 Unless it were to reduce the cost of cultivation in young plantations 

 on agricultural soil by the introduction during the first two years of 

 a crop of potatoes or other cultivated crop, a practice which may be 



