Some Problems of Re-afforestation. 9 



habit of growth and resistance to disease. In this country 

 Scots pines raised from Scottish seed ("native Scotch") give 

 the best results, and many nurserymen have had the experience 

 of burning large "breaks 1 ' of pines raised from continental 



I, because the plants were so unhealthy as to be unsaleable. 

 Probably such a tree as the Douglas fir, distributed as it is 

 over an immense area in Western America, has also several 

 varieties, indeed two the Oregon and Colorado have long 

 hern known. Of these, the green (Oregon) variety is by far 

 the better for general purposes, but even this variety may have 

 in fact is known to have sub-varieties which vary in value 

 for British conditions. The whole subject is of great importance 

 and should be thoroughly investigated. Meanwhile planters 

 must depend on their judgment in selecting plants by appear- 

 ance, unless they collect their own seed, in -which case healthy 

 well-grown parent trees should alone be utilised. 



A mistake, too often made in the past, should be avoided in 

 future, namely, complicated and irrational mixtures of species. 

 There is, no doubt, a good deal to be said for certain mixtures, 

 where one species is deep-rooted and thus gives support to 

 some shallow-rooted species, or where the ground vegetation is 

 suppressed by a dense-crowned species to the advantage of its 

 light-crowned neighbour. But the difficulties of management 

 are considerably increased when one has to regard the require- 

 ments of two kinds of tree in place of one, and the problem 

 becomes almost baffling where there are perhaps half a dozen 

 species equally distributed over the whole area. Often, in the 

 past, the main purpose of a mixture seems simply to have been 

 based on a desire to add variety to the woodland; or it may 

 have been the result of uncertainty as to whether some species 

 or other would succeed on the area. Again, the mixture may 

 have had for its object the production of an early return 

 through the agency of thinnings, as, for instance, where the 

 larch has been used to " nurse " up some species, such as oak, 

 of little value as young timber. This is quite a legitimate 

 purpose, provided too much is not sacrificed in its attainment, 

 but unless the removal of the nursing crop is attended to 

 betimes it may do a great deal more harm than good. A 

 mixture, much in vogue at one time, which looked attractive 

 on paper, but was really opposed to sound principles, con- 

 sisted in planting about 200 oaks or other hardwoods per 

 acre at, say, 15 ft. intervals, and filling up the ground with 

 some nursing species which were designed to be gradually 

 removed, leaving the oaks to form the final crop. The fallacy 

 of such a mixture consists in this that it gives no opportunity 

 to select the best formed and most vigorous individuals to con- 

 stitute the final crop. Under such a system every oak planted 



