CONIFEROUS FOREST TREES IN GREAT BRITAIN. bl 



the struggle for existence becomes too intense at a very early- 

 stage. A thinning made then is non-productive, while if the 

 wood is left alone its future management becomes very difficult, 

 for the formation of a good root-system is impeded and the 

 crowns become too small. There is a danger of wind and snow 

 damage which increases when a thinning is made. It is almost 

 certain that the minimum planting distance for this species is 

 6 feet. Under some conditions a considerably wider distance 

 may be desirable. There is no evidence that Douglas fir will 

 clean itself of its branches naturally, whatever the density of 

 planting. It is better to plant fewer plants and use the 

 money thus saved to prune the best trees when 15-20 

 years old. 



Owing to its rapid height-growth, Douglas fir is, par excellence, 

 a species which should be heavily thinned. It gives promise 

 of being the conifer which will enable us to obtain the largest 

 size of individual tree in the shortest possible time. This must 

 be one of the objects of forestry in this country, as most of our 

 big timber has been used for war purposes, and it should be 

 replaced as soon as possible. Experiments should be made to 

 determine how this can be best done. Sufficient dominant 

 trees of satisfactory shape could be selected when the first 

 thinning is made, and these favoured by the removal of the 

 other trees in subsequent thinnings. To obtain the best results, 

 it may be necessary to break the canopy permanently. 



Douglas fir is a most valuable conifer, and investigation 

 should be carried out to determine what are its minimum 

 requirements as regards soil, water supply, etc., and how it 

 should be tended to produce different results, such as maximum 

 quantity production, largest size of individual stem, and the best 

 quality of timber. 



From this brief discussion of our conifers, it will be seen that 

 we have much to learn regarding them. There is no place for 

 dogma at this stage of the development of forestry. All engaged 

 in it should acquire an enquiring mind. There is a great need 

 tor extensive and imaginative experimental work carefully 

 carried out and sanely interpreted. We should not limit our- 

 selves to that alone, however. Research is no mystic and 

 awesome ritual, it is largely the accurate determination of 

 cause and effect. All engaged in forestry should be researchers. 



VOL. XXXIV. PART I. F 



