FORESTRY 



3251 



FORESTRY: PRINCIPLES AND PRACTICE 



J. B. Ainsworth-Davis, Late Principal, Royal Atfrio. Coll., Cirencester 



The article Afforestation deals with another branch of this subject. See 



also Timber and the articles on the various forest trees e e Beech ; 



Birch; Oak; Pine, etc. 



Forestry is the science of culti- 

 vating trees, especially for pro- 

 viding timber. 



Apart from the chemical compo- 

 sition of the soil, the amount of 

 moisture it contains is a question 

 of vital importance in the proper 

 maintenance of a wood or forest. 

 Climate is altered by the establish- 

 ment of woods and forests. Within 

 a wood the air is cooler in the 

 summer time than it is in the open 

 air, but the opposite is the case in 

 winter time. This is due to evapor- 

 ation, which, in the active growing 

 season, is more abundant than in 

 the winter time, when growth is at 

 a standstill and sap is stagnant. 

 Problems of Soil and Climate 



It is mainly on the selection of 

 the suitable trees for the proper 

 soil that successful forestry de- 

 pends. No hard and fast rules can 

 be laid down, but it is certain no 

 trees will really thrive in a soil that 

 is waterlogged, that is to say, 

 where stagnant moisture is present 

 in large quantities. On moist soils, 

 such as are found at the sides of 

 natural water-courses, but where 

 the water is in circulation and per- 

 colating through the soil, the wil- 

 low, alder, spruce fir, and poplar 

 may be planted with reasonable 

 hopes of success. On chalky soils 

 larch, Scots pine, beech, oak, ash, 

 and sycamore are the best. On 

 the ordinary rich loam any British 

 timber tree will flourish. On 

 sandy soil, only the coniferous 

 trees, such as the pines, firs, and 

 spruces, may be expected to pro- 

 duce profitable results ; wl-ile on 

 the heavy clay lands the British 

 oak is the only tree, with perhaps 

 the solitary exception of the horn- 

 beam, which is likely to repay the 

 trouble of planting and upkeep. 



The most generally practised 

 system of forestry is that of utilis- 

 ing old pasture or waste lands, and 

 planting one- or two -year-old trees 

 upon it. These young trees are 

 roughly but simply planted by the 

 process of cutting a triangular or 

 tongue-shaped piece of turf up 

 with a spade, splitting the tongue 

 in the middle, loosening the soil 

 underneath, placing the young 

 tree in position, and then pressing 

 down hard upon it the two half 

 tongues of turf. Such young trees 

 are usually planted about 5 ft. 

 apart every way. In bleak and ex- 

 posed situations it is sometimes 

 the practice to harrow the surface 

 of the ground before planting, and 



to sow seed of the common gorso 

 or furze, which, being aquick-grow- 

 ing subject, will act as a "mother" 

 for three or four years to the 

 young trees, until they have fully 

 established themselves. Some- 

 times, however, when the soil hap- 

 pens to be rather more fertile than 

 was originally imagined, the gorse 

 will obtain such a hold upon the 

 place that it will probably strangle 

 all the trees it is intended to 

 " mother," and render replanting 

 necessary. 



Owing to the vagaries of the 

 British climate, the establishment 

 of a forest or wood from seed 

 rarely proves successful. But 

 where prime cost is a matter of con- 

 sideration, even if only one in four 

 of the trees sown turns out to be 

 fertile, the results will be found 

 eminently satisfactory financially. 

 In establishing a forest from seed 

 the surface of the ground must first 

 of all be broken up. This can be 

 done by a harrow or, in the case of 

 stiff clay lands, by the plough. It 

 is well to sow seed with a liberal 

 hand, as losses from dead seed, the 

 ravages of vermin, and bad weather 

 are enormous. The following quan- 

 tities of seed are ample for sowing 

 one acre of ground : Beech, 8 

 bushels ; elm, 15 Ib. ; larch, 15 lb.; 

 oak, 9 bushels ; silver fir, 30 lb. ; 

 Scots pine, 8 lb. 



Acorns and beech-mast are, of 

 course, much more bulky than the 

 seed of other native British forest 

 trees. A pound of Scots pine 

 seed consists roughly of 60,000 

 seeds, and larch bulks about the 

 same. Ten thousand acorns fill a 

 bushel measure, which would hold 

 50,000 beech nuts. 



Depredations by Rabbits 



Rabbits constitute a grave dan- 

 ger in all newly made plantations, 

 and the only effectual method of 

 guarding against their depredations 

 is wire netting well pegged down 

 and sunk into the surface of the 

 ground. Several instances are 

 recorded in which, during a hard 

 winter, rabbits have disturbed and 

 destroyed a whole plantation of 

 young firs by gnawing away the 

 bark of the trees, and leaving the 

 stems exposed to the frost. Where 

 sufficient labour is available, it is 

 well to cut a niche some 6 ins. or a 

 foot below the level of the ground 

 and bury or plant the wire netting 

 to that depth. 



. It is only to be expected that 

 young trees raised from seed sown 



FORESTRY 



thickly and indiscriminately will 

 die down right and left, especially 

 in dry and exposed situations. In 

 the S.W. of England, the sandy 

 heaths of Surrey and Hampshire, 

 and tke moist districts of Ireland, 

 plantations, especially of conifers, 

 will quickly establish themselves. 

 At the end of three years a fir plan- 

 tation may be considered to be a 

 commercial proposition, and the 

 young trees will have attained 

 sufficient strength to carry on until 

 thinning is requisite. It should be 

 borne in mind that conifers and 

 beeches prefer shady situations, 

 while the ash and the oak are better 

 in broad sunlight. 



Guarding against Decay 



One of the chief difficulties in 

 forming a new wood, or clearing up 

 and rejuvenating an old one, is 

 usually the presence of old and un- 

 healthy timber. All dead and 

 dying trees, ragged and tangled 

 undergrowth, and other unprofit- 

 able stuff must be promptly cleared 

 away in order to afford room for 

 new seedlings, which require light, 

 air, and sun. A competent forester 

 will watch keenly for signs of decay 

 among the trees under his care. 



Decay begins to take place as soon 

 as a tree has attained full maturity, 

 and ceases to put forth fresh 

 branches and vigorous leaves. It 

 has reached the zenith of its power 

 and should be at once cut down 

 and sold. If, for sentimental 

 reasons, the tree is allowed to stand 

 and continue to decay, it will 

 spread that decay to other trees, 

 and thus bring a plague upon the 

 whole plantation. The grand old 

 oaks, yews, and other trees which 

 are supposed to have existed at the 

 time of the Norman conquest, and 

 still continue to exist, are ex- 

 amples of splendid sentiment but 

 bad forestry, and it is well that 

 they are chiefly found in isolated 

 specimens, and not in groves or 

 forests, where they would cause an 

 incredible amount of damage. 



The question of thinning timber 

 is a vexed one. In the case of 

 larch, ash, and other close-growing 

 woods, thinning may be carried out 

 almost with impunity, for the 

 young poles find a ready and re- 

 munerative market. This does not 

 apply to the oak, beech, or other 

 trees where girth is a greater con- 

 sideration than height. The ideal 

 wood or plantation is the one 

 where the trees exhibit long and 

 straight trunks, with the minimum 

 number of side branches. Where 

 planting has been carried out 

 sufficiently closely, these side 

 branches die off naturally for want 

 of light and air, and this process or 

 operation is called natural pruning. 

 Pines and firs lend themselves 



