Problems in Reforestation 



By Arthur Smith, Pennsylvania. 



Reforestation problems (li\i<lc tliemselves broadly 

 into three main issues. The planting of forest trees 

 ( 1 ) upon land which has not, at least for several gen- 

 erations, been in forest before and which is of no real 

 use in an agricultural sense: (2) forest land from 

 which lum1:)ering operations have cleared away more 

 or less all trees and upon which there is no nattn"al re- 

 newal taking place, and (3) land tipon which the entire 

 growth has been destroyed by tire. The latter, espe- 

 cially in the case of coniferous forest, generally pre- 

 sents the most difficult problem, the more so the steep- 

 er the slope of the ground, because where hillsides 

 have been denuded of growth, from any cause, either 

 fire or lumbering, fur a greater or less ntimber of 

 years, erosion is causing the removal of the soil in 

 which trees can grow, and it is only a matter of time 

 when these areas will become impossible to reforest. 

 It is not diffictdt to imagine the condition of things 

 when the closing of the glacial period removed the ice 

 cap back to the arctic regions. At that period the en- 

 tire earth which had been covered by this ice cap must 

 have been absolutely devoid of plant life. How man^• 

 thotisands of years elapsed from the first sul)sequent 

 appearance of plant life in the form of lichens tn the 

 time wdien forests came into existence, we have no 

 means of knowing, but the point to l)e borne in mind 

 is, that thousands of acres of mountain and hillsides 

 are now rajsidly reverting to the conditions which pre- 

 vailed at the close of the ice age, and therefore the 

 longer reforesting is delayed the more difficult it will 

 be to carry out. 



Ultimate success in forest planting (lei)ends upon 

 securing a canopy at the earliest possible date ; this is 

 brought about by the density of growth. 



Density may he defined as the thorough shading of 

 the ground by the forest crop. In a wood of good 

 density the layer of fallen leaves is protected from 

 stm. wind and heavy rain, which would rot it too 

 quickly or wash it away; it lies upon the ground as a 

 mulch, slowly rotting and turning intf) food for the 

 trees, and its quantity is kept up and even increased 

 b}^ the annual fall of leaves. In this way the soil is 

 maintained stifficiently fertile for the trees to thrive. 

 As a rule dense or crowded Avoods keep u]) their own 

 density ; thin or open woods, not ripe for lumbering, 

 should have their density increased by underplanting. 

 Density depends chiefly upon the number of trees, but 

 partly also upon the thickness of their crowns. The 

 best density is usually found where trees are doing 

 ■well ; upon poor soil in exposed sites, although there 

 may be more trees per acre, the density is rarely so 

 good. Therefore trees should be planted closer upon 

 poor soil, especially on hillsides, than where the soil is 

 better and more level. I know there is a difiference of 

 opinion upon this point. y\ forester, wdio had gradu- 

 ated from a college of forestry, once told me he had 

 been taught there that trees should be given more 

 room upon poor soils than upon richer ones. But it is 

 obvious that the loss of fertility owing to insufficient 

 shading of the ground had been left out of considera- 

 tion and the importance of obtaining a canopy as soon 

 as possible entirely lost sight of. 



Canopy may be called the roof of a wood ; without 

 it there is no density. Young trees are said to form 

 canopy as soon as their branclies meet. At this period 

 the branches are resting upon the gromid and all 



growth, excepting that t)f the trees themselves, is 

 practicall)' smothered. As the trees ptish upward their 

 lower branches die from want of light, their stems 

 clear themselves and the canopy rises until it is many 

 feet above the ground : a more or less flat roof sup- 

 ported upon smooth clean stems as upon pillars. 

 Without density tall clean trunks are impossible, as it 

 causes the branches to die ofif before they become large 

 enough to form knots. A straight log free from knots 

 will invariably have a greater value than one double 

 the size that has been given room enough to produce 

 more or less thick branches. 



The object of underplanting thin or open woods is to 

 improve their canopy. This imderplanting should con- 

 sist of species which are more or less shade-bearers, 

 those liking shade the least being planted in the most 

 o])en s])ots. Among deciduous species beech will 

 stand more shade than an}^ and of the conifers wdiite 

 pine is probably the best shade-bearer, although in 

 Europe the silver fir takes the first place in this con- 

 nection. 



With the idea of obtaining a canopy earlier when 

 the entire ground has to be planted, what are called 

 "nurses" are sometimes used wdiich are cleared away 

 before they interfere with the growth of what is in- 

 tended to be the crop species. The nurse trees in the 

 case of conifers may be a species saleable for Christ- 

 mas trees, in which case they often bring in sufficient 

 cash to pay for the expense of reforesting up to that 

 time. Where the ground to be planted is naturally 

 covered with weeds and shrubs these act to a con- 

 siderable extent as nurses, care being taken to see 

 that the young trees are not smothered ; the latter is, 

 however, necessary in all cases. The removal of nurse 

 trees should be (lone gradually and first from that 

 portion of the planting which is the most thrifty, that 

 is, where the crop species are making the greatest 

 growth. Where hardwoods are planted for the main 

 crop, larch makes a good nurse. The Japanese species 

 has of late been planted ptire in many parts of the 

 Eastern States, but the European is considered more 

 drought resisting, although they are neither suitable 

 for very dry soil. 



The use of niu'ses is not absolutely necessary, as the 

 ])lanting of one species more thickly than is recjuired 

 for a ])ermanent crop answers the same ptirpose, pro- 

 vided thinning is done at the right time. If the earlier 

 thinnings are of no value the benefit to the main crop 

 from close planting more than pays for the extra 

 expense. 



In notes of this kind one can only deal with general 

 principles, as correct methods of carrying out details 

 always depend upon local conditions. 



OUR COVER ILLUSTRATION. 



Tlie illustration on our front cover page is a reproduc- 

 tion of a photograph of the garden of palms, under glass, 

 in the Missouri Botanical Gardens, St. Louis. Mo. We 

 have been fortunate in securing a photographic collection 

 of the new conservatories in Shaw Garden, Missouri 

 Botanical Gardens, never before published, which we 

 shall present to our readers in the I'ebruary issue of the 

 Chronicle. Tlie range of glass at Shaw (harden is con- 

 sidered one of the most interesting of any public institu- 

 tion in this country and, when finally completed, it wll 

 be one of the finest ranges of its kind in existence. 



