﻿.'{fl'J The A'rfr York Sl(il( (^nU(<jc of Forrsirif 



MK'iiMs 1 he (h'sl nict Mill (if \nrisc jiitjis <it' priiiicxal rorcsls. Njifurc 

 Hcin n\u)\i\ it |ir(iiii|it ly li» lirjil llic scjirs lliiis I'csiilt in;/, iiiul if 

 Icl'l 1(1 lici- own (|c\ic«'s would iilliinatcly JijrJiin piodiicc i\. climiix 

 type. Bill iimii impedes lier jil e\-ery fiirri either hy |)r('venliTif; 

 lerdicslfil inn or. \\ liere I'orf'stry is iirjict iced, liy ;iii ;ii*l»il rjiry 

 selection of the flit lire t'orest eiti/ens. tluit is, the trees. Nature's 

 methods ill the production of Ji clinnix forest when jiidf^ed hy 

 liiifiiici;il slnnd.'irds, jire neither rcdiKimicjd or iiecessjirily wise. 



FACTORS GOVERNING DISTRIBUTION OF FORESTS 



In ^eiier.'il trees nie impiirtiid to soil unless the soil cluirjtcters 

 jire of fin extreme type. K'eliit i\ '-ly few liii\c jirl)ilrnry soil ro- 

 (|uir('ments .'ind their nhsenee from tfiveti htcjilit ies is not, to be 

 construed .'is resulting from the type of terrniii but rntlier from 

 competition due Id niher f.'ictois. Those frees wtiich iire most, 

 Impjiily .'id.pisied to their eii\ iroiimeiits are bound to survive in 

 the warfare of mutual ad.jiistment owinj; to the advaiilnj^o nccni- 

 inj; from lieller ^rrowlli coiidil kuis. It is diily near the limits of 

 its ran|/e that a species may become exact in<j: as to soil, for here 

 llic balance which means the life or death of the orjjanisin is rnoro 

 (lolicjllely adjusted and an uiilav orahle soil may be siil'licicnt to 

 cjinsc the elimination of a species from a j^iven terrain. 



'rem|)cralure is the potent factor in controllintr tree distribii- 

 liou and results in forest belts which are determined, at least so 

 far as their jrencral contours arc concerned, by latitude. No pari, 

 of the earth is too hot to suppm't forests, other factors l)ein<; favor- 

 able, while the iidillicni lice liiiiil is beliexcd to be fixed by a 

 normal duration of lem|)erature (if .'>(! I^'iihr. for at least a month 

 each year.* Hut the contour lines nf f(M(>sf belts are not of neccs- 

 sily east and west cdiildiirs. 'reiiiperal iirc lliicliiales willi altitude 

 and with pi-dximity to laiLre bodies of water, that is. to oceans and 

 lar^re lakes. Mean aiimial lemperatiire decreases with altitude. 

 Lnrife waler areas lend to niddilx a cliinale dwintr lo the fact that 

 water cools and warms less rapidly than terrain, .\ddcd to llie 

 last is the cMTeci of warm or cobi ocean curri'iils which sweep 

 alonj; the continental coasts. |)dubilcss siipermaxiimiiii lempera- 

 tiire tbictuations of brief duralidu and infrccpKMil inteiwal are 

 ]>otent factors in detcrminin<; the limitations of species. 



Willie leiiiperalure results in broad belts of vcirelation of dif- 

 I'ercnl. ly|)es a\ailaliie nidislure i precipitat inn, humidily. watiM" 



*U ll.C Wiir.l Cliliuilr. cms. ,,,,y,. .'S 



