CONDITIONS OF DEVELOPMENT. 61 



amount of tiaiispinitioii to Iw ])ciforiiiea by tlic Ibliaf'e, and a.i,Miii with most species we must place 

 tliis traTispiratioii movement into relation with available soil )iioistuie, in order to determine what 

 the requirements and the most suitable habitat of the species are" ( \i. E. Feriiow). Hence we find 

 that east of the ]Mississi])pi IJivcr the Loii-;]car I'iiie occurs in ;,m catost frequency alonf,^ the isotherm 

 of 00° F. ranging to tlie ;>4 ' north latitude, while west of the Mississippi it follows a line between 

 the isotherms of 63° aud C4^ F. and is scarcely found north of the thirty-second parallel of north 

 latitude. Within this area of its distribution it is exposed to wide variation of temperature aud 

 moisture conditions. 



Under the influence of the vapor-laden breezes from the Mexican Gulf and an evenly distributed 

 rainfall ranging from 42 to (>?• inches during the year, the Longleaf Pine appears of the same thrift 

 and vigor of growth in the interior of Alabama under 'M^ to •i-'i'^ north latitiulc, witli the ther- 

 mometer falling as low as io 1<\ (10° O.) and a range of temperature of 93° (at Tuscaloosa), as it is 

 found in the subtropical belt of the coast with a maximum temperature of lOo^ F. ( IC C.) and a 

 range of temperature of 04° west of the .Alississippi IMver, although the temperature reaches 

 rarely a minimum of 15"' and 12'', respectively, at the nortliern limit of the tree in these States, the 

 diminished humidity of the atmosphere and lesser rainfall, particularly during the warmer season, 

 account for its absence. There can be no doubt that the greater exposure to the violeiue of the 

 siulden gusts of dry and cohl wiiul known in Texas as " dry ncu'thers" exercises also no small 

 influence in limiting the Longleaf Pine. 



AtiSOCIATKl) SPKCIKS. 



The Longleaf Pine is eminently a gregarious tree, covering areas of wide extent, to the almost 

 complete exclusion of any other S])ecies. In the Hat woods of the coastal plain, ])articularly near 

 its northern limit on the Atlantic Slope, it is not infrequently associated with the Loblolly Pine; 

 farther south aud along the Gulf Coast to the Mississippi River, more or less frequently with this 

 tree and the ( 'ubau Pine. In the up[)er part of the maritime pine belt it not rarely occurs together 

 with the Shortleaf Pine and the Loblolly Pine intermixed with the deciduous trees of the uplands, 

 viz, the Black Oak, Spanish Oak, Black-jack, Bitternut, Mockernut Hickories, and Black Gum. 



It will be apparent, from what has been said regarding the demands for light, that the asso- 

 ciated si)ecies must be either slower growers or later comers, if the Longleaf Pine is to survive in 

 the mixture. As has been pointed out elsewhere, with the culling of the Longleaf Pine from the 

 mixed growths it must soon cease to play a part in them, since its renewal under the shade of 

 the remaining associates is imj>ossible. 



ENEMIES. 



The greatest danger threatening the existence of the forests of Longleaf Pine must be ascribe<l 

 to the agency of man, since their destruction is caused chiefly by the reckless manner in which 

 they are depleted without heed to recuperation. The right of ownershij) has been generally 

 acquired on such low terms that since no value has been attached to the land without the 

 timber, despoliation has been carried on with no other object than the quickest return of 

 momentary profits. 



EXPLOITATION. 



Such management could not but entail tremendous waste, a large pen'cntage of the body of 

 the trees felled being left on the ground to rotor to serve as fuel for the conflagrations which scour 

 these woods almost every year. Infinitely greater than the injuries inflicted upon the forest by 

 the logger and by getting out cross-ties and hewn square timber, wliic^h consist chiefly in the 

 accumulation of combustibl(^ waste, are those caused by the pi-oductiou of naval stores. When 

 the fact is considered that the production of the 40,(IU(( barrels of spirits of turpentine, which on 

 an average duiing the latter half of this decade annually reached the market of Mobile alone, 

 implies the devastation of about 70,000 acres of virgin forest, the destruction caused by this 

 industry appears in its full enormity. Under the management of the turpentine orchards 

 prevailing at i)resent, trees of such small size are tapped that they are unable to resist the force 

 of the winds, and in a few years are inevitably prostrated, while the larger trees, weakened by the 

 severe gashes on almost every side, become largely wind-shaken and the timber after a few years 

 almost worthless. 



