CONDITIONS OF DEVELOPMENT. 61 



aiiiouiitof traiisiiiratiou to be perfurmecl by the l'oIiaj,'e, aud again with most species we must place 

 this traiispiiatiou movement into relation with available soil moisture, in order tt) determine what 

 the requirements and the most suitable habitat of the species are" (B. E. Fernow). Hence we find 

 that east of the Mississippi Kiver the Longieaf Tine occurs in greatest frequency along the isotherm 

 of GO^ l'\ ranging to the Si"^ north latitude, while west of the Mississippi it follows a line between 

 the isotherms of 03° aud 04° F. and is scarcely found north of the tiiirty 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 4L> to 03 inches during the year, the Longieaf Pine appears of the same thrift 

 and vigor of growth in the interior of Alal)ama under 34° to 35'= north latitude, with the ther- 

 mometer falling as low as 4° F. (10° C.) 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 lO-^o F. (40'^ O.) and a 

 range of temperature of 04^ west of the Mississippi liiver, although tlie temperature reaches 

 rarely a minimum of 15° and 12o, respectively, at the iiorthern limit of the tree in these States, the 

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

 acciiunt for its absence. There can be no doubt that the greater exposure to the violence of the 

 sudden gusts of dry and cold wind known in Texas as <' dry northers " exercises also no small 

 influence in limiting the Longieaf Pine. 



A.SSOCIATED SPKCIES. 



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

 complete exclusion of any other species. In the flat woods of the coastal plain, particularly near 

 its northern limit on the Atlantic Slope, it is not iufre((uently associated with the Tvoblolly Pine- 

 farther south and along the Gulf Coast to the Mississiiipi lliver, more or less fre(juently with this 

 tree and the Cuban Pine. In the upper 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 u])laiids, 

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



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

 ciated species must be either slower growers or later comers, if the Longieaf Pine is to survive in 

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

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

 the remaining associates is impossible. 



ENEMIES. 



The greatest danger threatening the existence of the forests of Longieaf Pine must be ascribed 

 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 ownership 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 percentage of the body of 

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

 these woods almost every year. Infinitely greater than the injuries inflicted ui)on the forest by 

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

 accninulation of combustible waste, are those caused by the production of naval stores. When 

 the fact is considered that the production of the 40,000 barrels of spirits of turpentine, which on 

 an average during 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 tlie foi-ce 

 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. 



