FORCING 



FORESTRY 



1267 



particularly when mixed with air, is very inflammable 

 and lighted matches, cigars or pipes must be kept 

 away. "Thirty or forty grammes of ether are enough 

 for one hundred cubic htres of air: one gramme equals 

 fifteen and one-half grains, one litre equals sLxty-one 

 cubic inches." The ether used is "pure sulfuric 

 ether which boils at 95° F." The plants are kept under 

 the influence of the ether for two days; sometimes they 

 are removed for two days and the etherization repeated 

 for the same length of time. Afterwards they are 

 placed in a coldhouse and "treated in the usual man- 

 ner." Lilacs "were in full flower eighteen days after 

 being placed in the greenhouse," one, "Marie Legraye 

 still earlier." Johannsen made hlacs "flower regularly" 

 the first two weeks in September which had been 

 etherized the first week in August." With other 

 shrubs, such as Rhododendron sinense (Azalea mollis), 

 Viburnum Opulus, Prunus triloba, Deulzia gracilis and 

 some of the spireas, the results were more or less 

 favorable." 



Trials with chloroform apparently have been less 

 successful and other anesthetics and stimulants have 

 been found failures. B_ M Watson. 



FORESTIERA (after Forestier, a French physician). 

 SjTi. Ad'dia. Oleacese. Sometimes grown as ornamen- 

 tal shrubs. 



Deciduous, rarely evergreen trees or shrubs: Ivs. 

 opposite, entire or serrate: fis. dioecious, apetalous, 

 ■with or without calj'x, in small, axillary clusters in 

 early spring, before the Ivs.; stamens 2-4: fr. a small, 

 mostly black, 1- or 2-seeded drupe. — About 15 species 

 from 111. south to Brazil and the W. Indies. 



The species in cultivation are shrubs with rather 

 small leaves, inconspicuous yellowish flowers before 

 the leaves and small dark purple or black, berry-like 

 fruits. F. acuminata is hardy in sheltered positions as 

 far north as Massachusetts, while F. ligustrina is some- 

 what tenderer. They prefer moist soil and are suited 

 for planting along streams. Propagation is by seeds 

 and layers. 



acuminata, Poir. (Ad'elia acuminata, Michx.). De- 

 ciduous shrub, to 10 ft. high, sometimes spiny, glabrous: 

 Ivs. slender-petioled, ovate-oblong or ovate-lanceolate, 

 remotely serrate, ll4rA in. long: staminate fls. in dense 

 clusters; pistUlate fls. in short panicles: fr. narrow, 

 oblong or cvhndrical, deep purple, falcate, acute, J^oin. 

 long. W. lU. to Texas. Mich.x. Fl. Bor. Amer. 2:225. 

 B.B. (ed. 2)2:728. 



ligustrina, Poir. (Ad'elia ligiistrirui, Michx.). Decidu- 

 ous shrub, to 6 ft., pubescent: Ivs. eUiptic-obovate to 

 oblong, obtuse, appressed-serrulate, about 1 in. long: 

 fls. in fascicles: fr. sessile, ovoid, obtuse, J-4in. long. 

 Tenn. to Fla. and Ala. 



F. neo-mexicana. Gray (A. panofolia, Coville). Shrub, to 10 

 ft.: Ivs. spathulate, almost entire, usually glabrous, grayish green 

 and rather small; fr. ovate or short-oblong, obtuse, iain. Texas to 



New Mex. and Colo. 



Alfred Rehder. 



FORESTRY is the rational treatment of forests; this 

 treatment may vary with the object in view. Forests 

 may subserve various objects, giving rise to three 

 classes of forests: thej' furnish wood materials for the 

 arts — supply forests; they furnish a soil cover, which 

 may prevent the blowing of the soil and formation of 

 sand-dunes, or may retard the erosion and washing 

 of the soil and may regulate the waterflow, or act as 

 a barrier to cold or hot winds, and exercise other bene- 

 ficial influences on climate and surroundings — protec- 

 tion forests; or, finally, they fiunish enjoyment to the 

 esthetic and sporting elements in man, as game-pre- 

 serves and parks — luxury forests. Any two or all three 

 objects may be attained simultaneously in the same for- 

 est. In the end, and in a more limited sense, forestry 

 is the art. and business of making revenue from the 

 growing of wood crops, just as all agriculture is finally 

 concerned in producing values from food crops and 



other crops. In the economy of agriculture, wood crops 

 may be grown on land that is too poor for field crops. 



This art is divided into two distinct and more or less 

 independent branches, namely silviculture, the techni- 

 cal branch, and forest management, the business 

 brancli. Silviculture is a branch of the larger subject 

 arboriculture, and comprises all the knowledge and 

 skill applied in producing the wood crop, relying 

 mainly on natural sciences. While horticulture and 

 silviculture have both to deal with trees, their object 

 and with it their treatment of trees are totally different: 

 the orchardist works for the fruit of the tree, the land- 

 scape gardener for the pleasing form; in both cases the 

 object is attained by the existence of the tree and its 

 single individual development; the forester is after 

 the substance of the tree, the wood; his object is finally 

 attained only by the removal of the tree itself. He 

 deals with masses of trees rather than individuals: it 

 is logs in quantity and of desirable quahty, clear of 

 knots, not trees, that he is working for; hence, his 

 treatment differs from that of the horticulturist. 



The clear long boles free of knots are secured by a 

 dense stand, when by the shade of neighbors the lower 

 branches are made to die and break off. When in this 

 way clear boles to a certain height are secured, the 

 stand is opened up by thinnings in order to secure 

 expansion of crown and thereby more rapid increase 

 in diameter of bole. There are several ways of repro- 

 ducing the crop, namely artificially by sowing or plant- 

 ing, the latter being done with one- to four-year-old 

 plants, at the rate of 1,500 to 4,000 to the acre; or by 

 natural regeneration, either by sprouts from the stump, 

 the so-called coppice, which is applicable to hardwoods 

 and for the production of fuel wood and small-dimen- 

 sion material, or else by seed from mother or nurse 

 trees. There are various procediu-es of seciu'ing a crop 

 by seed, a so-called timber forest, which differ by the 

 rapidity of the removal of the old crop or nurse trees, and 

 by the size and progress of the opening — strip system, 

 group system, selection system, and, the most refined, 

 shelterwood system. 



Siace the crop takes many years to mature — some- 

 times a century and more — in order to carrj' on a con- 

 tinuous forestry business, from which to secure annual 

 retm-ns, special arrangements pecuUar to this business 

 must be made: these arrangements, naturally influenced 

 by the economic conditions of the country, form the 

 subject of forest organization or management. 



The ideal of the forester to which he attempts a 

 gradual approach with his actual unregulated forest 

 is known as the "normal forest." It supposes that a 

 rotation has been chosen, i.e. a year or period when 

 the timber wiU be ripe (determined in various ways); 

 that as many stands are at hand as there are years in 

 the rotation, differing by one year from each other, so 

 that each year a mature area can be harvested — a 

 normal age-class gradation; that the increment on 

 the whole area is the best attainable for species and site 

 — a normal increment; that the amount of wood stand- 

 ing, the stock on which the increment is deposited, is 

 the proper one for each age-class — a normal stock. 

 This is the standard with which the actual forest is 

 compared to judge its abnormaUties, which by the 

 management are to be, as far as practicable, removed. 



Since the forest crop takes from thirty to one hundred 

 years and more to mature, i.e., to produce desirable 

 size, highest value, or best interest rate on the invest- 

 ment, it is a business which does not appeal to private 

 enterprise: the long-time element, as well as the influ- 

 ence of forests on water-flow and other cultural con- 

 ditions make forestry particularly a business to be 

 conducted by the state or other long-lived corporation. 



The horticulturist, as such, is mainly interested in 

 the rational treatment of such forests as have a pro- 

 tective value, influencing chmatic, soil and water con- 

 ditions in general and locally. 



