Trees coniferous

Softwood is generally considered to be that coming from a coniferous tree, ie, an evergreen tree having needle-like or scale-like leaves. There are exceptions to the evergreen rule, however. In addition, many hardwoods also may now be used in softwood plywood as core veneers. 

Tall oil rosin is obtained from crude tall oil obtained from the Kraft (sulphate) pulping of various coniferous trees in the paper manufacturing industry. During the Kraft pulping process the fatty acids and the resin acids from the coniferous wood are saponified by the alkaline medium. On concentration of the resulting pulping liquor, the sodium soap of these mixed acids rises to the surface from where they are skimmed out. By acidification of this material with sulphuric acid, the crude tall oil is obtained. Fractional steam distillation of the crude tall oil allows the separation of the tall oil fatty acids and the tall oil rosins [21]. 

Wadel,/, needle pin. nadelartig, a. needle-like, acicular. Nadel-ausschlag, m. throw (deflection) of the needle, -baum, m, coniferous tree, -biatt, n. (Bot.) acicular leaf, needle,... 

Modern charcoal retorts are charged with wood, biowaste (bark, sawdust, etc.), peat, and sometimes low-rank coals. Yield and properties (hardness, density, surface area, etc.) can vary widely so the desired end use must be considered. Charcoal from coniferous trees is soft and porous, while that from hardwoods is dense and strong. For barbecuing, charcoal is usually compressed into briquettes, with binders and additives chosen to improve handling and ease of ignition. 

Variability within plants and between individual plants from the same location, can be quite extensive (in the order of several %o), often as a result of differences in growing conditions (light intensity, humidity), that can vary over a very short distance (Saurer et al. 1995). Systematic differences seem to occur between life forms such as trees, shmbs, cushion plants, etc. (Tieszen 1991 Tieszen and Fagre 1993a Valentini et al. 1995, 1992), and between different botanical groups (for example, deciduous versus coniferous trees Leavitt and Newberry 1992 Ramesh et al. 1986 Stuiver and Braziimas 1987). 

Figure 7.2 Acid rain occurs when water comes into contact with sulfur and nitrogen oxides in the atmosphere, which can come from natural sources or from man-made sources like cars or power plants. These acid rain-damaged coniferous trees live in the Karkonosze National Park in Silesia, Poland.

Rosin is an organic flux that has long been used for soldering. It is a yellow, transparent, and relatively hard resin secreted from wounds in the trunks of coniferous trees. Rosin is insoluble in water, and its exact composition and structure are as yet unknown. 

Most wood can be classified into two broad categories, hardwood and softwood, terms that distinguish between the nature of the trees rather than between the properties in wood. The term hardwood, for example, refers to the wood of deciduous, broad-leaved trees such as birch, oak, and poplar, from the temperate and tropical regions of the world. Softwood, on the other hand, is used to refer to the wood of coniferous trees, needleleaved, evergreen trees such as fir, hemlock, and pine, which grow mainly in temperate and cold regions (see Table 71). The terms hardwood and... 

Maximum values of average Cd concentrations are revealed in stem wood of the Aspen tree (Populus tremula). Median values of Cd content in other types of both deciduous and coniferous trees are lower than 0.2 mg/kg (Table 3, Figure 10). 

Distribution of Cd content I mg/kg dw) in wood biomass of Coniferous trees... 

The content of nitrogen in fallen leaves as a major shedding component is about twice as much as that in the needles of coniferous trees. The total sum of ash elements in the leaves accounts for 3-5%, average about 4% on dry weight basis. Accordingly, the concentration of calcium increases from 0.5 to 4.0%, potassium from 0.15 to 2.0% and silicon with a wide variation. The row of nutrient uptake is as the following ... 

Oxygenated monoterpenes which are found in almost every bark beetle species attacking coniferous trees, include czs-verbenol 246, frans-verbenol 247, and myrtenol 248, representing primary products of allylic oxidation of the host terpene a-pinene 45. Further oxidation of 247 or 248 leads to the... 

Curtin, G.C., King, H.D., Mosier, E.L 1974. Movement of elements into the atmosphere from coniferous trees in subalpine forests of Colorado and Idaho. Journal of Geochemical Exploration, 3, 245-263. 

The pulp and paper industries use three types of raw materials, namely, hard wood, soft wood, and nonwood fiber sources (straw, bagasse, bamboo, kenaf, and so on). Hard woods (oaks, maples, and birches) are derived from deciduous trees. Soft woods (spruces, firs, hemlocks, pines, cedar) are obtained from evergreen coniferous trees. 

In the first practical application of plant antifeedants for forest crop protection and wildlife management, snowshoe hare, L. americanus, fed less on coniferous tree seedlings after they had been sprayed with pinosylvin or pinosylvin methyl ether (Sullivan eta/., 1992). 

Roy, J. and Bergeron, J. M. (1990a). Role of phenolics of coniferous trees as deterrents against debarking behavior of meadow voles Microtus pennsylvanicus). Journal ofChem-... 

Physical Form. Volatile liquid, colorless or yellow, which is a mixture of natural substances obtained ftom resinous exudates or resinous wood ftom living or dead coniferous trees, especially pine trees. The chemical composition can vary with the source and method of derivation, but a typical analysis of turpentine is a-pinene, 82.5% camphene, 8.7% (3-pinene, 2.1% unidentified natural turpenes, 6.8%. 

These materials seem best adapted for deweeding coniferous tree species, such as pines and junipers, which have considerable resistance to the oil sprays. Broadleaf species such as elm and walnut are seriously damaged or killed by moderate dosages of the oil sprays, and much research is needed to find if any of this group of plants are sufficiently resistant to warrant use of the mineral spirits as a selective herbicide. 

The form of the cellulose affects its permeability to acid, and the retention of spent acid in the fibres. Schur and McMurtrie [4] report that wood pulp cellulose from coniferous trees retains the more acid, the larger the diameter of the cellulose fibres. 

Wood pulp for nitration is made exclusively from coniferous trees, since it has been found that conifers give cellulose with long fibres, and hence mechanical losses are small. 

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