Spruce bark

Figure 9. Exposure pathways based on the averaged coefficients ofbiogeochemical uptake, Cb, of trace metals in Spruce Forest ecosystems of the Karelia top scheme represents the ecosystem with Podzols on diabase outcrops and bottom scheme represents the ecosystem with Podzols on gneiss outcrops. 1—spruce needles 2—spruce bark 3—hypnic mosses 4—leaves and twigs of blueberry (based on Dobrovolsky, 1994).

First, the concentration of Sr, Ba, and Ti in spruce bark is relatively higher than in needles, while the latter are enriched by Ni and Zn. Second, the concentration of Zn, Ba, Cu, and Cr is higher in blueberry roots, than in the aerial parts. Third, the effect of zonal and local factors is remarkable. For instance, the Sr content in the needles... 

Cell walls in the necrotic tissue of these wounds were browned. Staining with diazotized Q-tolidine and toluidine blue confirmed the polypheno-lic nature of these brown depositions, which may have resulted from the polymerization of the stilbenes present in large quantities in spruce bark. Phenolic residues were deposited on the walls of certain cells internal to the necrotic tissues by 10 days after wounding. By 36 days these cells had become thick-walled. The precise nature of substances responsible for this thickening has not been determined, variable responses being obtained with histochemical tests for lignin (cf. Table I). Suberin was detectable in cells immediately underlying the thick walled cells, which corresponded to the... 

Compound CAS Registry Number Pine bark Oak bark Spruce bark... 

Further work in Canada to produce rigid wet-process insulation boards from a bark-wood mixture was reported by Branion in 1961 (36). He made boards containing 85% poplar wood and 15% white spruce bark a few boards were made with added poplar or jack pine bark. White spruce bark worked best it appeared to cause a significant increase in tensile strength compared to boards made from 100% poplar wood fiber. This effect also was demonstrated in a hardboard. Other boards were made with up to 80% bark. Water absorption decreased as bark content increased. An effort was made to discover the bark ingredient responsible for the strength increase. After a series of extractions, the active component was concluded to be present in the holocellulose. 

Bowers W. W. and Borden J. H. (1990) Evidence for a male-produced aggregation pheromone in the four-eyed spruce bark beetle, Polygraphus rufipennis (Kirby) (Col., Scolytidae). J. Appl. Entomol. 110, 292-299. 

Leufven A., Bergstrom G. and Falsen E. (1984) Interconversion of verbenols and verbenone by identified yeasts isolated from the spruce bark beetle Ips typographus. J. Chem. Ecol. 10, 1349-1361. 

Sahota T. S. and Farris S. H. (1980) Inhibition of flight muscle degradation by precocene II in the spruce bark beetle, Dendroctonus rufipennis (Kirby) (Coleoptera Scolytidae). Can. J. Zool. 58, 378-381. 

Isorhapontin, a monoglucosylated stil-bene constituent of spruce bark, can be cleaved by a dioxygenase isolated from Pseudomonas strain TMY1009 (Kamoda et al., 1989). 

The Utilization of Aggregation Pheromone for the Control of the Spruce Bark Beetle... 

Traps compared to Trap Trees. Trap-trees have been used in Europe for more than 200 years to control the spruce bark beetle (14). One reason for developing pheromone traps is to replace the trap-tree method, which has become more and more expensive. An average trap-tree (20 cm d.b.h.) will be occupied by about 6500 beetles (12). Average trap-catches in 1980 were 7406 beetles. Within 2-3 weeks parent beetles occupying a trap-tree have utilized the phloem suitable for breeding so most of them emerge to attack another tree. After 3-4 weeks only 10-20% of the beetles are left. Trap-trees therefore have to be removed from the forest... 

Usually, lignitic ash contains a much higher proportion of alkali and alkaline earth elements, and consequently lower proportions of acidic oxides such as silica and alumina, than does ash from bituminous coals. These differences are illustrated by the data in Table II (1.). The data on spruce bark ash are taken from reference (4) and show the similarity of lignitic and woody ashes. Of interest are the contrasts between the lignite and bituminous averages first with regard to silica and alumina and, second, to lime, magnesia, and sodium oxide. 

The results are given in Tables 2 and 4 completed with the data of ash chemical composition [8], Accordingly, the results showed that ash sintering was dependent on the pressure of steam. For spruce bark, willows and alfalfa, as shown in Table 2, ash sintered stronger in pressurised conditions than at atmospheric pressure. 

To see the effect of tenq erature on the melting of carbonates, additional tests were carried out for spruce bark and willow in 30 bar steam and at 700 °C, which was clearly below the eutectic. The results showed that the spruce bark had no ash sintering but the willow ash was clearly sintered. This observation and the behaviour of alfalfa indicate that chemical compounds other than carbonates arc also involved in ash sintering. One explanation could be found in the chlorine chemistry Below 700 "C the major part of chlorine remains in ash. The chlorine content of Danish straw ashes, which were prepared at 550 °C in a laboratory furnace, is shown in Table 4. Mixtures of compounds CaCl and KCl, and also KCI and K2CO3 are possible. The former mixture has the eutectic of595 C and the latter 640 °C [11]. 

One of the interesting phenomena pertaining to the interaction between the plant -insect and the tree host containing monoterpens is the behaviour of the spruce bark beetle (Ips typographus). The main... 

Fig, (4). Transformation of host tree constituents in spruce bark beetle Ips typographus. 

Aggregation pheromones of spruce bark beetles, e.g., from the genus tps, were widely studied in order to fight back their destructive actions in the forests of Canada and Scandinavia. They tend to be simple metabolites of terpenes, present in the resin of the trees they live on, but a rather complicated system of chemical communication has evolved. A great amount of research was necessary to clarify the complicated systems of chemical communication within and between the species, and some points of interest are described here. The bark beetle attack from the genus Ips starts with a few males. If the tree is suitable for them, the pioneer beetles secrete pheromones... 

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