Norway Spruce Sapwood Research Articles

Upgrading of spruce wood with ethanolamine treatment

Wood is the most abundant non-toxic, recycable and biodegradable natural material, valued as a construction material because of its appearance and its high strength at low density. On the other hand its biodegradability is an important drawback. Improvement of decay resistance of wood with ethanolamine is described in this paper. Ethanolamine chemically reacts with wood (Norway spruce sapwood) and does not evaporate from it. During this reaction, significant amounts of oxygen are consumed. Upgraded specimens show increased fungal activity and increased combustibility. The treatment of the spruce wood samples with aqueous solutions of ethanolamine resulted in colour changes.

Internal oxygen levels decrease during the growing season and with increasing stem height

The oxygen levels in the sapwood of Norway spruce [Picea abies Karst. (L.)] trees were measured by GC-MS (gas chromatography – mass spectrometry) as stem growth progressed during the growing season. The measurements were made on 30-year-old, 13–15 m high, trees growing on three plots which were irrigated, left undisturbed or subjected to drought. The oxygen measurements were done at 1.5, 4 and 8 m above the ground. The internal oxygen levels dropped to about 5% of the level in air in irrigated trees, 1–3% in control trees and to below 1% in trees subject to drought between mid-July and mid-August. In the trees subjected to drought there where no differences in internal oxygen concentrations between the positions on the tree during the growing season except for a faster increase back to ambient concentration occurring in late August in the 1.5 m position. In trees growing on the two other plots the internal oxygen concentration was higher near the ground than at 4 or 8 m above ground during July and August. At all other dates there were no differences between the positions. The results indicate that there is an oxygen gradient with levels decreasing acropetally, giving indirect support to the hypothesis that oxygen is supplied to the growing stem in the transpiration stream.

The Effect of Bark Condition, Delivery Time and Climate-adapted Wet Storage on the Moisture Content of Picea abies (L.) Karst. Pulpwood

The wet-base moisture content (MC) in outer sapwood of Norway spruce (Picea abies (L.) Karst.) pulpwood in different wood management programmes from the forest to the mill was studied from the point of view of three objectives: (1) the importance of rapid raw material delivery, (2) the effect of bark condition as a result of harvesting during the late dormant season and the growing season, and (3) the possibilities for retaining the pulpwood MC using climate-adapted wet storage. The reduction in MC after felling was significant in the pulpwood stored without wet storage. When not wet-stored, pulpwood with a high degree of bark damage dried out more rapidly than wood with a low degree of bark loss. In pulpwood, wet-stored in accordance with climate-adaptation, the MC remained or increased during storage. The shorter the drying time before wet storage, i.e., faster delivery to the mill, the more significant the increase in MC. The increase in MC during wet storage was more significant in pulpwood with a low degree of bark damage. Climate-adapted wet storage reduced the variation of the MC. When conducted with fresh pulpwood, i.e., drying time shorter than 4 weeks (low bark loss) or 2 weeks (high bark loss), a more homogeneous MC distribution was gained.

Relation between leaf biomass and annual ring sapwood of Norway spruce according to needle age-class

The relationship between leaf biomass and sapwood area was investigated in a 35-year-old Norway spruce (Piceaabies (L.) Karst.) stand in mountainous conditions. Fifteen trees were destructively sampled to determine the needle biomass in several needle age-classes and whorls and the corresponding sapwood areas at the whorl branch bases and in stems at breast height. Leaf biomass/sapwood area ratio and specific leaf biomass (g•mm−2) were calculated for different needle age-classes and also for different positions in the vertical profile of the crown. The leaf biomass/sapwood area ratios were described by linear regression with a high coefficient of determination. Specific leaf biomass analysed in whorl branches was highest in the upper whorls but was decreasing downward through the profile; remained stable in the middle crown layer; and decreased again in the lower crown parts. Specific leaf biomass assessments for stems showed the largest and most increasing values in the youngest three needle age-classes followed by a decreasing trend of the specific leaf biomass in older needle age-classes. The mean values of specific leaf biomass were 1.08 g•mm−2 for branches and 1.02 g•mm−2 for stems. The results of our study are consistent with the "pipe model theory."

Fungal succession in sapwood of Norway spruce infested by the bark beetle Ips typographus

AbstractFungal invasion of Norway spruce sapwood was investigated during a period of 130 weeks fol‐lowing attack by the spruce bark beetle Ips typographus. Heavy beetle attack tended to overwhelm the trees quickly and no secondary resinosis was produced. Nonetheless, fungal penetration in the sapwood was initiated only slowly, although it accelerated during the fourth week after attack. Typically the leading edge of fungal penetration was a few millimeters in advance of the visible blue‐stain during the sapwood colonization. Fungi invaded the sapwood in a successional pattern with the most pathogenic species Ophiostoma polonicum first, followed by other beetle‐transmitted Ophiostoma and Graphium species. The later succession was probably influenced by sapwood moisture. Strong decaying white‐rotters invaded near the base of the trees, where sapwood moisture remained favourable, while cf. Trichoderma viride dominated in the drier parts or the trees.

Pectic enzyme activity of spruce (S) and pine (P) strains of Heterobasidion annosum (Fr.) Bref

Growth and pectic enzyme activity were compared between S and P intersterility groups of Heterobasidion annosum (Fr.) Bref. occurring in Europe. In living, infected root sapwood of Norway spruce ( Picea abies) (L.) Karst, the growth of P strains was significantly slower than that of S strains. The pectic activity of the P strains was greater than that of the S strains both in relation to mycelial production and to the protein content of the culture filtrate. Thin-layer chromatography of samples from cultures and reaction mixtures revealed qualitative and quantitative differences in substrate cleavage patterns between the two intersterility groups. Whereas S strains mainly produced exopolygalacturonase, P strains produced endopolygalacturonase. The P strains showed a high polygalacturonase activity both at pH 5 and pH 8. This intersterility group was also characterized by strong pectin lyase activity, particularly at pH 8. In infected root sapwood of spruce the P strains released more soluble polymers and oligomers from pectin than did the S strains. Thin-layer chromatography of reaction products showed that the cleavage patterns in vivo and in vitro were similar.

Species of Ophiostomataceae isolated from Picea abies infested by the bark beetle Ips typographic

Isolations of microorganisms were made from the sapwood of Norway spruce (Picea abies) (L.) Karst. infested by the spruce bark beetle Ips typographus L. The most important group of fungi isolated, the species of Ophiostomataceae, is treated. Ten species were isolated, of which Ophiostoma polonicum Siem. appears to be the most active invader of the sapwood. Three new species are described, Ophiostoma ainoae sp. nov., O. flexuosum sp. nov. and O. cucullatum sp. nov. and three new combinations are proposed, O. davidsonii (Olchow. & Reid.) comb. nov., O. europhioides (Wright & Cain) comb. nov. and O. sagmatospora (Wright & Cain) comb. nov.

Indirect Measurement of Pore Size and Permeability in Scots Pine and Norway Spruce

Five experiments to investigate the water relationships of Scots pine and Norway spruce sapwood are described. Field exposure of stakes, and their moisture characteristic relating wood moisture content to the water potential of the surroundings showed that spruce had a lower moisture content than pine under the same conditions. A pore size distribution derived from the characteristics showed more large pores in spruce than in pine, but in spruce there were also more small pores. The inference was that the large pores of spruce were readily accessible to water, allowing a fast rate of water uptake, as found in the wick action and swelling investigations, while the small pores were not accessible, resulting in a low rate of water uptake and a low rate of swelling. The possibility is briefly discussed that it is the pore size distribution of the two woods which determines their water relationships, and the difference in pore size which determines their treatability.

Changes in Sapwood of Roots of Norway Spruce, Attacked by Fomes annosus. Part I

AbstractChemical and physiological changes occurring in root sapwood of Norway spruce (Picea abies [L.] Karst.), when attacked by Fomes annosus (Fr.) Cke, were studied. The transformation of sapwood to reaction zone, induced by the fungal attack, implies a very sharp increase of carbonate content, correlated with higher amounts of potassium, calcium and magnesium. The buffer capacity of the reaction zone is strong, especially in the pH range 6–9. The high peroxidase activity in the rays of the sapwood is almost totally absent in the reaction zone, probably due to inactivating phenolic compounds. o‐Diphenol oxidase was detectable only in the presence of microorganisms. p‐Diphenol oxidase was active in connection with decaying wood but not in the reaction zone.