Articles containing the keyword 'Armillaria mellea'

A total of 146 Norway spruce-dominated clear-cutting areas and 140 of the sample plots included in the 7th National Forest Inventory in Finland were examined during 1974–78. The micro-organisms causing decay in Norway spruce (Picea abies (L.) H. Karst.) sample trees were identified. The most common causal agent of butt-rot was Heterbasidion annosum (Fr.) Bref. Other fungi causing decay in the spruce trees were Armillaria mellea (Vahl.) Quél, Stereum sanguinolentum (Alb. & Schw. ex Fr.), Resinicum bicolor (Alb. & Schw. ex Fr.) Parm. and Climacocystis borealis (Fr.) Kotl. & Pouz. Species of Ascocoryne were very often present in the decay. The decay caused by H. annosum was considerably more extensive than cases of decay where the fungus was not present.

The PDF includes a summary in Finnish.

• Hallaksela, E-mail: ah@mm.unknown

The study was carried out in a Norway spruce (Picea abies (L.) H. Karst.) stand in Southern Finland which was to be clear-cut due to decay. The species composition and incidence of decay fungi were investigated from the cut surfaces of the stumps. In addition, the colour and size of the decayed spot was observed.

About 28% of the total number of trees were decayed. Fomes annosus (Heterobasidion annosum) was the most common decay fungus. It was identified from 75% of the decayed trees, and was the sole agent in 43% of these trees. Armillaria mellea was the second commonest decay fungus. It decayed trees mostly in combination with Fomes annosus. The most common colours of the decay produced by F. annosus were reddish or yellowish brown. The decay caused by A. mellea was blackish brown. The causative agent cannot be reliably identified on the basis of the colour of the decayed part.

The PDF includes a summary in English.

• Kallio, E-mail: tk@mm.unknown
• Norokorpi, E-mail: yn@mm.unknown

In 1972, all Norway spruce (Picea abies (L.) H. Karst.) trees of a minimum 7 cm diameter at breast height growing in the sample plots of the Sixth National Forest Inventory were examined on the main island of Aland, Finland. The soundness of standing trees was estimated by means of external characteristics and increment borer chips. The trees were then felled and measured. They were cut into lengths, and the type and extent of decay were studied.

30% of the trees examined was affected by butt rot, ca. 3% by wound decay. A comparison of the results with those of the Sixth National Forest Inventory justifies the estimate that in Aland 23% of spruce trees exceeding 7 cm in diameter at 1.3 m had butt rot.

The proportion of decayed trees in the cubic volume was 31%. Decayed wood material accounted for 5% of the volume including bark. Butt rot increased towards the mature stands. The reduction in the number of timber trees due to decay was 14.5%, in their volume 21.5%, and in the volume of sulphite pulpwood 12%. The share of sulphate pulpwood increased from 1 to 10%. The total reduction in usable wood was 6.3%. The stumpage price of the trees fell by 10.3%. As the degree of decay increased the increment percentage of the trees decreased. The most common cause of butt rot was Fomes annosus (Heterobasidion annosum) found in 46% of the number of decayed trees. Armillaria mellea was found in 16%. Bacteria were found in 50% of the decayed trees.

The PDF includes a summary in Finnish.

• Kallio, E-mail: tk@mm.unknown
• Tamminen, E-mail: pt@mm.unknown