The structures of phytocoenoses and wood-destroying complexes (age,space and reproductive structures, fallen timber complexes, species composition of biotrophes and saprotrophes, their ratio and activity) were studied.
The research showed that the rate of infection by fungal biotrophes of climax forest with optimum structures of resistant phytocoenosis was less in comparison with the forests of other formations. The infection of productive climax forests in the mixed forest was on the average 15%, in the south taiga 17%, in the middle taiga 20%, in the north taiga 18%.
The ratio of fungal species, causing brown or white rots was about 1/2 in the forest of all the belts. The composition of fungal species did not change from belt to belt, but their ratio varied. The prevalence of the infection by fungal biotrophes of biogeocoenosis of other structures (subclimax, postclimax) in forest of all belts was much greater, reaching 30 to 40%.
The volumes of fallen timber in climax forest ranged from 1/4 to 1/2 of the growing stand. The average number of most important wood-destroying saprotroph fungi on fallen timber was 25 species in the mixed forest belt. In the more northern forest this quantity was significantly smaller.
The optimal ratio of the biotroph and saprotroph fungal species was determinant for the resistance of forest communities among other factors. Forest resistance depends on complete structure of phytocoenoses, fallen timber and fungal communities.
Key words: spruce forests, infection, wood-destroying fungi.
Correspondence: Vladimir G. Storodzenko, Institute of Forest Research of Russia Academy of Sciences, Uspenskoye, Moscow region, 143030 Russia
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