The Influence of the Concomitant Microflora on Establishment and Dieback of Decay Fungi in Standing Timber

Abstract

The microbiological aspects that designate development of decay in standing timber were assessed by determining the resistance to succession as well as the competitive saprophytic ability (kratovirulence, KV) of 40 species of wood destroying basidiomycetous fungi (WBF), proved to be members of 7 ecological categories. The categories (i) to (iv) comprise predominantly pathogenic WBF (pathogens) with high pathovirulence (PV) and correspondingly low KV properties that are dominant in the decay of standing timber. The categories (v) to (vii) include saprophytic WBF (saprophytes) with occasional or no PV and increasingly dominant KV properties which are native to slash and plant residues. On sterilely overgrown blocks of fertilized wood meal which had been exposed to airborne contaminants, most pathogens displayed the same degree of resistance to the insinuation of successive microbes as did the saprophytes. In the inoculation attempts of randomly contaminated wood meal, however, the low‐kratovirulence, pathogens were unable to repress the multitude of the antagonistic resident microorganisms in order to establish themselves in this substrate. In contrast, most high‐kratovirulence saprophytes reduced the number of, or completely eliminated, these antagonistic resident microorganisms in wood meal to create the preconditions for colonizing this substrate themselves for up to 1,200 days. In application of these results to the conditions in standing timber it is concluded that the wounded living tree involuntarily promotes the entry of a pathogenic WBF by keeping its natural antagonists down. The once established WBF can then protect its vegetative thallus itself from being overgrown by successive microbes.

10.1007/s10438-008-1010-6

“…2b). In contrast to the results reported in [20], we found no inhibition of heterotrophic microflora by P. ostreatus D1 under the experimental conditions. Such inhibition was noted by us during the first 14 days after inoculation of the solidphase culture, and then the heterotroph population rapidly increased.…”

“…Their degradation did not exceed 9%. These results are in good agreement with those reported in the literature [20,21]. Growth of P. ostreatus D1 in sterile soil did not affect the paraffin fraction throughout the experiment time regardless of the method of fungus inoculation.…”

“…Strains of the genera Phanerochaete and Trametes , most vigorously studied as PAH degraders, form weak and short-living mycelium in nonsterile soils. Thus, the first step in soil treatment is the choice of a fungal strain able to produce rich mycelium, viable for a long time [20].…”

“…It has been shown, for example, that intensely growing Marasmius oreades mycelium reduces the population of soil bacteria [1]. Moreover, some authors note inhibition of soil bacterium growth by P. ostreatus mycelium [20].…”

Two new antifungal metabolites produced by Sparassis crispa in culture and in decayed trees

“…In the living tree, the endogenous defences of the host may serve to exclude other micro-organisms from competition with such decay fungi, but this protection ceases on death of the host (Gramss, 1987) and the residual tissues, comprising the stump, then become available to a wide range of colonizers (cf. Rayner & Boddy, 1988).…”