Effects of silvicultural techniques on the diversity of microorganisms in forest soil and their possible participation in biological control of Armillaria and Heterobasidion

Abstract

Effects of different pre-planting soil preparations and post-harvest wood debris applications in a clear-cut Scots pine plantation, on the abundance, diversity, and activity of culturable microorganisms were investigated. The investigation was done 9 years after the re-plantings had been done. This formed part of an investigation of silvicultural practices for conservation and the biological control ofArmillariaandHeterobasidionin northern temperate forests (Poland). The treatments being compared, were expected to have altered the soil’s physical and chemical properties, and consequently, its biological properties. Only soft-rot microfungi from the Ascomycota and Zygomycota were detected in the soil. Fungi, including those antagonistic toArmillariaandHeterobasidion, were more abundant after shallow ploughing than after deep ploughing or ridging, and where chipped rather than coarse wood debris was left on the soil surface or incorporated. Scots pine trees had the most biomass and the least mortality after ridging and leaving coarse wood debris on the surface (associated with only a relatively moderate abundance of fungi).

Effects of preparation of clear‐cut forest sites on the soil mycobiota with consequences for Scots pine growth and health

“…Woody debris incorporated into the top soil, providing nutrients in the first 10 years, improved tree growth, while the removal of woody debris improved tree health. Better health of trees in soil 2 could have resulted from: (a) absence of Armillaria ostoyae and Heterobasidion annosum , which could be suppressed by the abundant mycobiota (Kwaśna, Walkowiak, Łakomy et al, ), and (b) more efficient photosynthesis, as an effect of the higher proportion of mycorrhiza.…”

“…Differences in soil fungal communities in managed and unmanaged forests or across temperate forest ecosystems have been studied in Germany (Goldmann et al, ; Wubet et al, ; Yurkov, Kemler, & Begerow, ) and in France (Buée et al, ). In Poland, the abundance and diversity of microorganisms in forest soils after different post‐harvest woody debris applications and pre‐planting soil preparations have been studied by Kwaśna, Łakomy, Gornowicz, Behnke‐Borowczyk et al, (), Kwaśna, Łakomy, Gornowicz, Mikiciński et al, (), Kwaśna, Walkowiak, Łakomy et al, (), Małecka & Kwaśna, () and Małecka, Kwaśna, & Szewczyk, (). The classical soil‐dilution method used by Kwaśna, Łakomy, Gornowicz, Mikiciński et al, () and Kwaśna, Walkowiak, Łakomy et al () enabled detection of active microfungi from the Ascomycota and Zygomycota.…”

“…In Poland, the abundance and diversity of microorganisms in forest soils after different post‐harvest woody debris applications and pre‐planting soil preparations have been studied by Kwaśna, Łakomy, Gornowicz, Behnke‐Borowczyk et al, (), Kwaśna, Łakomy, Gornowicz, Mikiciński et al, (), Kwaśna, Walkowiak, Łakomy et al, (), Małecka & Kwaśna, () and Małecka, Kwaśna, & Szewczyk, (). The classical soil‐dilution method used by Kwaśna, Łakomy, Gornowicz, Mikiciński et al, () and Kwaśna, Walkowiak, Łakomy et al () enabled detection of active microfungi from the Ascomycota and Zygomycota. In soils sampled after clear cutting, the active fungi were more abundant after deep ploughing, making holes for planting seedlings or shallow ploughing, than after deep ploughing or ridging, and where chipped rather than coarse woody debris was left on the soil surface or incorporated into the soil.…”

Soils from intercropped fields have a higher capacity to suppress black root rot in cassava, caused by Scytalidium lignicola

“…Studies have shown that biotic and abiotic soil attributes influence the suppression of plant diseases (Barros et al, ; Silva et al, ; Silva et al, ). However, biological factors were described as predominant in the suppression of most plant diseases caused by soil‐borne pathogens (Kwaśna et al, ). Other factors, such as increased organic matter content and recycling of macro and micronutrients that improve soil fertility, influence pH change and may increase the production by the plant of substances antagonistic to phytopathogens (Sales Júnior, Senhor, Michereff, & Medeiros, ).…”

“…Many factors may be involved in the interaction of soil attributes with the pathogen; however, organic matter and microbial populations are two major factors involved in the suppression of plant diseases caused by soil pathogens (Kwaśna et al, ). Nonetheless, there is still a gap in knowledge regarding the enzymatic activities involved in these systems, since these represent the link between organic matter degradation and microbial populations, and they may provide a sensitive tool for detecting changes in the soil (Medeiros et al, ).…”