Soil microarthropods in non-intervention montane spruce forest regenerating after bark-beetle outbreak

We studied Oribatida and Collembola in an old-growth Norway spruce (Picea abies) forest that suffered a massive bark beetle (Ips typographus) outbreak in the 1990s and gradually decayed. It was left to regenerate naturally without human intervention. There was a high abundance of a few tolerant species and lower numbers of sensitive silvicolous ones. The most dominant species were Tectocepheus velatus, Platynothrus peltifer and Isotomiella minor. Although the details, which determine the identity of successful species, remain unknown, parthenogenesis, high reproduction rate and detrito- or detritofungivorous feeding were the common features of the most dominant species in our study. Trait assessment showed an overall predominance of parthenogenesis and high abundance of detritivorous oribatids. The soil functions connected with Oribatida and Collembola seem to be still affected by the bark-beetle outbreak and our results indicate that the disturbance caused important changes in the functioning of the whole soil ecosystem.