Pathogens as creators of biodiversity. A study on influence of decayed bracket fungi on alpha diversity of microarthropods in the Karkonosze National Park, Poland

Abstract

Bracket fungi are organisms important to forestry, often perceived from the point of view of economic losses they cause, but they also play an important role in shaping biodiversity, e.g. by creating specific microhabitats to which their fruiting bodies belong. The fruiting bodies of this group of fungi are the place of occurrence of invertebrate assemblages specific for them, however, this topic is still poorly researched. The aim of the study was to assess the effect of the degree of decay (DD) of fruiting bodies on the microarthropod communities inhabiting them. The study material (100 fruiting bodies) was collected in the Karkonosze National Park, which areas were affected by a large-scale forest dieback process in the 1980s. 29,228 individuals of microarthropods belonging to 186 species were extracted. Oribatid mites were the most numerously represented group (87 species and 24,472 individuals) and the most numerous species was Carabodes femoralis (20,167 ind.). In addition to the species previously observed also in other substrates, species characteristic only for fruiting bodies of arboreal fungi were also observed (e.g. Hoploseius oblongus). Each DD's fauna differed from one another, in the majority of microarthropod groups there was a tendency for greater number of species and individuals in higher DDs; however, it was not a linear one. The NMDS and cluster analyses indicated that the 3 DD and 4 DD samples are similar to each other, whereas 1 DD and 2 DD samples differed from the samples belonging to the other DDs. Indicator species analysis has indicated species characteristic for each DD, among others Hoploseius oblongus for 1 DD and Zerconopsis remiger for 4 DD. The results encrease the knowledge on the poorly-understood aspekt of ecology and can be a useful source of information for effective protection of forest biodiversity and sustainable forest management.