Arthropod diversity in pristine vs. managed beech forests in Transcarpathia (Western Ukraine)

Pristine forests are generally assumed to be biodiversity hotspots. Is management detrimental to biodiversity? In some of the last European remains of pristine beech forest in Transcarpathia (Western Ukraine) the influence of forest management on arthropod biodiversity was assessed. Pitfall and flight interception traps were used to compare species numbers, abundances, Simpson diversity and species composition of beetles, spiders, millipedes and centipedes in pristine and managed forests. For the sum of all identified species and most taxonomic groups, species numbers and Simpson diversity were not significantly different between the two management regimes. Species numbers, abundances, and species composition of different beetle families, spiders, millipedes and centipedes differed more between the three regions (Jaremcha, Mala Uholka, Shyrokyj Luh) than between pristine and managed forest plots within the same region. Neither red-listed beetle species nor specialized saproxylic beetles were more diverse in pristine forests. But the latter were more abundant in pristine plots, where the amount of dead wood was up to twenty times higher than in the managed plots. We conclude that biodiversity in pristine beech forests is not generally higher than in managed beech forests. However, the much higher amount of dead wood in pristine forests provides a source habitat for saproxylic species spreading into managed forest plots in the same region, but not to distant forests, far from virgin forests, such as in Western Europe.