Using a combination of controlled experiments, field sampling, and different diet tracing methods we investigate links between various deadwood substrates which may serve as potential food resources and saproxylic beetles as their consumers. Saproxylic beetles are among the most important taxonomic and functional groups of insects in forest ecology, taking a significant part in the wood decomposition process. Our recent research has revealed that different feeding guilds of saproxylic beetles largely overlapped in their values of stable carbon and nitrogen isotopes, commonly used trophic biomarkers. We invesigate to what extent these similarities among feeding guilds are caused by an overall higher dependency of beetles on fungi or by more common mixed trophic strategies than currently acknowledged.

Petr Kozel, Pavel Šebek, Daria Congia, Michaela Helclová

Stable isotopes of saproxylic beetles reveal low differences among trophic guilds and suggest a high dependence on fungi