Isotopic signature (15N/14N and 13C/12C) confirms similarity of trophic niches of millipedes (Myriapoda, diplopoda) in a temperate deciduous forest

The species composition, abundance, and isotopic signature of millipedes (Myriapoda, Diplopoda) were investigated in seven biotopes of Kaluzhskie Zaseki State Nature Reserve. Nine Diplopoda species were found in total, and the local species diversity (within a sampling plot) reached seven species. The Diplopoda tissues were similar to the plant litter in the isotopic composition of nitrogen (delta N-15 was by 0.4aEuro degrees higher, on average), but were strongly enriched in heavy carbon (delta C-13 was by 4aEuro degrees higher, on average). Removal of mineral carbon from the cuticle reduced delta C-13 of Diplopoda by about 1.4aEuro degrees on average. Differences in the delta N-15 and delta C-13 values between the species did not exceed 2.5aEuro degrees. Differences in the isotopic compositions of the considered species were small, and, it is impossible to distinguish particular trophic guilds in the Diplopoda community. Analysis of the published data confirmed that isotopic differentiation of millipedes was much less pronounced than in other investigated groups of soil animals. Hence, millipedes of the deciduous forest form a uniform trophic group.