Role of allochthonous carbon in the energy of terrestrial invertebrate communities at different distances from the Black Sea and a freshwater lake (Isotopic Evidence)

Isotopic analysis has become an important tool in the study of lateral links between ecosystems. The isotopic composition of carbon in terrestrial and aquatic primary producers can differ significantly, which provides an opportunity to identify the “marine” or “freshwater” carbon in the tissues of terrestrial animals. We measured the isotopic composition of C and N in tissues of soil invertebrates and estimated the proportion of “aquatic” carbon in the energy budget of terrestrial food webs at different distances from the Black Sea and a freshwater lake. Terrestrial predators are actively subsidized with carbon from the Black Sea to distance of up to about 50 m. The carbon subsidy from the freshwater lake is significant in the zone extending no farther than the forest border (ca. 15 m). Thus, the effect of allochthonous organic matter on terrestrial communities in both cases manifests itself only in a relatively narrow coastal strip.