Fine‐scale variation in natural nitrogen isotope ratios of ants. Issue 3 (21st November 2015)

• Record Type: Journal Article
• Authors: Cronin, Adam L.; Donnerhack, Oliver; Seidel, Felix; Yamanaka, Toshiro
• Is Part Of: Entomologia experimentalis et applicata. Volume 157:Issue 3(2015:Dec.)
• Page Start: 354
• Page End: 359
• Publication Date: 2015-11-21
• Subjects: trophic level -- Mongolia -- baseline calibration -- Formicidae -- Hymenoptera -- Formica kozlovi -- Formicini -- trophic ecology -- mineral soil -- organic soil; Entomology -- Periodicals; 595.7
• DOI: 10.1111/eea.12370
• Languages: English
• ISSNs: 0013-8703

Abstract

Abstract: Stable isotopes provide a powerful means of elucidating the trophic ecology of organisms. Analyses of variation in the ratio of nitrogen isotopes (δ 15 N) can provide insights into the trophic position of species with broad diets and the ability to occupy multiple positions in food webs, such as ants. The most powerful studies compare subjects across various spatial scales, but to do so, local variation in δ 15 N baselines must be taken into account. To date, a wide variety of baseline calibration methods have been employed, leading some authors to suggest that a standard approach is needed, and that the reality of environmental variation necessitates that this should be at fine scales. In this study, we examine the fine‐scale variation in δ 15 N value of colonies of the ant Formica kozlovi Dlussky (Hymenoptera: Formicidae: Formicini) along a sloped transect in Mongolia, and compare these with values for associated soils in an effort to shed further light on this issue. We find variation in ant δ 15 N to the order of one trophic level (ca. 3‰), over a distance of only 1 km. Ant δ 15 N was highly correlated with soil δ 15 N, and variation in mineral soil δ 15 N explained ca. 81% of the variation in ant δ 15 N. This study underlines the importance of local‐scale baseline corrections for isotopic studies, particularly in environments where baseline variation might be expected. It further suggests that δ 15 N of mineral soils may provide a suitable baseline for ecological studies of terrestrial arthropods.