Multidimensional trophic niche revealed by complementary approaches: gut content, digestive enzymes, fatty acids and stable isotopes in Collembola

Trophic niche differentiation may explain coexistence and shape functional roles of species. In complex natural food webs, however, trophic niche parameters depicted by single and isolated methods may simplify the multidimensional nature of consumer trophic niches, which includes feeding processes such as food choice, ingestion, digestion, assimilation and retention. Here we explore the correlation and complementarity of trophic niche parameters tackled by four complementary methodological approaches, i.e., visual gut content-, digestive enzyme-, fatty acid- and stable isotope analyses – each assessing one or few feeding processes, and demonstrate the power of method combination. Focusing on soil ecosystems, where many omnivore species with cryptic feeding habits co-exist, we chose Collembola as an example. We compiled fifteen key trophic niche parameters for 125 species from 40 studies. We assessed correlations among trophic niche parameters and described variation of these param...