Applying stable isotopes to examine food‐web structure: an overview of analytical tools

Abstract

19Stable isotope analysis has emerged as one of the primary means for examining the structure and 20 dynamics of food webs, and numerous analytical approaches are now commonly used in the 21 field. Techniques range from simple, qualitative inferences based on the isotopic niche, to 22Bayesian mixing models that can be used to characterize food-web structure at multiple 23 hierarchical levels. We provide a comprehensive review of these techniques, and thus a single 24 reference source to help identify the most useful approaches to apply to a given data set. We

Isotopic variation among Amazonian floodplain woody plants and implications for food-web research

“…Our objectives were to: 1) compare d 13 C and d 15 N of woody plants from forests with contrasting watershed biogeochemistry and floristic composition (i.e., neutral, nutrient-rich white water vá rzea forest and acidic, nutrient-poor black water igapó forest; Worbes 1997); 2) assess the magnitude of within-site variation in d 13 C and d 15 N of leaves and fruits; 3) determine within-plant variation in d 13 C and d 15 N of leaf and fruit tissues; and 4) test the influence of isotopic variation on a mixing model predicting the relative contribution of C sources to the biomass of a fruit-eating fish species. We hypothesized that 1) woody plants of white-water and black-water flooded forests have different d 13 C and d 15 N signatures; 2) within-site variation in d 13 C in single floodplain forest sites is smaller than the variation previously reported at a regional scale in the central Amazonia (Martinelli et al 1991); 3) non-photosynthetic tissues, particularly fruits, have different isotopic signatures than leaves from the same plant; and 4) isotopic variation changes the predicted contribution of different C sources to the consumer biomass.…”

“…Amazonian floodplain forests cover an extensive area, have high floristic diversity and provide important resources for diverse consumer taxa. Nonetheless, natural variation in d 13 C and d 15 N in flooded forest plants has seldom been investigated, especially among samples from the same locality (e.g., Martinelli et al 1991Martinelli et al , 1992Martinelli et al , 1994. Given that local abiotic factors as well as plant traits cause isotopic variation, how much variation in isotopic ratios is expected among species within a local plant community?…”

“…Stable isotope analysis has become a primary tool in food-web studies to depict production sources supporting consumers and to analyze food-web structure (Boecklen et al 2011, Layman et al 2012. Use of stable isotopes in food-web research relies on natural variation in the abundance of stable isotopes within components of the ecosystem (Peterson & Fry 1987, Fry 2006.…”

The evolutionary adaptation of the C282Y mutation to culture and climate during the European Neolithic

“…Reconstructing diet from archaeological context relies on identification of archaeobotanical and archaeozoological remains, stable isotope analysis on human remains, and lipid and protein residue analysis from potshards (Kovačiková et al, 2012; Layman et al, 2012; Brown and Brown, 2013; Colledge and Conolly, 2014). Based on one or more of these analyses, a picture of the European Neolithic diet has begun to emerge.…”

Seasonal variability in baseline δ15N and usage as a nutrient indicator in Lake Poyang, China

“…The majority of communities have multiple food sources that have distinct nitrogen isotopic signatures occupying the same trophic level (Vander Zanden and Rasmussen 1999;Post 2002). These differences in the isotopic composition among primary producers create an isotopic baseline amalgam that needs to be accounted for when calculating diet or trophic position using stable isotopic methods (Casey and Post 2011;Layman et al 2012).…”