title: Intraguild predation in pioneer predator communities of alpine glacier forelands.
abstract: Pioneer communities establishing themselves in the barren terrain in front of glacier forelands consist principally of predator species such as carabid beetles and lycosid spiders. The fact that so many different predators can co-inhabit an area with no apparent primary production was initially explained by allochthonous material deposited in these forelands. However, whether these populations can be sustained on allochthonous material alone is questionable and recent studies point towards this assumption to be flawed. Intraguild predation (IGP) might play an important role in these pioneer predator assemblages, especially in the very early successional stages where other prey is scarce. Here, we investigated IGP between the main predator species and their consumption of Collembola, an important autochthonous alternative prey, within a glacier foreland in the Ötztal (Austrian Alps). Multiplex PCR and stable isotope analysis were used to characterize the trophic niches in an early and late pioneer stage over 2 years. Results showed that intraguild prey was consumed by all invertebrate predators, particularly the larger carabid species. Contrary to our initial hypothesis, the DNA detection frequency of IGP prey was not significantly higher in early than in late pioneer stage, which was corroborated by the stable isotope analysis. Collembola were the most frequently detected prey in all of the predators, and the overall prey DNA detection patterns were consistent between years. Our findings show that IGP appears as a constant in these pioneer predator communities and that it remains unaffected by successional changes.
authors.affiliation: Institute of Ecology, University of Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria; Meteoexploration.com, Höttingergasse 21/17, 6020, Innsbruck, Austria.
authors.forename: Lorna
authors.initials: L
authors.lastname: Raso
authors.forename: Daniela
authors.initials: D
authors.lastname: Sint
authors.forename: Rebecca
authors.initials: R
authors.lastname: Mayer
authors.forename: Simon
authors.initials: S
authors.lastname: Plangg
authors.forename: Thomas
authors.initials: T
authors.lastname: Recheis
authors.forename: Silvia
authors.initials: S
authors.lastname: Brunner
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Kaufmann
authors.forename: Michael
authors.initials: M
authors.lastname: Traugott
mesh_terms: D000818:Animals; D001181:Arthropods / Q000145:classification; D001317:Austria; D002247:Carbon Isotopes / Q000032:analysis; D001517:Coleoptera / Q000502:physiology*; D020387:Food Chain; D046448:Ice Cover; D009587:Nitrogen Isotopes / Q000032:analysis; D011235:Predatory Behavior; D017422:Sequence Analysis, DNA; D013112:Spiders / Q000502:physiology*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes
keywords: Carabidae; Collembola; Linyphiidae; Lycosidae; community assembly; multiplex PCR; primary succession; trophic interactions