Person:
Digel, Christoph

Profilbild
E-Mail-Adresse
Geburtsdatum
Forschungsvorhaben
Organisationseinheiten
Logo der Organisationseinheit
Organisationseinheit
Berufsbeschreibung
Nachname
Digel
Vorname
Christoph
Name

Filter

2019 - 201912020 - 20221
Filter zurücksetzen

Einstellungen

Suchergebnisse

Gerade angezeigt 1 - 2 von 2
  • Vorschaubild nicht verfügbar
    Veröffentlichung
    Predator traits determine food-web architecture across ecosystems
    (2019) Brose, Ulrich; Archambault, Phillippe; Barnes, Andrew D.; Digel, Christoph; Deutschland. Umweltbundesamt. Fachgebiet IV.1.3.1 - Ökotoxikologie und Umweltrisiken Pflanzenschutzmittel
    Predator-prey interactions in natural ecosystems generate complex food webs that have a simple universal body-size architecture where predators are systematically larger than their prey. Food-web theory shows that the highest predator-prey body-mass ratios found in natural food webs may be especially important because they create weak interactions with slow dynamics that stabilize communities against perturbations and maintain ecosystem functioning. Identifying these vital interactions in real communities typically requires arduous identification of interactions in complex food webs. Here, we overcome this obstacle by developing predator-trait models to predict average body-mass ratios based on a database comprising 290 food webs from freshwater, marine and terrestrial ecosystems across all continents. We analysed how species traits constrain body-size architecture by changing the slope of the predator-prey body-mass scaling. Across ecosystems, we found high body-mass ratios for predator groups with specific trait combinations including (1) small vertebrates and (2) large swimming or flying predators. Including the metabolic and movement types of predators increased the accuracy of predicting which species are engaged in high body-mass ratio interactions. We demonstrate that species traits explain striking patterns in the body-size architecture of natural food webs that underpin the stability and functioning of ecosystems, paving the way for community-level management of the most complex natural ecosystems.
  • Vorschaubild nicht verfügbar
    Veröffentlichung
    Biotic filtering by species' interactions constrains food-web variability across spatial and abiotic gradients
    (2022) Bauer, Barbara; Berti, Emilio; Ryser, Remo; Digel, Christoph
    Despite intensive research on species dissimilarity patterns across communities (i.e. BETA-diversity), we still know little about their implications for variation in food-web structures. Our analyses of 50 lake and 48 forest soil communities show that, while species dissimilarity depends on environmental and spatial gradients, these effects are only weakly propagated to the networks. Moreover, our results show that species and food-web dissimilarities are consistently correlated, but that much of the variation in food-web structure across spatial, environmental, and species gradients remains unexplained. Novel food-web assembly models demonstrate the importance of biotic filtering during community assembly by (1) the availability of resources and (2) limiting similarity in species' interactions to avoid strong niche overlap and thus competitive exclusion. This reveals a strong signature of biotic filtering processes during local community assembly, which constrains the variability in structural food-web patterns across local communities despite substantial turnover in species composition. © 2022 The Authors. Ecology Letters published by John Wiley & Sons Ltd.