Individuals in food webs: the relationships between trophic position, omnivory and among-individual diet variation

Trophic levels and trophic tangles: the prevalence of omnivory in real food webs.

The concept of trophic levels is one of the oldest in ecology and informs our understanding of energy flow and top-down control within food webs, but it has been criticized for ignoring omnivory. We tested whether trophic levels were apparent in 58 real food webs in four habitat types by examining patterns of trophic position. A large proportion of taxa (64.4%) occupied integer trophic position...

Running Head : Trophic Levels and Omnivory in Large Food Webs LIMITS TO TROPHIC LEVELS AND OMNIVORY IN COMPLEX FOOD WEBS : THEORY AND DATA RICHARD

While trophic levels have found broad application throughout ecology, they are also in much contention on analytical and empirical grounds. Here, we use a new generation of data and theory to examine long-standing questions about trophic-level limits and degrees of omnivory. The data include food webs of the Chesapeake Bay, USA, the island of St. Martin, a UK grassland, and a Florida seagrass c...

Omnivory and the stability of food webs.

The ecological concept of omnivory, feeding at more than a single trophic level, is formulated as an intermediate stage between any two of three classical three-dimensional species interaction systems-tritrophic chain, competition, and polyphagy. It is shown that omnivory may be either stabilizing or destabilizing, depending, in part, on the conditions of the parent systems from which it derive...

Landscape variation influences trophic cascades in dengue vector food webs

The epidemiology of vector-borne diseases is governed by a structured array of correlative and causative factors, including landscape (for example, rural versus urban), abiotic (for example, weather), and biotic (for example, food web) factors. Studies of mosquito-borne diseases rarely address these multiple factors at large spatial scales, which limits insights into how human alterations of la...

Variation in network structure among food webs