title: Relating trophic resources to community structure: a predictive index of food availability.
abstract: The abundance and the distribution of trophic resources available for consumers influence the productivity and the diversity of natural communities. Nevertheless, assessment of the actual abundance of food items available for individual trophic groups has been constrained by differences in methods and metrics used by various authors. Here we develop an index of food abundance, the framework of which can be adapted for different ecosystems. The relative available food index (RAFI) is computed by considering standard resource conditions of a habitat and the influence of various generalized anthropogenic and natural factors. RAFI was developed using published literature on food abundance and validated by comparison of predictions versus observed trophic resources across various marine sites. RAFI tables here proposed can be applied to a range of marine ecosystems for predictions of the potential abundance of food available for each trophic group, hence permitting exploration of ecological theories by focusing on the deviation from the observed to the expected.
authors.affiliation: Stazione Zoologica Anton Dohrn , Integrative Marine Ecology Department, Benthic Ecology Center , Punta San Pietro , Ischia 80077 , Italy.
authors.forename: Valerio
authors.identifier: 0000-0001-9766-8784
authors.initials: V
authors.lastname: Zupo
authors.affiliation: Department of Fish Ecology and Evolution, Centre of Ecology, Evolution and Biogeochemistry, EAWAG Swiss Federal Institute of Aquatic Science and Technology, Seestrasse 79, Kastanienbaum 6047, Switzerland; Division of Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, Bern 3012, Switzerland.
authors.forename: Timothy J
authors.identifier: 0000-0002-6971-6205
authors.initials: TJ
authors.lastname: Alexander
authors.affiliation: Institute for Marine and Antarctic Studies , University of Tasmania , GPO Box 252-49, Hobart, Tasmania 7001 , Australia.
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Edgar
keywords: abundance; feeding guilds; food webs; resources; trophic groups