부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ecolmodel.2005.04.002 Byline: Stefano Allesina (a)(b), Cristina Bondavalli (a), Ursula M. Scharler (c)(d) Keywords: Ecological networks; Aggregation; Trophospecies; Detritus; Food web; Ascendency Abstract: Ecological networks are quantitative, graph-based descriptions of ecosystems, consisting of compartments (trophospecies and nutrient pools) that exchange fluxes of nutrients or energy. Previous research pointed out how the model's design is a crucial task that can heavily influence analyses results, and how merging compartments for the purpose of comparing two or more different ecosystems can significantly alter the indices on which the comparison is based. All these works have been focused on the aggregation of trophospecies, whereas networks may comprise several nutrient compartments that may be lumped as well, either for lack of information or for comparison constraints. We show how the aggregation of these non-living compartments can have a greater influence on network analysis results than trophospecies clustering. This problem should on the one hand encourage modelers to make an effort to test the possible effects of aggregations, and on the other show how the role of non-living compartments could be very important in determining network dynamics. Author Affiliation: (a) Department of Environmental Sciences, University of Parma, Viale delle Scienze 33/A, 43100 Parma, Italy (b) Department of Fisheries and Wildlife, Michigan State University, 13 Natural Resources Building, East Lansing, MI 8824, USA (c) Chesapeake Biological Laboratory, University of Maryland, Center for Environmental Studies, Solomons, MD 20688, USA (d) Smithsonian Environmental Research Center, 647 Contees Wharf Road, Edgewater, MD 21037, USA Article History: Received 19 August 2004; Revised 31 March 2005; Accepted 6 April 2005