Seasonal changes in the positional importance of components in the trophicflow network of the Chesapeake Bay

Community-level processes may shape food web structure. In this paper, a gr aph theoretical study of the weighted trophic flow network of the Chesapeak e Bay ecosystem shows how important are positions in the energy (carbon) tr ansport system. The positional importance of components is compared to the quantity of energy flowing through them. We suggest that the congruence bet ween important network positions and large flows refers to the larger role of trophic interactions in community control. A seasonal dynamical analysis of the network has led us to the conclusion that winter is the season when the importance of predation is the highest. (C) 2001 Elsevier Science B.V. All rights reserved.