Meridith Bartley, Jonathan Bowers, Albert Meier

Abstract for Submission:

Ecological Society of America Annual Meeting:  2007

Where Do They Go When They Die?

ABSTRACT

Food webs and matrices are vital to understanding feeding relationships and ecology. Adjacency matrices can be employed to represent the direct relationships between predators and prey. These binary matrices utilize zeros to denote no direct link and ones to denote a direct link. We selected and analyzed a wide range of published food webs ranging from pine forests in the United States to tussock grasslands in New Zealand.  The food webs varied in number of distinguishable taxa present, functional diversity, and climates and habitats.  As a consequence we expect that our results are not specific to a given system. Each of these published food webs lack flows from organisms to detritus (despite the fact that organisms in these webs consume detritus), but did represent flows from detritus to organisms. The question arises: how does the inclusion of flows to detritus influence indirect connectance within large food webs?  By adding flows to detritus, the number of indirect paths of length n as well as indirect relationships throughout the systems increased.  For example, in the web describing a pine forest adding flows from organisms to detritus increased direct flows by 130%, and increased indirect connections of path length three by 5472%.