Page "Soil food web" Paragraph 7

Early food webs were topological ; they were descriptive and provided a nonquantitative picture of consumers, resources and the links between them.

Pimm et al.

( 1991 ) described these webs as a map of which organisms in a community eat which other kinds.

The earliest topological food web, made in 1912, examined the predators and parasites of cotton boll weevil ( reviewed by Pimm et al.

1991 ).

Researchers analyzed and compared topological webs between ecosystems by measuring the web ’ s interaction chain lengths and connectivity.

One problem faced in standardizing such measurements is that there are often too many species for each to have a separate box.

Depending on the author, the number of species aggregated or separated into functional groups may be different.

Authors may even eliminate some organisms.

By convention, the dead material flowing back to detritus is not shown, as it would complicate the figure, but it is taken account in any calculations.