Consumer–resource interactions

[2][3] Species at the bottom of the food chain, such as algae and other autotrophs, consume non-biological resources, such as minerals and nutrients of various kinds, and they derive their energy from light (photons) or chemical sources.

[citation needed] Another way of categorizing consumers, proposed by South African American ecologist Wayne Getz, is based on a biomass transformation web (BTW) formulation that organizes resources into five components: live and dead animal, live and dead plant, and particulate matter (such like composted carcass; rotting plant matter).

A carcasivore (Latin: carcasium=carcass), such as white-backed vulture, scavenge animal carcasses while a necrophage (Greek: nekros=dead body), such as a blowfly, mines dead flesh.

Victivores (Latin: victus=living) gather live plant material and thus include frugivores, nectivores, graminivores, granivores and folivores as subcategories.

Carnivore and herbivore are generic multigroup categories for gathers respectively of animal and plant material, irrespective of whether live or dead.