Terestre:
1 Frunza-->omizi-->pasari
2 Iarba -->caprioare-->lupi
3 Porumb sau alte cereale -->pasari--> om
4 Iarba-greiere-soparla-soim
Acvatice:
1 Microvietatile din apa-->pesti-->rechin
2 Alge-purice de apa-crap-stiuca
3 Alge-pesti fitofagi-pesti carnivori-om
