<a href="https://en.wikipedia.org/wiki/Aerobic_organism" class="extiw" title="w:Aerobic organism">Aerobic</a> carbon oxygen <a href="https://en.wikipedia.org/wiki/Biogeochemical_cycle" class="extiw" title="w:Biogeochemical cycle">cycle</a> (<b>P</b> = <a href="https://en.wikipedia.org/wiki/Primary_producers" class="extiw" title="w:Primary producers">producer</a>, <b>K</b> = <a href="https://en.wikipedia.org/wiki/Consumers_(food_chain)" class="extiw" title="w:Consumers (food chain)">consumer</a>, <b>D</b> = <a href="https://en.wikipedia.org/wiki/decomposer" class="extiw" title="w:decomposer">decomposer</a>)
<a href="//commons.wikimedia.org/wiki/User:Sponk" title="User:Sponk">Sponk</a>
<span class="int-own-work" lang="en">Own work</span>