The carbon cycle is the flow of carbon through the abiotic and biotic components of the biosphere. And what's amazing about the carbon cycle is that photosynthesis removes a ton of CO2, and that amount is roughly equivalent to the amount of CO2 that's added by cellular respiration. So in this way, these two processes feed each other. Cellular respiration produces CO2, and photosynthesis removes CO2 to generate biomass. Now, the major reservoirs of carbon include biomass, soil, sediment, fossil fuels, and in the atmosphere, there is some carbon dioxide.
Now, the nitrogen cycle is a particularly interesting one, because most nitrogen is actually found in the atmosphere. And nitrogen is only able to enter ecosystems through this special process called nitrogen fixation, which will be carried out by organisms like bacteria. And this is going to be super important, for supporting the growth of many primary producers, which need that nitrogen to live.
Now, the phosphorus cycle tends to recycle locally in ecosystems, unlike, for example, the water cycle or the carbon cycle that has very far-reaching effects. The phosphorus cycle tends to stay pretty local, because most phosphorus is found in rock and soil. So it's not going to get too far; it's not going to travel too far. That's all I have for this one. I'll see you guys next time.