Ecosystem Ecology

Carbon Cycle

1. Carbon enters the atmosphere as carbon dioxide from respiration and combustion.

2. Carbon dioxide is absorbed by producers to make carbohydrates in photosynthesis.

3. Animals feed on the plant passing the carbon compounds along the food chain. Most of the carbon they consume is exhaled as carbon dioxide formed during respiration. The animals and plants eventually die.

4. The dead organisms are eaten by decomposers and the carbon in their bodies is returned to the atmosphere as carbon dioxide. In some conditions decomposition is blocked. The plant and animal material may then be available as fossil fuel in the future for combustion.

driving forces of carbon cycle

marine biological activity, terrestrial biological activity, and human activity

carbon isotopes

help us track variation in atmospheric carbon and oxygen content and temperature

Ice Core Sampling

Analysis of air bubbles trapped in ice sheets. This sampling showed that CO2 concentrations were much lower during continental glaciations, but high during intervening warm periods.

carbon dioxide sources

1. fossil fuel burning

2. deforestation (tropics)

3. deforestation (outside the tropics)

co2 sinks

Photosynthesis

-plants

-algae

Oceans

-carbonate formation

long term carbon cycle

cycle where plants and animals die depositing carbon in the ground

Biogeochemical cycles on land

Biogeochemical cycles in the oceans

the nitrogen cycle

The transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere

The phosphorus cycle

the cyclic movement of phosphorus in different chemical forms from the environment to organisms and then back to the environment