The Carbon, Nitrogen and Phosphorus Cycles Nutrient Cycling The Carbon, Nitrogen and Phosphorus Cycles

Carbon Stores Carbon stores are also known as carbon sinks. - organic matter become buried on land and under the oceans. under great pressure over many years, coal, oil, and gas form. - Layers of shells also are deposited in sediments on the ocean floor Carbon stores are also known as carbon sinks.

So How does carbon Cycle? Photosynthesis: is a chemical reaction and atmospheric carbon dioxide gas into chemical energy: 6CO2 + 6H2O + sunlight  C6H12O6 + 6O2 Cellular respiration: plants and animals obtain energy by converting carbohydrates and oxygen into carbon dioxide and water. C6H12O6 + 6O2  6CO2 + 6H2O + energy The energy released is used for growth, repair, and other life processes.

Decomposition - decomposers break down large quantities of cellulose - Cellulose is a carbohydrate most other organisms cannot break down.

Ocean Mixing CO2 dissolves in cold, northern waters and sinks Ocean currents flow to the tropics where the water rises and releases CO2. Eruptions and forest fires – can also release CO2.

The Whole Carbon Cycle:

Nitrogen - In animals, proteins are vital for muscle function - in the structure of DNA and proteins - In animals, proteins are vital for muscle function - In plants, nitrogen is important for growth

- Approximately 78 percent of Earth’s atmosphere is N2 gas.

So How does Nitrogen Cycle? Nitrogen is cycled through 4 processes Nitrogen fixation Nitrification Uptake Denitrification

1. Nitrogen FiXation Nitrogen fixation is the conversion of N2 gas into compounds containing nitrates (NO3-)and ammonium (NH4+). Two ways of fixing nitrogen: Lightning - N2 reacts with O2 to get NO3- Nitrogen-fixing bacteria e.g. Rhizobium converts N2 to NH4+

2. Nitrification! 3. Uptake 4. Denitrification Nitrifying bacteria converts Ammonium (NH4+) is to nitrite (NO2–), and then to nitrate (NO3-). Usable forms of Nitrogen (nitrates/ammonium) are taken up by plant roots and used for plant proteins Nitrogen is returned to the atmosphere by denitrifying bacteria - Nitrates (NO3-) to Nitrogen (N2) 3. Uptake 4. Denitrification

The Whole Nitrogen Cycle:

The Phosphorous Cycle Phosphorus is not stored in the atmosphere. Phosphorus is essential for life processes in plants and animals. - a part of the molecule that carries energy in cells - promotes root growth, stem strength, and seed production. Phosphorus is not stored in the atmosphere. - trapped in phosphates (PO43–, HPO42–, H2PO4–) found in rocks and in the sediments on the ocean floor.

The Phosphorous Cycle Weathering releases phosphates from rocks. Weathering does not occur until there is geologic uplift, exposing the rock Two types: - chemical weathering, via acid precipitation or lichens - physical weathering, including wind, water and freezing

Nutrient Cycles: Phosphorous Cycle

How Changes in Nutrient Cycles Affect Biodiversity Any significant changes to any of these nutrients (C, N, or P) can greatly affect biodiversity. Carbon cycle changes can contribute to climate change and global warming. Increased levels of nitrogen & phosphorus can allow certain plant species to outcompete other species, decreasing resources for every species in the food webs.

Food Chain Song