13.5 Cycling of Matter

KEY CONCEPT Matter cycles in and out of an ecosystem.

Nutrient Cycles

Cycling maintains homeostasis (balance) in the environment.

•5 cycles to investigate:1. Water cycle2. Carbon cycle3. Nitrogen cycle4. Oxygen5. Phosphorus

Water cycle-

• Includes the following• Evaporation, transpiration,

condensation, precipitation

• The hydrologic, or water, cycle is the circular pathway of water on Earth.

• Organisms all have bodies made mostly of water.

Water cycle- http://www.youtube.com/watch?v=0_c0ZzZfC8c

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Carbon cycle-

•Photosynthesis and respiration cycle carbon and

oxygen through the environment.

Carbon http://www.youtube.com/watch?v=0Vwa6qtEih8cyclehttp://www.sciencelearn.org.nz/Contexts/The-Ocean-in-Action/Sci-Media/Animations-and-Interactives/Carbon-cyclehttp://www.windows2universe.org/earth/climate/carbon_cycle.html

Nitrogen cycle- Atmospheric nitrogen (N2) makes up nearly 78%-80% of air. Organisms can not use it in that form.Lightning and bacteria convert nitrogen into usable forms.

Nitrogen cycle- Only in certain bacteria and industrial technologies can fix nitrogen.Nitrogen fixation-convert atmospheric nitrogen (N2) into ammonium (NH4

+) which can be used to make organic compounds like amino acids.

N2 NH4+

Nitrogen cycle-Nitrogen-fixing bacteria:Some live in a symbiotic relationship with plants of the legume family (e.g., soybeans, clover, peanuts).

Nitrogen cycle- http://www.youtube.com/watch?v=w03iO_Yu9Xw&feature=related

•Some nitrogen-fixing bacteria live free in the soil. •Nitrogen-fixing cyanobacteria are essential to maintaining the fertility of semi-aquatic environments like rice paddies.

13.5 Cycling of Matter

Oxygen Cycle• The main processes

involved in the oxygen cycle are photosynthesis and cellular respiration.

13.5 Cycling of Matter

• Oxygen cycles indirectly through an ecosystem by the cycling of other nutrients.

oxygen

respiration

carbondioxide

photosynthesis

13.5 Cycling of Matter

geologic upliftingrain

weathering ofphosphate from rocks

runoff

sedimentationforms new rocks

leaching

phosphate in solutionanimals

plants

decomposers

phosphatein soil

• The phosphorus cycle takes place at and below ground level. (http://www.youtube.com/watch?v=RKkC2JpjaGc)– Phosphate is released by the weathering of rocks. – Phosphorus moves through the food web and returns to

the soil duringdecomposition.

– Phosphorus leaches into groundwater from the soil and is locked in sediments.

– Both mining and agriculture add phosphorus into the environment.

Toxins in food chains- While energy decreases as it moves up the food chain, toxins increase in potency. •This is called biological magnification

Ex: DDT & Bald Eagles