Cycles Cycles That That

Occur in Occur in Nature Nature

Water cycleWater cycle Moves between atmosphere, Moves between atmosphere,

oceans & landoceans & land 1 – water 1 – water evaporatesevaporates from the from the

oceanocean 2 – water also evaporates from 2 – water also evaporates from

plants during the process of plants during the process of transpirationtranspiration

3 – The evaporated water then 3 – The evaporated water then enters atmosphere as a gas enters atmosphere as a gas (water vapor) (water vapor)

4 – Vapor 4 – Vapor condensescondenses to form to form cloudsclouds

5 – when large enough, water 5 – when large enough, water will fall back to earth as will fall back to earth as precipitationprecipitation

6 – Water travels along the 6 – Water travels along the surface as surface as runoffrunoff or or seepageseepage

7 – Plants remove water by 7 – Plants remove water by root uptakeroot uptake

Water is always equal in the Water is always equal in the cycle.cycle.

The amount never changesThe amount never changes

Concerns(due to humans)Concerns(due to humans) Groundwater depletion due to Groundwater depletion due to

irrigationirrigation Unsafe drinking water due to Unsafe drinking water due to

pollution or animal waste. pollution or animal waste. (causes 80% of diseases in (causes 80% of diseases in undeveloped countries)undeveloped countries)

Carbon cycleCarbon cycle

Where is carbon stored?Where is carbon stored?

Carbon cycleCarbon cycle

Where is carbon stored?Where is carbon stored?

In EVERY LIVING THING!!!!In EVERY LIVING THING!!!!

PhotosynthesisPhotosynthesis: taken in by : taken in by plants & converted to sugarplants & converted to sugar

Cellular RespirationCellular Respiration: : releasedreleased

ErosionErosion & volcanoes: & volcanoes: releases COreleases CO22 in the air & in the air & oceanocean

DecompositionDecomposition: released : released (may be stored underground (may be stored underground as fossil fuels)as fossil fuels)

Human ActivitiesHuman Activities::

MiningMiningBurning fossil fuelsBurning fossil fuelsCutting / burning down Cutting / burning down

forestsforests

Nitrogen cycleNitrogen cycleNitrogen –make up proteins Nitrogen –make up proteins

and DNAand DNAWhere is most of it stored?Where is most of it stored? In the atmosphere!! (79%)In the atmosphere!! (79%)Plants and animals cannot take Plants and animals cannot take

nitrogen from the atmospherenitrogen from the atmosphere

1. Bacteria converts nitrogen gas 1. Bacteria converts nitrogen gas into ammonia in a process called:into ammonia in a process called:

nitrogen fixation.nitrogen fixation. 2. A 2. A differentdifferent bacteria converts bacteria converts

ammonia into nitrates and nitrites ammonia into nitrates and nitrites needed by plants to make proteins needed by plants to make proteins

3. Plants take in nitrogen (as 3. Plants take in nitrogen (as nitrates or nitrites)nitrates or nitrites)

4. Consumers get nitrogen by 4. Consumers get nitrogen by eating producerseating producers

5. Organisms die, and return 5. Organisms die, and return nitrogen to soil as ammonianitrogen to soil as ammonia

6. Some ammonia taken up by 6. Some ammonia taken up by producersproducers

7. Nitrates are converted into 7. Nitrates are converted into nitrogen gas by bacteria in a nitrogen gas by bacteria in a process called process called denitrificationdenitrification

8. Nitrogen gas returns to the 8. Nitrogen gas returns to the atmosphereatmosphere

Human activities can also add Human activities can also add Nitrogen:Nitrogen:

Use of fertilizers (travel by Use of fertilizers (travel by runoff)runoff)

Dumping raw sewageDumping raw sewage Burning fossil fuels & woodBurning fossil fuels & wood Leads to Leads to eutrophication (the eutrophication (the

end result is loss of oxygen end result is loss of oxygen from the water)from the water)

Phosphorus CyclePhosphorus Cycle1 – stored in rock (land & 1 – stored in rock (land &

ocean floor) & soilocean floor) & soil2 - Released by weathering & 2 - Released by weathering &

erosionerosion3 – travels in runoff3 – travels in runoff

4 – enters the ocean & gets 4 – enters the ocean & gets used by some marine used by some marine animalsanimals

5 – travels through the food 5 – travels through the food webweb

6 – returned to soil through 6 – returned to soil through wastewaste

Phosphorous CyclePhosphorous Cycle

Human ActivitiesHuman Activities