Biogeochemical Cycles CH 2.3 p 102-­‐105 Big Ques:on How does water, carbon, and nitrogen cycle between abio:c resources and organic maBer in ecosystems? What does ABIOTIC mean? -­‐ non-­‐living What is an example of an abio:c factor? “Organic Ma+er” = what the LIVING parts of an ecosystem are made of What is another word for living factors? -­‐ Bio:c What is maBer? l 
MATTER: Anything that takes up space & has mass l 
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ALL things, living or non-­‐living, are made of MATTER All living things also need to eat or absorb maBer, called NUTRIENTS, to live! NUTRIENT: any chemical substance that an organism needs to perform life processes l 
Examples: carbohydrates, proteins, fats, vitamins, water, minerals, oxygen, etc. l 
All of these things are made of MATTER l 
What is an example of a life process? Biogeochemical Cycles •  All maBer on earth is cycled through: –  living things (Bio) –  The earth’s geological processes (geo) –  Chemical processes (chemical) THE CIRCLE OF LIFE! •  Why a “cycle?” –  because maBer is transferred in con:nuous, never-­‐ending processes from the earth to one organism to the next, there’s no END! Example: - 
Grass (producer) gets nutrients from the air, soil, and water - 
Cow (1° consumer) eats the grass: - 
→ Nutrients are passed into the cow Human (2° consumer) eats the cow: - 
→ Nutrients are passed into the human When the “top” consumer dies, decomposers return the nutrients to the soil DECOMPOSERS HUMAN EARTH GRASS COW The WATER CYCLE Evapora:on and Transpira:on EVAPORATION -­‐Water rises into the atmosphere as water vapor (gas) -­‐Water is constantly evapora:ng from soil, organisms, and bodies of water (lakes, rivers, ocean, etc.) TRANSPIRATION When water evaporates from the surface of plant leaves. Condensa:on - 
Evaporated water vapor condenses into clouds PRECIPITATION When Water is transferred to Earth's surface - 
Falls from clouds as rain, hail, snow, etc. Percola:on Water “percolates” (soaks into) the ground and is stored as groundwater Groundwater and runoff from land surfaces flow into rivers/streams/lakes/oceans, where it evaporates and con:nues the cycle! Processing the Water Cycle: Much of the Earth’s surface in the United States that was previously a natural ecosystem has been paved over for roads, housing, etc. Which part of the Water Cycle would be most effected by this development? A. Precipita:on B. Evapora:on C. Percola:on D. Condensa:on Processing the Water Cycle: Scien:sts have gathered data from our Earth’s core and atmosphere that prove our planet’s temperature is quickly rising, called “global warming.” Which of the following parts of the Water Cycle would increase most during a period of global warming? A. Precipita:on B. Evapora:on C. Percola:on D. Condensa:on The Carbon Cycle •  All living things are made of molecules that contain Carbon –  Organic = living = contains carbon! •  Organic Molecules, Organic MaBer… •  Carbon is “the element of life!” The Carbon Cycle The Carbon Cycle •  Carbon is found in the atmosphere as CO2. •  Plants take CO2 in from the air, and in the process of photosynthesis, make carbohydrate sugars that are stored in the plant •  Animals eat the plants, and also store Carbon in their bodies •  Animals also breathe out CO2 back to the atmosphere as part of respira:on •  When any living thing dies, decomposers return some Carbon to the air as CO2, but the rest of the Carbon gets put into the soil or water DEAD -­‐ The Carbon compounds in decaying organisms deep underground or underwater are eventually turned into coal, oil, or gas -­‐ called “Fossil Fuels” -­‐ This Carbon is re-­‐released to the air as CO2 when people burn fossil fuels DEAD The Carbon Cycle CO2 in air Carbohydrates in plants Carbon in animals Burning Fossil Fuels Decomposers Break down decaying animals DEAD Carbon in soil Fossil Fuels Processing the Carbon Cycle Which correctly describes the rela:onship between plants, animals, and carbon? A. Plants increase atmospheric carbon, Animals decrease it B. Plants decrease atmospheric carbon, Animals increase it C. Both plants and animals increase atmospheric carbon D. Both plants and animals decrease atmospheric carbon Processing the Carbon Cycle Which of the following is a result of too much deforesta:on? A.  An increase in atmospheric carbon B.  A decrease in atmospheric carbon The Nitrogen Cycle l 
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Nitrogen is needed by all living things to build proteins Nitrogen is found in its gas form in the air around us - 
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but Plants and animals can't use nitrogen in its gas form! NITROGEN FIXATION: process where Nitrogen gas is converted into a form plants can use - 
This process is done by certain bacteria that live in the water, soil, or that grow on the roots of some legume (bean) plants l 
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Bacteria capture the nitrogen gas from the atmosphere and make it usable Plants then absorb the usable Nitrogen from the soil Animals eat the plants – and Nitrogen is passed along through the food chain •  Nitrogen is returned to the soil when –  Animals excrete wastes (pee or poop) –  living things die and are broken down by decomposers •  Nitrogen is returned to the air by denitrifying bacteria •  DENITRIFICATION: bacteria in the soil re-­‐convert nitrogen compounds into nitrogen gas Processing the Nitrogen Cycle Which organism does the process of Nitrogen Fixa:on? A. Animals B. Plants C. Bacteria D. Fungi Processing the Nitrogen Cycle Why is Nitrogen Fixa:on necessary? -­‐ Even though Nitrogen gas is in the air all around us, plants and animals cannot use it in its gaseous form Write your summary!! 2 main points!