Warm upGet out a piece of paper and complete this

assignment.Hypothesize: How would earth change if all

decomposers disappeared today?Something to think about:

What is the role of decomposers?How does this role relate to cycles of matter?

Bio- lifeGeo- earthChem- chemicals

SEV1aYou will…

Interpret processes in which elements, chemical compounds, and other forms of matter are passed from one organism to another as well as through the non-living elements of an ecosystem.

The lawMatter cannot be created or destroyed.With regards to matter, Earth is mostly a

closed system.Matter doesn’t leave or enter.What we have is recycled

We will examine the cycles of water, carbon, nitrogen, and phosphorus.

1. Hydrologic (water) cycleThree core processes to connect

EvaporationCondensationPrecipitation

Hydrologic cycleWhat happens to water on a hot

stove?Evaporation – liquid becomes gas

Liquid water Water vapor Transpiration – water evaporating

from leaves of plants

What if water vapor cools?Condensation

water vapor liquid water

warm moist air cools as it rises

Cool air can’t hold all that water vapor. Water condenses

into clouds.

Heavier water droplets fall to earth as precipitation: hail, sleet, snow, or rain

Water evaporates into warm air

Hydrologic cycle

2. Where is carbon?Carbon Distribution on Earth

70%

22%

4% 4%

CO2 in Ocean

CO2 in Rocks

Dead Organisms

Terrestrial Ecosystems

Human influenceAn increase in CO2

can raise the earth’s temperature.

Some human activities increase the CO2 in the atmosphere.

CO2 levels have risen 30% since 1800.

Human activitiesMaking concrete

CaCO3(s) CaO(s) + CO2(g)

Burning coal C(g) + O2(g) CO2(g)

Burning natural gasCH4(g) + 2O2(g) CO2(g) + 2H2O(g)

Burning gasoline2C8H18(g) + 25O2(g) 16CO2(g) + 18 H2O(g)

Carbon (C) CycleCarbon is the key ingredient in all living

things. 4 processes involved

1. Biological processes- Photosynthesis:

Absorbs CO2 CO2 + H2O sugar and O2

Respiration: Releases CO2 sugar and O2 CO2 + H2O

Decomposition: releases CO2

Carbon Cycle2. Mixed biogeochemical - burial of carbon-rich

remains become fossil fuels by pressure of overlying earth

3. Geochemical processes - release of CO2 by volcanoes

4. Human activity- mining, burning of fossil fuels, cutting down/burning forests

Carbon Cycle

3. Nitrogen CycleWhy should you care?

Nitrogen makes up this much of the air, but you can’t use it like that.

Plants need nitrogen to grow

You need nitrogen to make proteins.

What is nitrogen fixation?Nitrogen-fixing

bacteria living around roots turn atmospheric N2 to ammonia, NH3, or ammonium ions, NH4+.

Other soil bacteria may oxidize to NO2- or NO3-.

Herbivores get their N from plants

Carnivores get their N from herbivores

Omnivores can use both sources

Breaking down wastesDecomposers with bacteria

return N in urine, dung, decaying plants and animals to the soil

Bacteria return a small amount to atmospheric N2

Without these

organisms, N would be stuck in

corpses and wastes forever

Nitrogen Cycle

Nitrogen Cycle in depth1. Atmospheric N2 is converted to ammonia

NH3 or ammonium NH4+ or lightning converts N2 to Nitrogen oxides

2. NH3 & NH4+ are oxidized by soil bacteria to nitrite ions NO2- then to nitrate ions NO3-.

3. Plants take in nitrogen as nitrate ions.

Nitrogen Cycle cont’d4. Nitrogen passes through food chain5. When organisms die bacteria & fungi take

up some nitrogen. The rest is released as NH3 gas or NH4+

6. Denitrifying bacteria convert some NH3 back to N2 which returns to atmosphere

4. Phosphorus (P) CycleIf you like your teeth and skeletons, pay

attentionPlants source of P is soil & waterAnimals get their P

By eating plants By eating animals who eat plants

Phosphorus Cycle Phosphorus rarely occurs as a gas This is the slowest cycle

1. Erosion of rocks (phosphate PO43-)2. Plants take in PO4

3- through roots

3. Excess P in animal waste, decomposing animals and plants

4. Runs off into ocean and sinks to the bottom

Phosphorus Cycle

Cycles of matter Expert groups of four Answer these questions about each process

in your cycle. 1. Where does it occur?2. What is the name of the process?3. How does the matter change?4. How do people affect this process?

Create a visual aid for your project