Biogeochemical Cycles

How Can Abiotic Impacts Affect the Environment

Let’s first understand what natural processes occur on earth

Recycling in the BiosphereEnergy FLOWS through an Ecosystem

MATTER is the “stuff” that makes up everythingMatter CYCLES

Biogeochemical CyclesLaw of Conservation of Matter

Matter is never CREATED nor DESTROYED

Water cycle

Carbon cycle

Nitrogen Cycle

Phosphorous cycle

Sulfur cycle

Bio vs. Geo vs. ChemiBiological processes:

consist of any and all activities performed by living organisms.

Eating, breathing, metabolizing, releasing wastes

Geological Processes:Earth processesVolcanic eruptions, formation/breakdown of rock, cycling

of matter through earth’s surface

Chemical Processes:Ex. Formation of clouds/precipitation, chemical reactions

Water (Hydrologic) Cycle

Water (hydrologic) cycle Precipitation: any form of water that falls from the sky

Snow, rain, hail, sleet

Condensation: cooling of water that changes it from a gas to a liquid Example: formation of clouds

Evaporation: physical change of water from a liquid to a gas

Transpiration: Evaporation of water from the leaves of plants

Run off: flow of water from the land

Infiltration/percolation: water absorbs beneath he earth’s surface into the soil Ground water, Aquifer

Where’s all the H2O??Ocean’s are the major reservoir for

water

Other places:Rivers, lakesAtmosphere (gaseous h2o)UndergroundGlaciers (solid h2o)Within living things

Start thinking…

How do humans impact the water cycle?

We’ll come back to this thought…

Carbon CycleCarbon (C) is one of the most important elements

involved in chemical cycling

Atmospheric carbon is mostly in the form of CO2 (carbon dioxide)Extremely important for plants to carry out

photosynthesisAlso a green house gas- what helps warm the earth

Other forms of carbon are organic and inorganic forms.

Cycles through the atmosphere, the geosphere, the hydrosphere, and biosphere

Fig. 3-19, p. 70

Carbon dioxide in

atmosphereRespiration

Photosynthesis

Animals (consumers) Burning

fossil fuelsDiffusion Forest fires

Plants (producers

)Deforestation

Transportation RespirationCarbon in

plants (producers

)Carbon dioxide dissolved in ocean

Carbon in animals

(consumers) Decomposition

Marine food webs Producers, consumers, decomposers

Carbon in fossil fuels

Carbon in limestone or dolomite sediments

Compaction

Process

Reservoir

Pathway affected by humansNatural pathway

Movement of CarbonGoes into the atmosphere:

Burning of fossil fuels (combustion) Burning forests Respiration (breathing)

Dissolves into water Calcification- dissolved carbon transformed into calcium

carbonate (marine organisms)

Moves through living things, starting with plants and then through trophic levels

Moves through soil via living wastes and decomposition

Carbon in soil to water through erosion

Carbon CycleWhy is carbon important?

Calcium carbonate in your bones

Plants need carbon dioxide (CO2) for photosynthesis

What else needs carbon?

ALL living and some non living things are made out of carbon.

So what happens in the carbon cycle if..

Clearing large amounts of trees (deforestation)?Remember, plants take out CO2 from the

atmosphereCO2 is one of the green house gases that helps

warm the earth

How else are we putting putting carbon in the atmosphere??

Nitrogen Cycle

Nitrogen Cycle Most of the nitrogen on earth is in the atmosphere as N2 (pure

nitrogen gas) This is not a usable form for most living organisms Specialized bacteria transform N2 into usable forms

Nitrogen Fixation Conversion of N2 into NH3 and NH4

+ (ammonia and ammonium)

Nitrification Conversion of NH3 and NH4

+ into Nitrate ions (NO3-)

Assimilation: Plants take up NO3 and convert into organic nitrogen

compounds (proteins and nucleic acids)

Ammonification: Decomposition of nitrogen containing detritus into ammonia

and ammonium

Denitrification: Conversion of NH3 and NH4 back into N2 gas

Human Impact of Nutrient Cycles

Disruption of nutrient cycles has harmful effects on the biosphereBurning fossil fuels----> global warming

Increases CO2 (a green house gas!)Water pollution ------> intoxicating clean

waterAir pollution ------> Acid Rain

Destroying plants and aquatic systemsCoral reef Bleachinghttp://www.smithsonianmag.com/video/Climate

-Change-101-With-Bill-Nye-the-Science-Guy.html

Independent Seat WorkCarbon and Water Cycle Worksheet