1. Biogeochemical Cycles

2. How Can Abiotic Impacts Affect the Environment
Let’s first understand what natural processes occur on earth

3. Recycling in the Biosphere
Energy FLOWS through an Ecosystem
MATTER is the “stuff” that makes up everything
Matter CYCLES

4. Biogeochemical Cycles
Law of Conservation of Matter
Matter is never CREATED nor DESTROYED
Water cycle
Carbon cycle
Nitrogen Cycle
Phosphorous cycle
Sulfur cycle

5. Bio vs. Geo vs. Chemi Biological processes: Geological Processes:
consist of any and all activities performed by living organisms.
Eating, breathing, metabolizing, releasing wastes
Geological Processes:
Earth processes
Volcanic eruptions, formation/breakdown of rock, cycling of matter through earth’s surface
Chemical Processes:
Ex. Formation of clouds/precipitation, chemical reactions

6. Water (Hydrologic) Cycle

7. 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

8. Where’s all the H2O?? Ocean’s are the major reservoir for water
Other places:
Rivers, lakes
Atmosphere (gaseous h2o)
Underground
Glaciers (solid h2o)
Within living things

9. How do humans impact the water cycle?
Start thinking…
How do humans impact the water cycle?
We’ll come back to this thought…

10. Carbon Cycle
Carbon (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 photosynthesis
Also 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

11. Carbon dioxide in atmosphere Respiration
Photosynthesis
Animals (consumers)
Burning fossil fuels
Diffusion
Forest fires
Plants (producers)
Deforestation
Transportation
Respiration
Carbon in plants (producers)
Carbon dioxide dissolved in ocean
Carbon in animals (consumers)
Decomposition
Carbon in fossil fuels
Marine food webs Producers, consumers, decomposers
Figure 3.19: Natural capital.
This simplified model illustrates the circulation of various chemical forms of carbon in the global carbon cycle, with major harmful impacts of human activities shown by the red arrows. Question: What are three ways in which you directly or indirectly affect the carbon cycle?
Carbon in limestone or dolomite sediments
Compaction
Process
Reservoir
Pathway affected by humans
Natural pathway
Fig. 3-19, p. 70

12. Movement of Carbon Goes into the atmosphere: Dissolves into water
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

13. Carbon Cycle Why 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.

14. So what happens in the carbon cycle if..
Clearing large amounts of trees (deforestation)?
Remember, plants take out CO2 from the atmosphere
CO2 is one of the green house gases that helps warm the earth
How else are we putting putting carbon in the atmosphere??

15. Nitrogen Cycle

16. 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

17. Human Impact of Nutrient Cycles
Disruption of nutrient cycles has harmful effects on the biosphere
Burning fossil fuels----> global warming
Increases CO2 (a green house gas!)
Water pollution > intoxicating clean water
Air pollution > Acid Rain
Destroying plants and aquatic systems
Coral reef Bleaching
101-With-Bill-Nye-the-Science-Guy.html

18. Independent Seat Work
Carbon and Water Cycle Worksheet