1. Matter and Energy in The Environment
LS CH 20

2. ECOLOGY
The study (science) of the interactions between organisms and their environment.
Study of ecosystems
Includes everything in a given area:
Living things (biotic factors)
Nonliving things (abiotic factors)

4. What do Ecologists Study? (think-pair-share)

5. Abiotic Factors Any nonliving thing in an ecosystem Examples:
Still impacts organisms
Examples:
Sunlight
Atmospheric gases
Climate
Temperature
Soil
Water
Human impacts

6. The Sun The ultimate source of energy for our planet
Sun  Producers (photosynthesis)  Primary consumers  Secondary consumers  etc.
Also plays a role in many other abiotic factors
Evaporates water
Creates wind and weather due to heating patterns on Earth
Controls temperature

7. Why do we experience seasons?

8. The Earth is Tilted on its Axis
In our summer, the Northern Hemisphere tilts towards the sun, giving us more direct sunlight and keeping it warmer
The Southern Hemisphere tilts away, giving them winter
In our winter, the Northern Hemisphere is tilted away from the sun, giving us less direct sunlight (sunlight is spread out more) and cooling it down.
The Southern Hemisphere tilts towards the sun, giving them summer

9. Atmospheric Gases
The atmosphere is the layer of gases surrounding Earth
Atmospheric composition (learn these percentages)
Oxygen is breathed in by many organisms, and made by others
Nitrogen is used by many organisms

10. Climate and Weather
Climate is the average weather conditions in an area over a long period of time
NOT THE SAME AS WEATHER!
Includes precipitation, temperature, and wind
Weather is the current condition
A vast majority of scientists and researchers (97% who work in this area of research) believe that humans are changing the climate
Could have drastic impacts to many ecosystems

11. Temperature
How hot or cold something is (sort of… at least until Physical Science)
Most organisms can only survive within a certain range of temperatures
Polar bears in the desert, cacti in Antarctica…

12. Soil Made up of rock fragments, water, air, and bits of living things
Essential for survival of plants, and therefore all organisms
Bacteria within the soil break down dead organisms

13. Water Availability and quality important
Only raw material that all organisms on earth need
All organisms are made up of water
Animals drink it to stay alive
Plants need it for energy production and photosynthesis
Marine life and many protists live in it
While most of the earth is covered in water, it is not all in the proper form for all organisms to use

14. Human Impacts General Theme in Ecology
We tend to mess things up rather a lot
Humans are biotic factors, but we create a lot of abiotic factors
Pollution impacts ecosystems greatly
Buildings and roads fragment ecosystems
We also impact other abiotic factors
Water pollution
Climate change

15. Matter is cycled in nature
Matter Cycles
Water
Nitrogen
Carbon-Oxygen
Others we won’t be exploring

16. The Water Cycle Terms: Evaporation-Liquid to gas
Condensation-Gas to liquid
Precipitation-Water falling to earth’s surface
Transpiration-Water leaving plants
Exhalation-Water leaving as organisms exhale
Run-off- Water that travels over surfaces
Groundwater- The water stored underground

18. The Carbon-Oxygen Cycle
Oxygen is needed by much of the life on earth
Essential for the production of ATP during cellular respiration
Oxygen is produced by plants and phytoplankton (includes tiny plants, some bacteria, and some protists) during photosynthesis
The oxygen is then taken in by organisms to allow respiration to occur
Provides ATP so that cells can do their jobs
During respiration, Carbon Dioxide is produced

19. The Carbon-Oxygen Cycle Cont.
Carbon is found in the air in the form of carbon dioxide
Comes from:
Exhalation of organisms (created in cellular respiration)
Burning of fossil fuels
Fossil fuels are fuels made from the remains of organisms
Contributes significantly to climate change
Natural release of carbon from soil
Forest fires
Deforestation
Taken in by:
Soil
Photosynthetic organisms

21. CO2 As A Greenhouse Gas Carbon dioxide absorbs radiation from the sun
This traps it on earth (similar to a greenhouse trapping heat), increasing global temperatures
Global Warming (not a myth)
Over time, the average temperatures throughout the planet have increased
Climate change (also not a myth. Actually very terrifying)
Carbon Dioxide is not alone
Other gases (especially methane) are greenhouse gases
However, increased CO2 emissions are accelerating climate change faster than other gases

23. The Nitrogen Cycle Nitrogen is the most abundant gas in the atmosphere
Atmospheric electricity (lightning) causes nitrogen compounds to fall to the surface
Nitrogen is a component of DNA and of proteins
Organisms get nitrogen into their body by eating other organisms
Animals release Nitrogen into the soil through waste (fertilizer)
Also, when an organism dies, bacteria decompose the organism and turn the nitrogen into forms that plants can use
They also release nitrogen from the soil back into the atmosphere

25. Movement of Energy in an Ecosystem
Every living thing needs energy
The ultimate source of energy is the sun
Also a little bit of energy from Earth’s interior and hydrothermal vents in the ocean
The Law of Conservation of Energy
Energy cannot be created or destroyed. It can change forms. (More Physical Science!)

26. Types of Organisms (Review)
Producers
Able to make their own “food” (energy sources)
Can be done by photosynthesis or chemosynthesis
Chemosynthesis is like photosynthesis, only it uses chemical energy instead of sunlight
Occurs near hydrothermal vents
Often uses sulfur compounds
Consumers
Organisms that must consume food to get energy
Classified by type of food sources

27. Classifications of Consumers
Herbivores
Eat only plants
Carnivores
Mostly eat other animals
Omnivores
Able to eat both plants and animals
Humans, regardless of their diet, are omnivores
Decomposers
Feed on dead or decaying organisms

28. Transferring Energy in an Ecosystem
It all starts with the sun (or hydrothermal vents in some oceanic ecosystems)
Producers capture the sunlight and use it to make sugars
Consumers then eat the producers, collecting the sugars
Consumers and producers eventually die, and provide energy for decomposers
At each level, only about 10% of the energy is able to go on to the next level
Around 90% of the energy is used by the organism
Cannot be destroyed
Transferred to the environment as heat due to metabolism

29. Modeling Energy Transfer
Food chains
Very simple diagram showing one way that energy can be transferred
Not even close to complete
Very simplistic. Your teacher is not a fan…
Food Web
A more complex diagram showing many (or ideally all of) the feeding relationships in an ecosystem
Can still be sort of simple
Can be extremely complex
In either case, the arrows point to WHERE THE ENERGY IS GOING!

31. Energy Pyramids A different sort of diagram, related to the others
Shows how much energy is passed on to the next level

32. Food Web Drawing Requirements
Must include the sun (NOT AN ORGANISM!)
10 organisms (must be real, and must live in same ecosystems (i.e. no dragons, bigfoot, etc., and no sharks in a desert ecosystem. Questions, ask!)
At least 1 each of the following:
1 producer
1 herbivore
1 carnivore
1 decomposer
Label each organism with its common name, and what type of organism it is (producer, consumer, etc.)
Must be neat and include appropriate colors.