1. Science Behind Environmental Science
Chapter 2
Science Behind Environmental Science

2. Today:
I’m going to start off with a brief discussion of the water cycle and biotic vs. abiotic factors.
Then, we will go to the lab to start the terraria.

3. Natural Cycles Living organisms mostly composed of
carbon, hydrogen, nitrogen, and oxygen

4. Natural Cycles These elements used over and over again
Carbon atom found in sugar molecule of plant
Sugar consumed by an animal
Atom becomes part of animal muscle
When animal dies, it enters decomposers
Eventually, atom taken up by a plant again

5. Water One of most important resources
environmental effects and benefits
maintains more even temperature in environment
erosion
dilutes and flushes away contaminants

6. Water Biological effects and benefits required nutrient
controls temperature of organisms
solvent for nutrients
cools surface of skin and leaves
provides protection for some species

7. Water Cycle Water moves from What drives the water cycle?
ocean to atmosphere
to land in form of rain and snow
to rivers and stream
back to ocean
What drives the water cycle?
solar energy and gravity

8. Water Cycle Water enters atmosphere
evaporation from oceans
transpiration
controlled evaporation from pores in plant leaves
sweating
breathing
Moisture from these sources forms clouds

9. Water Cycle Moisture collects in atmosphere to form clouds
Clouds release stored water
rain and snow
Gravity draws water to Earth’s surface
Gravity draws water back to ocean

10. Conservation of Matter
Matter can be changed
from one form to another
Cannot be created or destroyed
by ordinary physical or chemical processes

11. Conservation of Matter
In nature
Organisms use food supply
Little waste generated
Natural processes can recycle this waste

12. Conservation of Matter
Human population generates waste that
is not easily disposed of
may persist in nature indefinitely
may be harmful or toxic

13. Ecosystems Organisms and surrounding environment Abiotic Biotic
all the biotic and abiotic components
Abiotic
nonliving components of ecosystem
Biotic
living components of ecosystem

14. Biotic versus Abiotic Biotic Abiotic trees decaying logs deer wolves
squirrels
worms in soil
bacteria in soil
Abiotic
water
oxygen gas
atmosphere
amount of sunlight
acidity of water
type of soil
acidity of soil

15. Next:
Make a list of at least 5 biotic and 5 abiotic factors that might effect your terrarium.
You will want to talk about these in your lab report when we are done with this lab so think of some good ones!
You will then look for any changes in these when you make your observations each day.
You will write another lab report when this is over, but it will be 1 per group.

16. Terrarium:
The whole point of this project is to observe the water cycle in action and create your own little artificial ecosystem.
You will be placing rocks, dirt, seeds, and water into bottle or jar and covering it with plastic.
We will then let them sit for a few days and you guys will need to come down during recess each day to make your observations.
I will be in the lab during that time so it will be unlocked.

17. Energy Laws First Law of Energy Energy cannot be created or destroyed
Can be converted
radiant to chemical energy
chemical energy to heat or kinetic energy
chemical energy to thermal energy
thermal energy to electrical energy

18. Energy Laws Second Law of Energy Every time energy is converted . . .
some energy is lost as heat

19. Flow of Energy An ecosystem is an energy system
All processes depend on energy
Nothing happens without flow of energy
Energy = ability to do work
moves from concentrated areas to become dispersed and unorganized

20. Flow of Energy
Energy source in most ecosystems = sun

21. Energy Flow Complete ecosystem has three types of organisms Producers
Transformers
Decomposers

22. Energy Flow Producers Transformers Decomposers
produce new food from photosynthesis
usually green plants
Transformers
change food into more complex organic molecules
Decomposers
break down organic materials for reuse

23. Energy Flow Four fundamental biotic processes synthesis photosynthesis
respiration
decomposition

24. Synthesis Change in composition, size, shape, structure
Organisms use nutrients, minerals, water
to produce growth and reproduction
Synthesis means “to make or form”

25. Photosynthesis Converts water and carbon dioxide into sugar
requires a catalyst
chlorophyll
green pigment
requires energy
from sun

26. Photosynthesis Photosynthesis original source of most food
also produces oxygen

27. Respiration Breaks down food to release energy
converts sugar into
water, carbon dioxide, and energy
Both plants and animals undergo respiration

28. Decomposition A special type of cellular respiration
Organic matter broken down to smaller organic compounds
Recycles chemicals in bodies of organisms
Follow-up Questions:
Oxygen is converted to what molecule during cellular respiration? Glucose is converted to what molecule during cellular respiration? What waste product is given off during decomposition?

29. Ultimate Concept John Muir Everything on Earth part of an ecosystem
“When we try to pick out anything by itself, we find it hitched to everything else in the universe.”
Everything on Earth part of an ecosystem
Everything is connected
Doing something to one part affects some or all parts of system