1. Chapter 3 The Biosphere
Pg. 63

2. 3-1 What is Ecology?
Ecology is the study of organisms and their environments. – interactions among organisms and between their environment.
The biosphere is the area on our
planet in which life exists. Combined portions of Earth in which all living things exist.
It includes land, water and air.
It extends 5 miles into the atmosphere
and 7 miles into the ocean.
It is the interactions between organisms, and the environments in which they live, that contribute to our ever changing biosphere.

3. Levels of Organization
To understand relationships in our biosphere we need to organize the living world into manageable pieces.
Organism
Population
Community
Ecosystem

4. Organism
One living thing. (ex. Mountain Lion)

5. Population
A group of organisms that are the same species and live in the same area. (ex. Mountain Lions) –

6. Community
Groups of different populations in the same area. Everything that’s alive! – species grouped in populations make up a communities
simplest grouping of more than one kind of organisms in the biosphere

7. Ecosystem
All of the living organisms in a particular place along with their nonliving, physical environment.

8. Ecological Research
Scientists conduct ecological research using three basic approaches.
Observing – used when entering an area
What species live here? How many individuals are there?
Experimenting
Testing a hypothesis in the field or in a lab imitation.
Modeling
Used to test phenomena that take place over long periods of time
Ex. Climate change
Using math formulas based on data through observation and experiments.

9. 3-2 Energy Flow
The flow of energy in an ecosystem is one of the most important factors that determine the systems capacity to sustain life.

10. Energy Sunlight is the main energy source for life.
Less than 1% of the suns energy is used by living things.
Energy from chemical compounds are the source of energy for some types of organisms.
Examples include mineral water that flows underground or chemicals that boil out of hot springs and undersea vents.

11. Producers
Only plants, some algae and certain bacteria can capture energy from the sun or chemicals and produce food.
Producers, or autotrophs (auto = self troph = feed) use energy from their environment to make living tissue and food (glucose).
Algae at the beginning of the food chain is an example. – Green Plants

12. Photosynthesis
Photosynthesis (photo = light synthesis = put together) is when autotrophs use light energy to convert carbon dioxide, CO2, and water, H2O, into oxygen and sugars (glucose).

13. On land, plants are the main autotrophs.
In water, the main autotrophs are the algae such as cyanobacteria.
It is because of these organisms that our atmosphere has oxygen for us to breathe.

14. Chemosynthesis
Chemosynthesis is when organisms use chemicals to make food (carbohydrates). Does Not require sunlight to live.

15. So, give me some examples of autotrophs?
Sun gazing video

16. Consumers
Organisms that rely on eating other organisms for their food are called consumers, or heterotrophs (hetero = other troph = feeding). They can not make their own food!
Animals, fungi and many bacteria.

17. Heterotrophs There are many different types of heterotrophs.
Herbivores obtain energy by eating plants.
Cows, caterpillars and deer
Carnivores obtain energy by eating other animals.
Snakes, dogs and owls
Omnivores can eat both plants and animals.
Humans, bears and crows
Detritivores feed on plant and animal remains (dead matter) called detritus.
Mites, earthworms and crabs
Decomposers break down organic matter into its basic chemicals.
Bacteria and fungi

18. Feeding Relationships
What happens to the energy in an ecosystem when one organism eats another?
The energy moves along a one-way path.

19. Energy in an Ecosystem
Energy flows through an ecosystem in one direction, from sun (or chemicals) to producers and then to consumers.

20. Food Chains
The energy stored in autotrophs (producers) passes through an ecosystem along a food chain.
A food chain is a series of
steps that shows the energy
transfer between organisms.
(The arrows are not
showing who is eating
whom!)

21. Food Webs
Food chains are a very simple way of showing energy transfer. If we really want to study an ecosystems feeding relationships, we need to look at food webs.
A food web links all of the food chains in an ecosystem together. It shows a network of complex interactions between organisms. – interconnected feeding relationships in an ecosystem.

22. Examples

23. Trophic Levels
Each step in a food web or food chain is called a trophic level.
Producers are the first trophic level.
Consumers are the second, third, etc. levels.

24. Energy Loss and Transfer
Only part of the energy stored in a trophic level is passed to the next level.
Organisms use some of the energy they consume for life processes (10%) such as movement, respiration, etc.
The remaining (90%) energy is lost to the environment as heat.
Only about 10% of the
energy in a trophic level
gets passed on to the next level.
Total amount of living tissue within a given trophic level = biomass pyramid

25. Section 3-3 Cycles of Matter
All organisms need more than energy to survive – carry out the essential life functions!
Water, minerals and other life-sustaining compounds
More than 95% of most bodies are made up of just 4 elements!
Oxygen, carbon, hydrogen and nitrogen.
These elements MUST be in a form that cells can take up!

26. Recycling in the Biosphere
Unlike the one way flow of energy in an ecosystem, matter (elements, chemical compounds, etc.) is recycled within, and between ecosystems.
Energy flows in one direction
Nutrients recycle

27. Biogeochemical Cycles
Biogeochemical cycles connect the biological, geological and chemical aspects of the biosphere.
Matter can cycle through the
biosphere because living
things do not use up the
matter, they transform it!
Matter can be made into
living tissue or passed out
of the body as waste.

28. Imagine
You are a carbon atom in a molecule of carbon dioxide floating in the air of a wetland.
The leaf of a blueberry bush absorbs
you during photosynthesis and
you become part of a sugar molecule
used to make fruit.
The fruit is eaten by a raccoon and
in a few hours you are passed out of
the animals body.
You are then swallowed by a dung
beetle and exhaled back into the air.

29. Simply put…
Biogeochemical cycles pass the same molecules around again and again within the biosphere.
With each breath you take,
you inhale hundreds of thousands
of oxygen atoms that might have
been inhaled by the dinosaurs!

30. The Oxygen Cycle

31. The Water Cycle
All living things require water to survive! Where does all this water come from?
The repeated movement of water between Earth’s surface and the atmosphere

32. Water Cycle Vocabulary
Evaporation: When liquid water turns into a gas.
Example: Puddle disappearing when the sun shines on it.
Transpiration: Evaporation from plant leaves.
Sublimation: When ice evaporates and turns into clouds.
Condensation: Water gas turning back into a liquid.
Example: When your windows fog up.
Infiltration: Water going into the soil.
Example: Watering a plant.
Precipitation: when water falls from the clouds to the ground as rain, sleet, snow, etc.

33. Nutrient Cycles
The food you eat provides energy AND chemicals that keep you alive!
Chemical substances that an organism needs to live are called nutrients.
Every living organism needs nutrients to build body tissue and to carry out essential life functions.
This means that the carbon cycle, nitrogen cycle and phosphorous cycle are very important!

34. The Carbon Cycle Carbon is an essential nutrient.
It’s a key ingredient in living tissue and in skeletons.
Four main processes move carbon through the biosphere.
Biological processes such as photosynthesis, decomposition and respiration
Geochemical processes such as erosion and volcanic activity.
Biogeochemical processes such as the burial and decomposition of organisms.
Human activities such as mining, burning forests and fossil fuels.

35. Carbon Cycle

36. Nitrogen Cycle
All organisms need nitrogen to make amino acids (the building blocks of proteins).
Nitrogen gas (N2) makes up 78% of our atmosphere.
Atmospheric nitrogen can only be used by certain types of bacteria that live in the soil or on legumes (peanuts, soybeans, etc.)
Ammonia (NH3), nitrate (NO3)
and nitrite (NO2) are found
in waste products of living
organisms as well as dead
and decaying matter.

37. Nitrogen Conversion
Nitrogen Fixation: When special bacteria in soil, or on legume plant roots, change atmospheric nitrogen (N2) into ammonia (NH3).
Process by which bacteria convert nitrogen gas in the air into ammonia
Other bacteria then change this ammonia into nitrates and nitrites that producers can use to make protein.
Consumers then eat the producers and reuse the nitrogen to make their own proteins.
Denitrification: changes
nitrates back into nitrogen gas.

38. Nitrogen Cycle

39. Phosphorus Cycle
Phosphorous is important to living things because it forms part of our DNA and RNA.
Unlike carbon, oxygen and nitrogen, phosphorous does NOT enter the atmosphere.
It remains mostly on land inside of rocks, soil and ocean sediments.
Is most likely to be a limiting nutrient in a fresh water pond.

40. Nutrient Limitation
The amount of nutrients in an ecosystem can limit an organisms growth.
Low amount of nutrients = growth limited
Large amount of nutrients = good growth
A limiting nutrient is a substance that is scarce or that cycles very slowly.

41. Problems…
When fertilizers washes off from a farmers field during a rain, it could end up in a river, lake or ocean.
This excess nutrient causes the algae to grow excessively (algal bloom).
More nutrients =
more growth from
producers
This runoff can
completely disrupt an
ecosystem.