1. Chapter 3: The Biosphere

2. Objectives Identify the levels of organization
Describe the methods used to study ecology
Identify the source of energy for life processes
Trace the flow of energy through living systems
Describe how matter cycles among the living and nonliving parts of an ecosystem.
Explain why nutrients are important in living systems.

3. What is Ecology?
Ecology is the scientific study of interactions among organisms and between organisms and their environment.
What does this mean?
How do we study these interactions?

4. We have to ask questions about events and organisms that range in complexity from a single individual to the entire biosphere.

5. Levels of Organization

7. Organism
An individual living thing

9. Population
Members of one species that interbreed and live in the same place at the same time.

10. Population
Compete for:
Food
Water
Shelter
Mates

11. Community Different populations that live together in a defined area.
Several populations interacting together.

12. Ecosystem
A collection of all of the organisms that live in a particular place, together with their nonliving, or physical environment.

13. Ecosystem Biotic Factors: living organisms within an ecosystem
Abiotic Factors: nonliving factors that help shape an ecosystem

14. Biomes
A group of ecosystems that have the same climate and similar dominant communities.

15. Biosphere
The highest level of organization that ecologists study is the entire biosphere itself.
The portion of
the Earth that
supports life.

16. BIOSPHERE
BIOME
ECOSYSTEM
COMMUNITY
POPULATION
ORGANISM

17. Ecological Methods
Ecologists use a wide range of tools and techniques to study the living world.
Apply the scientific method to do ecological research:
Observing
Experimenting
Modeling

18. Interactions Between Organisms
All organisms depend upon other living things and nonliving things to meet their needs, such as:
Food
Shelter
Reproduction
Protection
Thus, an interdependence exists among organisms and the environment 18

19. Energy Flow All living things need ENERGY to survive.
Where does this energy ultimately come from?

20. Autotrophs
Organisms that capture energy from sunlight or chemicals and use that energy to produce food.
Ex. Bacteria,
plants, and algae
Also called producers

21. Heterotrophs Rely on other organisms for their energy and food supply
Also called consumers

22. Types of Consumers Herbivores Carnivores Omnivores Detritivores
Decomposers

23. Herbivores
Heterotrophs that eat plants (1st order consumers) 23

24. Carnivores
Heterotrophs that eat animals
They come in many sizes! 24

25. Omnivores
Eat both plants and animals
Ex: humans, raccoons, bears 25

26. Detritivores
Animals that feed on animal remains and dead matter (collectively called detritus)
EX: mites, earthworms, snails, crabs 26

27. Decomposers
Break down decaying matter
Ex: bacteria and fungi 27

28. Feeding Relationships
What happens to the energy in an ecosystem when one organism eats another?
The energy moves along a one-way path.
Energy flows through an ecosystem in one direction, from the sun to autotrophs and then to various heterotrophs

29. Food Chains
The energy stored by producers can be passed through an ecosystem along a food chain, a series of steps in which organisms transfer energy by eating and being eaten.

30. A food chain shows how matter and energy cycle through an ecosystem
Each organism represents a trophic level, a step in the food chain.
Natural Food Chain
Sun Grass Rabbit Snake Hawk
The arrows show the direction that energy is transferred 30

31. Food Web
Shows all of the possible feeding relationships at each trophic level in the community.

33. Tertiary consumers Secondary consumers Primary Consumers- herbivores
Producers 33

34. Ecological Pyramids
A diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web.
3 types
Energy pyramids
Biomass pyramids
Pyramids of numbers

35. Energy Pyramid
Only part of the energy that is stored in one trophic level is passed n to the next level…. why?
Organisms use much of the energy that they consume for life processes (reproduction, respiration, and movement).
Only 10% of the energy available within one trophic level is transferred to organisms at the next trophic level.

36. Biomass Pyramid
The total amount of living tissue within a given trophic level is called biomass.
A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem.

37. Pyramid of Numbers
Pyramid based on the numbers of individual organisms at each trophic level.

38. Matter also is cycled throughout an ecosystem...
Water
Carbon
Nitrogen

39. Water
The water cycle is the continuous movement of water between Earth and its atmosphere.

41. Carbon Cycle
Carbon is an essential component of proteins, fats, and carbohydrates
The carbon cycle is a process by which carbon is cycled between the atmosphere, land, water, and organisms.

42. Carbon Cycle Four processes Respiration (adds) Combustion (adds)
Decomposition (adds)
Photosynthesis (removes)

43. Carbon Cycle
The carbon cycle has been operating to keep the amount of carbon dioxide in balance between the atmosphere and Earth.
HOWEVER, the burning of fossil fuels has added more carbon dioxide than can be removed by plants during photosynthesis.

44. Carbon Cycle
Carbon dioxide is considered a greenhouse gas …it traps heat on Earth.
This contributes to global warming, which has led to an overall increase in the Earth’s average temperature.

46. Nitrogen Cycle *78% of the atmosphere is composed of nitrogen
*Living things cannot use nitrogen in the atmospheric form
*Lightening and some bacteria convert nitrogen to usable forms, then producers use them to make proteins. Consumers then eat the producers and reuse the nitrogen to make their own proteins!
*When organisms die, decomposers return nitrogen to the soil and it is either reused or converted into nitrogen gas and returned to the atmosphere.

47. Nutrient Limitation
Primary Productivity—rate at which an organic matter is created by producers
Process can be limited by a lack of nutrients
How can people help avoid a shortage of nutrients?

48. A polar bear, its fur stained with algae, stands in its cage at Higashiyama Zoo in Nagoya, central Japan, Saturday, Sept. 6, Three polar bears at the zoo changed their colors in July after swimming in a pond with an overgrowth of algae, prompting many questions from visitors concerned about whether the animals are sick or carrying mold, a zoo official said. Credit: AP Photo/Kyodo News, Shuzo Shikano