1. Chapter 18 Table of Contents Section 1 Introduction to Ecology
Section 2 Ecology of Organisms
Section 3 Energy Transfer
Section 4 Ecosystem Recycling

2. Chapter 18 Objectives Identify a key theme in ecology.
Section 1 Introduction to Ecology
Chapter 18
Objectives
Identify a key theme in ecology.
Describe an example showing the effects of interdependence upon organisms in their environment.
Identify the importance of models to ecology.
State the five different levels of organization at which ecology can be studied.

3. Objectives Define: biosphere and ecology
Describe the two environmental conditions that are biological and physical components of an ecosystem
Define: autotroph, producer, heterotroph, consumer
Identify: types of consumers: carnivores, herbivores, scavenger, omnivores, decomposers, detritivores
Apply: a food web to an ecosystem
Explain: what the types of ecological pyramids illustrate and how energy is transferred

4. Ecology
Ecology is the study of the interactions between organisms and the living and nonliving components of their environment.

5. Interdependence: A Key Theme in Ecology
Section 1 Introduction to Ecology
Chapter 18
Interdependence: A Key Theme in Ecology
Organisms and Their Environments
Species interact both with other species, and their nonliving environment.
Interdependence is a theme in ecology—one change can affect all species in an ecosystem.
Wrote about it yesterday, take some examples

6. Chapter 18 Ecological Models
Section 1 Introduction to Ecology
Chapter 18
Ecological Models
Ecological models help to explain the environment.

7. Making an Ecosystem Model
Section 1 Introduction to Ecology
Chapter 18
Making an Ecosystem Model
Ecological models help to explain the environment.
Because ecology is so complex, and difficult to study, ecologists use ecological models to represent components of an ecological system. They can be used to understand interactions, and to make predictions about changes
Some models are physical, conceptual, or mathematical

8. Levels of Organization
Section 1 Introduction to Ecology
Chapter 18
Levels of Organization
Ecologists recognize a hierarchy of organization in the environment: biosphere, ecosystem, community, population, and organism.

9. Levels of Organization
Section 1 Introduction to Ecology
Chapter 18
Levels of Organization

10. Levels of Organization, continued
Section 1 Introduction to Ecology
Chapter 18
Levels of Organization, continued
The Biosphere
The broadest, most inclusive level of organization is the biosphere, the volume of Earth and its atmosphere that supports life.
Only the part of Earth that supports life
If earth were the size of an apple, the biosphere would be just the size of the peel

11. Levels of Organization, continued
Section 1 Introduction to Ecology
Chapter 18
Levels of Organization, continued
Ecosystems
The biosphere is composed of smaller units called ecosystems.
An ecosystem includes all of the organisms and the nonliving environment found in a particular place.
Pond ecosystem: fish, turtles, plants, algae, insects, bacteria
Also pH, levels of o2 and co2, amt of sunlight,

12. Levels of Organization, continued
Section 1 Introduction to Ecology
Chapter 18
Levels of Organization, continued
Communities, Populations, and Organisms
A community is all the interacting organisms living in an area.
Below the community level of organization is the population level, where the focus is on the individual organisms of a single species.
Community= may still include thousands of species
Mainly the interactions are studied
Population = members of the same species that live in one place at one time
In a community: wolves, deer, and mice live around a field. Wolves eat deer. Are mice impacted if a disease kills a large portion of the wolf population? (more competition between mice and deer for food– possibly fewer mice)

13. Niche
The specific role, or way of life, of a species within its environment is its niche.
A niche can be broad (species tolerates a variety of conditions, and uses a variety of resources)
A niche can be specialized (species only lives in a certain place and eats specific things)
Examples?
Barnacle example

14. Section 2 Ecology of Organisms
Chapter 18
Objectives
Compare abiotic factors with biotic factors, and list two examples of each.
Describe two mechanisms that allow organisms to survive in a changing environment.
Explain the concept of the niche.

15. Chapter 18 Ecosystem Components Biotic and Abiotic Factors
Section 2 Ecology of Organisms
Chapter 18
Ecosystem Components
Biotic and Abiotic Factors
Both biotic, or living, factors and abiotic, or nonliving, factors influence organisms. Examples of abiotic factors are climate, sunlight, and pH.
All components of an ecosystem are either biotic or abiotic

16. Comparing Biotic and Abiotic Factors
Section 2 Ecology of Organisms
Chapter 18
Comparing Biotic and Abiotic Factors
Click below to watch the Visual Concept.
Visual Concept
End here.

17. Organisms in a Changing Environment
Section 2 Ecology of Organisms
Chapter 18
Organisms in a Changing Environment
Acclimation
Some organisms can adjust their tolerance to abiotic factors through the process of acclimation.

18. Organisms in a Changing Environment, continued
Section 2 Ecology of Organisms
Chapter 18
Organisms in a Changing Environment, continued
Control of Internal Conditions
Conformers are organisms that do not regulate their internal conditions; they change as their external environment changes.
Regulators use energy to control some of their internal conditions.

19. Organisms in a Changing Environment, continued
Section 2 Ecology of Organisms
Chapter 18
Organisms in a Changing Environment, continued
Escape from Unsuitable Conditions
Some species survive unfavorable environmental conditions by becoming dormant or by migrating.

20. Section 2 Ecology of Organisms
Chapter 18
The Niche
A niche is a way of life, or a role in an ecosystem.

21. Chapter 18 Niche Section 2 Ecology of Organisms
Click below to watch the Visual Concept.
Visual Concept

22. Chapter 18 Objectives Section 3 Energy Transfer
Summarize the role of producers in an ecosystem.
Identify several kinds of consumers in an ecosystem.
Explain the important role of decomposers in an ecosystem.
Compare the concept of a food chain with that of a food web.
Explain why ecosystems usually contain only a few trophic levels.

23. Section 3 Energy Transfer
Chapter 18
Producers
Most producers are photosynthetic and make carbohydrates by using energy from the sun.
Using what process?

24. Section 3 Energy Transfer
Chapter 18
Consumers
Consumers obtain energy by eating other organisms and include herbivores, omnivores, carnivores, detritivores, and decomposers.
Difference between detritivores and decomposers (detritivores consume decaying organisms, decomposers break down dead organisms through decomposition)

25. Consumers can be primary, secondary, or tertiary

26. Chapter 18 Energy Flow Food Chains and Food Webs
Section 3 Energy Transfer
Chapter 18
Energy Flow
Food Chains and Food Webs
A single pathway of energy transfer is a food chain.
A network showing all paths of energy transfer is a food web.

27. Food Chain in an Antarctic Ecosystem
Section 3 Energy Transfer
Chapter 18
Food Chain in an Antarctic Ecosystem
Do you think leopard seal is the only thing a killer whale eats?
Do you think cod is the only thing a leopard seal eats?

28. Food Web in an Antarctic Ecosystem
Section 3 Energy Transfer
Chapter 18
Food Web in an Antarctic Ecosystem
Producers, consumers,

30. Chapter 18 Energy Flow, continued Energy Transfer
Section 3 Energy Transfer
Chapter 18
Energy Flow, continued
Energy Transfer
Ecosystems contain only a few trophic levels because there is a low rate of energy transfer between each level.
A trophic level is an organism’s position in a food chain or energy pyramid.
When an organism eats another, molecules are metabolized, and energy is transferred.

31. Energy Transfer Through Trophic Levels
Section 3 Energy Transfer
Chapter 18
Energy Transfer Through Trophic Levels
Energy pyramid. Represents the amount of energy stored as organic material at each level.
About 10% of energy is transferred to the next trophic level. (some organisms escape being eaten, not everything can be eaten, some energy is lost as heat)
Organisms are grouped based on how they obtain energy
Herbivores = primary consumers, etc.

32. Food Web in an Antarctic Ecosystem
Section 3 Energy Transfer
Chapter 18
Food Web in an Antarctic Ecosystem
If these organisms were to be arranged in a food pyramid, which would have the least amount of total energy available?
Which organism(s) would decrease if the cod was eliminated? What else might happen?

33. Chapter 18 Objectives Section 4 Ecosystem Recycling
Define: biogeochemical cycles, nutrients
Analyze: the water cycle, carbon cycle
Describe: the phosphorous cycle, nitrogen cycle

34. Ecosystem recycling
Biogeochemical cycles are the circulation of substances through living organisms from or to the environment.
As energy and matter flow through an ecosystem, matter must be recycled and reused.
Nutrients such as water, carbon, nitrogen, calcium, and phosphorus pass between the living and nonliving worlds.
Why do we say that nutrients cycle, but energy flows?
Nutrients = used over and over by organisms, energy flows in one direction and is used up and lost
Bio = life; geo = earth; chemical

35. The Water Cycle (hydrologic cycle)
Section 4 Ecosystem Recycling
Chapter 18
The Water Cycle (hydrologic cycle)
Key processes in the water cycle are evaporation, transpiration, and precipitation.
Through evaporation and transpiration, water vapor is added to the atmosphere
Precipitation can fall in the form of rain, snow, hail, or fog.
Transpiration?
Why do we need water? Bodies % water, needed for solubility, chemical processes, liquid matrix of cells, blood pressure, oxygen and hydrogen

36. Chapter 18 Water Cycle Section 4 Ecosystem Recycling
Where do you think your drinking water comes from?
Do you think most water vapor comes from evaporation or transpiration?
Aquifer = vast underground systems of porous rock that holds water

37. Chapter 18 Water Cycle Section 4 Ecosystem Recycling
Click below to watch the Visual Concept.
Visual Concept

38. Chapter 18 The Carbon Cycle
Section 4 Ecosystem Recycling
Chapter 18
The Carbon Cycle
Photosynthesis and cellular respiration are the two main steps in the carbon cycle.
Carbon dioxide is used by plants to make carbohydrates in photosynthesis.
Carbohydrates are broken down during cellular respiration, releasing carbon dioxide as a byproduct.
Why do we need carbon? many molecules in your body are carbon based (proteins, carbohydrates, lipids, nucleic acids)

39. Chapter 18 Carbon Cycle Section 4 Ecosystem Recycling
Fossil fuels are hydrocarbons, that come from decomposition of old life forms. By combusting fossil fuels, humans are releasing additional carbon dioxide into the atmosphere.

40. Chapter 18 Carbon Cycle Section 4 Ecosystem Recycling
Click below to watch the Visual Concept.
Visual Concept

41. Chapter 18 Nitrogen Cycle
Section 4 Ecosystem Recycling
Chapter 18
Nitrogen Cycle
In the nitrogen cycle, nitrogen circulates among the air, soil, water, plants, and animals in the ecosystem.
Nitrogen-fixing bacteria are important in the nitrogen cycle because they change nitrogen gas into a usable form of nitrogen for plants.
Why do we need nitrogen? Important part of amino acids  proteins

42. Chapter 18 Nitrogen Cycle Section 4 Ecosystem Recycling
Not usually in a form that is biologically useful (triple bonded). Bacteria take nitrogen from soil and fix it into a form that plants can take in (ammonia), then nitrogen is passed through the food web by eating plants. Nitrogen goes back into soil from waste (fertilizer) and death (decomposers break down materials)
Denitrifying bacteria = back into nitrogen gas

43. Chapter 18 Nitrogen Cycle Section 4 Ecosystem Recycling
Click below to watch the Visual Concept.
Visual Concept

44. Chapter 18 Phosphorus Cycle
Section 4 Ecosystem Recycling
Chapter 18
Phosphorus Cycle
In the phosphorus cycle, phosphorus moves from phosphate deposited in rock, to the soil, to living organisms, and finally to the ocean.
Important part of lipid bi-layer, DNA backbone, important in ATP

45. Phosphorous in rocks/ earths crust
Phosphorous in rocks/ earths crust. Through erosion and weathering, phosphorous runs off into water and dissolved. Dissolved phosphorous assimilated by plants, decomposers (death/waste), soil