1. Chapters 3-6: Ecology

2. Ecology
study of interactions that take place between organisms and their environment

3. Biosphere Part of the Earth that holds all living things
Air, land, and sea
Living things affected by nonliving and living things

4. Abiotic factors
Nonliving parts of an environment
Temperature, moisture, light, soil…etc
Biotic factors
All living organisms that inhabit an environment
Plants, other animals
Depend on others directly or indirectly
Food, shelter, reproduction, protection

5. Levels of Organization
Organisms make up  population
Group of organisms of the same species
Interbreed and live in the same area
Can compete for food, water, mates

6. # of populations make up  community
Made up of interacting populations
Change in a population can affect entire community

7. Populations + abiotic factors make up  ecosystem
Terrestrial (land): forests, meadows
Aquatic (water): oceans, lakes, ponds, rivers

8. Habitat: place where an organism lives
Can change or disappear because of natural and human causes
Niche: all the ways and adaptations a species uses in its environment
How it meets its needs for food, shelter, survival, reproduction
Biotic + abiotic parts of the environment

9. Predation consumers Eat plants and animals
Eat prey (animals that predators eat)
Fight for survival

10. Symbiosis
Relationship where there is a close and permanent association between different organisms
Means “living together”
3 kinds

11. Mutualism
Both species benefit (+,+)

12. Commensalism
one benefits and the other does not benefit or is harmed (+,o)

13. Parasitism
one benefits and the other is harmed (+,-)

14. How Organisms Get Energy
Sun is the ultimate form of energy and source for energy
Producers: autotrophs
Uses light to make own food (photosynthesis) and energy
Ex: grass, trees, green algae

15. Consumers Heterotrophs Eat other organisms to get energy
CANNOT make its own food

16. Herbivores
Only eat plants

17. Carnivores
Only eat animals

18. Omnivores
Eat both plants and animals

19. Scavengers
Eat on dead organisms

20. Decomposers
break down and release nutrients from dead organisms

21. Flow of Matter and Energy
You consume matter when you eat food
Carbon, nitrogen, other elements
Energy flows through levels of the entire ecosystem
Only some energy is transferred from 1 energy level to the next

22. Food Chains show how matter and energy move through an ecosystem
Nutrients and energy move from autotrophs to heterotrophs and then decomposers
Ex: grass  rabbit  wolf
Arrows indicate the direction energy is transferred from one organism to the next

23. Ecological Pyramid shows how energy flows through an ecosystem
Energy that is transferred from one trophic level to the next is only 10%

24. Trophic Level A feeding step in passing of energy and materials
Heterotroph
Heterotroph
Herbivore
Autotroph

25. Food Webs
all the possible relationships at each trophic level of a community

26. Chapter 3-6 Review #1:
Which of the following types of heterotrophs eat other animals?
a. omnivores & carnivores c. carnivores only
b. herbivores & omnivores d. carnivores & herbivores
2. Which of the following types of heterotrophs would bacteria and fungi be classified as?
a. detritivores b. herbivores c. carnivores d. decomposers
3. What is the one-way flow of energy in an ecosystem called?
a. food chain b. energy pyramid c. food web d. biomass pyramid
4. What is each step in a food chain or food web called?

27. Limiting Factors
Affect an organism’s ability to survive in its environment
Ex: water, food, predators, temperature
Density-dependent: disease, competition, parasites, food
Depend on the density of a population
Density-independent: affects all populations regardless of their density
Temperature, storms, floods, drought, and habitat disruption

28. Succession
Natural changes and species replacement that takes place in communities in an ecosystem
Occurs in stages
Primary succession
Colonizing bare land where there are no organisms
Pioneer species: 1st species in an area

29. Climax Community
Stable, mature community that has little or no changes in species

30. Secondary Succession
Changes that occur when existing community is disrupted by natural disasters or human actions

31. Biomes
Large group of ecosystems that share the same type of climax community
Terrestrial or aquatic
Aquatic: marine, estuaries, freshwater, swamps
Terrestrial: tundra, taiga, desert, grassland, rain forest, temperate forest

32. Population Growth Organisms can grow exponentially
Exponential growth: as a population gets larger, it also grows faster
J-shaped curve (diagram):

33. Growth will be limited at some point by limiting factors
Food availability, disease (ex: AIDS, influenza, TB, Dutch Elm disease, Pfiesteria), predators, lack of space
Results in an S-shaped curve
Diagram:
Carrying capacity: the number of organisms of a species that an environment can hold

34. Define these terms:
Birth rate
Death rate
Emigration
Immigration
Zero population growth

35. Biological Diversity
Biodiversity: the variety of species in a specific area
Loss of biodiversity is increasing
Extinction: disappearance of a species when the last organism dies
Ex:
Endangered species: # of species become low that can lead to extinction
Threatened species: population likely to become endangered

36. Cycles in Nature
Matter is constantly being recycled

37. Water Cycle
Water evaporates from lakes and oceans to become water vapor in the air
Water vapor in the air condenses to form clouds
More water condensation leads to precipitation, falling as rain, ice, or snow back to the ground
Cycle repeats constantly

39. Problems with the cycle:

40. Carbon Cycle Starts with autotrophs
Makes carbon molecules from CO2 during photosynthesis
Heterotrophs feed on autotrophs, getting those carbon molecules
Release CO2 back into the atmosphere

42. Problems with Cycle Global Warming: Greenhouse effect
Gases that lead to global warming

43. Nitrogen Cycle
Lightning and some bacteria convert nitrogen in the air into a usable form
Plants use nitrogen to make proteins
Herbivores eat plants
Convert nitrogen-containing plant proteins into animal proteins
Humans eat plants
Convert animal proteins to human proteins
Excess nitrogen in animals released in urine
Returned to water or soil
Nitrogen molecules return to the soil when animals die
Re-used by plants
Bacteria put nitrogen back into the air

45. Phosphorous Cycle
All organisms need phosphorus for growth and development
Plants get phosphorus from the soil
Animals get phosphorus by eating plants
Decompose when they die, returning phosphorus to the soil

47. Problems:
Eutrophication

48. Impact of Human Activities on the Environment
Population growth
Pollution
Global warming
Burning fossil fuels
Habitat destruction
Introducing nonnative species

49. Chapter 3-6 Review #2:
A lone elephant joining another herd of elephants is an example of
a. emigration c. immigration
b. parasitism d. exponential growth
2. What term is used to describe a species whose population is rapidly shrinking and might disappear completely?
a. endangered c. extinct
b. threatened d. invasive