1. Biological Communities
Chapter 18

2. How Organisms Interact in Communities
Section 18-1

3. Interactions Among Species
Species interactions have resulted from many years of evolution
Ex: flowers and pollinators
Coevolution = back-and-forth evolutionary adjustments between interacting members of an ecosystem

4. Predators and prey coevolve
Predation = the act of one organism feeding on another
Lions eating zebras, snakes eating mice
Parasitism = one organism feeds on and usually lives on or in another organism
do not typically kill host b/c need for food and to pass on offspring
Fleas, ticks, lice, mosquitoes, hookworms

5. Hookworm, flea, tick, head lice

6. Plant defenses against herbivores
Thorns
Spines
Prickles
Chemical compounds
Secondary compounds = defensive chemicals in plants
Mustard plant family produces mustard oils (mustard, cabbage, radish, horseradish)

7. Data Lab P. 383 Complete Data Lab Questions #1-4
Write questions and answers!

8. Symbiotic Species Are Shaped by Long-Term Relationships
Symbiosis = 2+ species live together in a close, long-term association
Parasitism
Predator-prey
Mutualism
Flowers and pollinators
Commensalism
Clown fish and sea anemones

9. Comparing Symbiosis Interaction Effect on Organism A
Effect on Organism B
Competition
Predator-prey
Parasitism
Commensalism
Mutualism

10. Symbiotic Relationships

11. Which is Which? Commensalism, Parasitism, or Mutualism
Lichens on a tree = mutualism

12. Clown fish in a sea anemone = commensalism

13. Bee pollinating flower = mutualism

14. Parasitic isopod on fish = parasitism

15. Bellringer
Read p. 386 – 387.
Describe a Cape May warbler’s fundamental niche.
Describe its realized niche.

16. How Competition Shapes Communities
Section 18-2

17. Competition Competition – when 2 species use the same resource
Resource must be in short supply and organisms are not always aware competition is taking place
Food, nesting sites, living space, light, mineral nutrients, water
Niche = how an organism lives; its “job” within the ecosystem

18. A Jaguar’s Niche Diet: mammals, fish, turtles
Reproduction: from June to August during the rainy season
Time of activity: hunt by day and by night

19. Niche Components
Humans Homo sapiens sapiens
Bacteria Escherichia coli
Green Tree Python Morelia viridis
Food/Diet
Reproduction
Time of Activity
Habitat
Organisms Interacted With

20. A species’ niche can vary in size
Fundamental niche = the entire range of conditions an organism is potentially able to occupy within an ecosystem
Several variables affect this

21. Dividing resources among species
Realized niche = the part of its fundamental niche that a species occupies
Reduces competition

22. Data Lab
P. 387 #1-6
Write questions and answers!

23. Competition’s Effect
Competition without division of resources (like the 5 species of warblers) leads to extinction
Predation can lessen competition and promote biodiversity = the variety of living organisms present in a community

24. Major Biological Communities
Section 18-3

25. Temperature and moisture
Climate = the prevailing weather conditions in any given area over a long period of time
Not same as temperature
Temperature & moisture help determine biological communities
Biome = a major biological community that occurs over a large area of land

26. 7 major biomes

27. Biomes Map Activity Color map using p. 392. Be sure to include a key.
Picture Notes for each biome. You will work with your teams to present the following about your biome:
Climate (rainfall & temperature)
Key characteristics/soil characteristics
2 examples of plants & 2 examples of animals
Typical geographic location

28. Which biome do you live in?
List the name and characteristics of your biome.

29. Aquatic Communities - Freshwater
Lakes, ponds, rivers, streams, some marshes and wetlands (2.1% of Earth’s surface)
All strongly connected to terrestrial habitats
3 zones of ponds & lakes:
Littoral zone
Limnetic zone
Profundal zone (not in all)

30. Aquatic Communities - Marine
Nearly ¾ of Earth’s surface
3 major kinds of habitats:
Shallow ocean waters
Large # species, lots nutrients & sunlight
Surface of the open sea
Plankton & photosynthetic organisms & commercial fish
Depths of the open ocean
Little to no sunlight, oxygen made by bacteria that use hydrogen sulfide gas from ocean vents

31. Estuaries Transition zones btw marine and freshwater environments
Lots of plants & algae b/c nutrients wash off land
Wildlife habitats
Filter sediments & nutrients & purify water draining off land
Protect coastal communities from erosion

32. Chesapeake Bay Largest estuary near us
Rivers and creeks from 6 states flow into it
Over-fishing and urban & agricultural pollution are destroying it