1. Community Interactions

2. Community Interactions
Powerfully affect an ecosystem
Include:
Competition
Predation
Symbiosis

4. Competition
When organisms of the same or different species attempt to use an ecological resource at the same place and the same time
Resource any necessity to life
Plants and animals compete
Winner and losers

5. Rules, rules, rules Fundamental rule in ecology
Competitive Exclusion Principle
No two species can occupy the same niche in the same habitat and the same time
Prevents competition

11. Predation
Interaction where an organism captures and feeds on another organism
Predator
Organism that does the killing and eating
Prey
Organism that is being killed and eaten (victim)

17. Symbiosis Any relationship where two species live closely together
Symbiosis literally means “living together”
3 main types
Parasitism
Mutualism
commensalism

18. What type of relationship is this?
Who is helping who?

19. Mutualism Both species benefit from the relationship A Happy couple
Flowers and bees
Flowers need bees for pollination, bees need flowers nectar

22. What type of relation ship is going on here?
Who is helping who?

23. Commensalism
One member of the relationship benefits while the other is neither harmed nor helped
One-sided
Food or shelter
Barnacles on whale

24. Ants and aphids

26. What type of interaction is going on here?

27. Parasitism
One organism lives on or inside another organism and harms it
Parasite obtains all or part of its nutrients from the other organism
Host
Organism that is harmed in relation ship; the one that provides the nutrients to the parasite
Parasite
Organism that gets its nutrients from the host
Do they want to kill their host?
No, because they need them…they will weaken or hurt the host in some way

32. Recap What are the three types of interactions in a community?
Competition
Predation
Symbiosis
What types do we have?
Mutualism
Commensalism
Parasitism

33. Ecological Succession
Do all ecosystems stay the same all the time?
What are some things that cause changes to ecosystems?
Natural and unnatural
Quickly and slowly

34. Ecosystems are constantly changing in response to human and natural disturbances.
As an ecosystem changes, older habitants die out and new organisms move in, causing more change

35. Ecological Succession
Series of predictable changes that occur in a community over time
Physical environment
Natural disturbance
Human disturbance

36. Primary Succession
Succession on land that occurs on surfaces where no soil exists
Volcanic eruptions
Glaciers melting

39. Stages of Primary Succession
Start with no soil, just ash and rock
First species to populate this area
“pioneer species”
For example, pioneer species on volcanic rock are lichens (LY-kunz)
Lichens made up of fungus and algae that can grow on bare rock
When lichens die, they for organic material that becomes soil…now plants can grow

40. Secondary Succession
Succession following a disturbance that destroys a community without destroying the soil
Natural
hurricane
fires
Human disturbances
Farming
Forest clearing

46. Succession in Marine Ecosystems
Deep and dark
Can succession happen?
1987 dead whale off of California
Unique community of organisms living in remains
Represents stage in succession in an otherwise stable, deep-sea ecosystem
Whale-fall community

48. Whale-Fall Succession
Begins when large whale dies
Sinks to barren ocean floor
Scavengers and decomposers flock to carcass , our first community
Amphipods
Hagfish
sharks
After a year, most tissues have been eaten
Now, second small community of organisms live here
Body is decomposing, releasing nutrients into the water
Small fishes
Crabs
Snails
worms
Only skeleton remains…
Third community moves in
Heterotrophic bacteria
Decompose oil in bones release of chemical compounds
Who uses these chemical compounds?
Chemoosynthetic autotrophs
In come the crabs, clams, and worms that feed on this bacteria

49. Study Chemical reactions, enzymes, and Chapters 3 and 4
Teacher,