1. Interspecific Interactions and the Ecology of Communities Chapter 57

2. Biological Communities
Community
“all the living organisms and the environment they live in”
Communities are characterized by:
Species diversity
“Number of different species present”
Species composition
“Number of individuals in each species”
Primary productivity
“Amount of energy produced”

3. Functional Roles of Living Organisms
Two types:
Autotrophs
Heterotrophs

4. Functional Roles of Living Organisms
Organisms are categorized by what they eat:
Primary consumers
Secondary consumers
Tertiary consumers

5. Roles Outside the Trophic Pyramid
Scavengers
Detritivores
Feed off detritus
There are 2 types of detritivores
Detritus feeders
Decomposers

6. Trophic Level Pyramid

7. Ecological Niche
Niche: “A species’ way of life or functional role in the ecosystem”
There are two types of ‘niches’
Fundamental niche
Realized niche

8. Niches - Competition
Because of competition, realized niches are much smaller than fundamental niches.
2 Types of competition:
Intraspecific competition
Interspecific competition
Exploitative competition

9. Ways to Avoid Competition
Resource partitioning
Morphological
Temporal
Spatial
Morphological
Spatial
Temporal

10. Predator–Prey
Predation and Coevolution

11. Predator–Prey
Morphological and Chemical defenses:

12. Protect themselves both offensively and defensively.
Prey
Protect themselves both offensively and defensively.

13. Mimi c r y
Wasp B a t e s I n
Moth
Honey bee
Flower Fly

14. Mullerian Mimicry

15. Species Interactions
Commensalism: “One species benefits. The other is neither hurt nor helped”
Mutualism: “both species benefit”
Parasitism: “one species benefits at the expense of another”

16. Commensalism
Mutualism
Parasitism

17. Ecological Succession and Disturbance
Primary succession
Secondary succession

18. Mt. St. Helen’s Succession
After eruption 1980
1st plant - Lupines
Today
Shrubs

19. Succession and Disturbance
Animal species in a disturbed community also change over time
As vegetation changes, animal habitat changes
Plants that need animals for pollination or to spread their seed take longer to return.