1. What Shapes an Ecosystem?

2. Biotic vs. Abiotic Biotic Factors: biological influences on organisms
Abiotic Factors: physical or nonliving
climate
Determines
an organism’s survival & growth
productivity of the ecosystem

3. Habitat vs. Niche Habitat: area in which the organism lives
biotic & abiotic factors
house
Niche: the way an organism
uses abiotic and biotic factors
how it gets food & what it eats
predators
job

4. Community Interactions
Competition: organisms try to use the same resource (necessity of life)
Predation: one organism catches & eats another

5. Community Interactions
Symbiosis - two species live closely together
Mutualims - both benefit; lichen, flower/bees
Commensalism - one benefits and one is not helped nor harmed; barnacles on a whale
Parasitism - one organism live on or inside another and harms it; parasite/host; tapeworms, fleas, ticks, lice

6. Ecological Succession
Ecosystems constantly change in response to natural and human disturbances
older inhabitants gradually die out
new organisms move in
further change
Ecological Succession – a series of predictable changes that occur in a community over time
slow change in the physical environment
sudden natural disturbance; clearing forest

7. Primary Succession Occurs on land where no soil exists
islands formed from volcanic eruptions
bare rocks exposed from glaciers melting
pioneer species:1st to populate the area
Lichen: add organic
matter to soil when
they die

8. Secondary Succession
Changes to existing community without removing the soil
cleared and plowed land for farming
wildfires burn woodlands

9. Climax Community
mature, stable community that doesn’t undergo further succession
old-growth forest in Pacific Northwest and Louisiana, and Arkansas