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Write your own FRQ for something we have learned in ecology. Then switch with a partner to have them answer the question.

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Presentation on theme: "Write your own FRQ for something we have learned in ecology. Then switch with a partner to have them answer the question."— Presentation transcript:

1 Write your own FRQ for something we have learned in ecology. Then switch with a partner to have them answer the question.

2 1,000 III II I 100 10 1 10050 0 Percentage of maximum life span Number of survivors (log scale) Ideal Survivorship Curves

3 Population Growth Models

4 Population Reproductive Strategies r-selected (opportunistic) Short maturation & lifespan Many (small) offspring; usually 1 (early) reproduction; No parental care High death rate K-selected (equilibrial) Long maturation & lifespan Few (large) offspring; usually several (late) reproductions Extensive parental care Low death rate

5 Ecological Niches An organism’s niche is the specific role it plays in its environment…its job! All of its uses of biotic and abiotic resources in its environment Ex: oak tree in a deciduous forest  Provides oxygen to plants, animals  Provides a home for squirrels  Provides a nesting ground for blue jays  Removes water from the soil

6 The Niche Ecological niche is the total of an organism’s use of biotic and abiotic resources in its environment Ex: Barnacle species on the coast of Scotland Compare and contrast fundamental and realized niches?

7 Competition Between Organisms Of Different Species Can Be Direct Or Indirect Interference − Directly fighting over resources Exploitative − Indirectly competing by consuming a common limiting resource (space) Apparent- Indirectly between 2 species both preyed upon by the same predator. Example: Species A and species B are both prey of predator C. The increase of species A will cause the decrease of species B because the increase of As would increase the number of predator Cs which in turn will hunt more of species B.

8 Competitive Exclusion Principle Sometimes referred to as Gause's law of competitive exclusion states that two species competing for the same resources cannot coexist if other ecological factors are constant. The competing species that has even the slightest advantage will dominate in the long term and emerge the victor. The loser will either relocate or become extinct. The principle has been paraphrased as "complete competitors cannot coexist".

9 Competition Between Organisms Of Different Species- Examine and interpret the results

10 Solutions to Competitive Exclusion Resource partitioning− sympatric species consume slightly different foods or use resources in different ways Ex: Anolis lizard sp. perching sites in the Dominican Republic

11 Solutions to Competitive Exclusion Character displacement− sympatric species tend to diverge in the characteristics that overlap Ex: Darwin’s finch beak size on the Galapagos Islands

12 Succession Ecological succession − transition in species composition over ecological time Pioneer organisms = bacteria, lichen, algae Climax community = stable Primary − begun in lifeless area; no soil, perhaps volcanic activity or retreating glacier. Secondary an existing community has been cleared by some disturbance that leaves the soil intact

13 Human Impact on Ecosystems Humans are the most widespread agents of disturbance – Reduces diversity – Prevent some naturally occurring disturbances


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