The document outlines key concepts in ecology, including: 1) Organisms require food, water, shelter and space to reproduce, and habitats provide these needs through biotic and abiotic factors like water, sunlight, and temperature. 2) Population size can be determined directly by counting, indirectly through evidence, through sampling, or mark and recapture methods. Population size fluctuates based on birth, death, immigration and emigration rates. 3) Organisms interact through adaptations, competition for resources, predation relationships, and symbiotic relationships like mutualism, commensalism, and parasitism.

2. I. EnvironmentA. Organism Needs1. Food2. Water3. Shelter4. ReproduceB. Habitat (place to provide above)1. Biotic Factorsi. Life influences

3. 2. Abiotic Factors (non-living)i. Waterii. Sunlightiii. Oxygeniv. Temperaturev. Soil

4. C. Levels of Organization1. Species: Group that can reproduce2. Population: All of one species in an area3. Community: all populations in an area4. Ecosystem: Community + Non-living surroundingsi. Ecologist

6. II. Population StudiesA. Determining Size 1. Direct (counting)2. Indirect: Evidence of organisms3. Sampling: Estimation4. Mark and Recapture

7. B. Changes1. Key Factorsi. Birth Rateii. Death Rateiii. Immigration: Moving Iniv. Emigration: Moving Out2. Population Graphs3. Density

8. C. Limiting Factors1. Food and Wateri. Carrying Capacity (Maximum amount)2. Space3. Weather

9. III. InteractionsA. Adaptations1. Natural Selection: Best survive to make next generation2. Niche: How an animal makes its living

10. B. Competition1. Organisms that use same resources fight

11. C. Predation1. One animal kills anotheri. Predator = Killerii. Prey = Animal being attacked2. Population Size3. Adaptations

13. D. Symbiosis1. Mutualism: Both benefit2. Commensalism: One benefits, other not harmed3. Parasitismi. Parasite: One Benefitsii. Host: One harmed

14. IV. ChangesA. Primary Succession 1. Pioneer Species: First to reach a new areai. Break apart rock ii. Death leads to first soils ii. Brought in by wind

15. B. Secondary SuccessionDevelopment from existing ecosystem

16. V. BiogeographyA. Definition1. Bio = Life2. Geo = Meaning EarthB. Continental Drift

17. C. Dispersal1. Wind and Water2. Life3. Limitsi. Physical Barrierii. Competitioniii. Climate

18. Quiz