1. Chapter 2 Fundamentals of Ecology Abiotic environment- consists of the nonliving aspects of an organisms surroundings. Biotic environment- consists of living organisms and the way they interact. Habitat and Niche: Habitat- the place in the environment where an organism is found. Can be subdivided into smaller subdivisions called microhabitats. Niche- an organisms role in it’s environment. Can be determined by abiotic factors, biological factors, and an organisms behavior.

2. Environmental Factors that Affect Animal Distribution Maintaining Homeostasis: Homeostasis- internal balance that organisms must maintain In order to survive. An organism’s ability to maintain this limits the areas in which it can live. Zone of stress- regions above or below the optimal range. Zone of intolerance- zone in which environmental variable is so far from the optimal range that the organism can’t survive.

3. Environmental Factors that Affect Animal Distribution Physical environment: light, temperature, salinity, pressure metabolism Biological environment: competition, predator-prey relationships, symbiosis

4. 1. Sunlight: The amount of available sunlight influences photosynthesis, Vision, and whether excessive levels are damaging to organisms in the form of desiccation. 2. Temperature: Ectotherm-obtains body heat from its surroundings. Endotherm- can maintain a constant body temperature

5. 1. Temperature can influence the distribution of organisms in shallow water and in the intertidal zone. 2. Oxygen dissolves easier in cool water than in warm water. 3. Salinity: Solutes are substances that are dissolved in water. Osmosis- the movement of water across a membrane is response to differences in solute concentration. Salinity is important in determining the distribution of organisms. Using the warm-up question explain what is: Hipotonic? Isotonic? Hypertonic?

6. 4. Pressure: Sea level= 1atm. Every 10 m(or 33ft) below sea level pressure increases by 1 atm. Metabolic Requirements: 1.Available dissolved nutrients and gases needed for metabolism, growth, and reproduction. 2. Anaerobic organisms thrive in oxygen free environments. How many atm of pressure are there at 4000 m bellow surface? At 8000 m?

7. Species Interactions: Interspecific competition- competition between similar species. Intraspecific competition- competition between members of a single species.

8. Competitive exclusion- is when one organism successfully out competes another organism and excludes it from a particular area or niche. Resource partitioning- the process of subdividing a niche into smaller niches. Competition- can occur when organisms require the same limited resource such as food or living space.

9. Keystone species- an animals presence that makes it possible for many other species to live there.

10. Keystone species- an animals presence that makes it possible for many other species to live there.

11. Symbiosis: Symbiosis-means living together 1.Mutualism- both organisms benefit from the relationship. Ex. clownfish and sea anemone. 2. Commensalism- one organism benefits, while the other is neither harmed nor benefitted. Ex. Remora fish and shark. 3. Parasitism- one organism, the parasite lives off another organism. Ex. Tapeworm living in a dog.

12. Population, Communities, and Ecosystems Population- is a group of the same species that occupies a specified area. Community- composed of populations of different species. Zones of the Marine Environment: Can divide marine environment into two divisions: A: pelagic division- composed of the ocean’s water (water column). B. Benthic division- ocean bottom.

13. A.Pelagic Division 1. Neritic zone- water that overlies continental shelves. 2. Oceanic zone- water that covers the deep ocean basins Also can de divided into photic (sunlight present) and aphotic (sunlight absent). B. Benthic Division 1.Intertidal zone- covered with water only during high tide. 2. Shelf zone- low tide to edge of continental shelf. 3. Bathyl zone- continental shelf-4,000m 4. Abyssal zone- 4,000-6,000m 5. Hadal zone- > 6,000m

14. Epifauna- animals that live on the bottom. Infauna- animals that live in bottom sediments.

15. Ecosystems: Some of the major marine ecosystems are estuaries, salt Marshes, mangrove swamps, rocky shores, sandy beaches, kelp Forests, coral reefs, and open ocean.

16. Energy flow Through Ecosystems: Producer- organisms able to produce their own food. In the marine environment, the most important photosynthetic organisms are phytoplankton. Chemosynthetic- uses the energy from chemical reactions, rather than sunlight to form organic molecules from carbon dioxide and other compounds. Consumers- rely on other organisms for food.

17. Food Chains and Food Webs Food Chain- sequence of feeding relationships among a group of organisms. Food web- a representation of the complex feeding networks that exist in an ecosystem.

18. Energy Flow through Trophic Levels: On Average only about 10% of the energy available at one trophic level is passed onto the next trophic level.

19. Biogeochemical Cycles: Biogeochemical cycle- a combination of biological, chemical, and physical processes that act to recycle nutrients. Essential Nutrients are water, carbon, nitrogen, and phosphorus. Hydrological cycle- is the cycling of water between the Atmosphere and land through evaporation and precipation.

20. Carbon Cycle- Co 2 from atmosphere is dissolved in seawater and used by producers through photosynthesis. When the food is metabolized in respiration the Co 2 is returned to the environment.

21. Nitrogen Cycle- producers like plants require nitrogen for protein synthesis and thus for proper growth. The nitrogen they need is Usually in the form of ammonia, ammonium, nitrite, or nitrate. 1. Producers use energy from photosynthesis to concentrate the nitrogen in their tissues and assemble it into amino acids and proteins.

22. Nitrogen fixation- converting atmospheric nitrogen into forms that are useable by producers, usually done by cyanobacteria. Upwelling- the process by which wind and ocean currents bring Nutrient rich material from the ocean bottom back to the photic zone.