1. CHAPTER 52 An Introduction to Ecology and the Biosphere

2. You Must Know  The role of abiotic factors in the formation of biomes.  Features of freshwater and marine biomes.  Major terrestrial biomes and their characteristics.

3. Ecology: the scientific study of the interactions between organisms and the environment  The ecological study of species involves biotic and abiotic influences.  Biotic = living (organisms – behaviors & interactions between organisms)  Abiotic = nonliving (temp, water, salinity, sunlight, soil)

4. Heirarchy  Organisms  Population: group of individuals of same species living in a particular geographic area  Community: group of populations of different species in an area  Ecosystem: community of organisms + physical factors  Landscape: mosaic of connected ecosystems  Biosphere: global ecosystem

6. Biomes: major types of ecosystems that occupy very broad geographic regions

7. Climate and elevation determine biomes Figure 34.12 Figure 34.7C

8. Climograph: plot of temperature & precipitation in a particular region

9. Tropical Forest

10. Desert

11. Savanna

12. Chaparral

13. Temperate Grassland

14. Northern Coniferous Forest

15. Temperate Broadleaf Forest

16. Tundra

17. Aquatic biomes  Aquatic biomes are distinguished based on the physical and chemical differences  Marine biome = ~3% salinity while freshwater = < 0.1%  Photiczone – light zone  Aphotic zone – no light zone  Pelagic zone – both combined  Benthic zone – made up of sediments in both photic and aphotic zone occupied by benthos that eat detrius.

19. Physical and chemical environments of aquatic biomes  Physical – Temperature, light penetration depth, and size.  Chemical – oligotrophic and eutrophic  Oligotrophic – Lots of oxygen – little nutrients  Eutrophic – lots of nutrients but little oxygen

20. Lakes Rooted plants float in littoral zone (photosynthetic zone) Non-rooted plants such as zooplankton found in limnetic zone (too deep for photosynthesis)

21. Wetlands Contains undated water or inundated at all times. High organic production by plants (with water), soils have low oxygen but incredible ability to filter dissolved nutrients. Wetlands allows woody plants with lilies and other plants to grow in water. Wetlands are important in purifying water which are being destroyed by humans.

22. Streams & Rivers Current defines streams and rivers. Streams and rivers have vertical zones. Nutrient content are found more in the mouth of the river. If there are high nutrients, then usually low oxygen level follows.

23. Estuaries Transition area between river and sea Salinity varies within estuaries. Saltmarsh grasses and algae are major producers in estuaries

24. Intertidal Zones Zones that is periodically submerged and exposed by tides Can have exposure to air and temperature Oxygen and nutrient levels are high due to the dies Animals have adapted the ability to attach to the hard substrate. Oil pollution = human impact

25. Oceanic Pelagic Zone (Open Water) Open blue water mixed by oceanic currents. Oxygen levels are high and nutrient levels are low. Phytoplankton dominates the zone. Overfishing has depleted fish stocks in all of Earth’s oceans.

26. Coral Reefs Formed by calcium carbonate skeletons Lives in photic zone of stable tropical marine environments. Requires high oxygen levels Contains unicellular algae (zooxanthellae) in the tissues of corals forming a mutualistic relationship with the coral. Contains a diverse group of cnidarians and animals.

27. Marine Benthic Zone Consists of the seafloor below the surface waters of the coastal zone. Receives no sunlight and water temperature declines with depth. Oxygen is usually at sufficient levels – soft sediments cover most of the benthic zone. Contains deep sea hydrothermal vents. Overfishing is the main impact

28. Biogeography Biogeography: geographic distribution of species  Factors:  Dispersal – movement away from area of origin  Behavior – habitat selection  Biotic factors – other species, food resources, competition, pollinators, predators  Abiotic factors – temp, water, oxygen, salinity, sunlight, rocks & soil