Chapter 6: Species Interaction & Community Ecology

1. Chapter 6: Species Interaction & Community Ecology www.aw-bc.com/Withgott

2. Species Interaction • competition • predation • parasitism • symbiosis • mutualism • amensalism • commensalism • herbivory

3. Competition • limited resources seeked by multiple • species (density dependant) organisms • food • shelter • water • mates • sunlight • Intraspecific: between different species • Interspecific: amongst individuals of the same

4. Intraspecific Competition • may exclude another species, also known also as competitive exclusion • example: zebra mussel • may coexist without interfering, also known as species coexistence. • example: rat and mongoose in Hawaii

5. Predation • structures the food web • influences community composition • helps determine the relative abundance of predator and prey • zebra muscle preys mostly on phytoplankton and some zooplankton • these populations dropped 70% in Lake Erie and Hudson River, but cyanobacteria are not predated so their population increased. • populations of ducks, muskrats, crayfish, flounder, sturgeon and eels prey on zebra muscle

6. Parasites • exploits other organisms without killing them immediatly, but may eventually cause death. • depends on the host for nourishment or other benefit while harming the host. • internal parasites: tapeworm, malaria, cholera, etc • external parasites: ticks, fleas, sea lamprey • Coevolution: host and parasite, as one changes, the other evolves to keep the interaction between them occuring

7. Herbivores • eat plants • plants evolve defence mechanisms • toxic or distasteful chemicals • volatile chemicals that atract predators • thorns • swelled stems where ants live and protect it

8. Symbiosis • Mutualism: relationship in which 2 or more species benefit from • mycorrhizae • human digestive tract and bacteria • pollinating plants and bee

9. Symbiosis • Amensalism: one is harmed while the other is unaffected. This is difficult to observe. • Commensalism: one species benefits and the other is unharmed. • epiphytes growing on other plants • barnacles attached to whales • clown fish living in anemonies

10. Trophic Levels • producers • consumers • detrivores • decomposers www.aw-bc.com/Withgott

11. Producers • autotrophs • first trophic level • green plants, cyanobacteria, algae use photosynthesis • chemosynthetic bacteria uses geothermal energy

12. Consumers • primary consumers: consume producers • anchovy consumes plankton • secondary consumers: predators that prey on primary consumers • tunaandcomorant, both eat small fishes • tertiary consumers: higher lever of predator • owls and hawks

13. Detrivores • scavenge the waste products or dead bodies of other community members • condor or vultures • millipedes • beetles

14. Decomposers • break down the material into its simple compounds plants can use • fungi • bacteria

15. Energy and Biomass • some energy is lost as waste heat • every trophic level has some energy loss • next trophic level has less energy available • energy loss varies • pyramid www.aw-bc.com/Withgott

16. Food Web condor killer whale sea birdseal tuna anchovie plankton

17. Keystone Species • indicator of the condition of the ecosystem as a whole • usually found at top of food chain • sea otter› feeds on urchins › feed on kelp • kelp maintains a balanced ecosystem

18. Disturbances • removal of keystone species • sea otter eaten by killer whales • spread of invasive species • kudzu • climate change • retrieve of a glacier • sudden events • hurricanes • floods • avalanches • volcano eruption

19. Responce to Disturbances • resistance: show no change even under presence of a disturbance • resilience: may show a change, but later returns to its original state • may show change and never return to its original state

20. Succession • changes in an ecosystem that follow a disturbance • Primary Succession follows a disturbance so severe that no vegetation or animal life is left • glacier • fires www.aw-bc.com/Withgott

21. Secondary Succession • follows a disturbance that not necessarily destroyed all living things, some are left and those are the building blocks of the future community • Mt. Saint Helen • Climax community remains in place with little modification until the next disturbance occurs

22. Invasive Species • non-native species that spreads widely becoming a dominant species • can potentially alter the community • introduced by accident • limiting factors are removed or not present • predator • competitor • parasites • weather change • ecological restoration Kudzu www.aw-bc.com/Withgott

23. Biomes • major regional complex of similar communities distinguished by a dominant plant • cover large geographic areas • largely in function of the climate • best indicators of an area's climate • aquatic systems also show biome patterns • altitude can vary biomes due to climate change, as you climb mountains, the biomes change in vegetation and animal species

24. Terrestrial Biomes • temperate deciduous forest • temperate grassland • temperate rainforest • tropical rainforest • tropical dry forest • savanna • desert • tundra • boreal forest • chaparral

25. www.aw-bc.com/Withgott Temperate Deciduous • loses leafs • precipitation is spread evenly through the year • relatively fertile soils • fewer species • oak, beeches, maples • central and southern Great Lakes

26. Temperate Grassland www.aw-bc.com/Withgott • more extreme summer and winter temperatures • limited amount of precipitation • grasses are supported more easily than trees • today mostly used for agriculture • bison, prairie dogs, antelope

27. Temperate Rainforest www.aw-bc.com/Withgott • heavy rainfall • coniferous trees • interior of forest is shaded and damp • fertile soil • soil susceptible to erosion if trees are cut down • north west of the US

28. www.aw-bc.com/Withgott Tropical Rainforest • high rainfall • dark and damp • lush vegetation • highly diverse communities • high number of different trees at low density • poor acidic soils, not proper for farming • closer to the equator: Central and S.America, Asia • uniform warmer temperatures year-round

29. www.aw-bc.com/Wighgott Tropical Dry Forest • warm year-round but highly seasonal precipitation • India, Africa, S.America, N. Australia • can be converted to agriculture • native plants adapted to the seasonal rains growing during wet season and become dormant during dry season.

30. Savanna www.aw-bc.com/Withgott • grassland with occasional clusters of trees • Africa, S.America, Australia, India • distinctive rainy season • animals migrate according to rain • water holes formed by rain

31. Dessert www.aw-bc.com/Withgott • driest biome, well under 25cm of rain/year • isolated storms months or years apart • vegetation depends on the rain amount • Sahara: very little rain • Sonora: enough rain to sustain vegetation • temperature variation may be dramatic • anatomical and behavioral adaptations • large ears to cool down • active at night • green trunk, leathery leaves and spines

32. Tundra www.aw-bc.com/Withgott • Russia, Scandinavia, Canada • extremely cold • lichens and scrubby vegetation, no trees • permanently frozen soil= permafrost • migrating birds are attracted to it in summer • polar bears and oxen are the few local species

33. Boreal Forest www.aw-bc.com/Withgott • also known as taiga • cooler dryer areas • long cold winters, short cool summers • few species of coniferous trees • poor soils, usually acidic • animals breed and eat during summer, some hibernate during winter • Canada, Alaska, Russia and Scandinavia

34. Chaparral www.aw-bc.com/Withgott • limited • evergreen shrubs, densely thicketed • highly seasonal • mild wet winters and dry summers • experience fires in summer • California, Mediterranean coast, Chile, southern Australia

35. Altitude Patterns similar to those created by Latitude THE END www.aw-bc.com/Withgott