Chapter 3 Communities and Biomes

1. Chapter 3 Communities and Biomes

2. Why do organisms live where they do? • They have found their niche! • Abiotic / Biotic Factors • Organisms must adapt to environment • Weaker organisms must move (lichen, trout)

3. Section 3-1 Communities (Pages 64-69) Changing with the environment • How would an open field change in 5, 20, 100 yrs? • Ecosystems change • Quick- fire, flood, clear-cutting • Slow- sapling growing into a mature tree

4. Limiting Factors • biotic or abiotic factor restricting an organism • Existence • Numbers • Reproduction • Distribution • Indirect affect on another population • Examples: grass, mice/hawks, rabbit

5. Ranges of Tolerance The ability to withstand fluxuation of a factor ( • Some species are more tolerable to water conditions • Catfish, trout, carp • Camel, roach, tree-line, salt, type of trees optimum range – greatest number of organisms zone of physiologic stress – organisms infrequent zone of intolerance – organisms absent

6. Succession orderly, natural changes that take place in the communities of an ecosystem Difficult to observe (decades  centuries)

7. Primary Succession • Development in a barren habitat with no soil. • Pioneer Organisms- 1st to inhabit (mosses and lichens) • Soil Formation • Weeds/ grasses/ shrubs/ trees • Climax Community Examples - volcanic eruption (lava), glacier, stripmining

8. Secondary Succession • Vegetation is destroyed, but still has soil • Pioneer Organisms- weeds • Grasses/ shrubs/ trees • Climax Community Examples – forest fires and clear-cutting

9. Climax Community a stable, mature community that undergoes little or no succession Where would you find these?

10. Primary vs. Secondary Succession • Similarities- • End with climax communities • Simple  complex • Differences- • Primary begins with no soil, secondary has soil • Which takes longer? • Pioneer species are different

11. How have humans contributed or disrupted ecological succession? • Disrupted • Landfills • Logging • Strip-mining • Building • Farming • Mowing grass • Roads • Contributed • Recycle (more land) • Planting trees • Planting grass • Adding topsoil

12. Section 3.2 Biomes (pages 70-74) Biome- ecosystems sharing the same climax community Climate determines the type of climax community.

13. Biomes Aquatic Biomes located in oceans, lakes, streams, ponds, or other bodies of water Marine- 75% of Earth Freshwater- 1% of Earth

14. Marine Biomes Oceans contain the largest amount of biomass, or living material, of any biome on Earth.

15. Marine Biomes • Intertidal Zone- shoreline between tides • Snails, starfish, mussels, barnacles • Photic zone – portion of the marine biome that receives sunlight • Plankton (most biomass) • Aphotic zone – deeper water that never receives sunlight (no photosynthesis)

16. Marine Biomes

17. Estuary Water where freshwater and salt water mix Brackish- fresh and saltwater mixed

18. Freshwater Biomes Stream, river, pond, lake • Grasses, algae, protists, insects, tadpoles, crayfish • Amount of light and the temperature decrease as you go deeper into a lake (limiting factor) • Bottom of lake- bacteria recycle nutrients

19. Terrestrial Biomes (Pages 74-83) Temperature and Precipitation are abiotic factors that influence the kind of climax community that develops.

20. Terrestrial Biomes

21. Tundra treeless land with long summer days and short periods of winter sunlight the temperature never rises above freezing for long, so only the top layer of soil thaws

22. Tundra underneath the topsoil is a layer of permanently frozen ground called permafrost the short growing season is limiting factor because producers are the beginning of the food chain

23. Taiga (Northern Coniferous Forest) land of mixed pine trees warmer and wetter than tundra long, severe winters and short, mild summers

24. Taiga topsoil develops from decaying coniferous needles, so it is acidic and poor in minerals more large species of animal are found in the taiga compared to the tundra

25. Desert dry, arid region with little to almost no plant life usually gets less than 25 cm of precipitation annually Not always warm

26. Desert deserts with some rainfall can sustain plants such as shrubs plants sometimes have spines, thorns, or poisons to discourage herbivores

27. Grasslands “Breadbaskets of the World”-grain production Savanna- contain few trees Prairie Pampas- Asia Steppe- Russia receive between 25 cm and 75 cm of precipitation annually

28. Grasslands occupies more area than any other terrestrial biome good soil for growing oats, rye, and wheat populated by large herds of grazing animals

29. Temperate Forest (Deciduous Forest) our biome 70 cm to 150 cm of precipitation annually

30. Temperate Deciduous Forest) trees lose their leaves annually (decidious) most species of bird leave this biome during the winter months

31. Tropical Rainforest warm temperature, high humidity, abundant rainfall most biologically diverse of the terrestrial biomes receive at least 200 cm of rainfall annually

32. Tropical Rainforest some receive up to 400 cm of rain annually tall, tightly-packed trees shade the forest floor so few plants grow there high rate of decomposition and poor soil due to the amount of rainfall

33. Terrestrial Biomes