Unit 1: Ecology

1. Unit 1: Ecology Chapters 2 through 5

2. Ecology • The scientific study of interactions among organisms and their environments.

3. Aspects of Ecological Study • Biosphere Portion of earth that supports life • Abiotic Factors Non-living parts of an organism’s environment • Biotic Factors All the living organisms that inhabit an environment.

4. Abiotic Factors • NON-LIVING parts of environment • Determine which species survive in an environment • Examples: • Temperature • Light • Moisture • Soil • Air Currents

5. Biotic Factors • All LIVING parts of an environment • Living things depend on one another • Need members of the species to reproduce • Competition for resources • Examples:

6. Five levels of Organization: • Organism – living thing • Populations – a) group of organisms of one species that interbreed and live in the same geographical region b) compete with each other • Communities – Several populations in the same region a) Compete or rely on each other

7. Ecosystems – Made up of the all biotic and abiotic parts of a region and their interactions Types include: terrestrial – land aquatic – fresh water marine – salt water (75% of Earth) • Biosphere From High in the atmosphere to the bottoms of the oceans

8. Organisms in Ecosystems • Habitat – place where an organism lives • Example: • Niche – How an organism interacts with surrounding ecosystem; how it meets its need for nutrients, shelter, reproduction, and survival. (The role or job of the organism) • Examples: Earthworms and soil, grass and the hillside, bees and flowers.

9. Types of Relationships between organisms: • SYMBIOSIS – a close and permanent association among organisms of different species. • Living Relationships • Feeding Relationships

10. Living Relationships Spanish Moss/ Trees benefits neutral Bee / Flower benefits benefits harmed Tick / Deer benefits

11. How Organisms Obtain Energy:Feeding Relationships • Sun – ultimate source of energy • Producers (Autotrophs) – Produce own food from the energy of the sun (Photosynthesis) • Consumers (Heterotrophs) – Obtain nutrients by consuming other organisms

12. Types of Heterotrophs • Carnivores -- • Scavengers-- • Herbivores -- • Omnivores -- • Decomposers -- eats other animals Feeds on already dead animals eats plants eats plants and animals Breaks down and absorbs nutrients from dead & decayed plants & animals

13. Food Chains • Pathway showing how MATTER and ENERGYmove through the ecosystem. • Algae Fish Heron • Arrow indicates direction of energy flow • Some energy is lost at each link in the form of heat. • Formed by 3 – 5 links or steps (called Trophic Levels)

14. Link in a food chain Many species can occupy same level A single species can feed on several trophic levels. Trophic Levels 3rd order Heterotroph 2nd order Heterotroph 1st order Heterotroph Autotroph

15. Food Webs • Expresses all of the possible feeding relationships in a community

16. Ecological Pyramids • Ecological Pyramids • Shows energy used in an ecosystem • Models the distribution of matter and energy within an ecosystem • Pyramid of Energy (HEAT) • Only 10% of energy is transferred from each succeeding trophic level • Energy lost in the form of heat (metabolism, building tissue, etc.)

17. Cycles in Nature Matter is constantly recycled in the environment through several environmental cycles: 1. Water Cycle 2. Nitrogen Cycle 3. Carbon Cycle 4. Phosphorous Cycle

18. Water Cycle

19. Water gets into air through: • Evaporation • Transpiration • Respiration • Water gets out of air through precipitation

20. Carbon Cycle

21. Animals or plants die and carbon is released by decomposers in the form of methane and Carbon Dioxide • Carbon trapped in soil becomes fossil fuels • Released back into atmosphere through pollution • Autotrophs (plants) take CO2 from air during photosynthesis (makes Oxygen and sugar) • Heterotrophs breath in Oxygen and release CO2back into the atmosphere during respiration

22. Nitrogen Cycle

23. Air is 78% Nitrogen, but plants can’t use it • Lightning and bacteria convert nitrogen in air into a usable form (Nitrate) (NO2) in the soil • Plants absorb the nitrogen through their roots and use it to make proteins • Herbivores eat the nitrogen rich plants. • Carnivores eat the Herbivores • When Animals urinate or die they return the nitrogen to the soil

24. Chapter 3 Communities and Biomes

25. Succession • Natural changes and species replacements that take place in the communities of an ecosystem • What would cause this?

26. Succession Continued • Occurs in stages • Decades or even centuries to see this process • Primary Succession – Colonization of new sites by communities of organisms. Ex. Lava flow

27. Pioneer Species • The first species to occur in an area after primary succession has occurred. • Lichen is a good example of the 1st species to appear

28. Climax Community • Stable, mature community that undergoes little or no change in species.

29. Secondary Succession • Sequence of community changes that takes place after a community is disrupted by natural disasters or human actions • Occurs in an area that previously contained life • Less time to reach a climax community here again because life already existed. • Examples: Forest Fires, hurricanes

30. Primary or Secondary Succession?

31. Primary or Secondary Succession?

32. Communities • Interacting populations of different species • How would a green lawn be like a community?

33. Limiting Factors • Environmental factors that affect an organism’s ability to survive • Any aboitic or biotic factor that restricts the existence, numbers, reproduction or distribution of organisms • Examples: food availability, predators, and temperature

34. Ranges of Tolerance • Population size varies according to its tolerance for environmental change. • Examples: Corn Crop affected by ranges of temperature Cat fish tolerance to low levels of oxygen

35. Biomes • Group of ecosystems with the same climax communities • Terrestrial (land) or Aquatic (water)

36. Marine Biomes • Largest amount of biomass (living material); mostly small organisms • Ecologists separate them into zones called photic, Aphotic

37. Marine Zones • Photic Zone – Shallow enough for sunlight to penetrate • Aphotic Zone – Deep area of the water that never receives any light. • Estuary – Coastal body of water surrounded by land in which fresh water and sea water mix

38. Plankton • Live in the photic zone • Base of all aquatic food chains • Both small and large organisms eat plankton

39. Terrestrial Biomes • Tundra • Tiaga • Desert • Grassland • Temperate Forest • Tropical Rain Forest

40. Tundra • Treeless land with long summer days and short periods of winter sunlight • South of the north pole (permafrost) • Topsoil is thin and can only support shallow rooted grasses and plants • Mosquitoes are very common

41. Tiaga • Northern coniferous forest full of Spruce & Fir trees • Stretches across Canada, northern Europe and Asia • Warmer & wetter than tundra • No permafrost

42. Desert • Driest biome • arid region with limited plant growth • Plants are hardy & waxy (reduces water loss) • Lizards, tortoises and snakes

43. GRASSLANDS • Large community covered with grasses • Occurs in climates with less water so forest can not survive • Yellowstone National park (Bison & deer)

44. Temperate Forest • 70-150 cm precipitation annually • Dominated by hardwood trees that lose their foliage annually • Squirrel, mice rabbits & bears

45. Tropical Rain Forest • more species of organisms than any other biome • Warm temperatures, lush plant growth • 200-600 cm of rain annually • Near the equator

46. Tropical Rain Forest Continued • Three areas of habitation • Ground level – leaves • Understory – air is still, humid, & dark, with lots of insects • Canopy – Strong wind, sunlight, rain. Monkeys and birds occupy this region.

47. Chapter 4 Population Biology

48. Population Growth • Increase in population size over time

49. Factors in Population Size • Immigration Movement into a population • Emigration Movement out of a population • Death • Birth

50. How fast do populations grow? • Grow exponentially – as population gets larger, it grows faster (more reproducing organisms) • J-Shaped Curve: Population size Can this continue forever? Time