Ecology

1. Ecology Biology 11

2. What is Ecology? • the study of the interactions that take place between organisms and their environments

3. The Biosphere • The part of the Earth that supports living things

4. Non-Living Environment • Abiotic factors are non living parts of an environment • Often determine which species survive in a certain environment • Include air currents, temperature, moisture, light, and soil

5. Analyzing Graphs • Question: How does an abiotic factor affect food production? • Green plants carry out the process of photosynthesis. Glucose, a sugar, is the food product made during this process. Glucose production can be used as a means for measuring the rates at which the process of photosynthesis is occurring.

6. Examine the following graph of a plant called saltbush.

7. What is the abiotic factor influencing photosynthesis? How does this factor affect photosynthesis? • How much glucose is being produced at 20 degrees?

8. 3. Based on the graph, at which temperature is glucose production greatest? 4. Does the graph tell you how the rate of photosynthesis might vary for plants other than saltbrush? Explain your answer.

9. What happens to the formation of glucose after the temperature reaches 30 degrees?

10. A complete study of an organism includes examination of the abiotic factors influencing the organism Ex. Study of salmon life cycle would include whether needed to lay eggs on rocky or sandy stream bottoms

11. Living Environment: Biotic Factors • All living organisms that inhabit the environment are called biotic factors • All organisms depend on others either directly or indirectly • Food, shelter, reproduction, protection…

12. Levels of Organisation • Population • A group of organisms of the same species that interbreed and live in the same area at the same time • Members of a population may compete for resources (food, water, mates, habitat…)

13. Communities • Made up of interacting populations in a certain area at a certain time • Ex. Birds eating insects, mushrooms growing on decaying leaves • A change in one population within a community may cause changes in other populations

14. Ecosystem • Made up of interacting populations in a biological community and the community’s abiotic factors

15. 2 major kinds of ecosystems: • Aquatic • Terrestrial

17. Symbiosis • Means living together • Is the relationship in which there is a close and permanent association between organisms of different species • Includes mutualism, commensalism, parasitism

18. Mutualism (+/+) • Both species benefit from association • Example: Ants and Acacia trees

19. Commensalism (+/0) • One species benefits, the other species is neither harmed nor benefitted • Example: Remora fish

20. Parasitism (+/-) • Harmful to one species but beneficial to the other • Evolved relationship where parasite harms, but does not usually kill host • Example: Tick

21. Brood Parasitism • Ex. Brown-headed cowbird • Lay eggs in nests of song birds

22. Other interactions… • Competition • Between individuals of the same species or between different species • For resources such as food, water, sunlight, space • Predation • One individual eats all (or part) of another organism

23. Altruism • A behaviour that may be a disadvantage to the individual, but benefits other • Or… a behavioural that is detrimental to the individual but favours the survival of that individuals genes through relatives

25. Ecosystems Change over Time • Succession: orderly, natural changes and species replacement that take place in the communities of an ecosystem • Takes place in stages • Different species of plants and animals may be present at each stage (different conditions) • Takes place over decades or centuries

26. 2 types of succession

27. 1) Primary Succession • Colonization of barren land (no living organisms) • Examples: Following volcanic eruption or retreat of glacier • First species to take hold are pioneer species (ex. Lichens) • Pioneer species eventually die, decay, and change the landscape for the next stages

28. Over time a climax community matures • This community is stable and undergoes little or no change • Could last hundreds of years

30. 2) Secondary Succession • Sequence of changes that takes place after an existing community is severely disrupted (ex. Forest Fire) • During succession the community of organisms inhabiting an area gradually changes • Secondary succession takes place in a region that previously contained life, and still contains soil. • Involves different pioneer species and takes less time to reach climax community than primary succession

32. Interpreting Scientific Illustrations • Succession is the series of gradual changes that occur in an ecosystem. Ecologists recognize two type of succession- primary and secondary. • Examine the graph. The lines marked 1 and 2 represent primary and secondary succession (but neither is defined for you)

33. Which line, 1 or 2, represents primary succession? Secondary succession? Explain.

34. 2) Which label, C or D, might best represent a climax community? Pioneer organisms? Explain. 3) What does the sudden drop at point C represent? What happens between D and E?

35. Begin Ecology Questions • Work on Vocab (due Friday)

36. Nutrient and Energy Flow Biology 11

37. The Producers • Autotroph- uses light energy or energy stored in chemical compounds to make energy rich compounds • Ex. Grass and trees

38. Photosynthesis • Process in chlorophyll that takes water, light, and CO2 and produces sugar • H2O + CO2  + light ---> C6H12O6or glucose • The sugar is then used as a building block for amino acids, cellulose, or starch (for the plant to use later)

39. Cellular Respiration • C6H12O6 + O2 → CO2 + H2O + Energy

40. Plants: • H2O + CO2  + light ---> C6H12O6 or glucose Us: • C6H12O6 + O2 → CO2 + H2O + Energy They keep making it, we keep breaking it down (they break it down too)

41. The Consumers • Organisms that get their energy from producers • Primary consumers: Obtain energy by directly consuming producer (herbivores) • Secondary consumers: Obtain energy by eating primary consumers (carnivores)

42. Energy flow: Producer Primary Consumer Secondary Consumer  Tertiary/Quaternary Consumer Decomposers- organisms that obtain energy through the break down of non-living organic materials (dead organisms) • Include bacteria and fungi.

43. Food Chain: simple model shows how matter moves through an ecosystem • Each organism in a food chain represents a trophic level

45. Food Web: show all possible feeding relationships at each trophic level within a community

47. Ecological Pyramids • Shows how energy moves through an ecosystem • Base of pyramid represents autotrophs (1st trophic level)

48. Some of the energy transferred at each trophic level enters the environment as heat (less available at each higher level) • ~10% of total energy is transferred from one trophic level to the next

49. Pyramid of Numbers

50. Pyramid of Biomass