2. ECOLOGY & FOODWEBS

3. S7L4 Students will examine the dependence of organisms on one another and their environments. –a. Demonstrate in a food web that matter is transferred from one organism to another and can recycle between organisms and their environments. –b. Explain in a food web that sunlight is the source of energy and that this energy moves from organism to organism. –c. Recognize that changes in environmental conditions can affect the survival of both individuals and entire species. –d. Categorize relationships between organisms that are competitive or mutually beneficial.

4. EQ’s to be answered in this unit: How is life like a web? Why is it necessary for everything in an ecosystem to work together? How do YOU fit into the larger world? How does a change in temperature and/or precipitation affect the living things in the environment? Why can’t there be a lone survivor? What effect does the environment have on organisms? How does the environment affect us?

5. Chapter 20, Section 1 p.675 We’ve learned about biomes, and about the characteristics of living things. Now we are gong to tie these things together by looking at…

6. p. 675 Habitats An environment that provides the things the organism needs (food, water, shelter) to live, grow, and reproduce One area may contain many habitats Organisms live in different habitats because they have different requirements for survival.

8. p. 675 Factors An organism interacts with both the living and nonliving parts of its habitat. P.675 - Biotic factors: living parts of a habitat. Ex: grass, plants, hawks, ferrets, badgers, worms, fungi, bacteria

9. P.676 – Abiotic factors – Nonliving parts of an organism’s habitat. Water – Organisms require water to carry on life’s processes, and water makes up a large part of organisms’ bodies. Sunlight – Needed for photosynthesis; without it, few organisms can survive. Oxygen – Can be obtained from the air or from water, and is essential for life. Temperature – help determine the types of organisms that can live in an area. Soil - contains rock fragments, nutrients, air, water, & decaying remains; type of soil determines plants, and for many organisms, soil is used as a home.

11. p.677 Levels of Organization 1) Species – a group of organisms that are physically similar and can mate with each other and produce offspring that can also mate and reproduce.

12. 2) Populations all the members of one species in a particular area.

13. 3) Communities all the different populations that live together in an area.

14. p. 678 4) Ecosystems The community of organisms that live in a particular area along with their nonliving surroundings.

15. BRAIN POP http://www.brainpop.com/science/population sandecosystems/ecosystems/zoom.weml

16. p.681 Studying Populations Sometimes we need to know the size of a population of organism in a particular ecosystem. We use several different ways to determine the population:

17. p.682 Direct Observation Counting all of the members in a population Ex: Counting all the crabs in a tide pool

18. p.682 Indirect Observation Observing signs of organisms rather than the organisms themselves Ex: Counting entrance holes to swallow nests

19. p.682 Sampling Making an estimate (an approximation of a number, based on reasonable assumptions). Ex: Counting number of organisms in a small sample area, then multiplying to find the number in a larger area

20. p.683 Mark-and-Recapture Studies Marking an organism, releasing it back into the wild, then returning at a later date to see how many organisms have marks, and how many do not. Ex: marking turtles, then coming back in 2 weeks and counting the number of marked turtles.

21. p. 684 Changes in Population Size Populations can change in size when new members join the population or when members leave the population.

22. p.684 Births and Deaths The birth rate of a population is the number of births in a population in a certain amount of time (ex: 600 per year) The death rate is the number of deaths in a population in a certain amount of time (ex: 400 per year)

23. p.684 The Population Statement If birth rate > death rate, population size increases. If birth rate < death rate, population size decreases

24. p.684 Immigration and Emigration The size of a population can also change when individuals move into or out of the population. Immigration means moving INTO a population Emigration means leaving a population

25. p.684 Graphing Changes in Population X axis shows time Y axis shows number of organisms

26. p.685 Population Density The number of individuals in an area of a specific size population density = Number of individuals Unit area

27. p.685-7 Limiting Factors An environmental factor that causes a population to decrease –Food and Water – often in limited supply –Space - if it gets too crowded, organisms don’t survive because their needs aren’t met. –Weather – temperature and rainfall can limit population growth Carrying Capacity – the largest population that an area can support

28. BrainPop Population Growth

29. p.700 Changes in Communities –Succession– the series of predictable changes that occur in a community over time.

30. p.701 – Primary Succession The series of changes that occur in an area where no soil or organisms exist. –Pioneer species– the first species to populate the area, carried by wind or water. They help break up rocks, building soil. Ex: mosses, lichens

31. Primary Succession

32. p.702 – Secondary Succession The series of changes that occur in an area where the ecosystem has been disturbed, but where soil and organisms still exist. Ex: fires, hurricanes, farming, logging, mining

33. Climax Community an ecological community that has reached the final stage of ecological succession. Watch this to see succession at work: Succession video! Succession video!

34. ENERGY FLOW Energy is transferred from one organism to another. Three methods of transfers –Food Chain –Food Web –Energy Pyramid

35. FOOD CHAIN Shows how energy passes from one organism to another. –A producer will ALWAYS be first. Producers make their own food through photosynthesis. (ex: plants, algae, some bacteria)

36. –CONSUMERS will be next: A herbivore will be second. –An organism that eats only plants (ex: rabbit, deer) A carnivore will be next. –An organism that eats other animals (ex: hawk, wolf) An omnivore can also be next. –An organism that eats both plants and animals (ex: bear, human)

37. A scavenger can also be next. –A carnivore that feeds on the bodies of dead organisms. (ex: catfish, vultures) A decomposer can also be next. –An organism that breaks down wastes and dead organisms and returns the raw materials to the ecosystem (nature’s recyclers!). (ex: worms, mushrooms, bacteria)

38. EXAMPLE GRASS RABBIT WOLF Producer Herbivore Carnivore

39. Grass  Grasshopper  Frog  Snake  Hawk GRASS (is eaten by a) GRASSHOPPER (which is eaten by) a FROG (which is eaten by a) SNAKE (which is eaten by a) HAWK Example of a Food Chain

41. Study Jam! http://studyjams.scholastic.com/studyjams/ jams/science/ecosystems/food-chains.htmhttp://studyjams.scholastic.com/studyjams/ jams/science/ecosystems/food-chains.htm

42. Food Web Each living thing in an ecosystem is part of multiple food chains. Each food chain is one possible path that energy and nutrients may take as they move through the ecosystem. All of the interconnected and overlapping food chains in an ecosystem make up a food web.

44. Study Jam! http://studyjams.scholastic.com/studyjams/ jams/science/ecosystems/food-webs.htmhttp://studyjams.scholastic.com/studyjams/ jams/science/ecosystems/food-webs.htm

45. ENERGY PYRAMID Shows how much energy is at each level of food chain Pyramid Levels –1 st level is carnivores Larger animals least energy –2 nd level is carnivores –3 rd level is herbivores –4 th level is producers Plants Most energy

46. ENERGY PYRAMID Carnivores Least Energy (Larger Animals) Carnivores Herbivores Producers (Plants) Most Energy

47. Let’s Review! Watch this video about ENERGY PYRAMIDS ENERGY PYRAMIDS Do ENERGY PYRAMID ACTIVITY

48. Where Does Energy Comes From? SUN –Provides energy for life on Earth

49. BRAIN POP http://www.brainpop.com/science/population sresourcesandenvironment/foodchains/zo om.weml

50. p.694 How Living Things Interact There are three major types of interactions among organisms: competition, predation, and symbiosis.

51. p.694 - Competition If two species occupy the same niche, one of the species will eventually die off. Competition is the struggle between organisms to survive as they attempt to use the same limited resource.

52. p.695 Predation An interaction in which one organism kills another for food Predator - The organism that does the killing. Prey – the organisms that is killed.

53. p.696 Adaptations Predator Adaptations – Help them catch and kill their prey. Ex: cheetah can run very fast. Prey Adaptations – Helps organisms avoid being killed. Ex: Skunk spray

54. p.697 Defense Strategies Mimicry– Having a strong resemblance to other predators Protective Coverings– Shield the organism from predators False Coloring– Scare potential predators away Warning Coloring– Bright colors warn predators not to eat them Camouflage – Hide from predators

55. SYMBIOSIS Relationship between species Types: –Mutualism: both benefit –Commensalism: one benefits, the other is not affected –Parasitism: one benefits, the other is harmed

56. Mutualism – Bees & Flowers Commensalism – Fish & anemones Parasitism – Ticks

57. BrainPop Time Again! http://www.brainpop.com/science/livingsyst ems/symbiosis/http://www.brainpop.com/science/livingsyst ems/symbiosis/

58. NICHE-Organism Survival Every organism has a variety of adaptations that are suited to its specific living conditions: –How does it find food and shelter? –How does it avoid danger? –How does it care for its young? –Does it have predators? –Can it cooperate with other animals? –Can it find prey (food)? A Niche is the role of an organism in its habitat, or how it makes its living.

59. Your Challenges: Show how you have mastered the standards: a)Draw a food web containing at least 10 organisms that shows matter being transferred and recycled. b)Show/Explain how the energy from sunlight moves from organism to organism. Include at least 5 organisms. c)Explain how a change in an environmental condition would affect the survival of an individual organism, the population, the community, and the ecosystem d)Describe 3 examples in your own life of relationships between organisms that are competitive and 3 that are mutually beneficial.

60. Let’s see if you can answer the EQ’s: How is life like a web? Why is it necessary for everything in an ecosystem to work together? How do YOU fit into the larger world? How does a change in temperature and/or precipitation affect the living things in the environment? Why can’t there be a lone survivor? What effect does the environment have on organisms? How does the environment affect us?