The Living Earth

1. The Living Earth

2. 1. Biosphere • Biosphere = the part of Earth that supports life • The biosphere has 3 parts: 1. LITHOSPHERE - Earth’s crust 2. HYDROSPHERE - all Earth’s waters 3. ATMOSPHERE – layer of gases surrounding Earth

3. Ecology • Ecology = the study of how organisms interact with each other and with their environment • Ecologists are scientists who study these interactions.

4. Organism Population Community Ecosystem #2. Ecological Organization (smallest to largest)

5. 3. Organism • Any living thing

6. 4. Population • Population = made up of all the organisms in an ecosystem that belong to the same species. Zebra Population

7. 5. Community • Community = all the populations in an ecosystem. • For example: a prairie community is made of all the populations of bison, grasshoppers, cowbirds, etc. in a prairie ecosystem

8. 6. Ecosystem • Ecosystem = consists of all the organisms living in an area and the nonliving features of their environment.

9. Draw pictures to represent the following terms. Organism Population Community Ecosystem

10. The living parts of an ecosystem are called biotic factors. 7. Parts of an Ecosystem • The non-living parts of an ecosystem are called abiotic factors.

11. 8. Habitat • Habitat = the place in which an organism lives • An organism’s habitat provides the kinds of food, shelter, temperature and the amount of moisture the organism needs to survive.

12. 9. Niche • An organism’s niche refers to how an organism survives, how it obtains food and shelter, how it finds a mate and cares for its young and how it avoids danger. “HOW IT DOES WHAT IT DOES”

13. 10. Competition • Competition occurs when two or more organisms seek the same resource at the same time.

14. Competition is most intense among individuals of the same species because they need the same kinds of food and shelter. • Competition limits population size. • Amount of shelter space is limited • Food becomes scarce

15. 11. Limiting Factors • A limiting factor is anything that restricts the number of individuals in a population. • Includes living and nonliving features of the ecosystem. • Egs. The availability of food, water, living space, mates, nesting sites and other resources are often limited.

16. 12. Carrying Capacity • Carrying Capacity = the largest number of individuals of one species than an ecosystem can support over time. • If the carrying capacity is exceeded, some individuals will not have enough resources. They could die or be forced to move.

17. For Example • The carrying capacity of a field is 50 cows. What does this mean? The field can support no more than 50 cows.

18. What happens if one more cow joins the field? Competition between cows would lead to a drop in population.

19. Feeding Relationships Food Chains and Food Webs

20. 1. Energy • The energy that fuels most life on Earth comes from the SUN. • The Sun’s energy is used to make energy-rich molecules in plants through a process called photosynthesis.

21. 2. Producers • Producers = organisms that use an outside energy source, like the Sun, to make food. • These are green plants. • Also called autotrophs.

22. 3. Consumers • Consumers = organisms that cannot make their own food and so must eat other organisms to obtain energy. • Also called heterotrophs.

23. There are 4 kinds of consumers: • Herbivores • Carnivores • Omnivores • Decomposers

24. 4. Herbivores • Herbivores are the vegetarians of the world. • They eat only plant material. • Egs: rabbits, deer, grasshoppers

25. 5. Carnivores • Carnivores = animals that eat other animals. • They are meat-eaters. • Egs: frogs, spiders, wolves, foxes

26. 6. Omnivores • Omnivores = animals that eat both plants and animals. • Egs: humans, pigs, raven, coyote

27. 7. Decomposers • Decomposers = animals that consume waste and dead organisms. • Egs: fungi, bacteria, earthworms

28. Help recycle once-living matter by breaking it down and returning the nutrients to the soil.

29. Grass Mouse Snake Bird 8. Food Chains • Food Chain = a simple model of the feeding relationships in an ecosystem. • Eg: • The arrow shows the flow of energy.

30. Food chains begin with the sun and end with a decomposer

31. An Aquatic Food Chain Plankton shrimp small fish large fish

32. Construct a food chain from the picture.

33. 9. Food Webs • Food Web = more complex model of feeding relationships in an ecosystem. • It is made of interconnecting food chains.

34. How many food chains are in this food web?

35. 10. Trophic Levels • Trophic levels refer to the feeding position in a food chain. • In a food chain, energy is passed from one link or trophic level to the next. 1st 2nd 3rd 4th

36. 4 3 2 1

37. Consumer - Decomposer 4 3 Consumer - Carnivore 2 Flow of energy Consumer - Herbivore 1 Primary producer Original source of energy for all life on Earth.

38. 11. How Energy Flows • The total energy passed from one trophic level to the next is only 10% of the energy received from the previous organism.

39. Grass Mouse Snake Bird • The rest of the energy (90%) is lost as heat or used up by the organism. • Therefore, as you move up the food chain, less and less energy is available. Which organism in the food chain gets the most energy?

40. Symbiotic Relationships

41. 12. Symbiosis • Symbiosis = any close relationship between species

42. 13. Mutualism • Mutualism = a symbiotic relationship in which both species benefit. • Examples: • crabs and anemones • algae and fungus

43. In lichens, both algae and fungus benefit. Algae make food and fungus protects algae. Sea anemones look like stinging tentacles on the crab claws. They get small pieces of food from crab.

44. 14. Commensalism • Commensalism = a symbiotic relationship in which one organism benefits and the other is not affected. • Egs: • Egret on rhino’s back • Clownfish and sea anemone

45. Egret is protected by rhino. Rhino is not affected by egret. Clownfish is protected by sea anemone’s stinging tentacles. Sea anemone is not affected.

46. 15. Parasitism • Parasitism = a symbiotic relationship in which one organism benefits but the other is harmed. Egs: roundworms, tapeworms Dog’s intestines with roundworms

47. 16. Predator and Prey • Predator = any organism that captures and eats another organism • Prey = the organism captured and eaten by predator