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2. Chapter 31 Ecology

3. Ecology • The interactions between organisms and their interrelationships with the physical environment. • Relationship between biotic and abiotic factors.

4. Ecological Organization Organism Population Community Ecosystem Biosphere

5. Organism • One member of a species found in a given area. • Ex: a single sunfish in a pond

6. Population • Includes all the members of a species found in a given area. • Ex: sunfish in a pond

7. Community • Includes all the populations in a given area. • Ex: all plants, animals, and microorganisms make up a pond community

8. Ecosystem • Includes all the members of the community plus the physical environment in which they live in.

9. Ecological Organization Population ( or ) Community ( + + ) Ecosystem ( ) Biosphere ( )

10. (I) Ecosystem • Is the structural and functional unit studied in Ecology.

11. (A) Requirements for a Stable Ecosystem • The ecosystem involves interactions between living and nonliving things. • Certain requirements must be met for a stable ecosystem to exist: • There must be a constant supply of energy (sunlight for photosynthesis). • There must be living organisms (producers) that can incorporate the energy into organic compounds (food). • There must be a recycling of materials between organisms and the environment due to decomposers. • Water, wastes, gases, Carbon, nitrogen

12. Limiting Factors • Determines the types of organisms which may exist in that environment. • Examples are: • A low temperature common to northern latitudes determines in part what species of plants can exist in that area. • The amount of oxygen dissolved in a body of water will help determine which species of fish will exist there.

13. Living factors These factors directly or indirectly affect the environment. Thus, the organisms, their presence, parts, interaction, and wastes all act as biotic factors. Nonliving factors. Physical and chemical factors that affect the capacity of an organism to live and reproduce. 1. Intensity and duration of light 2. Temperature range 3. Amount of moisture 4. Type of substrate 5. Availability of inorganic substances and gases 6. pH Biotic vs. Abiotic

14. Abiotic Factors • Nonliving factors. • The abiotic factors of an ecosystem include the physical and chemical factors that affect the capacity of an organism to live and reproduce. These factors are: 1. Intensity and duration of light 2. Temperature range 3. Amount of moisture 4. Type of substrate 5. Availability of inorganic substances and gases 6. pH

15. Biotic Factors • Living factors • These factors directly or indirectly affect the environment. • Thus, the organisms, their presence, parts, interaction, and wastes all act as biotic factors. • These interactions include: 1. Nutritional relationships 2. Symbiotic relationships

16. Relationships between Organisms • Symbiotic Relationship • Mutualism, Commensalism, Parasitism • Predator- Prey Relationship • Competition • (remember Beaks of Finches)

17. 1.Nutritional Relationships • Involves the transfer of nutrients from one organism to another within an ecosystem. • In terms of nutrition, organisms are either autotrophs or heterotrophs.

18. Types of Heterotrophs • Saprophytes- include heterotrophic plants, fungi, and bacteria which feed on dead organisms. Ex: mushrooms are saprophytes that feed off dead plants. 2. Herbivores- animals that feed on plants. Ex: deer 3. Carnivores- animals that consume other animals. Two types: a) predator – which kills and consume their prey. b) scavenger- which feed on the remains of animals they did not kill. 4. Omnivores- animals that consume both plants and animals (humans).

19. There are 3 basic organisms in a food web: • Producers: Autotrophs • Consumers- include all heterotrophic organisms. • Organisms that feed on green plants are primary consumers, or herbivores. • Secondary consumers, or carnivores, feed on other consumers. • Omnivores eat producers and consumers. • Decomposers

20. Decomposers

21. 2. Symbiotic Relationships • Different organisms may live together in a close association. • This is known as symbiosis. • There are three types: 1. Commensalism (+,0) 2. Mutualism (+,+) 3. Parasitism (+, -) KEY: + = benefits - = harmed o = not affected

22. 2. Symbiotic Relationships

23. Mutualism (+ , +) Both organisms benefit from each other. • Ex: Remember Jacques the Cleaner Shrimp and the ANEMONES from Finding Nemo???? • protozoan living in the digestive tract of termites. • Wood eaten by termites is digested by the protozoan. • Lichen: Fungi and algae living together (Lichen)

24. Commensalism • (+ , o) • In this relationship, one organism benefits and the other is not affected. • Ex: barnacles on a whale • EX: Remora on a shark

25. Parasitism • (+ , - ) • In this relationship, the parasite benefits at the expense of the host. • Ex: athlete’s foot fungus on humans tapeworm and heartworm in dogs. (Bloodworms Tapeworm Heartworms)

26. Competition • Different species living in the same environment, or habitat, may require the same resources. When the resources are limited, competition occurs among the species. • Competition- is the struggle between different species for the same limited resources. The more similar the needs of the species, the more intense the competition.

27. Competition 3. Each species occupies a niche in the community. A niche is the role the species plays, and includes the type of food it eats, where it lives, where it reproduces, and its relationships with other species. Ex. catfish and the Asian carp 4. When two different species compete for the same niche in a community, the weaker species is usually eliminated establishing one species per niche in a community.

28. (B) Competition Throw him back!! Throw him back!! NO,, I can’t compete with that!!!

29. Graphs showing competition between two species of Paramecium. Since each population alone prospers (top two graphs), when they are in a competition situation one species will win, the other will lose (bottom graph).

30. (II) Energy Flow Relationships • For an ecosystem to be self-sustaining, there must be a flow of energy between organisms. • The pathway of energy flow through the living components of an ecosystem are represented by food chains and foodwebs.

31. (A) Food Chains • Green plants and other photosynthetic organisms are the organisms in an ecosystem that can convert radiant energy from sunlight into food. • A food chain involves the transfer of energy from green plants through a series of organisms with repeated stages of eating and being eaten.

32. (B) Food Webs • In a natural community, most organisms eat more than one species and may be eaten, in turn, by more than one species. • Thus, the various food chains in a community are interconnected forming a food web.

33. (A) Food Chains

34. Energy Flow through a food Chain

35. Energy Flow

36. Food Chain

39. Antarctic food web Krill!

40. Antarctic food web

41. Do Now

42. (B) Food Webs

43. There are three basic classes of organisms in a food web: • Producers- include green plants and other photosynthetic organisms that synthesize the organic nutrients that supply energy to other members in the community. • Consumers- include all heterotrophic organisms. Organisms that feed on green plants are primary consumers, or herbivores. Secondary consumers, or carnivores, feed on other consumers. • Decomposers – are the organisms (saprophytes) that break down wastes and dead organisms so that chemical materials are returned to the environment for use by other living organisms.

44. (C) Pyramid of Energy • The greatest amount of energy in a community is present in the organisms that make up the producer level. • Only a small portion of this energy is passed on to primary consumers, and only a smaller portion is passed on to secondary consumers. • A pyramid of energy can be used to illustrate the loss of usable energy at each feeding level.

45. (C) Pyramid of Energy • A pyramid of energy can be used to illustrate the loss of usable energy at each feeding level.

46. Pyramid Of Biomass • The overall mass of organisms in a specified environment, usually measured in dry mass

47. Pyramid Of Biomass

49. (III) Cycle of Materials • In a self-sustaining ecosystem, various materials are recycled between organisms and the abiotic environment. • The recycling process allows materials to be used over and over again. • Three examples are: 1. Carbon-Hydrogen-Oxygen cycle 2. Water cycle 3. Nitrogen cycle

50. Carbon-Hydrogen-Oxygen Cycle • Carbon, hydrogen, and oxygen are recycled through the environment by the processes of respiration and photosynthesis.