2. 1 Chapter 3 The Principles of Ecology

3. 2 I- The Beginning of Ecology Natural history lead to ecology Science that studies the interaction between organisms and their environmentScience that studies the interaction between organisms and their environment Combines knowledge between many sciences: Biology, chemistry, physic and earth scienceCombines knowledge between many sciences: Biology, chemistry, physic and earth science

4. 3 I- B. The living Environment: Biotic factors All living things are found in a layer called the BiosphereAll living things are found in a layer called the BiosphereAll living things are found in a layer called the BiosphereAll living things are found in a layer called the Biosphere Biosphere is made up of different environments : Aquatic / TerrestrialBiosphere is made up of different environments : Aquatic / Terrestrial Environment consist ofEnvironment consist of –Nonliving factors ( Abiotic factors) –Living factors ( Biotic factors)

5. 4 I- C. Abiotic Factors Abiotic factors can have obvious effects on living things and often it determines which species can survive.Abiotic factors can have obvious effects on living things and often it determines which species can survive. Example: Grasslands only support small plants and many grassing animalsExample: Grasslands only support small plants and many grassing animals

6. 5 II- Levels of Organization All organisms depend on others for food, shelter, reproduction or protection.All organisms depend on others for food, shelter, reproduction or protection. Ecologist study interaction among organisms at several different levels.Ecologist study interaction among organisms at several different levels. Levels of organization provide a tool to use in planning their research.Levels of organization provide a tool to use in planning their research. –Example: Studying bees Vs. foxes

7. 6 Individual Individual Populations Populations Communities Communities Ecosystem Ecosystem Biospheres Biospheres Levels of organization. Page 59

8. 7 II- A. Interaction within Populations KINDS OF COMPETITIONS: among individuals in a population among individuals in a population between populations in a communitybetween populations in a community between communities in an Ecosystembetween communities in an Ecosystem HOW TO AVOID COMPETION Alternating generationAlternating generation MetamorphosisMetamorphosis

9. 8 ALTERNATING GENERATION

10. 9 METAMORPHOSIS

11. 10 II- B. Individuals interact in Communities No population or organisms lives independently of other species.No population or organisms lives independently of other species. Community is a collections of interacting populationsCommunity is a collections of interacting populations Change in one population causes change in anotherChange in one population causes change in another –Example: more people less vegetation

12. 11 II- C. Interaction between Abiotic and Biotic factors Ecosystems are interaction among the populations in a community and their physical surroundings.Ecosystems are interaction among the populations in a community and their physical surroundings. Kinds of ecosystems:Kinds of ecosystems: –Terrestrial –Aquatic ( 75% of earth’s surface)

13. 12 II- D. Where and how organisms live Every organism plays a role in their communityEvery organism plays a role in their community All help maintain a balance (Homeostasis)All help maintain a balance (Homeostasis) Role played is the organism’s NICHERole played is the organism’s NICHE Habitat is place where organism livesHabitat is place where organism lives –many species usually share habitats

14. 13 III- How organisms Interact Feeding relationships: How organisms obtain energy Autotrophs = capture and store light energyAutotrophs = capture and store light energy Heterotrophs = depend on autotrophs for a food sourceHeterotrophs = depend on autotrophs for a food source Carnivores = organism that depends on other heterotrophs as a food sourceCarnivores = organism that depends on other heterotrophs as a food source

15. 14 III- How organisms Interact part 2 Scavengers = depend on dead organisms as food sourceScavengers = depend on dead organisms as food source Omnivores = eat a variety of food both plants and animalsOmnivores = eat a variety of food both plants and animals Decomposers = break down and absorb nutrients from dead organismsDecomposers = break down and absorb nutrients from dead organisms

16. 15 III- B. Close relationship for survival Symbiosis : close and permanet association between organisms of different species.Symbiosis : close and permanet association between organisms of different species. Commensalism: one species is benefited and the other is neither helped or harmedCommensalism: one species is benefited and the other is neither helped or harmed Mutualism: both species benefitMutualism: both species benefit parasitism: one benefits at the expense of the otherparasitism: one benefits at the expense of the other

17. 16 III- B. Close relationship for survival more Symbiotic relationshipsmore Symbiotic relationships –parasitism: one benefits at the expense of the other

18. 17 IV- A. Matter & Enery in Ecosystem Food ChainFood Chain –each link provides less energy then the previous. (energy loss by heat and motion) –3links in a food chain good / 5 are bad –each level or link is called a Trophic level –many food chains cross and interconnect this is called a (Food Web)

19. 18 Food Web

20. 19 Pyramid numbers

21. 20 Energy Pyramid

22. 21 IV- C. Cycling maintains Homeostasis Water cycleWater cycle Carbon dioxide cycleCarbon dioxide cycle Nitrogen cycleNitrogen cycle Phosphorus cyclePhosphorus cycle

23. 22 Water cycle

24. 23 Carbon Dioxide cycle

25. 24 Nitrogen cycle