1. WARM UP  What do you call the first level of a food pyramid? –Primary consumer –Producer –Secondary consumer –Tertiary consumer

3. Chapter 5 How Ecosystems Work

4. Chapter 5 Section 1 : Energy Flows in Ecosystem

5. Energy  Flow of energy through ecosystem is one of the most important factors that determines the system’s capacity to sustain life  Without a constant supply of energy an organism cannot survive

6. Producers  Sunlight main energy source for life on Earth  Less than 1% of sun’s energy that reaches Earth is used  Some organisms use stored energy in inorganic chemicals  Producers- organisms that make their own food from sunlight or inorganic chemicals –Also called autotrophs

8. Energy From the Sun  Converts sunlight to chemical energy through photosynthesis  Adds oxygen to the atmosphere  Takes carbon dioxide from atmosphere  On land plants are main autotrophs  In freshwater and marine ecosystems algae are main autotrophs  In wetlands photosynthetic bacteria are main autotrophs

9. Life Without Light  Relies on energy within inorganic molecules –Chemosynthesis –Performed by bacteria Exist in large numbers –Live on volcanic vents on ocean floor, hot springs and wetlands

10. Consumers  Get energy from other organisms –By consuming them  Called heterotrophs –Types: Herbivores- plant eaters Carnivores- meat eaters Omnivores- eat both Detritivores- eat dead matter Decomposers- break down organic matter

11. Feeding Relationships  Energy moves in a one way path through ecosystems –Sun to autotroph to consumers  Relationships are based on who eat whom

12. Food Chains  Series of steps in which energy is transferred by eating and being eaten  Contains one organism at each step

13. Food Webs  Complex network of food chains  Multiple organisms at each step

14. Trophic Levels  Each step in a food web or chain –Producers make up 1 st trophic level –Consumers make up 2 nd, 3 rd and higher levels

15. Ecological Pyramids  Diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or web  Three types: –Energy pyramids –Biomass pyramids –Numbers pyramid

16. Energy Pyramids  Only part (10%) of energy stored in one trophic level is passed on to the next  Most used to perform life functions  Rest released as heat

17. Biomass Pyramid  Total amount of living tissues within a trophic level is called biomass  Represents total amount of potential food available for each trophic level in an ecosystem

18. Numbers Pyramid  Based on numbers of individuals at each trophic level  This pyramid is not always in pyramid shape

19. Warm Up – Monday 3/4  What does a biomass pyramid show?

20. Chapter 5 Section 2: Cycles of Matter

21. Needs of an Organism  All organisms need more than energy to survive –They need: Water Minerals Life sustaining compounds  More than 95% of the body is made up of: –Oxygen –Carbon –Hydrogen –Nitrogen

22. Recycling in the Biosphere  Matter is recycled within and between ecosystems  Passed through biogeochemical cycles  Matter is transformed as it is recycled –The air you breath may have been once been inhaled by a dinosaur

23. The Water Cycle  All living things require water  Moves between oceans, atmosphere and land  Evaporates from oceans and lakes or transpires from leaves, enter the atmosphere and condenses to form precipitation, excess water runs off to form streams which run into oceans or lakes

25. Nutrient Cycles  Nutrients- –All chemical substances that an organism needs to sustain life –Needed to build tissues and carry out essential life functions –Carbon cycle, nitrogen cycle and phosphorus cycle all cycle nutrients

26. Carbon Cycle  Carbon key ingredient in living tissue –Biological processes such as photosynthesis, respiration and decomposition take up and release carbon and oxygen –Geochemical processes, such as erosion and volcanic activity, release carbon dioxide to the atmosphere and oceans –Mixed biogeochemical processes, such as the burial and decomposition of dead organisms and the conversion under pressure into coal and petroleum, store carbon underground –Human activities, such as mining, cutting and burning forests

27. Nitrogen Cycle  All organisms require nitrogen to build amino acids –Only certain types of nitrogen are able to be used by organisms –Bacteria can use nitrogen gas and convert it to ammonium, nitrates and nitrites through nitrogen fixation –Producers use these forms of nitrogen to build proteins –Consumers eat the producers and make their own proteins –Decomposing organisms return nitrogen to the soil as ammonium –Some of this ammonium is used by producers, some converted back to nitrogen gas by bacteria

28. Phosphorus Cycle  All organisms require phosphorus to make DNA and RNA –Not common in atmosphere –Remains in rocks, minerals and ocean sediments –Some washed into streams with runoff Used by marine organisms –Some is used by producers, bind phosphates to organic compounds –Consumers eat the producers and obtain phosphorous

29. Nutrient Limitation  Primary productivity –Rate at which organic matter is created by producers  Affected by available nutrients –If nutrient is in short supply it is a limiting nutrient

30. Chapter 5 Section 3 : How Ecosystems Change

31. Ecological Succession  Ecosystems and communities are always changing in response to natural and human disturbances –Older inhabitants die out –New organisms move in causing more change

32. Primary Succession  Occurs on surfaces where no ecosystem has existed before –Lava field –Bare rock exposed by glacier melt  1 st species are pioneer species –Lichens move in an break down rock into soil –As lichens die they add organic matter to soil

33. Secondary Succession  Occurs on surfaces where soil already exists –Plowed fields –Burned woodlands  Grasses begin to grow  Shrubs begin to grow  Trees begin to grow  Will eventually form a mature stable ecosystem –Climax community

34. Pioneer Species  First species to populate an area

35. - species that influences the survival of many other species Bats are considered keystone species of many ecosystems. KEYSTONE SPECIES