2. __________  _____________  ____________ ORGANISMSPOPULATIONSCOMMUNITY BIOLOGY; Miller and Levine; Prentice Hall;2006 SAME SPECIES LIVING TOGETHER IN AN AREA Ex: “herd” DIFFERENT POPULATIONS LIVING TOGETHER IN AN AREA ECOLOGY

3. ____________  ___________  _____________ ECOSYSTEMSBIOMES IMAGE SOURCES: see last slide All the organisms that live in a place together with their NON-living environment Group of ecosystems that have same climate and similar communities BIOSPHERE The portion of the planet in which all life exists

4. The scientific study of interactions of organisms with each other and with their environment = ______________ The portion of the planet in which all life exists = _________________ (includes land, water, atmosphere) ECOLOGY BIOSPHERE http://jaeger.earthsci.unimelb.edu.au/Images/Topographic/Whole_Earth/Earth_100.jpg Extends from about 8 km above the Earth’s surface to 11 km below the ocean’s surface

5. WHAT SHAPES AN ECOSYSTEM? __________________ All the living things an organism interacts with __________________ All the non-living things that affect an organism Ex: climate, temperature, sunlight soil, humidity, wind BIOTIC FACTORS ABIOTIC FACTORS Images from: Pearson Education Inc; Publishing as Pearson Prentice Hall

6. Habitat vs. Niche Habitat= the area where an organism lives. Niche= physical and biological conditions necessary for an organism to live; also, what it eats and who eats it.

7. The Earth is SOLAR POWERED! _____________ is the main source of energy for life on Earth. http://www.animation-station.com/smileys/index.php?page=17 SUNLIGHT ALL LIVING THINGS USE ENERGY

8. AUTOTROPHS = PRODUCERS Can make their own food Most autotrophs use _______________ to capture solar energy Main producers on land = green plants In water = algae BIOLOGY; MIller and Levine; Prentice Hall; 2006 PHOTOSYNTHESIS ALL LIVING THINGS USE ENERGY

9. HETEROTROPHS = CONSUMERS ________________ = eat only plants ________________ = eat only animals ________________ = eat both plants & animals http://gallery.hd.org/_exhibits/natural-science/_more2003/_more09/elephant-eating-greenery-in-Addo-Park-Eastern-Cape-South-Africa-2-WL.jpg http://personal.ecu.edu/wuenschk/rabbit-wolf.gif http://www.rodsguide.com/bears/eating.jpg HERBIVORES CARNIVORES OMNIVORES

10. HETEROTROPHS = CONSUMERS ________________ = feed on plant & animal remains EX: mites, earthworms, snails, crabs ________________ = break down and absorb organic matter EX: bacteria & fungi http://montereybayphotos.com/images/nature/2.jpg http://www.fwnp.com/bracket-fungi.htm DETRITIVORES DECOMPOSERS

11. Each step in a food chain or web = _______________ ______________ ALWAYS make up the ________ trophic level. http://home.insightbb.com/~g.mager/Pond/Ecosystem.htll TROPHIC LEVEL PRODUCERS FIRST

12. Lower levels must be bigger to support the level above. Only about_____ of the energy from each level is passed on. http://home.insightbb.com/~g.mager/Pond/Ecosystem.htll 10%

13. Some energy is used for life processes such as growth, development, movement, metabolism, transport, and reproduction. The rest is lost as ________ http://home.insightbb.com/~g.mager/Pond/Ecosystem.htll HEAT

14. Ways organisms interact ______________________ Between SAME and DIFFERENT kinds of organisms Compete with each other for available resources __________________________ Between DIFFERENT kinds of organisms Hunt and kill other organisms to supply their energy needs __________________________ Between SAME kind of organisms Live together and help each other __________________________ Between DIFFERENT kinds of organisms live in close association with another kind of organism COMPETITION PREDATION SYMBIOSIS COOPERATION

15. COMPETITION Organisms in an ecosystem have to compete with each other for available resources: Food Shelter Mates

16. COMPETITION If resources are scarce, some organisms will starve and populations will decrease. If resources become more plentiful, populations will increase. Competition in nature often results in a winner and a loser... SURVIVAL OF THE FITTEST!

17. If a nutrient is in _____________ OR __________________ it will LIMIT the growth of the population = _____________ LIMITING FACTOR SHORT SUPPLY CYCLES SLOWLY http://www.wspa-international.org/exhibition/gallery/large_DeadKenyan%20droughtSPANA.jpg During this drought, there was not enough food available and many kangaroos starved.

18. Food Chain: simple model of how energy and matter pass through an ecosystem

19. Food Web: series of interrelated food chains

20. Trophic Level: each “level” in a food chain

21. How organisms obtain their energy Organisms that produce their own food are called autotrophs Autotrophs include organisms that complete photosynthesis and chemosynthesis Organisms that obtain nutrients from other organisms are called heterotrophs Heterotrophs include those that eat only autotrophs and those that eat other heterotrophs

26. Producers Autotrophs- organisms that capture energy from sunlight or chemicals and use that energy to produce food. Photosynthesis- use light energy to create high energy sugars. Chemosynthesis- use chemical energy to produce sugars. (bacteria do this)

27. Food Chains A food chain is a series of steps in which organisms transfer energy by eating, and being eaten. Energy always flows in one direction from autotrophs to heterotrophs. Arrows show direction of energy flow!

28. Food Webs When the feeding relationships in an ecosystem form a network of complex interactions. Trophic level- each step in a food chain or food web. Producers make up the first trophic level, consumers make up the second, third, or fourth. 1P1P 1C1C 2C2C 3C3C

29. Biomass Pyramid- Represents the amount of potential food available for each trophic level in an ecosystem. Biomass- The total amount of living tissue within a given trophic level. Measured as grams of organic matter per unit area. Pyramid of Numbers- Based on the numbers of individual organisms at each trophic level.  

30. Energy Pyramid- Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level. Energy consumed is lost from life processes and as heat. 100% 10% 1% Ecological Pyramids

31. Growth Curves Logistic growth occurs when a populations growth slows or stops following a period of exponential growth. Exponential growth occurs when the individuals in a population reproduce at a constant rate.

32. Carrying Capacity Represents the largest number of individuals that the environment can support. Often labeled “K”

33. Limiting Factors Limiting factor is a factor that causes a population growth to decrease. Density Dependent limiting factors depend on population size. ex: competition, predation, parasitism Density Independent limiting factors affect all populations, regardless of population size. ex: weather, natural disasters, clear cutting

34. Human Population Growth Demography is the study of human population growth statistics Demographers study growth rate, age structure, and geographic distribution Unlike other organisms, humans are able to reduce environmental effects on growth by eliminating competition for food, increasing food production, and controlling disease organisms

35. Effects of birthrates and death rates In the United States, declining death rates have a greater effect on total population growth than increasing birthrates When fertility rates are high, there is higher human population growth unless the death rate is also high The birthrate, death rate, and fertility rate provide clues to determining population growth rate

36. Other factors that affect population growth Age Structure affects population growth because if most people are out of their child bearing years, the fertility rate is low Immigration (moving in) and Emigration (moving out) do not affect the total worldwide population but, does affect national population growth rates