COMMUNITIES & ECOSYSTEMS. Professor Andrea Garrison Biology 11 Illustrations 2010 Pearson Education, Inc. unless otherwise noted

Transcription

1 COMMUNITIES & ECOSYSTEMS Professor Andrea Garrison Biology 11 Illustrations 2010 Pearson Education, Inc. unless otherwise noted

2 COMMUNITIES & ECOSYSTEMS Ecosystem = groups of organisms living together in nature, interacting with each other and with the physical, non-living environment 2

3 COMMUNITIES & ECOSYSTEMS Ecosystem = groups of organisms living together in nature, interacting with each other and with the physical, non-living environment Biotic environment = living organisms 3

4 COMMUNITIES & ECOSYSTEMS Ecosystem = groups of organisms living together in nature, interacting with each other and with the physical, non-living environment Biotic environment = living organisms Abiotic environment = non-living features 4

5 COMMUNITIES & ECOSYSTEMS Ecosystem = groups of organisms living together in nature, interacting with each other and with the physical, non-living environment Biotic environment = living organisms Abiotic environment = non-living features Ecosystem = biotic + abiotic environments and all interactions 5

6 Biotic Environment = Community 6

7 Biotic Environment = Community Each type of organism = species 7

8 Biotic Environment = Community Each type of organism = species Species = similar organisms capable of interbreeding and producing fertile offspring 8

9 Biotic Environment = Community Each type of organism = species Species = similar organisms capable of interbreeding and producing fertile offspring Population = all members of a single species within a given area 9

10 Biotic Environment = Community Each type of organism = species Species = similar organisms capable of interbreeding and producing fertile offspring Population = all members of a single species within a given area Thus, community = all populations in given area 10

11 Two common threads throughout all interactions in ecosystem Movement of energy through the ecosystem Movement of matter (nutrients within ecosystem) 11

12 Movement of energy through ecosystem 12

13 Movement of energy through ecosystem Energy begins in the abiotic environment Source is usually sunlight 13

14 Movement of energy through ecosystem Energy begins in the abiotic environment Source is usually sunlight Energy trapped in biotic environment Photosynthesis - uses solar energy to take simple compounds and convert them to complex compounds needed by living organisms 14

15 Movement of energy through ecosystem Energy begins in the abiotic environment Source is usually sunlight Energy trapped in biotic environment Photosynthesis - uses solar energy to take simple compounds and convert them to complex compounds needed by living organisms Autotrophs = organisms capable of converting non-food energy into energy in molecular bonds of food molecules 15

16 Conversion of simple molecules to more complex molecules 16

17 Energy moves through the biotic environment 17

18 Energy moves through the biotic environment Heterotrophs = organisms which cannot make their own food; must eat other organisms 18

19 Energy moves through the biotic environment Heterotrophs = organisms which cannot make their own food; must eat other organisms Food chain or food web 19

20 Energy moves through the biotic environment Heterotrophs = organisms which cannot make their own food; must eat other organisms Food chain or food web Each step is trophic level = Level at which an organism feeds in food chain or web 20

21 Energy moves through the biotic environment Heterotrophs = organisms which cannot make their own food; must eat other organisms Food chain or food web Each step is trophic level = Level at which an organism feeds in food chain or web Producers Primary consumer (herbivores) Secondary consumer (primary carnivores) Tertiary consumers (secondary carnivores) 21

22 FOOD CHAIN 22

23 FOOD WEB 23

24 Energy moves through the biotic environment Heterotrophs = organisms which cannot make their own food; must eat other organisms Food chain or food web Each step is trophic level = Level at which an organism feeds in food chain or web Producers Primary consumer (herbivores) Secondary consumer (primary carnivores) Tertiary consumers (secondary carnivores) Decomposers very important trophic level 24

25 Decomposers feed on every trophic level for energy eat organic wastes and dead organisms Return nutrients to soil 25

26 As energy passes through food chain, it is transformed from one form to another 26

27 As energy passes through food chain, it is transformed from one form to another Never 100% efficient 27

28 As energy passes through food chain, it is transformed from one form to another Never 100% efficient 1 st Law of Thermodynamics Cannot create nor destroy energy (can change forms) 28

29 As energy passes through food chain, it is transformed from one form to another Never 100% efficient 1 st Law of Thermodynamics Cannot create nor destroy energy (can change forms) 2 nd Law of Thermodynamics When energy changes forms, some lost as waste heat 29

30 MOVEMENT OF ENERGY THROUGH FOOD CHAIM/WEB NEVER 100% EFFICIENT 30

31 As energy passes from one trophic level to another, average 90% lost as waste heat at every step Energy moves through the ecosystem and leaves as waste heat Cannot be used again 31

32 ENERGY PYRAMID 32

33 FEEDING THE WORLD S POPULATION 33

34 Movement of matter (nutrients) through the ecosystem 34

35 Movement of matter (nutrients) through the ecosystem Nutrients move through trophic levels of food chain/web 35

36 Movement of matter (nutrients) through the ecosystem Nutrients move through trophic levels of food chain/web Recycled within ecosystem by decomposers 36

37 Movement of matter (nutrients) through the ecosystem Nutrients move through trophic levels of food chain/web Recycled within ecosystem by decomposers Biogeochemical cycles Carbon cycle Oxygen cycle Water cycle Nitrogen cycle 37

38 BIOGEOCHEMICAL CYCLES Nutrients (matter) exist in finite amounts Cannot create more Nutrients are stored in abiotic environment pulled into biotic environment through biological & geological processes Nutrients are recycled over and over Ecosystems must make do with what is there If nutrients leave the ecosystem, they cannot be replaced 38

39 BIOGEOCHEMICAL CYCLES 39

40 CARBON CYCLE Carbon reservoir is CO 2 in the atmosphere Carbon is pulled into food chain/web through photosynthesis Carbon moves through the food chain/web through predation Carbon eventually ends up at decomposers Carbon leaves all levels of food chain/web through respiration and returns to atmosphere 40

41 CARBON CYCLE 41

42 OXYGEN CYCLE Oxygen reservoir is the atmosphere Respiration by animals and plants converts O 2 to CO 2 in atmosphere Photosynthesis by plants converts CO 2 to O 2 in atmosphere Carbon is pulled off CO 2 and ends up in carbon cycle Respiration and photosynthesis closely connected drive the oxygen cycle 42

43 OXYGEN CYCLE CO 2 in air P/S Respiration O 2 in air 43

44 OXYGEN CYCLE closely connects with carbon cycle CO 2 in air P/S Respiration carbon in plants O 2 in air 44

45 WATER CYCLE Water reservoir is combination of ocean, lakes, streams, ground water Water cycle driven by evaporation and precipitation Evaporation pulls water out of terrestrial and marine ecosystem and converts it to gas Precipitation (driven by cooling temperatures) creates rain, snow, etc, and releases water in different locations of the globe 45

46 WATER CYCLE 46

47 NITROGEN CYCLE Nitrogen reservoirs are atmosphere (as N 2 ) and soil (as nitrate) N 2 cannot be used by plants or animals Must be converted to nitrates by bacteria (nitrogen fixation) Nitrates recycled in environment If nitrates lost from environment, replenished from N 2 in atmosphere by nitrogen fixation 47

48 NITROGEN CYCLE 48

49 ENERGY & NUTRIENT FLOW IN ECOSYSTEM 49

50 ENERGY & NUTRIENT FLOW IN ECOSYSTEM 50

51 EUTROPHICATION DUE TO HIGH NUTRIENTS heavy algal growth due to high levels of fertilizers 51

52 NUTRIENT RUN-OFF IN AGRICULTURAL WATERSHED 52

53 GULF OF MEXICO DEAD ZONE nitrogen run-off results in high algal growth decomposition of algae as they die uses up oxygen (dark blue indicates lack of life) 53

54 BIOMES Terrestrial Biomes Major terrestrial life zone, characterized mainly by type of plants, also temperature and amount of rainfall Differ from ecosystem in that biomes do not include physical environment and all interactions READ about Biomes in Chapter 18, KNOW the terrestrial biomes 54