Sustainability Of Ecosystems. Unit 1. Science 1206

Transcription

1 Sustainability Of Ecosystems Unit 1 Science

2 ECOLOGY The study of the interrelationships between organisms, and between those organisms and their environment. What are some natural resources, both RENEWABLE and NON-RENEWABLE, that are found on Earth? 2

3 Let s examine one of these resources, the FISHERIES: What words or phrases describe the fisheries resource in the past? 3

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6 What HAPPENED to the fishery? Fish stocks depleted - overfishing New Fishing Technology - fishfinders, dragnets, trawlers Scientific research - greater understanding What FACTORS do people consider when managing resources TODAY? Social Factors culture, politics, values, needs Economic Factors industry, jobs Environmental Factors nature, beauty 6

7 SUSTAINABILITY living WITHIN the EARTH s LIMITS. meeting the needs of the PRESENT without compromising the ability of the FUTURE to meet their needs. AKA: SUSTAINABLE DEVELOPMENT 7

8 SUSTAINABILITY DIAGRAM Blue Man Group 8

9 Paradigm Shift PARADIGM - the way humans view the world. PARADIGM SHIFT - a rare and significant change in the way humans view the world (i.e., a change in our paradigm!) 9

10 Examples: SHAPE OF THE EARTH FLAT vs. ROUND ORBITING OF PLANETS Sun around the Earth. Earth around the Sun. SANTA CLAUS Paradigm Shift Brings us presents! NO Santa Claus? What? 10

11 THE ECOLOGY PARADIGM SHIFT PAST: EXPLOITATION resources were UNLIMITED and put on the Earth for our SOLE benefit Humans can take what we want as often as we want PRESENT: SUSTAINABILITY Resources are LIMITED We are CARETAKERS of the Earth We must practice SUSTAINABILITY (wisely manage our resources) 11

12 HOMEWORK: 1. How is Earth like a spaceship? List at least 3 ways that Earth and a spaceship are similar. 2. Why are these practices NOT sustainable? clear-cutting a forest damming off a river permanently 3. Give an example of ONE paradigm shift in history that we DID NOT discuss in class. 12

13 Factors Affecting Sustainability ecosystem - A community of organisms and the physical environment in which they live. habitat - the place where an organism lives. (not the organisms home ) 13

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15 Factors Affecting Sustainability abiotic factors - the NON-LIVING FACTORS which affect life in an ecosystem. abiotic factors include: 1. space 2. temperature 3. oxygen 4. light 5. water 6. inorganic and organic soil nutrients 15

16 Factors Affecting Sustainability biotic factors the LIVING FACTORS which affect life in an ecosystem. biotic factors include: 1. decomposing animals 2. disease 3. predator/prey 4. competition 5. symbiosis 16

17 Symbiosis symbiosis is a relationship in which different species of organism live in close association such that at least one benefits. 17

18 Symbiosis There are 5 Types of Symbiotic Relationships 1. Mutualism 2. Commensalism 3. Parasitism 4. Parasitoidism 5. Predator-Prey 18

19 1. Mutualism BOTH organisms BENEFIT. Examples: Polyp and hermit crab Pollination Egyptian plover and crocodile 19

20 2. Commensalism ONE organism benefits, ONE organism neither benefits nor is harmed Examples: Beaver and fish Trees and nesting birds Anemonefish/anemone 20

21 3. Parasitism One organism, a PARASITE, benefits while another, the HOST, is harmed. Examples: Tapeworm and human 21

22 4. Parasitoidism One organism benefits while it slowly kills the host Example: Parasitic wasp and other insects Parasitic wasp in action 22

23 5. Predator-Prey One organism benefits by quickly killing its host Example: Lion and zebra Lynx and snowshoe hare Polar Bear Attacks Seal 23

24 FEEDING RELATIONSHIPS in ECOSYSTEMS Topics: Trophic Structure Types of Organisms Food Chains/Webs Pyramid of Energy Population VS. Community Ecotone Microecosystem 24

25 TROPHIC STRUCTURE Trophic structure describes feeding relationships in an ecosystem. Types of Feeders PRODUCER CONSUMER DECOMPOSER 25

26 PRODUCERS AKA: AUTOTROPHS ( self-feeders ) Organisms that CAN produce their own food using PHOTOSYNTHESIS. Examples: Plants Algae 26

27 CONSUMERS AKA: HETEROTROPHS CANNOT produce their own food so they feed on OTHER organisms. 27

28 HERBIVORE TYPES OF CONSUMERS: Eats plants eg: CARNIVORE Eats other consumers Can be either a PREDATOR or a SCAVENGER (or both) eg: Moochers of the Caribbean 28

29 TYPES OF CONSUMERS: OMNIVORE Eats plants AND animals eg: 29

30 CATEGORIES OF CONSUMERS PRIMARY (1 o ) AKA: FIRST ORDER consumers Feed on PRODUCERS Considered the SECOND trophic level. SECONDARY (2 o ) SECOND ORDER consumers Feed on PRIMARY CONSUMERS Considered the THIRD trophic level. 30

31 CATEGORIES OF CONSUMERS TERTIARY (3 o ) THIRD ORDER consumers Feed on SECONDARY CONSUMERS Considered the FOURTH trophic level. 31

32 DECOMPOSERS AKA: DETRITIVORES or SAPROBES Organisms that get their nutrients by breaking down DETRITUS (detritus is decaying plants or animals) 32

33 FOOD CHAIN A diagram that defines ONE SINGLE CHAIN of feeding relationships Starts with PRODUCERS and connects with arrows up to the TOP CARNIVORE Ex: Hawk Downy Woodpecker Spruce budworm Black spruce tree 33

34 FOOD CHAIN Why do food chains usually only go up as high as the third order, or tertiary consumer? Energy decreases as it is passed up the food chain, and the top levels have the least energy, so they are limited in levels. 34

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36 FOOD WEB A diagram that shows ALL OF THE POSSIBLE FOOD CHAINS in an ecosystem. 36

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38 PYRAMID OF ENERGY A diagram that shows the passage of ENERGY though a food chain. Energy is measured in Joules, symbol J. PRODUCERS always have the most energy (bottom level) TOP CARNIVORES always have the least energy (top level) 38

39 PYRAMID OF ENERGY About 10 % of the total energy is passed on from one trophic level to the next. 90% is lost due to life processes such as: 39

40 PYRAMID OF ENERGY... Example: Corn Mouse Snake Hawk J 1000 J 100 J 10 J 40

41 POPULATION Members of the SAME SPECIES living in the same ecosystem or habitat Examples: Caribou population in Labrador Brook trout population in George s Lake 41

42 COMMUNITY ALL POPULATIONS of the different species in the same ecosystem or habitat. Example 42

43 ECOTONE The border BETWEEN two different ecosystems Ex: area between: Because they have species from TWO ecosystems, they have a high BIODIVERSITY. BIODIVERSITY refers to the number of species in an ecosystem, and the variety within those species 43

44 ECOTONE... Why is biodiversity important to an ecosystem? A higher level of biodiversity means that the ecosystem is more stable in the long-term. 44

45 MICROECOSYSTEM A very small ecosystem eg: an ecosystem in a decaying fallen log. an ecosystem in a puddle of water. 45

46 HOMEWORK!!! Do questions 2, 4, and 5 on page 23. Read CORE LAB on page Do PRE-LAB question!!! 46

47 ENERGY FLOW IN ECOSYSTEMS 47

48 TOPICS 1. ENERGY FROM THE SUN PERCENTAGES ALBEDO EFFECT PHOTOSYNTHESIS and CELLULAR RESPIRATION THERMODYNAMICS 2. PYRAMIDS PYRAMID OF ENERGY PYRAMID OF BIOMASS PYRAMID OF NUMBERS 3. ROLES IN ECOSYSTEMS KEYSTONE SPECIES ECOLOGICAL NICHE INTRASPECIFIC VS. INTERSPECIFIC COMPETITION EXOTIC SPECIES 48

49 ENERGY FLOW IN ECOSYSTEMS The SUN is the source of energy for most life on Earth. 49

50 ENERGY FLOW IN ECOSYSTEMS The majority of the Sun s energy heats the atmosphere, earth s surface, and water. 30 % is reflected by Clouds and the Earth s Surface 69 % warms the atmosphere, land, and hydrosphere 1 % generates wind patterns % is used for photosynthesis 50

51 ALBEDO EFFECT Albedo is a measure of the AMOUNT of sunlight REFLECTED by an object. Expressed as a decimal value eg: 27 % reflection by clouds is 0.27 LIGHT-COLOURED objects have a HIGH ALBEDO. DARK-COLOURED have a LOW ALBEDO. GREENHOUSE GASES have a low albedo. 51

52 ALBEDO EFFECT 52

53 PHOTOSYNTHESIS a biochemical process PRODUCERS use the Sun s energy, carbon dioxide, and water to produce sugar and oxygen. CHEMICAL EQUATION: 6 CO H 2 O + Sun s Energy C 6 H 12 O O 2 53

54 PHOTOSYNTHESIS Oxygen is needed by CONSUMERS. Sugars are used for energy for nearly ALL LIFE on EARTH. 54

55 CELLULAR RESPIRATION a biochemical process CONSUMERS release the energy stored in the sugar consumers use sugars and oxygen to produce carbon dioxide, water, and energy for life processes. 55

56 CELLULAR RESPIRATION CHEMICAL EQUATION: C 6 H 12 O O 2 6 CO H 2 O + Energy Cellular Respiration is the OPPOSITE reaction to Photosynthesis 56

57 What kinds of life processes? 57

58 HOMEWORK Page 33 - Numbers 4 a), c), d) 58

59 THERMODYNAMICS the study of ENERGY CHANGES (ex: chemical energy to heat or light) FIRST LAW OF THERMODYNAMICS Energy CANNOT be CREATED NOR DESTROYED, only TRANSFERRED FROM ONE FORM TO ANOTHER. SECOND LAW OF THERMODYNAMICS During energy transfers, SOME ENERGY is LOST as HEAT ENERGY and is not passed on. 59

60 PYRAMIDS PYRAMID OF ENERGY (See Sept. 20) We can represent ENERGY TRANSFER in an ecosystem with a pyramid of energy. What % is passed from one trophic level to the next. 60

61 PYRAMIDS There are 2 other types of pyramids that are USEFUL GRAPHICAL INDICATORS of ecosystem patterns: PYRAMID OF BIOMASS PYRAMID OF NUMBERS 61

62 PYRAMID OF BIOMASS PYRAMIDS BIOMASS is the mass of an organism WITHOUT water (its dry weight). Measured in kg. This pyramid shows the TOTAL BIOMASS of all organisms at each trophic level. Similar to a Pyramid of Energy. 62

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64 PYRAMID OF NUMBERS PYRAMIDS - Shows the TOTAL NUMBERS of all organisms at each trophic level. - Sometimes, these are NOT shaped like pyramids. 64

65 PYRAMIDS??Pyramid of Numbers?? If the following was a rough sketch of our pyramid of energy, would the pyramid of numbers look the same? 65

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67 HOMEWORK Page 39, # 3, 4, 5, 7, 14 Draw 3 pyramids (energy, biomass, and numbers) for the following food chain: HAWK (1, 10 J, 5 kg) WOODPECKER (10, 100 J, 10 kg) WORM (1000, 1000J, 50 kg) FIR TREE (1, 10000J, 150 kg) 67

68 ROLES IN ECOSYSTEMS It is time to discuss some of the interrelationships that take place in ecosystems between species. Some specific roles organisms can take on include: KEYSTONE SPECIES ECOLOGICAL NICHE INTRASPECIFIC VS. INTERSPECIFIC COMPETITION EXOTIC SPECIES 68

69 KEYSTONE SPECIES A species so important to ECOSYSTEM STABILITY, that if that species declined, the ecosystem might collapse. Why is it called keystone? It is an analogy for a keystone that holds together an archway. eg. A sea otter is a keystone in the CALIFORNIA KELP ecosystem. Without otters, kelp does not grow. 69

70 SEA OTTER... Otters :) Keystone Species 70

71 ECOLOGICAL NICHE An organism s NICHE is the role it plays in an ecosystem. Includes everything an organism does to survive and reproduce such as: Feeding relationships Habitat Breeding grounds/behaviors Activity times Competitive relationships 71

72 ECOLOGICAL NICHE Organisms tend to have UNIQUE niches, based on where and how they are best adapted to survive. 72

73 ECOLOGICAL NICHE eg. Galapagos Island Finches Found on the Galapagos Islands, 600 miles west of Ecuador in South America Island is about 4 million years old, and largely untouched by humans. Charles Darwin studied these finches in 1835 and his studies helped him navigate the theory of EVOLUTION in his book, THE ORIGIN OF SPECIES. If was thought, a windstorm blew one finch species to the island. Left undisturbed for many centuries, and with very little competition and many available niches, this little finch evolved into many SUBSPECIES, all adapted to a DIFFERENT NICHE. 73

74 GALAPAGOS ISLAND FINCHES... Galapagos Finches 74

75 COMPETITION Sometimes in nature there is COMPETITION for NICHES when two or more organisms have similar requirements for SPACE, FOOD, and/or WATER. Survival of the Fittest usually prevails 2 MAIN TYPES: INTRASPECIFIC COMPETITION Between the SAME SPECIES EX: INTERSPECIFIC COMPETITION Between DIFFERENT SPECIES EX: 75

76 INTRASPECIFIC COMPETITION Same species competing 76

77 INTERSPECIFIC COMPETITION Different species competing penguins versus pelicans 77

78 EXOTIC SPECIES These are NON-NATIVE species that are not natural parts of ecosystems. Compete INTERSPECIFICALLY with native species in the area. Examples: Moose in NL 4 in 1904 Green Crab in Atlantic Canada Zebra Mussels (p ) HHW video 78

79 EXOTIC SPECIES GREEN CRAB 79

80 Read p P. 44, # 2, 3, 4 HOMEWORK 80