Paradigm Shift: Embracing Sustainability and Understanding Ecology

1. Introduction • Our past ancestors stood on the face of this Earth with the belief that it was a tremendously large and flat world. • The Earth, in their view, was the center of the universe. • People believed humans were totally unrelated to other animal life here on Earth; that humans were placed on this earth to rule over and make use of the boundless resources, put here for the sole benefit of humans. Water, land, air, minerals, forests, fish, and all other resources, both renewable and non-renewable, were all considered to be in endless supply.

4. Paradigm The way that humans view the world is known as a paradigm. • "The earth and all things on it exist for the sole benefit of humans" was an old world paradigm. This paradigm was the reason that western civilization was created on the premise of unlimited exploitation of the earth! • Today it is clearly understood by most people that the early views were wrong. • The old paradigms have been replaced by new paradigms.

5. Paradigm Shift • Changes in paradigms are known as paradigm shifts. Humans no longer regard the Earth as the centre of the universe. • Humans now recognize that the Earth is a sphere rather than flat. • The Earth's resources are not in endless supply for our plunder. • We are the caretakers of this world and we must take responsibility for its sustainability. • These are all examples of paradigm shifts. • The paradigms of modern man differ from the paradigms of our forefathers.

6. Sustainability • The modern paradigm views the Earth as a sustainable system provided that renewable resources are not used at a faster rate than they are replaced or recycled. • The term sustainability means that the system can meet the needs not only of our present human population, but also those of the future.

7. Introduction to Ecology • Is the scientific study of the interactions of organisms and their environment • Interactions of organisms and their environment includes how the environment affects the organism and how the organism affects the environment • Ecosystem – is a community of organisms and their physical environment

8. An ecosystem is a community made up of animals, plants, and micro-organisms, together with the environment where they live. • Members of the community depend on each other and their environment for food and shelter. • Ecosystems have four main components: air, water, land and living creatures. • Every ecosystem on Earth depends on water, of varying amounts, for its survival.

11. Abiotic Factors • Space • Temperature • Oxygen • Sunlight • Water • Inorganic and organic soil nutrients

12. Biotic Factors • Detritus • Disease • Predator\Prey interactions • Competition

13. Symbiotic Relationships • Are biotic relationships in which two or more organisms live in close association with each other to the benefit of at least one • Five types • Mutualism – results in mutual benefit to both organisms • Commensalism – one organism benefits the other neither benefits nor is harmed • Parasitism – one organism benefits and the other one is harmed • Parisitoidism – one benefits but the other is eventually killed • Predation – the interaction is beneficial to one and the other is killed

14. Mutualism

15. Predation

16. Commensalism

17. Parasitism

18. Parasitoids

19. Trophic Structure • Each step in the food chain is called a trophic level • Refers to the feeding relationships within the ecosystem • Five levels 1. Primary producers – also called autotrophs – they produce their own food • Consumers – heterotrophs – organisms that eat other organisms • 4 types of consumers • Herbivores – eat plants • Carnivores – eat animals • Omnivores – eat both plants and animals • Saprobes – decomposes – eat dead plants and animals 2. Primary consumers – feed directly on plants 3. Secondary consumers –feed on primary consumers 4. Tertiary consumers – top consumer because it is at top of food chain 5. Decomposers

20. Trophic Structure (cont’d) • Feeding relationships within an ecosystem are generally called a food web • The food web consists of all the possible food chains within the ecosystem

23. Your Turn • Read pg. 8 – 13 • Questions Pg. 13 # 1,2,3,4(a)(c) • Read pg. 22 – 23 • Questions Pg. 23 # 1 – 6 • Read pg. 34 – 39 • Questions Pg. 39 # 1 -7 • Pg. 46 # 6

24. Succession • Ecological succession refers to the series of ecological changes that every community undergoes over long periods of time. • succession begins with relatively few pioneering plants • The plant life serves as food, and often shelter for the animal life that can survive in that environment. • succession in the plant life is paralleled by a succession in animal life. • as a result succession, a primitive community develops. • organisms that make up the primitive community gradually change the environmental conditions so each successive community paves the way for the next. • Each successive community becomes more complex until it becomes a final, sustainable, stable community called a climax community. • In an ecosystem with a climax community, the conditions continue to be suitable for all the members of the community. • The climax community is the final stage of ecological succession.

25. Primary Succession • primary succession occurs in an area where there is no soil or previous forms of life. • occurs in an area such as a freshly cooled lava field, or a newly formed sand dune. • on land, primary succession is a very slow process because it begins with the formation of soil. • The soil forms as a result of weathering and the action of pioneer organisms. • Large rocks are broken down into smaller pieces and eventually bacteria, fungi, and lichens inhabit the area. T • these organisms are known as pioneer organisms because they are the first type of life to inhabit the region.

26. The pioneer organisms add organic matter to the primitive soil, changing the conditions of the microenvironment so that mosses, ferns, and other primitive plants begin to take over. • Grasses may eventually replace the more primitive plants and when they die, they make the soil even richer. • Shrubs grow and shade the grass causing it to die. • Then trees may grow and shade out the shrubs. • Seedlings of other trees may grow well in the shade. • In this way, one community of trees will be succeeded by another community with different trees.

27. Secondary Succession • Secondary succession occurs in an area in which an existing community has been partially destroyed and its balance upset, either by natural causes, such as fire, or as a result of human activity, such as the cutting of a forest, or abandoning a farm. • The major difference between primary and secondary succession in a terrestrial environment is that in secondary succession, soil already exists. S • seeds of plants will begin to grow. • Those that do grow will come from dormant seed already in the soil, or will come from plants in communities nearby.

28. The seeds will establish a community but succession will eventually result in a climax community that is often the same as would normally be found in the typical climax community in the region. • An abandoned farm may become a forest given enough time. • The final climax community is generally the same as the climax community that surrounds the disturbed area. • The series of stages leading to the climax community will not be the same as for a primary succession that created the original climax community.

29. Factors that contribute to ecological succession: • The type of climax community that is established will depending on the environmental conditions of the area. • The most important environmental conditions that affect succession include: • climate (temperature, precipitation, and availability of sunlight), • soil (salinity, fertility, moisture, texture, etc.), • and geographical features (latitude, altitude, and proximity to mountain ranges or large bodies of water).

30. Every ecosystem exists because there is a balance between its members (producers, herbivores, omnivores, predators, scavengers, parasites, competitors, decomposers, etc.) and its abiotic environment (climate, soil, availability of sunlight, pH, oxygen levels, salinity, etc.). • It is this balance between the biotic and abiotic factors that creates the stability of the ecosystem.

31. In general, the greater the biodiversity, the greater the stability.

32. Your Turn • Search the web to find at least one example to illustrate either primary succession or secondary succession. Prepare a presentation, including a sequence of diagrams or images, to describe the changes that occur during succession and lead to the formation of a climax community. Your series of diagrams or images should identify the different types of plant and animal life found at each stage in the process, and clearly identify the type of climax community formed at the end of the process of succession. You presentation should include answers to each of the following questions: • What is succession? • What factors contribute to succession? • What are the characteristics of a climax community?

33. Energy Flow in Ecosystems • Vast majority of all life on earth depends on sunlight as its source of energy • Actual amount of light that reaches the surface of the earth id affected by the albedo effect • The albedo effect is a measure of the amount of light reflected from an object

35. Energy Flow in Ecosystems (cont’d) Photosynthesis is a biological process whereby the suns energy is used by green plants to manufacture sugar – oxygen is also produced Carbon dioxide + water + sunlight = sugar + oxygen The sugar that is produced serves as the source of energy for nearly all life. The passage of food from producer to various consumers is called afood chain

36. Energy Flow in Ecosystems (cont’d) • The transfer of energy through an ecosystem is never 100% efficient since each organism must use some of the energy for its own existence.

37. Energy Flow in Ecosystems (cont’d) • The energy budget or the amount of energy that is available to an ecosystem depends on its producers • Ecologists have adapted the 10 % rule, put simple “ only 10% of the available energy at one trophic level is passed on to the next level”

38. Energy Flow in Ecosystems (cont’d) Example Corn – primary producer -10 000 J Mouse – primary consumer - 1 000 J Snake – secondary consumer - 100 J Hawk – tertiary consumer - 10 J The idea that each higher trophic level has less energy available is known as the pyramid of energy

39. Energy Flow in Ecosystems (cont’d) Hawk Snake Mouse Corn Pyramid of Energy

40. Pyramid of Biomass • Since the amount of water present within the tissues of different organisms varies, biologists use the dry mass of the organism for comparison since it is believed that dry mass more closely reflects the actual amount of "living matter" in the organism. • The dry mass is known as biomass. The availability of energy will also affect the number of organisms and the mass of the organisms at each trophic level. • In general, the higher the amount of available energy the higher is the biomass (dry mass) at each trophic level. • The pyramid of biomass is a graphical representation of the total biomass of all the members of each trophic level. • Generally the pyramid of biomass has the same shape as the pyramid of energy.

41. Pyramid of Numbers • The pyramid of number is the third type of graphical representation used by biologists to study ecosystems. • The pyramid of number is often similar in shape to the pyramid of energy or biomass, but there are exceptions. • Consider a single spruce tree in a boreal forest (biomass = 100 kg) which is infested by 100,000 spruce bud worms (total biomass = 10 kg), which are in turn eaten by 5 insect eating birds (total biomass = 1 kg). • The pyramid of biomass would appear normal (base representing 100 kg, middle piece representing 10 kg, and a top piece representing 1 kg). • The pyramid of number for this example will not look normal. • The pyramid of number would have a very small base representing the producer (1 tree), a very large herbivore level (100,000 spruce bud worms), followed on top by a small predator level (5 birds).

43. Your Turn • Pg. 39 # 9 - 14

44. # 9 • Less than 10% of the energy in a produces is transferred to a primary consumer because it uses the rest to carry on photosynthesis, grow new tissue, reproduce, etc.

45. # 10 • The mouse uses some of the energy ot acquired from its plant food in metabolism, growth, locomotion, etc

46. # 11 • To construct a pyramid of numbers, you would have to count all of the organisms in the population making up the food chain

47. # 12 • A pyramid of numbers does not show energy flow because of the potential disparity in the sizes of the organisms. • It is not a good indicator of the health of an ecosystem

48. # 13 • A pyramid of energy for a grassland in winter would show considerably less energy at the producer level than a grassland in the summer. The grassland receives less solar energy in the winter than in the summer. • Day is shorter and covered by snow

49. # 14 • The pyramid of numbers for a deciduous forest has a small base because it doesn’t take many trees to produce a large biomass. • The large biomass is shown by the large base of the pyramid of biomass.