Science 421

1. Science 421 Ecology The study of the interaction of living things & their environment What else does it mean these days? Ecology is...

3. Chapter 1 - Diversity in Ecosystems • The Earth’s regions differ in their: • Temperatures • Light intensity • Water availability • Weather • Species • Read pages 8 & 9 and complete question 1.

4. 1.1 The Silence of the Frogs • Amphibians are found almost everywhere there is water on the planet. • Amphibians have two lives and live within two ecosystems: • 1. Eggs laid in water grow into a tadpole; • 2. Froglet (lose their tail and adapt to living on land and breathing air). • Croaking Frogs...

5. Over 30% of North American frogs and toads are in trouble. A change in either of their ecosystems can result in a decline in amphibian population. • Amphibians are an indicator species, meaning if they start to die off, it is a sign that the ecosystem is in trouble. • Complete questions 1 - 6 on page 13.

6. Factors Affecting Frog Populations • 1. Loss of Habitat – Road construction, deforestation, etc. • 2. Air and Water Quality - Frogs are able to breath through their thin skin, therefore pollutants are able to pass through their skin. • 3. Ultraviolet Radiation – Causes skin damage to amphibians. • 4. Climate Change - Global warming increases temperatures and reduces wetlands/habitats. • Planet Earth Frogs...

7. Use your text & define the following terms in your notes: • Ecosystem • Decomposers • Herbivores • Food Chain • Detritus • Carnivores • Producers • Omnivores • Consumers

8. 1.2 Canada’s Endangered Species • Canada has over 250 species of plants and animals that are at risk. There is a classification system to describe the risk to each species.

9. Classification Description/Example • Vulnerable At risk due to declining numbers in some areas. • Example: Grey Fox – Ontario

10. Classification Description/Example • Threatened Likely to become endangered if factors are not reversed. Ex.- Wood Bison

11. Classification Description/Example • Extirpated No longer exists in specific areas, but can be found in others.(Black bear no longer on PEI since 1930.)

12. Classification Description/Example • Endangered Close to extinction in all parts of Canada. Ex.-Eastern Cougar

13. Classification Description/Example • Extinct A species that does not exist anywhere. Ex.-Passenger Pigeon • Complete questions 1, 2 and 4 on page 15.

14. 1.3 Extinction in the Modern World Humans have influenced the process of extinction for many species over the past 50 years.

15. Extinction Timeline • 1600 - 1900 -An average of one species every 4 years. • 1980 –present - An average of over 10,000 per year.

16. Causes of Extinctions • Asteroids - Asteroids impacted with the Earth & caused a large cloud of dust blocked light from the sun, & set off many volcanoes.

17. Climate Change - A change in a species’ environment forces them to adapt or die.

18. Pressure of Competition- 2 species may compete for the same food sources and/or habitat. One wins, the other adapts or dies. • Human Factors - Logging, oil exploration, expanding cities, expansion of agriculture, introduction of new species (purple loosestrife)

19. Effects of Extinction • Biodiversity is the variety of life on Earth. It is the number of species in an ecosystem. The loss of one species impacts the entire food chain & ecosystem. • YouTube - Official video of the International Year of Biodiversity 2010

20. Restoring Balance • Due to the effects on a food chain, it is extremely difficult to restore the balance once an a species has been removed • Questions 1-5, 6a; pg. 19

21. Pestsare organisms that cause problems for humans. • Why are pests such as mosquitoes, termites, caterpillars and weeds needed? • Mosquito larvae provide food for fish and adult mosquitoes are food for birds. • Some insect “pests” are needed by plants for pollination, while others, such as wasps, help decompose tissues of dead plants and animals. • Weeds: source of food for animals, & can help anchor the soil, preventing erosion.

22. Define the following Ecology Terms: • Abiotic • Biotic • Population • Community

23. Ecology -the study of how organisms interact with each other. • Abiotic factors- non-living things in an ecosystem. Ex:- light, soil, wind, temperature • Biotic factors -living things in an ecosystem • Population -all of the members of the same species living in an ecosystem. • Community - all of the populations of species in an ecosystem. • Do # 1-5 on pg. 23.

24. Example: A pond ecosystem • Consists of a habitat with populationsof aquatic plants, waterside plants, micro-organisms (in the mud at the bottom of the pond), fish and birds. The organisms together make up a community of living things.

25. DO NOT COPY DOWNEcologists can study: • - A population and how it interacts in the ecosystem. (Coyotes) • - A community and how all species interact (biotic factors). • - An ecosystem including all biotic factors and the physical environment, or abiotic factors.

26. Quiz! • Identify each of the following as either biotic or abiotic. • Identify each of the following as either a species, a population, community or ecosystem. Grass Worms Temperature Soil Marsh The Mallard ducks in a marsh All fish in the stream The white spruce trees behind the school The trees, birds, insects, mammals, plants and amphibians in the forest Brookvale Demonstration Woodlot

27. An ecotone is a transition area between two different ecosystems where species from each can interact. There is often greater diversity in the ecotone than in either of the two ecosystems bordering it. • An area with greater biodiversity is less fragile consumers have more food sources; don’t have to rely on only 1 source. An ecotone guards against extinction.

28. 1.8 Comparing Ecosystems • Artificial ecosystems -human made. (Ex. farms, parks) • A natural ecosystem - made by nature. Species are able to interact with their surroundings freely. Humans will still have an impact on the ecosystem but they do not control it.

29. Albedo effect - % of light an object reflects. The higher the Earth’s albedo, less energy is absorbed and therefore less energy is available for maintaining the Earth’s temperature. 30% Photosynthesis: 0.023% 70%

30. 1.11 Following Energy Movement in Ecosystems YouTube - How Ecosystems Work | Biology | Ecology • Energy is constantly moving within our ecosystems. To understand how living things gain their energy we must look at trophic levels (position in the food chain). • Most ecosystems only contain about three trophic levels consisting of: • 1. Autotrophs - make their own food - producers. • 2. Heterotrophs - can’t make their own food – consumers (can be broken down into sub-levels)

31. Fourth Trophic Level Tertiary Consumers • Eat secondary and primary consumers. (Heterotroph) • Bear, cougar • Third Trophic Level Secondary Consumers • Eat primary consumers and producers. (Heterotroph) • Eagles, wolves • Second Trophic Level Primary Consumers • Eat producers for food. (Heterotroph) • Deer, mice, bugs • First Trophic Level Producers • Make their own food from basic nutrients and sunlight. (Autotrophs) • Grass, berries, trees

32. A food web is graphical representation of the feeding relationships between organisms in an ecosystem. In reality a single organism can be a part of many food chains.

34. DO NOT COPY • Ecosystems with the greatest biodiversity are the most stable they have complex food webs and therefore the removal of one consumer or one producer may have only a small impact on the ecosystem and the overall web.

35. Sunlight • Source of all energy on earth • Less than 1% is used for photosynthesis (conversion of solar energy into chemical energy sugar molecules)

36. Energy Transfer • Each time energy is transferred from one organism to another, there is a change of form. (i.e. plant used most of the sun’s energy to grow only a small fraction of sun’s energy is passed onto an animal that eats the plant) • As you move through a food chain, less energy is available to each organism.

37. LAWS OF THERMODYNAMICS • 1st Law – Energy is not created nor destroyed, only changed from 1 form to another • 2nd Law – During an energy transfer, some of the energy is converted into thermal energy or heat which is released to the environment

38. Energy use by organisms: • - Growth, repair and survival • - Given off as heat and used in respiration. • - Excretion (although decomposers actually use this energy in a different food chain). • - Transport of materials in the body, and for movement. • All the energy used in these ways returns to the environment, and is not available to the next trophic level.

40. Human Use of the Energy in Ecosystems • Two main revolutions have increased our energy demands on ecosystems and have reduced the amount of energy available to other organisms. • 1. Agricultural Revolution • 2. Industrial Revolution

41. End of Chapter 1 – class test on Tuesday, June 2nd.

42. Section 2.1 Cycling of Matter in Ecosystems • Please answer the following questions in your notebooks. Please use your textbook and provide complete answers. Define matter. • What is an organic compound? • What is an inorganic compound? • What does the term cycling (or recycling) mean? • What do we mean when we say that matter is recycled? • Is food organic or inorganic? Explain the “cycling” of organic matter within living things. • Decay is a process involved in the cycling of matter. Please explain this process. • Using the information in this section make a diagram (or drawing) to show how matter is cycled within an ecosystem. Please use the following terms and organisms in your explanation: plants, inorganic molecules, inorganic nutrients, soil bacteria, fecal matter, rabbit, fox, decomposing bodies. Please ensure that your diagram looks like a cycle. • Please complete Questions 1, 2, 4-6 on page 51.

43. Chapter 2Cycling of Matter in Ecosystems • Matter – anything that has mass & takes up space • Organic substances contain: • carbon • Hydrogen • Sometimes nitrogen • sometimes oxygen • Example: proteins, sugars, and fats. • Inorganic substances Do not contain the combination of carbon AND hydrogen. Ex: carbon dioxide (CO2), water (H2O) and ammonia (NH3).

44. Cycling of Organic Matter • Continuously being recycled. • Limited amount of materials found on the Earth means they must be recycled for life to continue. • Example: Carbon molecules are recycled over and over . some part of your body may contain a carbon molecule which was part of a dinosaur over 70 million years ago!

45. Cycling of Organic Matter

46. (Eaten by) (Eaten by) (Eaten by) • Plant Rabbit Fox (feces) (Turns it into) (Eaten by) • soil bacteria inorganic molecules plant roots plant

47. 2.2 Pesticides • Pests are organisms considered to be harmful or inconvenient (e.g. weeds, insects, fungi or rodents.)

48. Pesticides are chemicals designed to kill pests.

49. Why use pesticides? • 30% of the annual crop in Canada is lost to pests (i.e weeds, rusts, moulds, insects, birds and small mammals). This may increase the cost of food. • Malaria (causes fever and can lead to death) is transmitted by a mosquito. • Increases the yield of crops. • Prevents allergies from mold and mildew

50. First Generation Pesticides • 500 BC sulfur was used to repel insects • 15th century arsenic, lead and mercury were applied to crops as insecticides • 2 Problems: substances killed insects but were also highly poisonous to people AND these pesticides remained in the soil for a long time. • 1763 - gardeners began to use natural plant extracts ( uses the plants’ own chemical defenses) to kill insects.