1. What is Ecology? 4 The study of living things in relation to each other and to their environment.

2. An Introduction to Ecology 4 Common Terms Used in Ecology: –Habitat –Population –Community –Ecosystem Source from: Environmental Science: Working With the Earth. (6th ed.)

3. The Ecosystem 4 A self-regulating community of plants and animals interacting with one another and with their non-living environment. 4 An ecosystem contains two basic components: –Physical factors –Biotic factors

4. The Ecosystem 4 These two factors affects the number, types, distribution, behaviour, and adaptation shown by organisms. Source from: Environmental Science: Working with the Earth. (6th ed.)

5. Physical Factors 4 Physical factors: –Temperature –Light –Wind –Water –Soil

6. Biotic Factors 4 Refer to all organisms in an ecosystem. They may interact with each other in more than one way. 4 Living organisms can be divided into three main classes: –Producers –Consumers –Decomposers

7. Energy flow within an ecosystem 4 Food Chain –Producers ----> Primary Consumers ----> Secondary Consumers -----> Tertiary Consumers –It represents the sequence in which food materials are transferred from one organism to another.

8. Energy flow within an ecosystem Source from: Environmental Science: Working with the Earth. (6th ed.)

9. Energy flow within an ecosystem Source from: Environmental Science: Working the Earth. (6th ed.)

10. Energy flow within an Ecosystem 4 Roles of Producers, Consumers and Decomposers in Relation to Energy flow. –Producers absorb light energy and convert them to chemical energy to be stored –Consumers feed on producers and one another, then energy transferred.

11. Energy flow within an Ecosystem –Decomposers When break down their food, and energy locked in the dead bodies, faeces and excretory products is released and lost from the ecosystem.

12. Energy flow within an Ecosystem 4 Food Webs –Food chains appear in interconnected forms which are called food webs.

13. Energy flow within an Ecosystem Source from: Environmental Science: Working the Earth. (6th ed.)

14. Energy flow within an Ecosystem 4 Trophic Levels –The position that an organism occupies in a food chain is called its tropic level. Source from: Environmental Science: Working the Earth. (6th ed.)

15. Energy flow within an Ecosystem 4 Energy Transfer between Trophic Levels Source from: Environmental Science: Working the Earth. (6th ed.)

16. Energy flow within an Ecosystem 4 Only 10% of energy used by the organism. Energy lost: –as heat during respiration –in activities, –through excretion, egestion and death. 4 Food chain rarely includes more than five trophic level. 4 Energy cannot be recycled and re-used.

17. Energy flow within an Ecosystem 4 Ecological pyramids. Source from: Environmental Science: Working the Earth. (6th ed.)

18. Energy flow within an Ecosystem 4 Pyramid of energy –The energy available for growth decreases along a food chain. 4 Pyramid of numbers –The drop in numbers of organisms at each trophic level 4 Pyramid of biomass –Biomass is the total mass of organisms in a trophic level.

19. Energy flow within an Ecosystem Source from: Environmental Science: Working the Earth. (6th ed.)

20. Cycling of Materials in Ecosystems 4 Carbon Cycle Source from: Environmental Science: Working the Earth. (6th ed.)

21. Cycling of Materials in Ecosystems 4 Nitrogen Cycle Source from: Environmental Science: Working the Earth. (6th ed.)

22. Ecological Interdependence of Organisms 4 In an ecosystem, organisms may interact with each other in many different ways: –Predation –Competition –Mutualism –Commensalism –Parasitism

23. Ecological Interdependence of Organisms 4 For each type of interrelationship, the organisms concerned may be benefited (+), harmed (-), or not affected (0) Type if interrelationshipOrganism 1 Organism 2 PredationPredator + Prey - Competition - - Mutualism + + CommensalismCommensal + Host 0 ParasitismParasite + Host -

24. Man and Micro-organisms

25. Micro-organisms 4 Micro-organisms are very small organisms that can be only seen by a microscope. 4 There are 5 major types of micro-organisms: â Bacteria â virus â fungi â protozoa â algae

26. Useful Micro-organisms 4 Wine and Bread Making: Anaerobic bacteria + Sugar --> Alcohol + CO 2 4 Bacteria and Fungi as Decomposers 4 Symbiotic Bacteria in Leguminous Plants 4 Bacteria and Fungi in Sewage Disposal 4 Antibiotics

27. Harmful Micro-organisms 4 Causing Diseases. 4 Spoilage of Food and Useful Materials

28. Food Preservation 4 Food is preservation so that they can be transported long distance and stored for long periods. 4 Food preservation is designed to kill the micro-organisms and/or slow down their growth rate.

29. Common Food Preservation Methods 4 Heating 4 Canning and bottling 4 Pasteurization 4 Refrigeration 4 Freezing 4 Drying (Dehydration) 4 Smoking

30. 4 Pickling 4 Osmotic preservation 4 Ultra high temperature (UHT) treatment 4 Adding preservatives Common Food Preservatives Methods Pickling food. Source from: Biology: A Modern Approach 2. (2nd ed.)

31. Man’s Effect on His Environment

32. Land Use 4 Monoculture means remove diversity of species of plant from a place and replace it with a dense single species year after year. 4 Deforestation is uncontrolled cutting down or burning of trees.

33. Effects of Deforestation Source from: Environmental Science: Working the Earth. (6th ed.)

34. Pollution 4 Pollution is the introducing of substance to air, water, soil, or food that threatens the health, survival, or activities of human or other living organisms. 4 Pollutants is the chemical or forms of energy that can causes pollution.

35. Air pollution 4 Pollution of atmosphere. 4 Causing by burning fossil fuels in power plants, factories and vehicle engines. Vehicle engines produce air pollutants such as CO, lead, and dust particles.

36. Major Air Pollutants 4 Carbon Monoxide. 4 Carbon Dioxide. 4 Sulphur Dioxide and Nitrous Oxides. 4 Carbon and Dust Particles. 4 Lead 4 Radioactivity.

37. Formation of Smog In normal condition, the warm and polluted air can be dispersed into high attitudes. When temperature inversions occurs, the cool air is trapped by the warm air above, so the polluted air cannot be dispersed and remains in the city. Source from: Environmental Science: Working the Earth. (6th ed.)

38. Water Pollution 4 Pollution of water bodies such as steams, lakes and seas. 4 Caused by discharge of domestic, industrial and agricultural wastes to the water bodies.

39. Acid Rain Formation Source from: United States Environmental Protection Agency.

40. Major Types of Water Pollution 4 Chemical pollution. 4 Sewage and Manure. 4 Detergents and Inorganic Fertilizers. 4 Oil Pollution. 4 Thermal Pollution.

41. How Red Tides Kill Aquatic Organisms? 4 Rich nutrients in pollutants leading to algal bloom. 4 The dead bodies of algae provide nutrients for the growth of saprophytic bacteria, leading rapid increase of tits population. 4 The bacteria kills the aquatic organisms in three ways:

42. 4 Use up the oxygen in water. 4 Accumulate in gills of organisms. 4 Excrete toxins which may kills the organisms.

43. Noise Pollution 4 Noise is any unpleasant sound in the environment. 4 Common noise is come busy traffic, piling, aircraft, or playing mah-jong in mid- nigh,etc. 4 The degree of loudness is measured in decibels. (db) 4 Noise above 60db is harmful to human.

44. Conservation 4 Conservation is the management of environment in a planned and sustainable way so that the environment is least disturbed and able to yield the best benefits to mankind. Source from: Environmental Science: Working the Earth. (6th ed.)

45. Needs of Conservation 4 To meet the needs of ever increasing human population, mankind exploited environment in insensible ways. 4 These activities deplete the environment and deprived the natural, leading the Earth become unsuitable for all forms of life, including the human himself. 4 Conservation must be taken to save the ecosystem and human himself.

46. The Principle of Conservation 4 Recycling of Used Materials. 4 Pollution Control. 4 Conservation of Wild Life. Africa elephants were killed their tooth to make ivory goods. Legislation of abandon trading of ivory goods was established in 1989. Source from: Environmental Science: Working the Earth. (6th ed.)

47. Sewage Treatment Source from: Water Supplies Department, HKSAR.