ECOLOGY

1. ECOLOGY Dominican College, Griffith ave.

2. Section 1 – Factors affecting Organisms

3. Environmental Factors Affecting Organisms • Environmental Factors • Abiotic Factors • Biotic Factors • Climatic Factors • Edaphic Factors • Aquatic Factors

4. Abiotic Factors These are non-living factors and include: • Currents: Plants and animals get washed away. There is a need for attachments. eg Limpets have a muscular foot: Seaweeds have holdfasts • Steepness: Steep slopes lose water quickly. Fewer organisms will grow higher up the shore where it is very steep

5. Abiotic Factors • Exposure: Plants and animals lose water when the tide is out. To prevent dessication, plants and animals have shells or mucilage. • Aspect: This is the direction a surface faces. South facing slopes have more plant growth.

6. Biotic Factors These are living Factors: • Food: The more available food, the more organisms that will survive. eg More plankton…more limpets…more dog whelks • Predation: These reduce the number of prey. eg More dog whelks…less limpets

7. Biotic Factors • Humans: May have a negative effect on the environment. eg Pollution • Competition: Competition for scarce resources (food/space/light/mates). eg Limpets and barnacles compete for space on a rock. Seaweeds compete for light

8. Climatic Factors Refers to weather over a period of time • Temperature: Determines the rate of reactions. eg the amount of growth in a plant • Salinity: Organisms need to be specialised to live in such a harsh environment like saltwater (Crabs have osmoregulators)

9. Climatic Factors • Light Intensity: This affects the rate of photosynthesis. eg Plankton grows best in the upper layers of water due to the higher rate of light intensity. • Humidity: The more the humidity, the less the evaporation.

10. Edaphic Factors Pertaining to soil. • Soil Type: Sandy soil loses water while clay soil retains • Soil pH: Plants are adapted to specific soil pH’s. • Humus: Vital to plant life. Binds soil particles…retains water and minerals… provides food for worms.

11. Edaphic Factors • Air Content: Oxygen is essential for life. • Water content: Essential for life. • Mineral content: Necessary for healthy growth.

12. Aquatic Factors • Light: May not penetrate too far down into the water. • Currents: May wash away organisms. • Wave Action: May physically damage organisms. • O2 Conc: Not as plentiful in water as Air.

13. Section 2 – Energy flow

14. Trophic Levels This refers to the feeding level/stage to which an organism belongs Trophic Level 1 Producer Trophic Level 2 Primary Consumer Trophic Level 3 Secondary Consumer Trophic Level 4 Tertiary Consumers (PROBABLY the top carnivore)

15. Energy Flow All food is ‘grass’. ‘Grass’ absorb only 1% of the suns energy. Producers only pass 10% of their energy to the next trophic level. For this reason food chains are limited. In general should only have a max of 4 trophic levels.

16. Food Chain The simplest way to represent the flow of energy in an ecosystem. Plankton Limpet Whelk Producer Primary Secondary Consumer Consumer

17. Food Web Two or more interlinked food chains.

18. Food Web Two or more interlinked food chains.

19. Section 3 – Definitions

20. Ecology • The study of the interactions between living things (organisms) and between organisms and their environment.

21. Biosphere • That part of the planet containing living organisms. The biosphere is the living world. It extends high into the atmosphere, to the bottom of the ocean, and deep down into caves.

22. Ecosystem This is a group of clearly distinguished organisms that interact with their environment as a unit.

23. Habitat A habitat is a place in which you find animals and plants. The kind of animals and plants which can live in a habitat depend upon what the habitat is like. Is it very hot or cold? Is it very wet or dry?

24. Producers & Photosynthesis Green plants are producers: this means that they use the sun's energy in photosynthesis to produce new living material. All food chains start with a producer.

25. Carnivores & Herbivores Animals, fungi and bacteria are all consumers. They get their energy by eating other living things. Primary consumers eat plants, we also call them herbivores. Some herbivores, like limpets, graze on plants. Carnivores are secondary consumers, they eat other animals.

26. Carnivores

27. Omnivores Some animals can choose between being a herbivore and being a carnivore: they eat both animals and plants and they are called omnivores. They are either primary or secondary consumers.

28. Scavengers Scavengers are also consumers, but they wait for their prey to die first. eg. Sandhoppers and bacteria

29. Niche***** This is the functional role of an organism in an ecosystem or habitat (The feeding role of the organism). • What it eats • What it is eaten by • How it interacts with others and with its abiotic environment.

30. Pyramid of Numbers Represents the number of organisms at each stage (trophic Level) in a food chain. (Makes it easy to compare numbers at a glance).

31. Pyramid of Numbers Cntd Normal Pyramid of Numbers: Gull Starfish Mussels Plankton

32. Pyramid of Numbers Cntd Inverted Pyramid of Numbers: Hawk Oak Tree Blackbirds Spiders GreenFly

33. Pyramid of Numbers Cntd Inverted Pyramid of Numbers:

34. Pyramid of Numbers Cntd Parasitic Pyramid of Numbers: Rose Bush Mites GreenFly

35. Section 4 – Recycling

36. Nutrient Recycling This is the way in which elements or minerals are: • Absorbed by organisms • Released when organisms die • Absorbed by other organisms Elements are exchanged between the living and non-living components

37. The Carbon Cycle Carbon is normally exchanged in the form of CO2. The carbon cycle is the way in which CO2 is taken from and added to the environment

38. The Carbon Cycle

39. The Carbon Cycle

40. The Carbon Cycle

41. The Carbon Cycle 3 groups of organisms have roles to play. • Plants – Remove Carbon by Photosynthesis and release it by Respiration • Animals obtain Carbon by eating plants and release it by Respiration • Microbes decompose dead materials and return Carbon to the environment

42. The Nitrogen Cycle

43. The Nitrogen Cycle

44. The Nitrogen Cycle

45. Human Impact on ecosystems • Pollution • Conservation • Waste Management

46. A) Pollution Any undesirable change to the environment. • Domestic – household waste • Agricultural – disposal of slurry sileage effluent as well as overuse of fertilisers • Industrial – smoke causing acid rain

47. Case Study 1: Air Pollution and the Depletion of the Ozone Layer Ozone is a gas that surrounds the earth and protects the earth from the harmful UV rays. The Cause: It is being depleted by the use of: • CFC’s in aerosols • Freon gas in fridges • Industrial detergents

48. Case Study 1 The Effects: • Increased numbers of skin cancers • Serious damage to crops • Concern that Plankton numbers will be depleted……less food……less organisms

49. Case Study 1 The Control: • Reduction of use of CFC’s • Replacement of CFC’s with HFC’s which break down more quickly • Don’t dump fridges into landfill which will release the freon gas.

50. Case Study 2 – Excessive Fertiliser or Animal Waste on Grassland The Cause: • Excessive fertiliser or animal wastes may wash into streams.