1. National 5 Biology Unit 3
Life on Earth
Lesson 2

2. Section 3. 16 – Biodiversity and the Distribution of Life
By the end of this section you should be able to:
Describe the terms biodiversity, habitat and ecosystem.
Describe biotic, abiotic and Human influences that affect biodiversity in an ecosystem.
Describe biotic factors include grazing and predation.
Describe the effect of human influence on biodiversity in an ecosystem e.g. deforestation and desertification.
State that pH and temperature are abiotic factors.
State that Biomes are regions of our planet distinguished by their similar climate, flora and fauna.
State that global distribution of biomes can be influenced by temperature and rainfall.
State that an ecosystem consists of all organisms living in a particular area and the non-living components with which the organisms interact.
State that a niche is the role that an organism plays within a community
Give examples of organisms’ interactions with others in the community including competition, parasitism, and predation.

3. The members of the community are interdependent.
Animals and micro-organisms depend on the plants for:
FOOD AND OXYGEN

4. Plants and animals depend on micro-organisms for:
Decomposing waste and releasing nutrients into the environment.

5. Animals depend on the plants for:
SHELTER AND CAMOUFLAGE

6. Plants depend on the animals for:
SEED DISPERSAL AND POLLINATION

7. What is a biotic factor?
A 'biotic factor' is any living component that affects another organism.

8. E.g. Grazing / Predation

9. Affects on Grazing on Biodiversity
Low - small number of vigorous species dominate, reducing biodiversity.
Medium/High – gives other species a chance to compete, increasing biodiversity.
Very high - damages all species, reducing biodiversity.

10. The effect of grazing on biodiversity
Grazing is a biotic factor which affects biodiversity in an ecosystem.
Complete sheet 13 and 14

11. Low levels – small number of vigorous species dominate reducing biodiversity
Medium/High levels – gives other species a chance to compete increasing biodiversity (weaker species thrive)
Very High – damages all species, reducing biodiversity
Very High
Low
Medium
High

12. What is an abiotic factor?
An ‘abiotic factor' is any non-living component that affects an organism.

13. pH Temperature Some plant species prefer particular pH ranges.
An increase in acidity in ponds can kill fish species
Species are adapted to specific temperature ranges.
A change from the norm can kill species.

14. Abiotic factors: Using resources in the ecosystem
What resources will an organisms use in its ecosystem?
Water
Sunlight
Nutrients

15. Measuring abiotic factors
LIGHT INTENSITY
Use a light meter
Direct sensor towards the light source
Read the correct scale

16. Measuring abiotic factors
TEMPERATURE
Use a thermometer/ temperature probe
Do not cover sensor
Read the correct scale

17. Measuring abiotic factorspH
Use a pH meter
Place the clean probe in the soil/water
Read the correct scale

18. Measuring abiotic factors
SOIL MOISTURE
Use a moisture meter
Place the clean probe into the soil
Read the correct scale

19. Location
Light Meter
Temperature
pH Meter
Soil Moisture

20. A ‘human factor' is any factor that is caused by humans.
What is a human factor?
A ‘human factor' is any factor that is caused by humans.

21. Humans have influenced the environment and in doing so the biodiversity within the ecosystems.

22. Deforestation Pollution Desertification
Can be toxic to species, reducing biodiversity.
Destroys habitats, reducing biodiversity.
Desertification
The formation of deserts from the persistent degradation of dryland ecosystems by variations in climate and human activities.

23. Natural disasters and the responses to them have a negative impact on biodiversity

24. Conservation
Preservation, protection, or restoration of the natural environment, natural ecosystems, vegetation, and wildlife.

25. Threatened with extinction
Endangered species
Threatened with extinction

26. Acid Rain

27. Fumes from industry power stations and cars cause acid rain.
What are the disadvantages of burning fossil fuels?
Fumes from industry power stations and cars cause acid rain.
…which damages buildings, plants and wildlife

28. Formation of Acid Rain
Acid rain forms when fossil fuels are burned. The products from this are released into the atmosphere e.g. sulphur dioxide where it dissolves in water in the clouds and then rains down on us.

29. Rain is naturally acidic since carbon dioxide dissolves in rain to produce ___________ acid.
The combustion of _________ fuels since the industrial revolution has (increased/decreased) the acidity of rain by adding more _______ _______ to the atmosphere.
The sulphur compounds in coal produce _________ __________ when they burn. This dissolves in the rain eventually producing ___________ acid (H2SO4).
Cars with petrol engines produce another problem. The high temperature spark causes the ______ and _________ from the air to combine to produce _________ _________ (e.g. NO2). This gas dissolves in water forming _________ acid (HNO3)
The presence of all three gases, (CO2, SO2 and NO2), increases the acidity of the rain. Acid rain causes several problems.
carbonic
fossil
Carbon dioxide
Sulphur
dioxide
sulphuric
nitrogen
oxygen
Nitrogen oxides
nitric

30. Areas of Europe Effected by Acid Rain

31. Acid rain damages stonework all over the world
Germany
London
Egypt

32. Effects on trees and fish?