Download National 5 Biology Unit 3

National 5 Biology
Unit 3
Life on Earth
Lesson 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.
The members of the community are interdependent.
Animals and microorganisms depend on
the plants for:
FOOD AND OXYGEN
Plants and animals depend on micro-organisms for:
Decomposing waste and releasing nutrients into the
environment.
Animals depend on the
plants for:
SHELTER AND
CAMOUFLAGE
Plants depend on
the animals for:
SEED DISPERSAL
AND
POLLINATION
What is a biotic factor?
A 'biotic factor' is any living component that affects another
organism.
E.g. Grazing / Predation
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.
The effect of grazing on biodiversity
Grazing is a biotic factor which affects biodiversity in an
ecosystem.
Complete
sheet 13
and 14
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
Low
Medium
High
Very
High
What is an abiotic factor?
An ‘abiotic factor' is any non-living component that affects an
organism.
pH
Temperature
Some plant species
prefer particular pH
ranges.
Species are adapted
to specific
temperature ranges.
An increase in acidity
in ponds can kill fish
species
A change from the
norm can kill species.
Abiotic factors: Using resources in the
ecosystem
What resources will an organisms use in its ecosystem?
•Water
•Sunlight
•Nutrients
Measuring abiotic factors
LIGHT INTENSITY
Use a light meter
Direct sensor
towards the light
source
Read the correct
scale
Measuring abiotic factors
TEMPERATURE
Use a thermometer/
temperature probe
Do not cover sensor
Read the correct
scale
Measuring abiotic factors
pH
Use a pH meter
Place the clean probe
in the soil/water
Read the correct
scale
Measuring abiotic factors
SOIL MOISTURE
Use a moisture meter
Place the clean probe
into the soil
Read the correct
scale
Location
Light
Meter
Temperature
pH
Meter
Soil
Moisture
What is a human factor?
A ‘human factor' is any factor that is caused by humans.
Humans have influenced the
environment and in doing so the
biodiversity within the ecosystems.
Deforestation
Pollution
Destroys habitats,
reducing biodiversity.
Can be toxic to
species, reducing
biodiversity.
Desertification
The formation of deserts from
the persistent degradation of
dryland ecosystems by variations
in climate and human activities.
Natural disasters and the responses to
them have a negative impact on
biodiversity
Conservation
Preservation, protection, or restoration
of the natural environment, natural
ecosystems, vegetation, and wildlife.
Endangered species
Threatened with extinction
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
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.
Rain is naturally acidic since carbon dioxide
carbonic acid.
dissolves in rain to produce ___________
The combustion of _________
fuels since the
fossil
industrial revolution has (increased/decreased)
Carbon _______
dioxide
the acidity of rain by adding more _______
to the atmosphere.
Sulphur
The sulphur compounds in coal produce _________
__________
dioxide when they burn. This dissolves in the
sulphuric acid
rain eventually producing ___________
(H2SO4).
Cars with petrol engines produce another problem.
nitrogen
The high temperature spark causes the ______
oxygen from the air to combine to
and _________
Nitrogen_________
oxides (e.g. NO2). This gas
produce _________
dissolves in water forming _________
acid (HNO3)
nitric
The presence of all three gases, (CO2, SO2 and
NO2), increases the acidity of the rain. Acid rain
causes several problems.
Areas of Europe Effected by
Acid Rain
Acid rain
damages
stonework
all over the world
Germany
London
Egypt
Effects on trees and fish?