Transcript A Study of an Ecosystem Powerpoint

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Syllabus
• You are required only to study any one
ecosystem,
• and to know five animals
• and five plants from your ecosystem.
Biodiversity in Ireland
Eco Eye, Series 9, Episode 2
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The study of an ecosystem involves studying a
number of sample habitats, as follows:
1. Mapping
2. identifying plants and animals
3. estimating the numbers of plants and animals
4. measuring the environmental (abiotic) factors
5. presenting the information
What to observe in an Ecosystem
Form a general overview of the area to be
studied:
Name the types of habitat within the
ecosystem as each habitat will have its own
populations of organisms which interact with
each other and with the non-living
environment.
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Habitats within the Woodland Habitat:
•
•
•
•
•
•
•
Soil,
ditch,
oak aerial system,
hedgerow,
stone wall,
oak root system.
Page 1 of Ecology Report
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Sketch of Ecosystem
1. Mark off the sample area by using poles with
string or flags or by other visible markers
2. Draw a sketch of Ecosystem including
features such as a road, wall, path, trees,
bushes etc
• Page 3 of Ecology Report
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ecosystem-video
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Organism Distribution
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Plants
Grasses
Clover
Buttercups
Dandelions
Daisies
Nettles
Poppies
Thistles
Dock
Primrose
Bluebell
Animals
H = herbivore, C = carnivore, O = omnivore,
D = detritus feeder (detritus is dead and decomposing
organisms)
Earthworms (D)
Caterpillars (H)
Rabbits (H)
Snails (H)
Ladybirds (C)
Badgers (O)
Slugs (H)
Bees (H)
Foxes (C)
Spiders (C)
Wasps (H, C)
Hedgehogs (O)
Beetles (C, H, O)
Butterflies (H)
Thrushes (C)
Aphids (H)
Moths (H)
Blackbirds (O)
Qualitative survey
A study determining the types of plants or
organisms presence/absence in a habitat.
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Carry out a qualitative study and note the
diversity of flora and fauna in the
ecosystem.
1. Use an identification Key to identify five
animals and five plants
2. Note the habitat in which each organism was
found.
3. Note a structural or behavioural adaptation of
the organism.
4. Repeat this procedure to identify any five
plants Identify
•Page 4 of Ecology Report
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Keys
• A key asks questions which pinpoint one
feature after another of an organism and, in a
stepwise fashion enable us to identify it.
• A simple key consists of pairs of questions to
which you answer ‘yes’ or ‘no’
• You then look to the right of the set of
questions, and using the number indicated,
move down to the correct set of alternatives.
• Continue to do this until a name is reached,
often accompanied by a drawing, which
matches your specimen
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ECOSYSTEM
FAUNA
FLORA
Woodland
Owl, woodlouse, deer,
centipede.
Arum lily, oak tree,
ivy, holly, moss
Grassland
Slug, snail, earthworm, Daisy, grass,
field mouse, spider.
dandelion, clover,
plantain
Hedgerow
Butterfly, wren, rabbit,
hover fly, hedgehog
Herb Robert,
blackthorn, cow
parsley, goose
grass, hawthorn.
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Sampling
1. Random sampling – avoids bias and ensures
that all areas within a habitat have an equal
chance of being sampled by using a quadrat.
2. Systematic sampling – here samples are taken
at regular intervals throughout the study area.
This type of sampling is used where there is
an obvious environmental gradient e.g. on a
rocky seashore.
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Quantitative survey
• Quantitative Study provides a record of the
numbers of plants and animals present in a
sample area of the selected ecosystem
• A quantitative study of plants and animals of a
sample area of the selected ecosystem is
carried out using
1. Percentage frequency and
2. percentage cover techniques.
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Collecting plants and animals involves some of
the methods shown in the table below
Device
Procedure
Collected
Knife
Cut
Plants,
Trowel
Dig
Pooter
Suck
Plants, animals in
soil
Insects
Beating Tray
Shake bushes
Crawling animals
Pitfall trap
Sink into soil or
sand
Crawling animals
Sweep net
Sweep through
grass
Insects
A Quadrat
• Usually square shaped
• A frame that forms a known area usually
0.5m X 0.5m = 0.25m2
• Used for random sampling of plants or some
slow moving animals
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Gridded Quadrat
Page 6 of Report
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1. Determining the Percentage Cover
of Sedentary Species
• Can be measured using a gridded quadrat
• An area of ground occupied by aerial parts of
individual plants is examined and counted
• Results are expressed as a percentage of the
total quadrat area
• Results can be presented as a pie chart or
histogram.
• More than one plant may be hit/ present in
each grid, because plants overlap in layers
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Percentage Cover procedure
• Throw a quadrat at random
• Record the plant hit at each sampling point
• Repeat for a number of throws
• Tabulate results
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Quantitative % cover study of plants
lant Name
1
2
3
4
5
6
Quadrat throw
7
8
9
10 Total Hits Total Points
% Cove
No. of hit s
% Cover 
 100
Τot al no. of po int s
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Tabulation of results
Plant Name % Cover
Buttercup 20%
Daisy
12%
Dandelion 14%
Grass 46%
Other
8%
1
10
1
2
12
0
2
6
6
6
5
2
3
1
2
6
12
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Quadrat Throw
4 5 6 7
8 2 1 5
2 4 4 2
1 4 4 2
14 15 14 15
0 0 2 1
8
5
4
3
13
0
9
7
3
1
11
3
10
5
2
6
4
8
Total Hits
50
30
35
115
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Total Points % Cover
250 20%
250 12%
250 14%
250 46%
250 8%
Auto
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Calculations
Plot Graph
%
F
r
e
q
u
e
n
c
y
X axis = Organisms
Y axis = % Frequency
Page 5 of Report
Organisms
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% Cover
8%
20%
Buttercup
Daisy
12%
46%
14%
Dandelion
Grass
Other
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2. Percentage Frequency
• The probability of finding a named plant within
the sample area in a number of quadrats
• May be expressed as a percent of the total
number of quadrats sampled
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Percentage Frequency Procedure
1. Throw the quadrat randomly in the sample area
2. Record the presence or absence of a named
organism within each quadrat
3. Repeat for a number of throws
4. Tabulate results
Page 8 of Report
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A quantitative study of plants
Organism
1
2
3
Frequency
4
5
Frequency
Quadrat throw
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7
8
9
10 Total Frequency % Frequency
No. of quadratscontainingorganism
No. of quadratsthrown
If percentage is required multiply frequency by 100
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Tabulation of results
Organism Name% Frequency
Buttercup
50%
Daisy
40%
Dandelion
60%
Grass
40%
1
Y
N
Y
N
2
N
Y
N
N
3
N
N
N
Y
Quadrat Throw
4 5 6 7
Y Y N Y
N N Y Y
Y Y Y N
Y N N N
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N
N
Y
Y
9
Y
Y
Y
Y
10 Total Frequency % Frequency
N 5
5/10
50
N 4
4/10
40
N 6
6/10
60
N 4
4/10
40
% Frequency
Auto
Calculations
60%
50%
40%
% Frequency 30%
% Frequency
20%
10%
0%
Buttercup
Daisy
Dandelion
Grass
Plant name
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Conduct a Quantitative Survey of Plants
and measure 3 abiotic factors
Method: Line Transect
1. Put a measuring tape straight across the habitat
2. Walk beside the line and record the name of
each plant touching the line at a certain point.
3. Repeat all along the length of the line transect.
4. Record 3 abiotic factors at each point
5. Combine the results to establish plant
distribution.
6. Relate the distribution to the variation of the
environmental factors.
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To conduct a quantitative study of organisms
along a belt transect
Record % cover or number of a named organism in each quadrat along the transect
Position of quadrat on belt transect
Organism Name
0
% Cover = No. of hits  100
No. of points on quadrat
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Measure Abiotic Factors
Page 9 of Report
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• Abiotic and biotic factors
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Choice of Habitat
Relationship between an organism’s suitability
to its habitat and abiotic factors to include a
measurement of any three abiotic factors:
• pH
• Temperature (air and
ground or aquatic)
• Light intensity
• Water current
• Air current
• Dissolved oxygen
• Mineral content
• Percentage air in soil
• Percentage water in soil
• Percentage humus
• Salinity
• Degree of exposure
• Slope
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Observe the influential abiotic factors i.e.
if it is exposed, sheltered, flat, on a slope,
what direction does it face, influence of
wind direction, intensity, drainage, etc.
What is the influence of the nonliving(abiotic) components on the flora
and fauna of the ecosystem?
Page 9 of Report
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Hygrometer - used to measure relative
humidity – composed of a wet and a dry
bulb thermometer.
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Wind speed - Anemometer
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Rainfall – Rainfall gauge is used to
measure the amount of rainfall in mm.
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Soil Temperature - Thermometer
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Air Temperature - Thermometer
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Light meter
Used to
measure the
light intensity
in units
called lux.
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Adaptations of Organisms to
their Environment
• Need to know structural, competitive or
behavioural adaptation by organisms
• Note an adaptation feature by any
organism in your selected ecosystem
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An adaptation is a process, change, method,
characteristic or feature that an organism or
species possesses, develops or evolves that
suits/adjusts the organism to its environment
to increase its chances of survival and reduce
competition.
Examples:
• Ladybird warning colouration
• Field mice are nocturnal: predator
avoidance.
• Page 11 of Report
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Adaptation
Benefit
Beak
Shape adapted to method of feeding e.g. pointed
beak suitable for probing the ground for
earthworms e.g. blackbird
Slimy mucus
Prevents e.g. snails, earthworms, etc. from drying
out as it travels across dry terrain
Body colour
Provides camouflage and protects animals from
predators e.g. woodlice
Sharp claws
For digging e.g. badger
Tail
Aids balance e.g. Squirrel on tree tops
Bright body
colour
Deters predators e.g. ladybird (also releases toxic
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fluids to deter predators)
Hairy skin and fur Traps a layer of air – insulation
Long canine teeth Kill prey and tear flesh
Speed of predator Usually faster than its prey
Long/big ears
Good hearing to detect predator
Nocturnal
Predator avoidance e.g. field mice
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Look for inter-relationships between the various living
organisms in the ecosystem
Explain and identify the role of the organism in
energy transfers.
Construct
1. food chains
2. A food web
3. A pyramid of numbers
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Identify and use various apparatus required
for collection methods in an ecological study
Collection apparatus
•Name:
•How used:
•Type of organism collected :
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Biodiversity
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Cryptozoic trap
• A piece of wood or
stone which is left on
the ground.
• After a suitable
interval, animals such
as slugs, woodlice,
centipedes and
millipedes will be
found underneath.
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Pitfall Trap
• Jam jar buried in
ground and covered
with raised flat stone.
• Used to collect
ground surface
animals insects,
nocturnal and diurnal
• e.g. spiders,
centipedes, woodlice,
beetles, etc.
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Mammal Trap
• Used to collect
small
mammals
• e.g. mice,
voles, etc.
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Insect net
• Used for catching flying
insects.
• The net part should be
sufficiently long so that
the mouth frame seals off
the end of the net which
contains the catch when
the net is laid flat.
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Sweep Net
• Used to collect
insects from tall
grass
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Beating tray
• This is a white tray, cotton
sheet or large sheet of
white paper.
• It is placed under a bush
or tree branch.
• The tree branch is shaken
suddenly and vigorously.
• Insects and other
invertebrates fall onto the
tray.
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Pooter
• Used for picking up very
small animals.
• Suck through
mouthpiece (end of
which is covered with
muslin) and the animal
is taken into jar through
the hose.
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Sieve
• Organisms that live
in leaf litter can be
extracted by using a
sieve with a mesh
size of about 5 mm.
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Tullgren Funnel
• Used to extract animals
from soil by heating the
soil on one side
• The animals are driven
out of the soil by heat
from a lamp and fall
through a wire gauze
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Collection Methods
Method
Used for collecting
Small nocturnal animals
e.g. slugs, woodlice
Small animals that walk along
Pitfall
the surface of the ground
e.g. beetles, spiders
Tullgren
Small animals from leaf litter and
funnel
soil samples e.g. worms, spiders
Insects and spiders from the surface
Pooter
of leaves and leaf litter
Sweep
Insects from long grass and vegetation
Mammal trap Small mammals e.g. mice , shrew
Cryptozoic
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Conduct a Quantitative Survey of fast moving
Animals, e.g. fieldmouse population
Day 1
1. Capture field mice using small mammal
traps.
2. Record the number of captured mice e.g. 20.
3. Mark each with a dab of red paint on the
belly surface.
4. Release each at their capture site.
5. Allow time for the mice to readjust to normal
conditions.
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Day 2
1. Capture field mice as before.
2. Record the number captured e.g. 18.
3. Record the number of recaptures (marked
mice) e.g. 6.
4. Return the mice to the habitat at their
capture site.
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• the capture–recapture method, i.e.
Number =
C 1st × C 2nd
_____________
M 2nd
Calculation:
Population = Day 1 Captures x Day 2 Captures
Number of Recaptures
= 20 x 18
6
= 60 mice
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Analysis
Prepare a brief report of the results
obtained
Identify possible sources of error in such a
study.
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Errors During Fieldwork
1. Bias: purposely choosing sample sites to
get ‘good results’ or avoid work.
2. Too Few Sample Sites: may not give
accurate representative results.
3. Surveyor Variation: students vary in ability,
commitment and interest.
4. Equipment Quality: measurement and
trapping success will be affected.
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5. Changing Nature: results may depend on the
time of day, season or year.
6. Chance: cannot survey every square centimeter
so even with many sites some species may be
missed.
7. Improper Trapping Techniques: all evasive
species may not be captured and/or insufficient
numbers captured in follow up surveying.
• The study of an EcT
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CHAPTER 6
STUDY OF AN ECOSYSTEM
• A suitable key
is used to identify and name organisms.
• A qualitative study
records the presence or absence of species.
• A quantitative study
records the number of each species.
• Quantitative studies can be:
• subjective (i.e. a personal judgement is made as to the
number)
• objective (i.e. an independent method of calculating
numbers is used)
• Subjective methods are not recommended,
because they depend on individual judgements, which
may vary from person to person.
CHAPTER 6
STUDY OF AN ECOSYSTEM
• Errors may arise in the study of an
ecosystem in the following ways:
• mistakes may be made in judgement and
recording
• conditions change in the ecosystem over
time
• accidental discoveries may be made
• the habitats studied may not accurately
reflect the overall ecosystem
CHAPTER 6
STUDY OF AN ECOSYSTEM
• A quantative study of plants in a habitat involves using:
• quadrats, which are examined for:
(a) Percentage cover of plants or stationary animals.
(b) Frequency
• transects:
(a) Line transect (rope marked at intervals – record what
touches the line).
(b) Belt transect (equivalent to quadrats taken in a line –
methods used are the same as for quadrats).
CHAPTER 6
STUDY OF AN ECOSYSTEM
Three sample abiotic factors
Ecosystem
Sample factors
Rocky seashore
Measured by
Exposure to air
Air temperature
Wave action
and exposed habitats
Position on shore
Thermometer
Compare sheltered
CHAPTER 6
STUDY OF AN ECOSYSTEM
Three sample abiotic factors
Ecosystem
Sample factors
Measured by
Grassland
Air temperature
Thermometer
Soil pH
indicator
Light intensity
pH meter or universal
Light meter
CHAPTER 6
STUDY OF AN ECOSYSTEM
Effects of abiotic factors
Ecosystem
Abiotic factor
Influence
Rocky seashore Exposure
Different species of
wrack and animals are
found on different
zones of the shore
Temperature
Periwinkles are
arranged along a
temperature gradient
Wave action
High wave action
forces plants higher on
the shore,
and favours
species with narrow
fronds
CHAPTER 6
STUDY OF AN ECOSYSTEM
Effects of abiotic factors
Ecosystem
Abiotic factor
Grassland
Air temperature
differences in different
grassland
plants (and animals)
Influence
Temperature
parts of the
will affect how well the
grow
Soil pH
Soil pH will favour
some plants and
therefore some
animals
Light intensity
at higher light
Grasses grow better
intensities
CHAPTER 6
STUDY OF AN ECOSYSTEM
• Organisms show many adaptations that allow them to
survive in their habitat.
• The results of a study
can be presented in tables,
lists,
charts,
graphs,
diagrams, etc.
• The results of a study should include food chains, food
webs, and pyramids of numbers.
• The work carried out in Activities 2–5 should be
presented in a portfolio.