Quantitative Analysis of Three
Ecosystems for Leaving Certificate
Biology
Co.Wexford Education Centre Teacher Design Team
2005-2006
Catherine Doyle
Louise Murphy
Pat O’Leary
Margaret O’Neill
Contents
Introduction
Page 3
The Rocky Seashore
Page 6
The Woodland
Page 15
The Grassland
Page 21
Acknowledgements
We would like to acknowledge the support of the Biology Support
Service. We would also like to extend our appreciation to
Co. Wexford Education Centre for the provision of their facilities.
Finally our thanks go to the principals of the following schools for
their understanding and support.
Gorey Community School.
Bunclody Vocational College.
Loreto Secondary School, Wexford.
F.C.J. Secondary School, Bunclody.
2
Introduction
This booklet has been designed with a view to providing help for
teachers with the practical part of the Ecology section of the
Leaving Certificate Biology syllabus. Three ecosystems,
woodland, grassland and the rocky seashore were selected as
representative of the many available for study. Five plants and five
animals were chosen for each ecosystem and both Latin and
common names as well as photos are included for all organisms.
Tables with sample figures are provided to allow for calculation of
percentage frequency, percentage cover and population density. A
sample calculation for each is also included, accompanied by a
graphical representation of results.
Animals
Many animals in the woodland and grassland ecosystems can
easily be missed because they hide or move away when
approached. In order to identify these animals and to carry out a
quantitative study it is necessary to capture them by:
Mammal trap
Pitfall trap
Insect net
Pooter
3
Capture – Recapture Method
Once captured the animals should be counted and then marked in
such a way as not to endanger them or inhibit their activity. The
captured animals are released near to where they were captured. A
second visit is necessary. On the second visit the captured animals
are counted as before and the number of marked animals that were
recaptured is noted.
The following formula gives an approximation of the total
population of that animal in that ecosystem.
Total Population =
No. of animals caught on 1st visit x No. of animals caught on 2nd visit
No. of marked animals recaptured on the 2nd visit
Sample Calculation Total Population Field mouse
Number of animals caught and marked on 1st visit = 20
Number of animals caught on 2nd visit
=15
Number of marked animals caught on 2nd visit
=5
Total population = 20 x 15 = 60
5
4
Plants
In carrying out the percentage cover or population density study of
certain plants it must be decided before the field trip how the plants
are to be counted.
Example Ivy/Bramble
 If several branches of the same plant are inside the quadrat is
each one counted as one plant?
 Do you source the root of the plant and count that as one
plant? What if the root is outside the quadrat?
A decision on these types of questions should be agreed upon and
understood by all students involved in the study so as to ensure the
collection consistent data and keep human error to a minimum.
5
The Rocky Seashore
6
Seashore Introduction
For the study of the rocky seashore ecosystem we chose an area of
study 50m from upper to lower shore, 60m wide. This gave a total
area of 3000m2.
A belt transect was laid out and 10 quadrats were placed at 5m
intervals along its length. We have included a percentage cover
study for the seashore animals since many of them remain in situ.
Quadrats of side 0.5m were used to collect data for frequency and
population density tables.
0.5m Quadrat
Grid quadrats were used for percentage cover tables.
0.5m Grid Quadrat
The five plants (flora) and five animals (fauna) chosen are shown
below.
7
Flora and fauna of the seashore
Bladder Wrack
Fucus
vesiculosis
Limpet
Patella vulgata
Sea Lettuce
Ulva lactuca
Sea Anemone
Urticina felina
Gutweed
Enteromorpha
intestinalis
Barnacles
Chthamalus
stellatus
Serrated Wrack
Fucus serratus
Dog Whelk
Nucella lapillus
Eggwrack
Ascophyllum
nodosum
Edible
Periwinkle
Littorina
littorea
8
Percentage Frequency Seashore Plants
The presence or absence of each plant is recorded for each quadrat
as shown in the table below.
Plant
Bladder wrack Fucus vesiculosus x
Sea lettuce Ulva lactuca
x
Gut weed Enteromorpha intestinalis √
Egg wrack Ascophyllum nodosum x
Serrated wrack Fucus serratus
x
1 2
x x
x x
x √
x x
x x
Quadrat Number
3 4 5 6 7 8
√ √ √ √ √ √
x √ √ √ x x
√ x x x x x
x √ x √ √ √
x √ √ √ √ x
Total
9 10
√
x
x
√
x
% Frequency
7
3
3
5
4
Sample Calculation: Percentage Frequency of Bladder wrack
1. Count the number of quadrats in which the plant is present
= 7.
2. Divide by number of quadrats to get frequency
7/10 = 0.7
3. Multiply by 100 to get % frequency
0.7 x 100 = 70%
% Frequency Seashore Plants
70
60
Bladder wrack
Sea lettuce
Gut weed
Egg wrack
Serrated wrack
50
40
30
20
10
0
Plants
9
70
30
30
50
40
Percentage Frequency Seashore Animals
The presence or absence of each animal is recorded for each
quadrat as shown in the table below.
Animal
Limpets Patella vulgata
Sea Anemone Urticina felina
Barnacles Chthamalus stellatus
Dog whelk Nucella lapillus
Edible periwinkle Littorina littorea
x
x
√
x
x
1 2
x x
x x
√ √
x x
x x
Quadrat Number
3 4 5 6 7 8
x x √ √ √ √
x x x x √ √
√ x x x x √
√ x √ √ √ x
x √ √ √ √ √
Total
9
% Frequency
10
√
x
x
x
√
5
2
5
4
6
Sample Calculation: Percentage Frequency of Limpets
1. Count the number of quadrats in which the animal is present.
= 5.
2. Divide by total number of quadrats to get frequency.
5/10 = 0.5
3. Multiply by 100 to get % frequency.
0.5 x 100 = 50%
% Frequency Seashore Animals
60
50
Limpets
Sea Anemone
Barnacles
Dog Whelks
Edible Periwinkle
40
30
20
10
0
Animals
10
50
20
50
40
60
Percentage Cover Seashore Plants
A “hit” point is chosen in each square of the grid quadrat e.g. the
point of intersection of the vertical and horizontal lines. A pen is
placed at this point and if it touches an organism it is recorded as a
“hit” for that organism. In a 5x5 quadrat the maximum number of
hit points is 25. This procedure is repeated for each of the 10
quadrats and figures recorded as shown in the table below.
Plant
1
Bladder wrack Fucus vesiculosus 0
Sea lettuce Ulva lactuca
0
Gut weed Enteromorpha intestinalis 2
Egg wrack Ascophyllum nodosum 0
Serrated wrack Fucus serratus
0
Quadrat Number
2 3 4 5 6 7 8 9 10
0 0 20 23 16 20 25 6 12
0 0 0 5 3 1 0 0 0
0 10 3 0 0 0 0 0 0
0 0 0 3 0 2 14 20 8
0 0 0 18 10 21 0 0 0
Total Hits
% Cover
122
9
15
47
49
Sample Calculation: Percentage Cover of Sea Lettuce
1. Count total number of hits.
9
2. Divide by total number of possible hits.
9/250 = 0.036
3. Multiply by 100 to get percentage cover.
0.036 x 100 = 3.6%
% Cover Seashore Plants
Bladder wrack
Sea lettuce
Gut weed
Egg wrack
Serrated wrack
11
48.8
3.6
6
18.8
19.6
Percentage Cover Seashore Animals
A “hit” point is chosen in each square of the grid quadrat e.g. the
point of intersection of the vertical and horizontal lines. A pen is
placed at this point and if it touches an organism it is recorded as a
“hit” for that organism. In a 5x5 quadrat the maximum number of
hit points is 25. This procedure is repeated for each of the 10
quadrats and figures recorded as shown in the table below.
Animal
Limpets Patella vulgata
Sea Anemone Urticina felina
Barnacles Chthamalus stellatus
Dog whelk Nucella lapillus
Edible periwinkle Littorina littorea
1
0
0
7
0
0
Quadrat Number
2 3 4 5 6 7 8
0 0 0 0 1 1 1
0 0 0 0 0 0 1
20 3 1 0 0 0 0
0 0 2 0 8 2 3
0 0 0 6 2 1 3
Total Hits
9
0
1
1
1
0
10
2
0
0
0
4
% Cover
5
2
32
16
16
Sample Calculation: Percentage Cover of Barnacles
1. Count total number of hits.
32
2. Divide by total number of possible hits.
32/250 = 0.128
3. Multiply by 100 to get percentage cover.
0.128 x 100 = 12.8%
% Cover Seashore Animals
Limpet
Sea Anemone
Barnacles
Dog Whelk
Edible Periwinkle
12
2
0.8
12.8
6.4
6.4
Population Density Seashore Plants
The number of each plant in each quadrat is counted and recorded
as in the table below.
Plant
1
Bladder wrack Fucus vesiculosus
0
Sea lettuce Ulva lactuca
0
Gut weed Enteromorpha intestinalis 5
Egg wrack Ascophyllum nodosum
0
Serrated wrack Fucus serratus
0
1.
2.
3.
4.
2
0
0
0
0
0
Quadrat Number
3 4 5 6 7
0 3 2 3 4
0 0 6 11 1
18 3 0 0 0
0 0 5 0 4
0 0 4 4 5
Average Density (no./m2)
Total
8
4
0
0
2
6
9 10
1 2
0 0
0 0
3 1
0 0
19
18
26
15
19
1.9
1.8
2.6
1.5
1.9
Sample Calculation of Population Density for Gutweed:
Count the total number and divide by 10 to get the average.
26/10 = 2.6
Calculate the area of the quadrat
0.5m x 0.5m = 0.25m2(i.e.4 quadrats per m2)
To calculate the density, multiply the average by 4.
2.6 x 4 = 10.4 animals per m2
To calculate the total population, multiply the density by the
area of the ecosystem:
10.4 plants/m2 x 3000 m2 = 31200 plants
Population Distribution Seashore Plants
Bladder wrack
Fucus
vesiculosus
Sea lettuce Ulva
lactuca
Number of Plants
20
15
10
5
0
1
2
3
4
5
6
7
8
Quadrat Number
13
9
10
Gut weed
Enteromorpha
intestinalis
Egg wrack
Ascophyllum
nodosum
Serrated wrack
Fucus serratus
7.6
4.4
10.4
6
7.6
Population Density Seashore Animals
The number of each animal in each quadrat is counted and recorded
as in the table below.
Animal
1
Limpets Patella vulgata
0
Sea Anemone Urticina felina
0
Barnacles Chthamalus stellatus 10
Dog whelk Nucella lapillus
0
Edible periwinkle Littorina littorea 0
1.
2.
3.
4.
2
0
0
25
0
0
Quadrat Number
3 4 5 6 7 8
0 0 0 2 1 1
0 0 0 0 0 1
5 1 0 0 0 0
0 4 0 9 5 4
0 0 11 6 3 5
9
1
1
2
3
1
10
2
0
0
0
9
Total
Average
7
2
43
25
35
Density (no./m2)
0.7
0.2
4.3
2.5
3.5
2.8
0.8
17.2
10
14
Sample Calculation Population Density Dog Whelk
Count the total number and divide by 10 to get the average.
25/10 = 2.5
Calculate the area of the quadrat
0.5m x 0.5m = 0.25m2(i.e.4 quadrats per m2)
To calculate the density multiply the average by 4.
2.5 x 4 = 10
To calculate the total population, multiply the density by the
area of the ecosystem:
10 animals/m2 x 3000 m2 = 30000 animals
Number of Animals
Population Distribution Seashore Animals
Limpets Patella
vulgata
30
25
20
15
10
5
0
Sea Anemone
Urticina felina
Barnacles
Chthamalus
stellatus
Dog whelk
Nucella lapillus
1
2
3
4
5
6
7
Quadrat Number
14
8
9
10
Edible
periwinkle
Littorina littorea
The Woodland
15
Woodland Introduction
An area of study measuring 25m x 50m was marked off. This gave
a total area of 1250 m2.
Ten quadrats were chosen at random and data recorded for
percentage cover, percentage frequency and population density as
outlined in the tables below.
Quadrats of side 0.5m were used to collect data for frequency and
population density tables.
0.5m Quadrat
Grid quadrats were used for percentage cover tables.
0.5m Grid Quadrat
The five plants (flora) and five animals (fauna) chosen are shown
below.
16
Flora and fauna of the woodland
Wild Garlic
Earthworm
Allium
ursinum
Lumbricus
terrestris
Bluebell
Woodlouse
Hyacinthoides
non-scripta
Armadillidium
vulgare
Wood
Sorrel
Devils
Coach-horse
Oxalis
acetosella
Staphylinus
olens
Primrose
Harvestman
Primula
vulgaris
Phalangium
opilio
Lesser
Celandine
Ladybird
Coccinella
septempunctata
Ranunculus
ficaria
17
Percentage Frequency Woodland Plants
The presence or absence of each plant is recorded for each quadrat
as shown in the table below.
Plant
Bluebell Hyacinthoides non-scripta
Wood sorrel Oxalis acetosella
Wild garlic Allium ursinum
Primrose Primula vulgaris
Lesser celendine Ranunculus ficaria
1
X
√
X
√
√
2
√
√
√
X
√
Quadrat Number
3 4 5 6 7 8
X X √ √ √ X
√ X X X X √
√ X √ √ X X
X √ X √ √ √
√ X X X √ √
Total
9
X
√
X
X
√
10
√
X
√
X
√
% Frequency
5
5
5
5
7
Sample Calculation: Percentage Frequency of Primrose
1. Count the number of quadrats in which the plant is present
= 5.
2. Divide by total number of quadrats to get frequency.
5/10 = 0.5
3. Multiply by 100 to get % frequency.
0.5 x 100 = 50%
% Frequency Woodland Plants
70
60
50
40
30
20
10
0
Bluebell
Wood Sorrel
Wild Garlic
Primrose
Lesser Celendine
1
Plant
18
50
50
50
50
70
Percentage Cover Woodland Plants
A “hit” point is chosen in each square of the grid quadrat e.g. the
point of intersection of the vertical and horizontal lines. A pen is
placed at this point and if it touches an organism it is recorded as a
“hit” for that organism. In a 5x5 quadrat the maximum number of
hit points is 25. This procedure is repeated for each of the 10
quadrats and figures recorded as shown in the table below.
Plant
Bluebell Hyacinthoides non-scripta
Wood Sorrel Oxalis acetosella
Wild Garlic Allium ursinum
Primrose Primula vulgaris
Lesser celendine Ranunculus ficaria
1 2
0 10
2 7
0 3
5 0
3 7
Quadrat Number
3 4 5 6 7 8 9
0 0 14 16 13 0 0
5 0 0 0 0 3 12
8 0 3 4 0 0 0
0 10 0 9 7 5 0
2 0 0 0 7 4 3
Total Hits
10
3
0
3
0
0
Sample Calculation: Percentage Cover Bluebell
1. Count total number of hits.
= 56
2. Divide by total number of possible hits.
56/250 = 0.224
3. Multiply by 100 to get percentage cover.
0.224 x 100 = 22.4%
Percentage cover Woodland
Bluebell
Wood Sorrel
Wild Garlic
Primrose
Lesser Celendine
19
% Cover
56
29
21
36
26
22.4
11.6
8.4
14.4
10.4
Population Density Woodland Plants
The number of each plant in each quadrat is counted and recorded
as in the table below.
Plant
1
0
2
0
2
2
Bluebell Hyacinthoides non-scripta
Wood Sorrel Oxalis acetosella
Wild Garlic Allium ursinum
Primrose Primula vulgaris
Lesser celendine Ranunculus ficaria
2
4
4
1
0
4
Quadrat Number
3 4 5 6 7 8
0 0 6 7 5 0
3 0 0 0 0 1
5 0 1 2 0 0
0 3 0 2 1 2
1 0 0 0 3 1
Total
9
0
10
0
0
1
10
1
0
1
0
0
Density (no./m2)
Average
23
20
10
10
12
2.3
2
1
1
1.2
Sample Calculation of Population Density for Wild Garlic
1. Count the total number and divide by 10 to get the average.
10/10 = 1
2. Calculate the area of the quadrat
0.5m x 0.5m = 0.25m2
3. To calculate the Density: multiply the average by 4.
1x4=4
4. To calculate the total population, multiply the density by the
area of the ecosystem:
4 plants/m2 x 1250 m2 = 5000 plants
Population Distribution Woodland Plants
Bluebell
Hyacinthoides nonscripta
Wood Sorrel Oxalis
acetosella
Number of Plants
12
10
8
6
Wild Garlic Allium
ursinum
4
Primrose Primula
vulgaris
2
0
1
2
3
4
5
6
7
8
Quadrat Number
20
9
10
Lesser celendine
Ranunculus ficaria
9.2
8
4
4
4.8
The Grassland
21
Grassland Introduction
An area of study measuring 25m x 50m was marked off. This gave
a total area of 1250 m2.
Ten quadrats were chosen at random and data recorded for
percentage cover, percentage frequency and population density as
outlined in the tables below.
Quadrats of side 0.5m were used to collect data for frequency and
population density tables.
0.5m Quadrat
Grid quadrats were used for percentage cover tables.
0.5m Grid Quadrat
The five plants (flora) and five animals (fauna) chosen are shown
below.
22
Flora and fauna of the grassland
Dandelion
Woodlouse
Taraxacum
officinale
Armadillidium
vulgare
Plantain
Ladybird
Plantago major
Coccinella
septempunctata
Daisy
Aphid
Bellis perennis
Sitobian avenae
Rye Grass
Earthworm
Lolium perenne
Lumbricus
terrestris
Clover
Slug
Trifolium repens
Deroceras
reticulatum
23
Percentage Frequency Grassland Plants
The presence or absence of each plant is recorded for each quadrat
as shown in the table below.
Plant
Daisy Bellis perrenis
Dandelion Taraxacum officinale
Plantain Plantago major
Clover Triflolium repens
Grass Lolium perenne
1
√
x
x
√
√
2
√
x
√
√
√
3
x
√
√
√
√
Quadrat Number
4 5 6 7 8 9
x √ x x √ √
√ x √ x √ √
√ x √ √ x √
√ √ √ √ √ √
√ √ √ √ √ √
10
√
√
√
√
√
Total
% Frequency
6
6
7
10
10
60
60
70
100
100
Sample Calculation: Percentage Frequency of Plantain
1. Count the number of quadrats in which the plant is present.
=7
2. Divide by total number of quadrats to get frequency.
7/10 = 0.7
3. Multiply by 100 to get % frequency.
0.7 x 100 = 70%
% Frequency Grassland Plants
100
Daisy
80
Dandelion
60
Plantain
40
Clover
20
Grass
0
Plant
24
Percentage Frequency Grassland Animals
The presence or absence of each animal is recorded for each quadrat
as shown in the table below
Animal
Earthworm Lumbricus terrestris
Woodlouse Oniscus asellus
Slug Deroceras reticulatum
1
x
√
√
2
√
x
√
3
√
√
x
Quadrat Number
4 5 6 7 8 9
x √ √ x x √
x √ √ x x x
√ x x √ √ √
10
√
√
√
Total
% Frequency
6
5
7
60
50
70
Sample Calculation: Percentage Frequency of Woodlouse
4. Count the number of quadrats in which the animal is present.
= 7.
5. Divide by total number of quadrats to get frequency.
7/10 = 0.7
6. Multiply by 100 to get % frequency.
0.7 x 100 = 70%
% Frequency Grassland Animals
70
60
50
Earthworm
Woodlouse
Slug
40
30
20
10
0
Animal
25
Percentage Cover Grassland Plants
A “hit” point is chosen in each square of the grid quadrat e.g. the
point of intersection of the vertical and horizontal lines. A pen is
placed at this point and if it touches an organism it is recorded as a
“hit” for that organism. In a 5x5 quadrat the maximum number of
hit points is 25. This procedure is repeated for each of the 10
quadrats and figures recorded as shown in the table below.
Plant
Daisy Bellis perrenis
Dandelion Taraxacum officinale
Plantain Plantago major
Clover Triflolium repens
Grass Lolium perenne
1
17
0
0
12
17
2
9
0
21
16
19
Quadrat Number
3 4 5 6 7 8
0 0 19 0 0 21
9 21 0 14 0 18
15 6 0 24 20 0
21 24 17 4 8 21
25 20 12 18 24 16
9
16
12
8
23
24
10
11
7
22
17
21
Total Hits
% Cover
196
81
116
163
196
78.4
32.4
46.4
65.2
78.4
Sample Calculation: Percentage Cover of Plantain
1. Count total number of hits.
= 116
2. Divide by total number of possible hits.
116/250 = 0.464
3. Multiply by 100 to get percentage cover.
0.464 x 100 = 46.4%
% Cover Grassland Plants
Daisy
Dandelion
Plantain
Clover
Grass
26
Population Density Grassland Plants
The number of each plant in each quadrat is counted and recorded as
in the table below.
Plant
Daisy Bellis perrenis
Dandelion Taraxacum officinale
Plantain Plantago major
Clover Triflolium repens
Grass Lolium perenne
1.
2.
3.
4.
1
3
0
0
6
6
2
2
0
9
10
13
Quadrat Number
3 4 5 6 7 8
0 0 7 0 0 6
2 7 0 2 0 6
7 1 0 10 3 0
9 14 8 2 4 18
18 14 9 11 15 7
9
3
6
1
12
10
10
2
3
11
10
10
Total
Average
Density (no./m2)
23
26
42
93
93
2.3
2.6
4.2
9.3
9.3
9.2
10.4
16.8
37.2
37.2
Sample Calculation Population Density Dandelion
Count the total number and divide by 10 to get the average.
26/10 = 2.6
Calculate the area of the quadrat
0.5m x 0.5m = 0.25m2
To calculate the density multiply the average by 4.
2.6 x 4 = 10.4.
To calculate the total population, multiply the density by the
area of the ecosystem:
10.4 plants/m2 x 1250 m2 = 13000 plants
Population Distribution Grassland Plants
Number of Plants
20
Daisy Bellis perrenis
15
10
5
0
1
2
3
4
5
6
7
8
Quadrat Number
27
9 10
Dandelion
Taraxacum officinale
Plantain Plantago
major
Clover Triflolian
repens
Grass Lolium
perenne
Population Density Grassland Animals
The number of each animal in each quadrat is counted and recorded
as in the table below.
Animal
Earthworm Lumbricus terrestris
Woodlouse Oniscus asellus
Slug Deroceras reticulatum
1.
2.
3.
4.
1
0
3
2
2
1
0
1
Quadrat Number
3 4 5 6 7 8 9
4 0 7 2 0 0 1
6 0 2 7 0 0 0
0 2 0 0 5 3 3
10
3
8
2
Total
Average
Density (no./m2)
18
26
18
1.8
2.6
1.8
7.2
10.4
7.2
Sample Calculation Population Density Earthworm
Count the total number and divide by 10 to get the average.
18/10 = 1.8
Calculate the area of the quadrat
0.5m x 0.5m = 0.25m2
To calculate the density, multiply the average by 4.
1.8 x 4 = 7.2
To calculate the total population, multiply the density by the
area of the ecosystem:
7.2 animals/m2 x 1250 m2 = 9000 animals
Number of Animals
Population Distribution Grassland Animals
9
8
7
6
5
4
3
2
1
0
Earthworm
Lumbricus terrestris
Woodlouse Oniscus
asellus
Slug Deroceras
reticulatum
1
2
3
4
5
6
7
8
Quadrat Number
28
9
10