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Class Level and Curriculum Links
Leaving Certificate Biology:
1.5.4 Choice of Habitat
1.5.7 Analysis
Investigating plant zonation
on bogs using a belt transect
Aims
1. to describe the topography of the bog surface.
2. to measure the depth of the water table
3. to study the distribution of plants on the bog in relation
to surface topography and the water table depth.
4. to measure the pH of the bog water and peat soil.
5. to relate adaptations in the structure of the bog plants to
the habitat in which they grow.
Method
Set up a belt transect on the bog surface where there is a clear
undulating pattern of hummocks, lawns and pools. Each member
of the group should record a half metre distance or one station
along the transect on the work sheet provided overleaf.
1. Lay a tape measure along the bog surface to show the position
of the transect.
2. Insert a series of bamboo rods at 1 metre intervals along
the transect, using the tape measure as a guide.
3. Tie string between each rod. Make sure it is level across
the transect.
4. Lay down a series of 50cm2 quadrats along the transect. Quadrat
1 lies between 0 and 50cm, and Quadrat 2 between 50 and 100cm.
5. Write a general description of the entire transect.
6. Measure the distance between the string and the bog surface
at 25cm intervals. Record the results. This gives a profile of
the transect and describes the topography of the bog.
7. Measure the percentage ground cover of at least five species
occurring along the transect, in each 50cm2 quadrat. First identify
all the species present, then record their cover. Note: the total
cover in a quadrat can be more than 100%. This is because there
is more than one layer of plant types present. In bogs there
is a dwarf shrub layer, a herb layer, and a moss layer. Each
layer can cover 100% of the quadrat.
8. Record the presence of open water and the depth of the water.
Measure the pH of the water and the peat soil.
9. Plot the profile of the bog surface, the water table and a
series of separate histograms of the percentage cover of each
plant species along the transect.
10. Interpret the results. Describe the structure of the bog
surface and the degree of wetness of each zone. Describe the
distribution of plants according to the different zones by comparing
the profile diagram with each plant cover histogram. Link the
structural adaptations of the plants to the zone in which they
grow on the bog. Prepare a report on this investigation.
| Section Number | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Distance (m) | 0.25 | 0.75 | 1.25 | 1.75 | 2.25 | 2.75 | 3.25 | 3.75 | 4.25 | 4.75 | 5.25 | 5.75 |
| Distance between bog surface and string (cm) | ||||||||||||
| Open water depth (cm) | ||||||||||||
| Plant name and % cover | ||||||||||||
Description of Belt Transect: ______________________________________________________________________________________
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