Random Sampling and Comparing Meadows
Name:
Introduction
The task presented to you will allow you to use random sampling in a controlled environment to
measure the abundance of various different species on a area of Grassland located in Waun Las
National Nature Reserve in the UK.
Working in pairs you will be given the opportunity to explore two different ways of measuring
abundance:
•
density: the number of individual plants in a quadrat
•
frequency: the proportion of quadrats each species occurs in
In your pairs you will measure these 2 forms of abundance on 2 separate quadrates located in
different locations. These quadrate will be designated to you.
The Sites
Site A is a species-rich hay meadow, which is managed organically and traditionally, allowing time
for plants to flower and seed. It is low in nutrients, fairly damp and high in plant diversity. The
yellow rattle, a hemiparasite which gains some of its nutrients from the roots of neighbouring
palnts, has significantly helped to reduce the dominance of large leaved grasses.
Site B is an agriculturally-improved cattle-grazed meadow. Here, the nutrient levels are fairly high,
bulky grasses dominate and it is low in plant diversity.
Practical
In you pairs locate your designated quadrat for site A using the following link:
http://www-saps.plantsci.cam.ac.uk/ecology/siteA/
Using your species identification (density) results table try and measure the species density in your quadrat
i.e. the number of plants of the species in table in your quadrat.
Record your findings in the following table:
Plant
Number of plants
Common mouse-ear
Anthoxanthum oderatum
Meadow buttercup
Ranunculus acris
White clover
Trifolium repens
Common sorrel
Rumex acetosa
Others
Next try to measure frequency by recording the presence and absence of a species from your quadrat.
Use the table below to record your findings
Plant (common name)
Plant (Latin name)
Present
Absent
Common mouse-ear
Anthoxanthum oderatum
Marsh thistle
Cirsium palustre
Common spotted orchid
Dachtylorhiza fuchsii
Catsear
Hypochoeris radicata
Field woodrush
Luzula campestris
Lousewort
Pedicularis sylvatica
Ribwort plantain
Plantago lanceolata
Yellow rattle
Rhinanthus minor
Common tormentil
Potentilla erecta
Meadow buttercup
Ranunculus acris
Creeping buttercup
Ranunculus repens
Common sorrel
Rumex acetosa
Dandelion
Taraxacum officinale
White clover
Trifolium repens
Nettle
Urtica dioica
Once you have recorded for findings from Site A repeat the methods used for Site B which be
located using the following link:
http://www-saps.plantsci.cam.ac.uk/ecology/siteB/
Species density table. Site B
Plant
Number of plants
Common mouse-ear
Anthoxanthum oderatum
Meadow buttercup
Ranunculus acris
White clover
Trifolium repens
Common sorrel
Rumex acetosa
Others
Species Frequency table. Site B
Plant (common name)
Plant (Latin name)
Common mouse-ear
Anthoxanthum oderatum
Marsh thistle
Cirsium palustre
Common spotted orchid
Dachtylorhiza fuchsii
Catsear
Hypochoeris radicata
Field woodrush
Luzula campestris
Lousewort
Pedicularis sylvatica
Ribwort plantain
Plantago lanceolata
Yellow rattle
Rhinanthus minor
Common tormentil
Potentilla erecta
Meadow buttercup
Ranunculus acris
Creeping buttercup
Ranunculus repens
Common sorrel
Rumex acetosa
Dandelion
Taraxacum officinale
White clover
Trifolium repens
Nettle
Urtica dioica
Present
Absent
In order to be able to measure the frequency of a species accurately all data collected from each
quadrat needs to be collected.
Once you have completed all four tables place your results in the class quadrat spreadsheet (on
Peters computer).
Once this is complete it will be posted on the Wiki page for you to analyse the data.
Results/ Questions
1. In the quadrate you measured which species was most common in site A? Which was most
common in site B?
2. In the quadrats you measured was there more flower species located in one site than the
other? If so which site had more flower species and why do you think they may have occurred?
3. Using the class data set calculate the percentage frequency of each species for site A and then
site B. Record your results into a table. (This is calculated by the number of times present out
of 10 x 100)
4. Using the results graph the species frequency of Site A and Site B
5. Comparing the 2 graphs which site had the greatest amount of species diversity? Why do you
think this is the case?
6. Is there a species or multiple species which is found in both Site A and Site B? If so is it
prevalent in one site more than another?
7. Until 15 years ago both sites were used extensively for agricultural pruporpes. Both sites had
cattle grazing occurring and used artificial fertiliser. Recently however these practices stopped
and organic farming occurred on both sites with no chemicals used to clear the land. However
species B still has extensive grazing occuring. Knowing this information do you think that
grazing has a vast impact on species diversity and frequency? What may be the reasons for
this?
8. Quadrats were used to provide data for this experiment. This is a form of random sampling.
Why is the use of this method helpful in obtaining data on species abundance?
9. Name another method of random sampling which may have also been used in this experiment
to obtain data?
10. Do you think that the same/similar results would of been achieved is harphazardous sampling
occurred instead? Explain you answer