Essay on sand dune investigation

Submitted By khorrom
Words: 1796
Pages: 8

The theory that formed the basis of our investigation
According to the theory that forms the basis of our investigation, sand dune characteristics vary as distance from the sea is increased to the inland. As mentioned before the characteristics are ph level, soil moisture, organic matter and species diversity. In embryo dune, percentage of exposed sand is 80.there is very little mixed salt and fresh water. The ph level is over 8 and only salt tolerant plant species can survive here such as sand couch and lyme dune is move to next stage of fore dune percentage of bare sand is decreased to 20.There is some humous ,very little moisture and fresh water. The soil at this stage is slightly alkaline and some xerophytic specie survives here by succulent leaves to store water. As fore dune develop into grey dune, percentage of bare sand is less than ten. Humus increases inland, water content still low and there is fresh water underneath the soil. The acidity of the soil increases inland from ph 6.5 to 7.species such as creeping fescue, sea spurge, some marram,sotton grass and heather colonise the land. Behind the yellow and grey dunes, very little new sand is added from the beach, so these wasting dunes and dune heath exhibit smaller dune features. Plant such as heather, gorse, broom and buckthorn can thrive here as the soil is more acidic, humus-rich and water retentive. In time the rear of the dune system may be colonised by pine, birch and oak, which are the first type of woodland that in time could reflect the climatic climax vegetation for the British Isles.

Description of collecting primary data
We used systematic sampling at regular intervals. We used line transect to measure distance from the sea to inland. We went in one straight direction from the sea and measured every 10m for 100m then every 20 for 140m afteter 100m from the sea.
What are the limitations of the method?
There was human error thorough out the process. This was estimating percentage of species diversity by inspection. Therefore, this would affect the accuracy of our results. Our result can be partially reliable due to the fact it was taken by us.the data may be inaccurate. We may have biased it to get the results to be reliable. Quadrate might not be big enough. Areas in-between not been sampled.
Description of collecting secondary data
Q: What data was collected?
Ans: We have collected data for ph level, organic matter and moisture content.
Q: How it was collected?
Ans: Some of the data were collected from the internet and other was collected from the previous felid investigation.
Q: What kind of sampling method was used?
Ans: As we have taken the data from secondary source, sampling method was irrelevant to the data.
Q: Why this data was collected?
Ans: The data was collected to see the relationship and type of correlation that could have existed between the variable we have collected in primary data.
Q: Outline one technique you used to present your results from the data collected.

Q: Outline the use of one or more technique used to analyse your results.
We used spearman’s rank coefficient to analyse our results we have taken from the secondary data. It allows us to see the significance of the relationship between the variables.
What stage did it involve when using this method?
According to the formula :
1- (6∑▒d^2 )/(n(n-1))

Where d2 is difference of two ranks and ∑▒d^2 means sum of the difference squared.
N = number of sample or data.
We have to use this spearman’s rank coefficient formula to work out the significance. So fist thing we did was ranking the data for each variable then find the difference between each of the data for different variable. Then squared the difference to get rid of (-) sign and added all the d2.then we multiply the d2with 6 and divided by n (n-1).then we took the value away from 1 to get 0.98 and then used spearman’s rank coefficient table to see the significance of…