• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Species diversity on the Ynyslas sand dunes.

Extracts from this document...


Species diversity on the Ynyslas sand dunes For this work we went to the Rheidol study centre near Aberystwyth in Wales. From here the field work was carried out on the Ynyslas sand dunes near the River Dovey mouth on the west coast of Wales (see map). Sand dune formation To form the following things are needed: supply of sand wind stabiliser Stage 1 - Sand particles are transported by the prevailing wind by the process of saltation. If there is a stabiliser, an obstacle, sand is deposited on the leeward side where it can no longer be picked up be the wind. The grains build up and form a small dune. Stage 2 - Dune continues to grow and in colonised by pioneer species such as marram grass. The roots bind the sand and the shoots trap more sand and an embryo dune is formed. Stage 3 - The dune increases in size and is colonised by further species, making it more stable. New dunes form in front of older ones. The unique formation system of sand dunes leads to plant succession and zonation on the dunes. While doing trail work on dune vegetation I noticed that the number of species present increased as the age of the dunes increased. I can see from research that the probable reason for this is that the older dunes are at a later stage of succession than the younger ones so will have a higher diversity of plant species. ...read more.


meters from rank number of rank D D� 1st dune species 0 1 0 1.00 0.00 0.00 50 2 1 2.00 0.00 0.00 100 3 3 3.00 0.00 0.00 150 4 6 4.00 0.00 0.00 200 5 7 5.50 -0.50 0.25 250 6 9 8.00 -2.00 4.00 300 7 7 5.50 1.50 2.25 350 8 8 7.00 1.00 1.00 400 9 10 9.00 0.00 0.00 450 10 11 10.00 0.00 0.00 ?D�=7.5 Rs = 1 - 6?D� = 1 - (6 x 7.5) = 1 - 45 = 1 - 0.0455 n(n� - 1) 10(10� - 1) 990 Rs = 0.955 Where: Rs is the Spearman rank correlation coefficient D is the difference between the 2 ranks n is the number of sets of data Critical values for Rs n 5 6 7 8 9 critical value 1.000 0.886 0.786 0.738 0.683 n 10 12 14 16 18 critical value 0.648 0.591 0.544 0.506 0.475 When compares to the critical value the Spearman rank coefficient of correlation is much larger. This allows the null hypothesis to be rejected as it proves that there is a significant correlation between the number of species and the distance from the 1st sand dune. The Rs value is positive therefore the correlation is positive. The results are significant at the 0.05 level. This means that the results would have occurred by chance in fewer than 1 in 20 occasions. ...read more.


With no results it can not be proved that the embryo dune do follow the trend, but, from observation, there appeared to be only 1 species present, which indicates that they do follow it, thus supporting the conclusion. Time limited the size of the area that could be sampled. There was only time to do one transect and the sample intervals were increases from 30m to 50m for the same reason. From the earlier work on the dunes 50m sampling intervals were judged to be sufficient. The sand dunes cover a large area. The profile of the dunes and the position on blow outs and slacks changes though out this area. By only doing one transect the effect of these changes on species diversity could not investigated. Also it allowed only a relatively small area of the sand dunes to be sample. This could reduce the validity of the conclusion. As the results follow the typical pattern of species diversity discovered in research the conclusion drawn is most likely a valid one. The anomalous results do not limit the conclusion as they were investigated and a reason for them was found, therefore do not effect the conclusion made. To improve the investigation more time would be needed so more transects could be done. This would show more accurately the effect of distance from the 1st dune has on the species diversity by enabling a larger proportion of the dunes to be sampled. Also, if the embryo dunes could be sampled the results could be used to support, or undermine the conclusion. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Living Things in their Environment section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Living Things in their Environment essays

  1. Marked by a teacher

    Research question - Is using dogs for work ethical?

    5 star(s)

    Yes, because it benefits humans 4. Yes, but not on Dogs 5. No, they are suffering for Human purposes Do you think that dogs should be used for entertainment- such as racing? 1.No 2. No 3.No 4. No 5. Not sure Do you think that dogs believe that having a dog for a pet is ethical?

  2. Marked by a teacher

    An experiment to investigate the species diversity in non-trampled and trampled areas.

    4 star(s)

    All measurements will be double-checked. RISK ASSESSMENT: As the investigation has to take place on the common, insects and any other species in the common could cause an irritation. It will be a safe option to apply insect repelent before doing the preliminary work. Whilst walking on the grass insects, and any other species in the habitat of study, may get trampled on and killed.

  1. Marked by a teacher

    Animal Testing

    4 star(s)

    Botulinum produces botulin which produces limp muscular paralysis. Mice are injected with the Botox samples in order to get an idea of the harm the sample could do to humans. The number of people demanding Botox is increasing which means every year more animals are dying. Many people do not think of Botox as cosmetic but as medical

  2. Branded Bleach is more effective at killing E. coli than Non branded bleach - ...

    After said time remove the dishes from the incubator. It is apparent that there are areas around the paper discs where the bacteria have been killed; this is known as the zone of inhibition. The more effective the bleach solution is the area of the zone of inhibition will be greater.

  1. Is the preferred habitat of moss on the North side of a Yew Tree ...

    However, on the bark of the Yew trees at one meter high there was very often 0% moss coverage, if there was any moss on the tree it was always lower down near the base. Therefore, to improve this technique I could have sampled the moss coverage for all trees at a lower height such as 10-20cm.

  2. The effect of competition on the distribution of marram grass.

    Infiltration rate was also recorded. This calculated the rate at which water filters through various soil types. A 250cm3 measuring cylinder was pushed into the ground so that the 20cm3 line was level with the ground. The cylinder was filled with water and a stopwatch was started as the level of water crossed the 250cm3 mark.

  1. Animal behaviour and research into attitudes on animal testing.

    This means that the results wouldn't be of any use. * Apart from being tested on for life-saving drugs, animals are also used for testing cosmetic products, which are not life-saving. People argue that this is just needless pain that the animals suffer.

  2. Investigating adaptation, competition and zonation of barnacles, Chthamalus stellatus (Poli) and Balanus balanoides (Linneas) ...

    This was overcame this when carried out in the initial investigation. The barnacles are hardly distinguishable to the naked eye; the differences arise mainly with the shape of the barnacle and the difference of the Scutum and Tergum (Operculum) indicated by 1.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work