Describe and explain the findings of the vegetation quadrats along a transect on Studland sand dunes. Figure 1 Figure 1 The results of the vegetation quadrats along a transect on Studland sand dunes showed that the amount of vegetation increased and changed, while the percentage of bare ground decreased as the sampling sites increased. The reasons behind this can be explained by clarifying what a typical transect is, starting with low embryo dunes near the shoreline and much taller mature dunes several hundred meters back from the shore (as indicated in Figure 1).
As you follow the transect from the beach, the dunes get older and the vegetation changes, gradually coving more and more bare sand and increasing in height. A graph to show % vegetation cover on Studland Dunes A graph to show % vegetation cover on Studland Dunes The data suggests that at the first sampling point that there is no vegetation present. This can be justified by the fact that the sample was taken just as the dunes started on the embryo dune.
Therefore reasons for no vegetation is that there are extreme conditions at this point; very high pH values (8+); rapid drainage; no humus; high wind speed and lots of salt spray, all of which make it almost impossible for vegetation to grown and the colonies, furthermore this dune can be disappear as quickly as they form. From the graph we can see that sample site 2, 3 and 4 that is on average 98% bare ground and some vegetation is appearing as is suggests there is 2% marram grass, and at sample site 5 and 6 have a 100% cover in marram grass.
I think the reasons for this is because there is sparse vegetation it must be a fore dune and sample 5 and 6 might be on a yellow dune. The percentages can be explained by using knowledge of the fore and dunes which are similar except for the their maturity (yellow dunes being older and slightly more developed). Thus, the vegetation has started to grow there because there is reduced winds speed (although its still high, marram grass has long deep roots), decreased pH values (marram grass is salt tolerant), water is lightly more retentive (marram grass has inrolled leaves to reduce moisture loss), some humus is formed and the dune surface is continuously blow away and replaced by new sand (when t is replaced it accumulated around vegetation, however strangely marram grass thrives on being buried in sand). At sample sites 7 to 10 the graph suggest that many plants are co-existing and are also closer together which is suggested by the fact that there is 0% for bare ground, also the height of vegetation increases to 90cm, which are all characteristics of grey dunes.
The wider variety, and the densely population vegetation can be explained by the features of the dune, which is a lower pH, less wind (shelter by seaward dunes), therefore less mobile sand, thus sand no longer accumulating and higher humus content all of which combine together to make a better habitat for vegetation. Lastly sample sites 11-16 must be the mature dunes, however the graph also indicates this as almost all those samples have a large percentage of heather, which is extremely common in mature dunes.
Mature dunes are perfect for acid loving plants (like heather) and a wide variety co-exist together, in mature dunes there is normally acidic soils, increased organic mater content (humus), rich in nutrition and shelter developed for seaward dunes. In sample site 14 it is almost an anomaly for mature dunes, in retrospect the sample could have been in a dune slack as it is a 100% moss, because in dune slacks you find moisture loving plants, which can survive in damp low lying hollows, when there is a high water table in winter and varying pH habitat, all of which moss could with stand.
Overall the graph to showing the percentage of vegetation cover and height on Studland Dunes can be explained by understanding the transect of the beach, as vegetation changes along the transect according to the pH, wind condition, the soils moisture, and all other factors which have been said above depending on the dunes maturity.