Lichen Coverage on Winterton Dunes

On the 21st October 2022, I went to Winterton-on-Sea to find whether the coverage of lichen (pictured above) present on the dunes was altered due to prolonged footfall (in the form of paths).

Background Information:

Located on the East of Norfolk, the dunes are a Natural Nature Reserve (NNR) due to its unique flora and fauna found within them. What makes them special is the fact the area is acidic, like the dune systems of the Baltic (North-eastern Europe) and shares greater ecological similarities there than other places along the North Norfolk coast. The low pH is because of the high calcium carbonate content within the lithosphere.

Here, over 170 species of bird have been recorded (including both breeding and overwintering birds), including little terns (Sternula albifrons), nightjar (Caprimulgidae family), and marsh harriers (Circus aeruginosus). Natterjack toads (Epidalea calamita) have also been recorded as well as over 110 species of moth, including the rare pigmy footman (Eilema pygmaeola), and fenn’s wainscot (Protarchanara brevilinea).

Winterton has many paths present (which can be seen below), and this could influence the lichen, in the form of inhibiting, stimulating, or having no effect on growth.

Map source: Google Earth (2022)

Methodology and Results:

For this investigation, we (my group) looked at the percentage coverage of lichen present along a transect perpendicular and across the paths. We looked at this at three different paths: medium, small, and big. This was to see whether the intensity of footfall influenced the lichen coverage.

To do this, we used 0.5m quadrats and estimated the percentage present within that area. We did this along three transects on each path, and our results are shown below:

From this I decided to find the mean, so easier comparisons could be made, and a graph can be produced from the values calculated.

From this graph, lichen coverage is much lower around quadrats 5 and 6 than the rest. The midpoint between these two quadrats marked the centre of each path, which proves that footfall reduces (and in some places, inhibits) the growth of the lichens. The more paths present amongst the dunes, the less lichen coverage there will be.

Also, the small path is shown to have some coverage of lichen, suggesting that lichen may still be able to grow under less intense footfall.

Improvements to this study:

If I had more time on this investigation, I would have taken more transects along each path to increase the accuracy of the results.

I would also find a more accurate method of determining lichen cover within each quadrat. For example, if one quadrat square equalled 4%, then half a square would be 2%.

Also, due to the larger path being much larger than the small path, we had to give one pace between the medium path samples (quadrats), and three paces between the big path samples (the small path samples were taken directly next to each other). An improvement could be measuring a distance between each sample rather than estimating.

Management Recommendations:

To increase the abundance and/or distribution of these lichens, management would have to be put forward to prevent more paths being created. These methods could also benefit other rare organisms, not just the lichen.

One potential method is the use of fencing to physically prevent people entering set areas, which would hopefully allow more lichen growth. This would be effective at keeping people off the lichen; however, some people may see it as unaesthetically pleasing. It will require occasional maintenance due to the ongoing succession of the dunes, and damage from climatic events (for example, storm surges).

Another method could be the use of set pathways to deter people from using alternate paths. This could be done via the use of wooden board walks, and this would also benefit other flora. The construction of these paths can damage the dune system (amount of damage depending on the paths placement), and like with the fencing idea, would require maintenance every now and then.

One final idea could be the greater use of signs to show people which paths to walk along or not to walk along. Similar signs can also be used to tell people to stay on the paths and to spread awareness of the lichens (and other rare flora). The problem here would be people who ignore the signs, and others with dogs who want to let them off leads. Likewise with the other two ideas, maintenance would be needed to check the signs for vandalism (for example).