Sand Dunes Day (Wednesday/Thursday)

Soil samples taken every 20m inland from the drift line. Note the change in colour from bare sand to rich brown earth soil beneath the dune woodland

Soil samples taken every 20m inland from the drift line. Note the change in colour from bare sand to rich brown earth soil beneath the dune woodland

No embryo dunes this year (2014) the winter storms have undercut the front of the dunes

No embryo dunes this year (2014) the winter storms have undercut the front of the dunes

Plant Survey 2014 - Lots of moss this year - it's been a wet winter...

Plant Survey 2014 – Lots of moss this year – it’s been a wet winter…

Damp but not disheartened!

Damp but not disheartened! 2014 dune profiling saw a much lower risk of sunburn…

IMG_2645

Kite diagrams showing changing distribution of different plant species. The dune profile beneath shows the topography of the dunes. Later we can add temperature, soil and wind speed data to show changing conditions away from the sea.

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Dune profiling

This afternoon the students measured slope angles along a transect of the dunes to gather data to draw a dune profile.

This dune slack has a range of wetland species present including creeping willow, reeds and birch. This spring the water table is as high as it has been for 30 years.

This dune slack has a range of wetland species present including creeping willow, reeds and birch. This spring the water table is as high as it has been for 30 years.

group and pony

There are 16 hardy Welsh ponies on the dunes that graze a fenced area. This helps keep the fescue grass under control allowing smaller flowering species to thrive (e.g. the Bee Orchid). The ponies are moved to another area in the summer when the plants are flowering.

early morning oxwich bay running club

The pre-breakfast running club (3 members so far 😦 )were treated to a beautiful sunrise over the dunes.

dune transect

At the top of the foredune ridge the yellow/mobile dunes are covered in marram grass – although this has been trampled away in areas to leave bare sand that is being removed by deflation to leave blowouts.

groups on the beach before survey

The sand dune groups prepare to set off on their transects

Grace and poniesblog

This pupil didn’t let the ponies get in the way of a nice straight transect…

dune profiling technique

excellent dune profiling technique

early morning dunes blog

looking over the dunes from the sea – marram grass in the foreground, dune scrub in the background

dune management talk

The manager of the Oxwich NNR talks to us about managing the dune system to maximise species diversity.

dune management talk blog 2

Before setting off to do plant surveys on the dunes we had some expert advice and a plant identification lesson from the manager of the NNR at Oxwich.

The cockle shell path marks the main footpath across the dunes. The calcium carbonate shells are the same Ph as the shell-sand of the dunes to minimise the environmental impact of the path.

The cockle shell path marks the main footpath across the dunes. The calcium carbonate shells are the same pH as the shell-sand of the dunes to minimise the environmental impact of the path.

Aims of the day:

  • To find out about the structure and management of a sand dune system (a psammosere)
  • To learn new data collection techniques – dune profiling and vegetation survey
  • To learn new ways of presenting data – kite diagrams and dune profiles
  • To work successfully as part of a team
  • To get to know our local environment around Oxwich

IMG_0212    Oxwich Dunes (Burrows)

The structure of a sand dune system (idealised model)
The structure of a sand dune system (idealised model)
This sequence of changing vegetation and conditions is what we might expect to find on a natural sand dune system. Why might Oxwich not conform?

This sequence of changing vegetation and conditions is what we might expect to find on a natural sand dune system. Why might Oxwich not conform?

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