FSC | Field Studies Council

Field Studies Council: Bringing Environmental Understanding to All

Habitats & Conservation

Slapton Ley National Nature Reserve covers an area of 214.7 hectares; the nature reserve supports a diverse range of habitats including the beach, shingle ridge, woodland and freshwater and surrounding vegetation. The principal habitats are more specifically described on the accompanying habitat map.

Strong storms erode shingle and create new areas for wildflowers to colonise. On the shingle ridge backslope we cut small areas of gorse to slow down the process of succession. We manage the beach to protect the shingle ridge and the road from storms.

We manage the woodland very lightly to encourage a natural process of growth and decay. A small area of coppice is managed as an educational demonstration.

The Ley receives a vast amount of water from the surrounding river catchments. We monitor water quality and are involved with various projects influencing the land management within the catchments.

 

The Beach

Slapton sands could be considered a deceptive name as the beach is actually made from shingle, small pieces of rock eroded by aerial and sub-aerial processes, such as wave action. These particles are then transported around by the waves and deposited adding to beachmaterial.  One key process affecting beach size and shape is longshore drift, this happens when waves hit the shore at an angle and will move sediment in a certain direction along a stretch of coastline.

Slate is the bedrock of Start Bay and so is found in the cliffs bordering the beach, it is a metamorphic rock, changed from clays by heat and pressure, but is relatively soft and so erodes easily.  You may find large pieces of slate near the cliffs that have recently been eroded but because it breaks down quickly it is hard to spot much slate on the centre of the ridge.

Schist is a very resistant metamorphic rock, and forms Start Point headland jutting out to sea at the south end of Start Bay.  It was formed in the Devonian around 395 million years ago.  The schist and some of the slate has seams of quartz running through it, quartz is the most abundant mineral in the Earth's crust and you will be able to find plenty of it on the ridge.  It is a milky white.  You can find some igneous rock on the beach, most transported by rivers that have their source on Dartmoor.  Quartzite is pinkish and forms a very smooth pebble.  It can be found just offshore and was transported up onto the beach by rising sea levels

Most of the shingle making up the ridge is flint; it makes up about 80% of the material on the beach.  Flint is only found about 30-40km offshore from the present day coastline which suggests that Slapton Sands originates from this area.

During the last ice age sea levels dropped dramatically as water was stored in ice sheets, with the coastline much further out than present day a flint beach was formed - with flint being eroded from the sea floor by wave action.  As the ice age ended, around 10,000 years ago, sea levels began to rise as melt water from the ice sheets returned to the oceans.  The rising sea levels the flint beach landward through a process called roll-over, with beach material being moved from the front of the beach, over the crest and to the rear of the ridge and thus over time the whole beach is moved backward.  Around 3,000 years ago the ridge reached the headlands at Strete Gate and Torcross, its current position, but even now Slapton Sands is moving slowly landward.

 

The Shingle Ridge

Slapton sands consists of a shingle bar dividing the freshwater Ley from the sea - it is a dynamic environment, by its nature the shingle is quite unstable  - this results in the shingle ridge being a challenging environment for plants to establish.  Walking along the seaward side of the ridge you will be unlikely to come across any signs of vegetation until you reach the upper parts of the beach near the strand line, here plants can start to take hold - perhaps using nutrients from deposited seaweed as a starting point a few pioneer species can establish.  Any closer to the sea and the area is too frequently disturbed and lacking in resources to allow any plants to grow.

 

Woodland

Slapton Ley plays host to a variety of wooded habitats, ranging from ancient woodland through small hazel coppice to wet alder and willow woodland. Here we take a look at three of the principal wooded habitats, how they differ, and the management prescriptions in place for each of them.

Slapton Wood - Ancient Woodland

Slapton Wood, situated in the Northwestern corner of the reserve, is an Ancient Woodland (an area that has been wooded since 1600AD - Slapton Wood is mentioned in the Domesday Book), and as a result has very little active management.

In practise what this means is that the only work that goes on in Slapton Wood is to maintain the network of footpaths and steps, which includes the clearing of dead, dying or dangerous trees when they pose a threat to public safety.

The wood itself is mostly composed of Sweet Chestnut and Oak, with a reasonable amount of Ash and Beech also present. An understorey of Hazel and Holly can be found throughout most of the wood.

Southgrounds Wood - Hazel Coppice

The hazel coppice at Southgrounds is a fine example of a traditional form of woodland management being exercised for a modern conservation purpose.

A coppiced woodland is managed on a rotational basis and can be done with many types of tree, some species responding better and yielding more wood than others. The woodland to be coppiced is split up into compartments, with one compartment being cut each year. Trees of the species to be coppiced are cut down, stimulating vigorous regrowth and opening up the canopy, allowing more light to reach ground level and increasing the diversity of ground flora.

Coppicing, historically, was a means of providing a sustainable resource - the actual wood being coppiced was used for a variety of purposes such as buildings, fencing, firewood and charcoal. Modern technologies and the increased use of alternative materials has seen traditional coppices decline and in many places disappear throughout the last century.

France Wood - Semi-natural Broadleaved Woodland

France Wood, is a tranquil wood just inland from Ireland Bay. Within the wood are the ruins of the France farmhouse buildings - a reminder of the evacuation of the Slapton area for the D-Day practice landings in 1944.

Access to France Wood is restricted to the general public, though events run from the Field Centre. A 100-year Management Plan prescribes the removal of the non-native Sycamore in blocks on an annual basis. Click the thumbnail below for a map showing the areas that have been cleared of Sycamore over the last 45 years.

 

Freshwater

Slapton Ley ('Ley' is a local term for 'lake') is the largest natural body of freshwater in southwestern England. The 70-hectare expanse of open water is host to a variety of plants, birds, mammals, fish and invertebrates, each contributing to this fragile ecosystem.

However, Slapton Ley is a eutrophic water body, meaning that at times the Ley is prone to algal blooms. These reduce the amount of light entering the Ley and cause many water plants to die. Bacteria breaking down this dead matter use up the oxygen in the water, which has knock on effects for the many animals which rely on the Ley as their home and food larder.

Eutrophication occurs when an area of water is rich in mineral and organic nutrients (in this case Nitrates and Phosphates), providing enough raw materials for spores of algae to 'bloom' into large, plant-like organisms that fill the water. This process is usually at it's worst towards the end of a warm, dry summer, when water levels drop and the water temperature increases, leaving a stagnant, nutrient-rich pool of water - the ideal conditions for algae to thrive.

The process of erosion across the Slapton catchment leads to something known as DWPA - Diffuse Water Pollution from Agriculture. This phenomenon, caused by steeply-sloped agricultural land draining into rivers and ultimately the Ley, is a difficult problem to try and tackle. A European project called 'Cycleau' attempted to address this and other catchment-based problems at Slapton and 10 other river catchments across North-western Europe (click here for more details).

The Slapton Ley catchment can be split into three main sub-catchments; the Gara river, the Start stream, and the Stokeley stream (see map above). The Gara river catchment is by far the largest of the three, providing the majority of the water that flows into the Ley, entering the nature reserve at the northern end of the Higher Ley.

The Slapton Wood Stream is the final tributary to join the Gara river and is frequently used as a study site, either to sample freshwater invertebrates or to consider the response of a watercourse to a rainfall event.