Sand Dunes Are a-Changin

By Bev Philips from Dynamic Dunescapes Edited by Emma Brisdion

Coastal sand dunes are mysterious habitats, constantly shifting, beautiful, and full of specialised wildlife...

They burst with rare orchids, butterflies and bumblebees, offer homes for rare reptiles like sand lizards and provide sanctuaries for birds, insects, amphibians, and mammals.

Dunes are our most dynamic landscape, ceaselessly growing and shifting and in doing so providing niche habitats with distinctive flora and fauna.

Because of the sheer breadth of biodiversity that they can sustain, sand dunes are increasingly recognised as important habitats and awarded protection. Over 50 sand dune systems in the UK are deemed to be of national importance, and over 120 have been declared as Sites of Special Scientific Interest (SSSIs).

Braunton Burrows is one of the largest sand dune systems in the British Isles, situated in the estuary of the Taw and Torridge Rivers in North Devon. Privately owned by Christie’s Estate and at the heart of the North Devon Area of Outstanding Natural Beauty (AONB), it is a UNESCO-designated Biosphere Reserve, and a special place where local communities and interested stakeholders work together to conserve the biodiversity and culture of the site.

Braunton Burrows

These dunes got their name thanks to the rabbit population, which kept the scrub levels on the dunes low for many years. By grazing vegetation and preventing large areas of the dunes from becoming smothered by scrub, rabbits kept the dunes in excellent condition. They allowed rare dune-specialist plants and flowers to thrive; this was certainly no mean feat when you consider that Braunton Burrows flanks the 3.5-mile-long sandy beach of Saunton and covers approximately 1000 hectares.

Nestled between the high ridges of dunes are low-lying depressions known as dune slacks. These slacks are often rich in plant life, particularly rare and local species. Braunton Burrows has a vast dune slack vegetation area, representing a significant proportion of the national resource. When these slacks lie close or below the water table, freshwater pools often form, supporting a diversity of life. Some are seasonally flooded as the water table rises in the winter months, and others remain damp or hold permanent water year-round. Some are home to plants such as orchids which like damp conditions, while others are overgrown with scrub. The slacks are rich in species such as marsh pennywort (Hydrocotyle vulgaris), marsh helleborine (Epipactis palustris), creeping willow (Salix repens) and round-leaved wintergreen (Pyrola rotundifolia). Dune slack pools provide essential homes for birds and amphibians. At Braunton Burrows newts, frogs and toads use the pools for breeding in and hibernating in the mud over winter. Elsewhere in the UK, the very rare natterjack toad breeds in the warm, shallow slacks on sand dunes and sandy heaths. Although the pools look inviting for swimmers, swimming in the deeper slacks and pools disturbs and even damages flora and fauna.

However, our sand dune systems and the habitats that they provide are in trouble. Over the past 100 years, many sand dunes have become overgrown with vegetation, which has stabilised much of the sand that many rare species of plant and animal are adapted to live in, and so dune biodiversity is on the decline.

Climate change, previous land management which encouraged scrub growth, air pollution, and a loss of grazing by cattle and by rabbits which were wiped out by myxomatosis have all accelerated plant growth and seen our sand dunes slowly turn into scrubland and woodland.

A combination of pressures has meant that we are left nowadays with only a small fraction of the dune slacks present a century ago and many of their flora and

fauna species are threatened. In many places, dune slacks have been destroyed over the past century by coastal developments including industry and housing, golf courses, drainage and sea defence works. Nutrient enrichment of water reaching slacks is also a serious threat because it leads to increased plant growth of non-specialised plants, which makes it hard for dune slack specialists to compete for space.

But there is hope! Dynamic Dunescapes is a large and ambitious project, funded by the National Lottery Heritage Fund and the EU LIFE Programme, which is working hard to restore 7,000 hectares of coastal sand dunes across England and Wales.

From Cornwall to Cumbria, teams from Natural England, Plantlife, National Trust, Natural Resources Wales and The Wildlife Trusts will be using pioneering conservation techniques to rejuvenate the dunes and make their shifting sands the perfect home for our threatened wildlife again. Our work in Devon involves tackling overgrown areas by creating new areas of bare sand. This will give our local threatened bare sand-loving wildlife, like sand lizards and a huge variety of plants, places where they can thrive again. This will also mean more sand is available to move through the area and build up dune ridges. As we remove scrub to allow some of these dunes the freedom to shift naturally again, we’ll also be removing invasive plant species such as Japanese rose and sea buckthorn; these plants, which don’t usually grow at this site, can grow very quickly and outcompete native species which have always been a part of this landscape. We’ll also restore the dune slacks. By removing some of the fast-growing willow species, we can improve the slack pools which are essential for many of the dunes’ important amphibian and plant species, ensuring that our dune wildlife is protected.

For more information about Dynamic Dunescapes and to find out how you can get involved at your local sand dune site, visit dynamicdunescapes.co.uk.

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