Dynamic Dunescapes: shifting sands – dune rejuvenation
A followup to a previous article from Dynamic Dunescapes
By Tim Braund, Dynamic Dunescapes Engagement Manager
New resources created for Sand Dune Managers and Owners
Dynamic Dunescapes is an ambitious project, rejuvenating some of England & Wales' most important sand dunes for people, communities and wildlife. The concept of dune rejuvenation is still relatively unknown and conventional management remains that dune systems need to be stabilised particularly for flood and coastal protection.
To help with understanding these new approaches, and to give guidance to sand dune managers and owners, the Project has developed two online, e-learning courses for both sand dune managers and for citizen scientists and volunteers involved in dune management.
These are supported by a detailed Sand Dune Manager’s Handbook, and a range of case studies all freely available on the Dynamic Dunescapes website.
What’s the problem?
Many of us know and love sand dunes as beautiful coastal landscapes, but they are also important biodiversity hotspots. Dunes are a sanctuary for rare species which are perfectly adapted to live in sand. At a healthy dune system, you could find thriving populations of orchids, bees, toads, birds and lizards.
However, these specialist plants and animals are at risk. Indeed, sand dunes are one of Europe’s habitats most at risk from biodiversity loss. Over time, many dunes have become covered by grass and scrub which have over-stabilised the sand, and invasive species have overtaken native ones. Invasive and rank vegetation also enrich the soil increasing the organic content in these normally nutrient poor locations thus further favouring aggressive invasive growth. Nitrogen deposition adds fuel to the fire and sensitive dune plant populations become swamped and outcompeted.
We now know that a dune environment needs areas of freely moving sand, healthy sheltered dune slacks, (damp or wet hollows), and areas with low vegetation to support its diverse wildlife. We’re using pioneering conservation techniques to rejuvenate the dunes and make their shifting sands the perfect habitat for threatened wildlife again.
What is dune rejuvenation?
Dune rejuvenation means looking at dunes which have become stabilised over time and creating areas of bare sand restoring some of the natural mobility that has been lost from the dune system.
The aim of the management techniques being used is to encourage natural dune dynamics, enabling the combination of wind, sand, water and plants to rejuvenate over-stabilised dune systems. Healthy dune systems require mobile dunes ideal for early successional plants and animals. Inland the landscape tends towards semi-fixed and fixed dunes, including dune slacks where specialist species able to cope with salty environments and variable water availability thrive.
Creating notches in fore dunes and re-profiling slacks are important to allow sand to move through the dunes and for the dunes to shift. With more bare sand exposed, windy conditions create ‘sand rain’ where sand from one part of the dune is lifted and dropped elsewhere. This benefits early sand dune succession species and provides ideal conditions for specialist and pioneer sand-loving wildlife.
The project is also undertaking turf-stripping to remove the accumulated layers of enriched topsoil which both exposes bare sand and reveals the ideal substrate for dune plant species. This technique has been shown to double plant species numbers in a turf-stripped area several years after the intervention.
Conservation grazing using cattle, ponies and sheep, (including the reintroduction of rabbits at some sites), will ensure that grassland sward heights are kept low and varied because of different grazers. This creates the ideal habitats for insects, wildflowers and ground-nesting birds.
Management at scale
Scrub clearance, scrapes, turf-stripping, invasive species removal are all proven management techniques but are often undertaken on a small scale. Supported by National Lottery Heritage Fund and the EU LIFE Programme, Dynamic Dunescapes partners (Natural England, Plantlife, Natural Resources Wales, National Trust and The Wildlife Trusts) are working at a landscape scale using industrial machinery. For optimal impacts, a combination of conservation management interventions is required to re-establish natural dune dynamics.
An important message is that the partnership is seeking to establish more bare sand, not all bare sand in our work to replicate natural processes. There will be times and locations where it may be appropriate to stabilise mobile dunes where there are genuine and ongoing threats to roads, homes and businesses. Any conservation management action to rejuvenate dune systems, encouraging natural dune dynamics to benefit rare and endangered species, will be evidence-based, policy-led and will have involved active consultation, listening to the range of sometimes conflicting views and ideas. At Project sites, works on dunes only take place following extensive environmental and geomorphological surveying to ensure that it is the right course of action for the wildlife, and that these techniques will have a positive impact on the dune system for many years to come.
As with all good conservation projects, it will be the right action in the right place at the right time.
Find out more from Tim.Braund@plantlife.org.uk
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