Soil and… Sand Dunes?
December 5th is World Soil Day – a day designated by the United Nations to raise awareness of the importance of healthy soils.
Soil may not be the first thing you think of when picturing sand dunes, but the soil layer that forms on the top of older dunes plays a vital role in dune lifecycles and helps support a range of important and threatened species. It’s just as important to keep these soils healthy, but ‘healthy soils’ look a little different on a sand dune. Unlike most other habitats, sand dunes need nutrient poor, sandy soils to support wildlife and this has been the focus of much of our restoration work.
Why nutrient poor?
In the early stages of a dune’s lifecycle the habitat is made up of specialist plants suited to the sandy, harsh conditions. However, as the dunes mature and stabilise, other more generalist species move in and begin to take over. During this process, the organic matter added to the soil as the plants decompose starts to affect the nutrient balance. This accelerates the rate of generalist and invasive species moving in and these plants then outcompete the delicate, specialist dune species that are unable to adapt to the new, more fertile soil.
This is bad news for rare sand dune species who are sensitive to high nutrient levels and to overcrowding, such as the fen orchid and dune gentian, as they face habitat loss and even the possibility of being wiped out completely in local areas.
What we’re doing
To help protect our threatened sand dune species, we’re carrying out restoration works across 7,000 hectares of important coastal dune habitat in England and Wales. This includes the processes of turf stripping and scrub removal to help reintroduce areas of bare sand, and low-nutrient soil.
Turf stripping in South Walney
Turf stripping is when the top layer of organic material is scraped away from the soil to expose the sand underneath. This increases the amount of habitat available for rare species such as the sand lizard, which burrow into the sand, and the species of plant that thrive in the low-nutrient conditions.
Before and after scrub removal in Cleethorpes dunes
Scrub removal involves getting rid of dense, rank or overgrown vegetation. We carry out scrub removal on specially selected areas of a dune to remove any invasive or detrimental plant species – such as sea buckthorn. By doing this, we create space for the specialist species to flourish. Removing these larger, more robust plants also helps to create more movement in the sand as the root systems are no longer providing stability to the soil, and they’re not adding as much organic matter to the soil, which would increase its nutrient content.
How you can help protect soils
There’s lot of ways you can help protect soils both at home and when you’re out and about. If you’re visiting a sand dune, make sure to take all your litter home with you or use the bins provided. This is especially important if you’re visiting with a dog – please use the dog poo bins on site! Dog poo acts as a fertiliser when left on the sand to decompose and this threatens the species that need nutrient poor soil conditions. At home, you can help to protect soils by using organic, peat free composts and by being mindful of chemical use.
If you’d like to know more about World Soil Day, head to the United Nations website.
About the Author
Communications Officer, Dynamic Dunescapes
After studying wildlife ecology and conservation at university, I joined the world of communications via zoos and spent a few years working in bird of prey conservation, before joining the Dynamic Dunescapes project. I'm passionate about connecting people with stories and knowledge that'll empower them to make a difference and learn more about our natural world.