It’s the largest surviving open heath in West Norfolk, and it’s now been saved for the future. Belona Greenwood looks at the restoration and regeneration of Grimston Warren
It is hard to imagine what Grimston Warren must have been like when just a decade ago it was shoulder to shoulder conifer trees. Then the commercial plantation would have enclosed an unnatural silence, a kind of dead-living wood unlike the bird-busy skies of today. After extensive restoration work by the Norfolk Wildlife Trust, Grimston Warren is now open to the sweep of enormous East Anglian skyscapes and the wind which sheets across the land. It is on the way back to what it used to be before its 109 hectares was turned over to monoculture forestry against all the advice of renowned botanists in 1967.
The heathland is part of the Gaywood Valley Living Landscapes Project. The project covers an area of over 4,000 hectares, encompassing the watershed of the Gaywood River, which flows into King’s Lynn. It houses a rich mosaic of habitats such as heathland, chalk stream and wetland as well as urban areas. According to The Norfolk Wildlife Trust, some of the habitat is ‘rarer than rainforest.’ Roydon Common which adjoins Grimston Warren is the largest surviving open heath in West Norfolk and it is a highly protected site with a whole host of protected, special status acronyms after it; NNR, National Nature Reserve, SAC, Special Area of Conservation and an SSSI, a Site of Special Scientific Interest.
What Roydon and Grimston have among other things is precious valley mire or in everyday parlance the kind of bog that Shrek would be more than happy to wallow in. The mire in this region is rare on a European level. Heather, gorse, silver birch trees, rare sedges, rushes and mosses and purple moor grass provide habitat for the rare natterjack toad, the nightjar, black darter dragonflies and the beautiful, endangered silver-studded blue butterflies.
In spring and summer, the heathland is festive with the colour of purple heathers and the almost fluorescent yellow of gorse. Endangered plants like the insectivorous sundews which glitter in the morning light and supplement poor nutrition from the soil by attracting and digesting insects have a home on the intermesh of wetland. The delicate blue marsh gentian, a rare and scattered plant is making forays in the region along with the Norfolk Flapwort. This plant with its thick, seaweed-like curling foliage was only found at two sites in the UK a decade ago, Scarning Fen in Norfolk and in Cumbria. Now, it has the opportunity to thrive in the newly created wilderness.
The view across the valley is one of the best in Norfolk. And as any well-being expert will add, even five minutes in a green space is good for mental health; imagine what a good walk can do. It is, as Brendan Joyce, Chief Executive of the Norfolk Wildlife Trust, will tell you, ‘a big oasis of wildness.’
But the wildness that is Grimston Warren today did not come about without massive capital input and huge effort.
“It cost hundreds or thousands of pounds,” says Brendan Joyce.
“Conservation on this scale requires almost the same approach as intensive agriculture. We needed big machinery which used up quite a lot of capital although we were able to get an income from the timber.”
The equivalent of a combine harvester for trees was brought in. It was fixed with sensors which measured the size of the trunks, Brendan Joyce explained, and then it cut the tree, stripped the branches and loaded the lorry. What is left is called the brash, and at Grimston, there were hundreds of tonnes of broken branches and tree litter. This bio-mass was sent to the power station at Thetford or was used in garden mulch.
“Some of it,” said Joyce, “was used in landscaping to create some variety in the environment.”
Even then, that is still only some kind of beginning for heathland regeneration. It must have looked like the set for a sci-fi film, acres of emptiness and tree stumps. This called for another machine but this one instead of chopping was used for grinding the tree stumps into the ground.
“The tree stump grinding took weeks and weeks,” said Joyce. “After that you have got a layer of pine needles, very acidic and not much will grow in it. You do not want that, what you want is the underlying area that’s quite sandy and that is where the seeds of heather are.”
Seeds can lie dormant for as many as 60 years and like magic rejuvenate and start to sprout given the right conditions. Sprigs of heather began to appear and like magic, sprigs of bracken, which, Joyce pointed out, are a lot less welcome and need to be controlled. The transformation of Grimston was carbon-negative according to the University of East Anglia’s Carbon Innovation Centre. 90% of the material was recycled and used.
“They felt it was very good,” said Joyce, “and heathland itself acts as a carbon sink.”
It doesn’t take long for the wildlife to start returning. Nocturnal Nightjar numbers are growing after catastrophic falls due to serious loss of habitat following the Second World War. They are best spotted at dusk, while another shy endangered inhabitant, Britain’s only poisonous snake, the adder is back and woodlarks are ground-nesting.
“It is very good,” said Joyce, “and it will continue over the next ten years.”
Grimston Warren is only one part of the Gaywood Valley Living Landscapes Project. The aim of this national approach is to help wildlife adapt to climate change by expanding and reconnecting wildlife habitats. It means an ecological network in Norfolk which will allow threatened species to roam. Part of that plan is the active acquisition and sympathetic management of land.
To this end, NWT has put a deposit on 95 acres of land that fits like a piece of jigsaw into the Gaywood Valley habitat puzzle. Donations are being sought from the public to help raise £250,000 to buy the land before the end of March.
It’s an important area that has been intensively farmed and sits along the top lefthand side of Roydon Common. It is, along with work with local landowners engaged on Higher Stewardship Schemes, all part of the restoration of a beautiful valley. KL