Situated to the south west of Castle Cary is the Dimmer ‘tip’, a landfill site. The tip is in current use - but large parts have now been reclaimed.

The original clay that covered the site was removed and stored and has now been spread over a multi-decker sandwich of rubbish. This giant sandwich creates a gently southerly sloping plateau that is in places a good ten metres above the surrounding farmland. Piercing the crust of this bleak plateau are numerous periscope-like pipes that allow methane gas to escape the mouldering mass below. The prevailing wind carries the sweet whiff of decay and the cries of myriad gulls, crows and starlings from the newly dumped rubbish on the still active area of the site.

This may not sound like an appealing prospect, but on the opposite side of the site to the still active area is the Carymoor Environmental Centre. This beautiful building is home to the Carymoor Environmental Trust. One of the objectives of the Trust is to manage the reclaimed land and in so doing transform a landfill site into an area rich in wildlife. There are a number of on-going projects in partnership with various universities and organisations [see Research home page].

Butterfly Habitat Creation
The Butterfly conservation project is being undertaken by the West Country Branch of Butterfly Conservation.

The aim of the three year project is to create and extend habitat for butterflies, using waste materials, if possible. Another of the major aims is to provide a nature trail with display boards that detail the natural history of butterflies, with an emphasis on those species found at Carymoor. The Environmental Centre is now visited by school parties on an almost daily basis during the educational year, and the butterfly project will be a major part of these visits.

Because our project was one of the first to be developed at Carymoor we were able to choose an area of land that we felt would be most attractive for butterflies. If you imagine the giant sandwich mentioned in the first paragraph, then the butterfly project is two acres of the southern corner of the sandwich. The southern edge is already attractive to a wide range of the commoner butterflies. This southerly-facing bank is an area of long wild grasses. Numerous browns and skippers (including the Essex) are found here. However, the banks that are immediately adjacent to the butterfly project are special. These are translocated grasslands.

When the original clay capping was removed, a small area of species-rich grassland was also saved. This was transferred to our corner of the site. This small area of grassland is very colourful, with Dyer’s Greenweed and Spiny Restharrow and many other wild flowers. It is also home to two localised species of butterfly: the Grizzled and Dingy Skippers.

Above the bank on the plateau, conditions are a little more harsh. The clay capping is saturated with water in the winter months and becomes brick hard during the summer. The whole of the capped area is exposed with little or no shelter. It was efforts to counter these harsher conditions that drove the planning of the scheme.

The design
At the end of the year 2000, a long linear mound was constructed using unwanted clay and soil. This mound was made with the kind assistance of Wyvern Waste, who provided the heavy machinery and manpower. To add an element of fun, the mound was formed into a shape that represented a stylised sea serpent or ‘great orm’. I had first thought of a Wyvern but this has too complex a shape for our purposes. Our serpent has a head, flipper and tail and is over 150 metres long.

The real purpose of the serpent mound, however, was to create a series of shallow south-facing bays. A profile of the mound would show that it has a steep north-facing side, a shallower south-facing slope and a flat top approximately 2 metres above ground level.

The south-facing slope was then covered with rubble that had previously been used to provide an access road for building the Environmental Centre. The rubble helps to improve the drainage of the slope. The next job was to cover the south facing slope with three different kinds of material. This took some time, as it is impossible to get lorries up onto the plateau during the wetter months.

The first material is crushed concrete, used to cover the south-facing slope of the head and the neck of the serpent. This material is available on-site, where a huge concrete crusher grinds up breeze blocks, slabs of concrete and other rubble.

During the summer months I managed to locate some chalk that was being excavated from a building site in Dorset. Two hundred tons were imported and eventually laid on the southern side of the serpent’s body and flipper.

Finally, as a contrast, oolite from a local quarry was used to cover the south-facing slope of the serpent’s tail.

All of these three materials or substrates are rich in calcium carbonate and are also nutrient-poor. These two qualities are helpful in creating grasslands in which many species of butterfly revel. Many of our rarer butterflies’ foodplants are found in these grasslands but one of the great attributes of these materials is the sparse, low, butterfly-friendly grassland they produce - especially when they are on a south-facing slope.

Crushed concrete is very alkaline and experiments in the past have recommended adulterating it with subsoil to dilute it, as few plants can survive in these alkaline conditions. However, this has not proved the case and the first results are quite encouraging. Chalk downland will be familiar to everyone reading this and in time the area covered in chalk will come to resemble typical downland.

Oolite is also a limestone, a strand of which surfaces in the Mendips, which is where our oolite came from. Like chalk, it is a soft limestone. This quality allows it to absorb and retain water for some time - unlike some of the harder limestones. In earlier experiments I have found oolite to be the easiest substrate with which to establish exciting butterfly grassland slopes.

After the substrates were laid they were planted with numerous wildflower plant plugs and cuttings and sown with flower seed and sheep’s fescue grass seed. The majority of these seeds and plugs were selected because they have some benefit to butterflies and moths. Some were sown to provide variety and colour.

The serpent was designed to provide a strip of grassland rich in foodplants and nectar plants growing in a warm south-facing situation. It was also designed to provide shelter. The north facing slope of the serpent has been planted with numerous shrubs and trees to help increase the sheltering effect of the mound. (Many of these trees are also butterfly food and nectar plants.)

Much of the sowing, planting and path making of the butterfly area was carried out by Julia Percy and her B.T.C.V. helpers. Julia, Dr Angus Davies, Linda Shaw and Raymond Wheeler are the transect recorders for the site.

The serpent only takes up part of the area. She is guarding her eggs, which are on the southern side of the site. The eggs are a series of low chalk mounds. The mounds will enable us to grow nectar-rich plants to provide interest around the site. To help increase shelter, a low gorse hedge has been planted. This hedge helps protect the serpent’s eggs. The rest of the site, the clay capping, is being planted and sown using the translocated grassland as a model.

The final part of the construction - that of the Dragon's eye - was completed on 30th March 2004, the build part of the project is now complete - bring on the lepidoptera!

You are most welcome to visit the project: to see the dragon either email or ring the Environmental Centre to arrange a visit or come to one of our regular open evenings.

For more general information, you can phone Andrew George, on 01373 812270.

Printer friendly version : Back to main research page

@ Carymoor Environmental Trust Updated April 2004