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Holtspur Bottom Butterfly Reserve

How we manage the reserve

sheep grazing the meadows Sheep grazing the meadows in winter.

Butterflies and other insects have very particular requirements when it comes to the kind of habitats they are attracted to, and where they can breed successfully. Holtspur Bottom is managed carefully to try to provide suitable habitat for the largest number of butterflies possible, given the type of land we have.

The meadows
The meadows are classic chalk grassland, and are attractive for species such as the Large, Small, and Essex Skipper, Common, Small, and Chalkhill Blue and Marbled White butterflies. We need to ensure that the wild flowers that are so attractive to these butterflies and other insects are not overwhelmed by the more vigorous, coarser grasses. This means we have to keep the nutrient levels in the soil as low as possible, to discourage the more vigorous plants. To do this, we have adopted a traditional management plan of cutting and grazing. We allow the plants to flower and set seed in the summer, then cut the meadows, and remove the hay (so that it doesn't rot down and increase the nutrient levels). Finally, we aim to graze with sheep over the winter, to get rid of any coarser grasses that are left. The other major management task is the annual removal of ragwort. Common ragwort has been an ongoing problem at Holtspur Bottom since we took over management of the reserve. Volunteers are always welcome to help us to control the spread of this plant!

You will notice areas in the top meadow where we have scraped away the topsoil to expose the underlying chalk, and piled the soil behind. We now have three such scrapes, with the third created in Spring 2014. Many invertebrates rely on having bare soil to complete their life cycle, and so these scrapes offer an ideal habitat. Because they are south facing, and sheltered by the soil piled up behind them, they warm quickly, and so are very attractive to butterflies and other insects. We have planted Horseshoe Vetch and Kidney Vetch here, the larval foodplants for the Chalkhill Blue and Small Blue butterflies, and we have been successful in attracting both butterflies to breed on the reserve. If you visit us over winter, when we have sheep grazing, you may notice that a couple of areas in one of the meadows are surrounded by plastic fencing. This is because the sheep would rather eat these vetches than our coarser grasses, and so we try to exclude them from this area. Since it is also one of the warmest areas of the reserve, in the past sheep have congregated here to sleep and then defecate. The droppings tend to enrich the soil over time, and encourage exactly the kinds of vigorous plants we are trying to discourage here.

Triangle Bank
Triangle Bank is the largely north-facing slope between the entrance area, and the main meadow area of the reserve. There is a shelter belt of trees here, together with some rough grassland. As far as we are aware, it has never been 'improved' for agricultural purposes. Currently we are trying to manage the large quantity of Dogwood that is growing here, as it tends to shade out everything else. Once it has been removed, we hope for a wonderful crop of orchids here. It is also the area where we traditionally have the winter bonfires, to burn the scrub we clear from the rest of the site. Ash from the bonfires tends to enrich the soil, and in summer you will find large patches of nettles growing at the bottom of Triangle Bank, as well as in the entrance area itself. The nettles are the larval foodplant for a number of our native butterflies, such as the Comma, Peacock, Red Admiral, and Small Tortoiseshell, and so provide suitable habitat for a range of butterflies that could not breed on the chalk grassland meadows.

Reserve entrance Elm flower buds
After installing the new, larger vehicle gates, we now have a large mound of earth (to your left as you enter the reserve). We plan to shape this into a south-facing slope, planted with violets, (probably the Common Dog-violet, Viola riviniana) to try to attract the Dark Green Fritillary butterfly. There are records of this butterfly in the Holtspur Valley, but no reported sightings at Holtspur Bottom in recent years. During the summer months, you will also see large patches of nettles in this area, where it joins Triangle Bank. There are also seven disease-resistant Elm trees that were planted a few years ago. Elms are the larval foodplant of White-letter Hairstreaks, and with so few Elm trees left in the UK, this may become a valuable resource for this species in the future. We are also replacing the wild privet that was lost from this area, a favourite nectar source of the adult White-letter Hairstreak, which is listed as a Priority Species on the UK Biodiversity Action Plan (UK BAP). There is also an Oak tree in this area, that was planted in memory of Rob Larkin, who did so much for the Holtspur Bottom Reserve in the early years (see History of Holtspur Bottom for more information).

There are also lots of Garlic mustard plants (Alliaria petiolata), also called Jack-by-the-hedge next to the gate, the larval foodplant of the Orange-tip butterfly, which can be seen on the reserve in April and May.

The public footpath
scallop in hedgerow As well as keeping the footpath clear for walkers, we try to create "scallops" along the length of this path: small areas where we cut back the scrub growth to create sheltered spaces for butterflies. As they are south-facing, these areas are quick to warm, and even very early in the season, you may spot butterflies sheltering here. Larvae will also develop much faster here than in colder parts of the reserve and the freshly cleared ground will receive more light which should encourage the germination of flower seeds. Hopefully in a few years' time there will be a greater variety of plants growing along this sunny hedge. We also need to control the countless self-seeded ash saplings that would quickly grow and shade the entire area, as well as controlling other invasive plants such as Dogwood.

From April onwards, you may see Speckled Wood butterflies in this area, making the most of the dappled sunlight.

Other areas of the reserve
Apart from occasional cutting, some of the other areas of the reserve, such as the perimeter paths, receive minimal management, to allow the insect species that prefer longer grasses to thrive. We understand that some visitors may see these areas as 'untidy', but they do represent a valuable habitat in their own right to many insects, including the increasingly scarce Glow worm (Lampyris noctiluca).

You may also be interested in:
Plants on the reserve
Dates of our conservation work parties. Most work parties take place over the winter, though some occur during the summer months as well. Tools and full instructions are provided. Please wear sturdy footwear, bring gardening gloves, a drink and a snack.
Details and photos of previous work parties at Holtspur Bottom

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