Fraser Down Nature Reserve:
A Jewel in the Betchworth Biodiversity Crown
Simon Humphreys
A Jewel in the Betchworth Biodiversity Crown
Simon Humphreys
Fraser Down Nature Reserve is located in the Betchworth Hills at the northern tip of the Betchworth Biodiversity Line on the west side of Pebblehill Road. It’s a 30 acre Surrey Wildlife Trust (SWT) reserve which forms part of the Mole Gap to Reigate Escarpment Site of Special Scientific Interest. As an SSSI it is of national importance for wildlife, particularly its chalk grassland, scrub and woodland and the species these habitats support.
Figure 1 Location of Fraser Down and view from the Down looking south east
When Fraser Down was purchased by SWT in 2008 most of the open chalk grassland had been lost to invasive Hawthorn scrub as the site had not been managed for about 50 years. The small amount of grassland that had survived was rank and species-poor as a result of decades of not being grazed. So, for example, there were virtually no flowering orchids on the reserve at that time. Since then volunteers from the Dawcombe Conservation Group, which has also managed Dawcombe Nature Reserve on behalf of the Trust since 1982, have cleared approximately 15 acres of scrub at Fraser Down to restore species-rich chalk grassland on the site.
Figure 1 Location of Fraser Down and view from the Down looking south east
When Fraser Down was purchased by SWT in 2008 most of the open chalk grassland had been lost to invasive Hawthorn scrub as the site had not been managed for about 50 years. The small amount of grassland that had survived was rank and species-poor as a result of decades of not being grazed. So, for example, there were virtually no flowering orchids on the reserve at that time. Since then volunteers from the Dawcombe Conservation Group, which has also managed Dawcombe Nature Reserve on behalf of the Trust since 1982, have cleared approximately 15 acres of scrub at Fraser Down to restore species-rich chalk grassland on the site.
There are now nine species of orchid including some, such as Pyramidal orchid, in their thousands. The same dramatic increase has occurred with other flowering plants. For example there were about six thousand flowering Cowslips this year just in one field and they are still increasing. All of the nearly 200 plant species now found on the site have appeared naturally from the seed-bank present in the soil following clearance of the scrub by the volunteer group and the re-introduction of grazing.
Figure 2 Some of the wonderful orchids (left) and cowslips (right) on Fraser Down
The profusion of flowering plants now provide essential nectar and pollen for a plethora of invertebrates, including many which are rare in Britain. At the last count 574 species of moths have been found on the reserve. Although often overlooked as pollinators, some plants such as Fragrant orchid have specially adapted flowers where the nectar is only accessible to insects with long tongues, such as butterflies and moths, so these invertebrates are essential for the pollination of such plants.
Figure 2 Some of the wonderful orchids (left) and cowslips (right) on Fraser Down
The profusion of flowering plants now provide essential nectar and pollen for a plethora of invertebrates, including many which are rare in Britain. At the last count 574 species of moths have been found on the reserve. Although often overlooked as pollinators, some plants such as Fragrant orchid have specially adapted flowers where the nectar is only accessible to insects with long tongues, such as butterflies and moths, so these invertebrates are essential for the pollination of such plants.
Over 300 other species of invertebrate have now been found on the site, a quarter of which are classified as being rare and/or endangered. These include many species of solitary bees and wasps, hoverflies, beetles and spiders amongst others. Some of the invertebrates that are able to fly are likely to travel between Fraser Down and the gardens managed by residents along the Betchworth B-Line. Although residents may not get many of the rarer, specialist chalk grassland species found at Fraser Down, you might get some of them so keep your eyes peeled!
Major scrub clearance on the site is now largely complete, so management has mainly switched to maintaining and further improving the grassland. Much of this involves preventing the scrub coming back. At working parties we use tools called "Tree Poppers" to pull scrub seedlings/saplings up to 4-5 ft tall out of the ground, roots and all, with larger scrub being cut at the base using bow-saws and loppers.
To maintain and improve the grassland about 20 of SWT's Belted Galloway cattle are brought in to graze the reserve each year between late July and October. Although they do browse the scrub to a certain extent, grazing alone will not prevent scrub from re-invading the grassland. Instead the main objective of grazing is to limit the dominance of grasses in the sward. This may sound odd for a grassland but doing so allows wildflowers to establish and thrive, especially the finer plants. Grazing also creates bare ground and diversity in the height and density of the sward, something conservationists call "structure", all of which are extremely important for invertebrates. So grazing is preferable to mowing/cutting for both plants and invertebrates, but cutting areas of grass in gardens which have been left for wildflowers is entirely appropriate where it isn't usually possible to have a herd of cows!
Figure 3 Grazing Belted Galloway cattle (left), clearing scrub on the chalk grassland (right).
Although invasive scrub such as Hawthorn and Dogwood can lead to the loss of grassland if left unchecked, having some scrub is vital for wildlife such as invertebrates and and many of the 67 species of bird seen on the reserve. To maintain diversity in the structure of this habitat some mature scrub has been retained and a limited amount of small scrub is allowed to grow back where the soils are deeper. A proportion of these patches are then removed each year and other new patches allowed to develop. This means there's a constant cycle of scrub of all sizes on the reserve to provide the diverse range of conditions which are needed by different plants, invertebrates, birds, etc.
Most of the woodland at Fraser Down has only established through self-seeding since the 2nd World War, although there are two areas of older woodland, possibly ancient woodland, on the steeper slopes. In order to create diversity of structure and habitat within the woodland and to connect grassland on the reserve to grassland on neighbouring land to the west, we have created "rides" through the woodland. In this context rides are nothing to do with horses! They are simply open routes which create diversity in woodland and allow invertebrates to move through it, along with flowering plants to provide nectar.
Due to the sensitivity of many of the species present, Fraser Down is not open to the public. So the site has a much lower profile than many of the Trust's reserves where visitors are welcomed, and it may be that you haven't even heard of the reserve. Fraser Down is managed entirely by volunteers, so if anyone is interested in joining the group then please contact me ([email protected]). The volunteers come from all ages and walks of life, and have a wide range of experience from complete novices to over forty years managing sites. We have working parties on two Sundays each month between Sept and April. Please do get in touch if you would like to join us.
Simon Humphreys is the Voluntary Reserve Manager, Dawcombe & Fraser Down Nature Reserves, Surrey Wildlife Trust [email protected]
Major scrub clearance on the site is now largely complete, so management has mainly switched to maintaining and further improving the grassland. Much of this involves preventing the scrub coming back. At working parties we use tools called "Tree Poppers" to pull scrub seedlings/saplings up to 4-5 ft tall out of the ground, roots and all, with larger scrub being cut at the base using bow-saws and loppers.
To maintain and improve the grassland about 20 of SWT's Belted Galloway cattle are brought in to graze the reserve each year between late July and October. Although they do browse the scrub to a certain extent, grazing alone will not prevent scrub from re-invading the grassland. Instead the main objective of grazing is to limit the dominance of grasses in the sward. This may sound odd for a grassland but doing so allows wildflowers to establish and thrive, especially the finer plants. Grazing also creates bare ground and diversity in the height and density of the sward, something conservationists call "structure", all of which are extremely important for invertebrates. So grazing is preferable to mowing/cutting for both plants and invertebrates, but cutting areas of grass in gardens which have been left for wildflowers is entirely appropriate where it isn't usually possible to have a herd of cows!
Figure 3 Grazing Belted Galloway cattle (left), clearing scrub on the chalk grassland (right).
Although invasive scrub such as Hawthorn and Dogwood can lead to the loss of grassland if left unchecked, having some scrub is vital for wildlife such as invertebrates and and many of the 67 species of bird seen on the reserve. To maintain diversity in the structure of this habitat some mature scrub has been retained and a limited amount of small scrub is allowed to grow back where the soils are deeper. A proportion of these patches are then removed each year and other new patches allowed to develop. This means there's a constant cycle of scrub of all sizes on the reserve to provide the diverse range of conditions which are needed by different plants, invertebrates, birds, etc.
Most of the woodland at Fraser Down has only established through self-seeding since the 2nd World War, although there are two areas of older woodland, possibly ancient woodland, on the steeper slopes. In order to create diversity of structure and habitat within the woodland and to connect grassland on the reserve to grassland on neighbouring land to the west, we have created "rides" through the woodland. In this context rides are nothing to do with horses! They are simply open routes which create diversity in woodland and allow invertebrates to move through it, along with flowering plants to provide nectar.
Due to the sensitivity of many of the species present, Fraser Down is not open to the public. So the site has a much lower profile than many of the Trust's reserves where visitors are welcomed, and it may be that you haven't even heard of the reserve. Fraser Down is managed entirely by volunteers, so if anyone is interested in joining the group then please contact me ([email protected]). The volunteers come from all ages and walks of life, and have a wide range of experience from complete novices to over forty years managing sites. We have working parties on two Sundays each month between Sept and April. Please do get in touch if you would like to join us.
Simon Humphreys is the Voluntary Reserve Manager, Dawcombe & Fraser Down Nature Reserves, Surrey Wildlife Trust [email protected]