10Peaks Brecon Beacons 2017 – Ecological Briefing Notes
Ourea Events’ races are located in Britain’s greatest upland areas that often contain features of outstanding biodiversity value and importance. Occasionally, the features that provide this interest can be vulnerable to the wear and tear that may result from the passage of event participants. The risk of ecological damage is carefully assessed during early stages in the planning process for each event, when every effort is made to avoid sensitive ecological interest areas that could be disturbed by the event.
We are keen to encourage personal route selection choices by participants on our events to further avoid the risk of local ecological disturbance. This Ecological Briefing Note has been prepared for the 2017 10Peaks™ Brecon Beacons event to identify key ecological interest features that contribute to the special character of the event area, with route selection comments to help minimise the risk of localized ecological disturbance.
The 2017 10Peaks™ Brecon Beacons event area is located within the Brecon Beacons National Park, extending across an area of varied sedimentary geology with distinctive glacial landforms. The great variety of rock types and topography within the event area is reflected in a variety of upland wildlife habitat and vegetation types. Extensive tracts of significant upland habitat and vegetation are present, including areas of national and international nature conservation importance.
The courses pass through landscapes of distinctive geological character, including a complex series of limestone and gritstone strata to the west of the event area, and the striking landforms of glaciated old red sandstone to the east. The 2017 10Peaks™ Brecon Beacons courses cross areas of high level nature conservation importance, crossing various types of upland grassland, blanket bog, streams and rivers. Of particular interest are several locations known for their striking arctic alpine flora. These include one area of International nature conservation importance, and three areas of National nature conservation importance.
The majority of the 2017 10Peaks™ Brecon Beacons route will follow existing hill paths, helping to avoid the risk of disturbance to sites and features of special nature conservation interest. For localised situations where event participants might be required to cross areas of land not crossed by hill paths this ecological briefing note should be used to support personal route choices that will avoid the risk of significant ecological disturbance. This ecological briefing note has also been produced to communicate the special upland environmental interest of the event area to enrich the experience of participating in the 10Peaks™ Brecon Beacons event.
- Dry acid grassland is a widespread vegetation type within the event area, where centuries of livestock grazing has converted heather moorland to open grassland. These areas provide a relatively robust vegetation type that can generally withstand the trampling effects of hill running.
- Specialised arctic-alpine plant species are present at locations within dry acid grassland on higher level, north-facing slopes throughout the event area. These species are part of a relict post-glacial flora that survives in British uplands and comprises some of the most highly valued nature conservation sites in the Brecon Beacons National Park. It is important to avoid vegetation disturbance wherever possible in situations where route choices involve crossing steep, north-facing slopes.
- Nutrient-rich groundwater can appear as springs on high level, steep slopes where vegetation rich in specialised arctic-alpine moss and liverwort species can be present. Wherever possible, route choices should avoid disturbance to these features.
- Areas of wet acid grassland will be encountered on courses where impeded drainage occurs within relatively level acid grassland areas or where groundwater emerges at the surface as seepages across more steeply sloping ground. Wet acid grassland can be of special nature conservation interest, in particular where groundwater seepages provide conditions for communities of specialised mosses, liverworts and other plants. These vegetation types can be vulnerable to persistent disturbance effects of trampling and should ideally be avoided wherever possible by selecting routes that keep to dry acid grassland to by-pass wet grassland patches.
- Wet acid grassland at groundwater seepages on steep ground can be difficult to avoid where they cross valuable contouring lines. Complete avoidance of these areas could involve a significant route change and deviation from the desired contour level. Despite this, it would be ideal if damage to seepage zone vegetation could be minimised, often located within shallow gulleys, re-entrant features or associated with ground level rock outcrops that cross steep slopes.
- Dry calcareous grassland is a locally extensive vegetation type within the western part of the event area, occurring as hill pasture over limestone and lime-rich moraine deposits. This vegetation type is often accompanied by low rock outcrops and scree slopes. Dry calcareous grassland within the Brecon Beacons is an important vegetation type, and includes several uncommon plant species. The vegetation typically forms on relatively shallow soils and as such can be quickly eroded by trampling. Some of the highest quality grassland of this type develops on shallow soils over limestone rock outcrops and within areas of limestone scree and as such are especially vulnerable to erosion. Care should be taken with route selection through areas with grassland, limestone rock outcrops and scree to avoid excessive vegetation wear, especially when negotiating vegetated outcrops and scree.
- On hillsides, soil movements within dry acid and calcareous grassland areas can develop well-defined micro-terrace systems, often referred to as sheep walks or trods. These typically follow the contours and can provide extremely useful running lines. Grassland vegetation at the edge of these micro-terraces is often friable and easily dislodged. Care should be taken when using these features for contouring to avoid running on the edge of these terraces to minimise grassland damage. Areas of saturated ground are widespread features where groundwater issues into terrace formations. These locations are especially vulnerable to running damage and should be avoided where possible.
- Heather moorland is relatively localised within the Brecon Beacons. Where present, this vegetation type typically forms on relatively well-drained soils and can sustain relatively high levels of trampling. Where courses cross heather moorland on sloping ground there is a greater risk of trampling damage to vegetation, especially where well-used routes that cause corridors of soil erosion create a risk of gulley formation.
- Blanket bog is an important feature of several locations within the event area. Many of these areas comprise degraded blanket bog where peat hags (erosion gulleys) have formed where bog vegetation has been lost and the underlying peat is being eroded. Vegetation loss may have been caused by a variety of factors in the past such as air pollution, moorland management with burning and drainage, but the resulting loss of peat and blanket bog vegetation is an important conservation management issue for the Brecon Beacons National Park. In many cases, the bare peat exposed in hags may have become stabilised, allowing a slow recovery of blanket bog vegetation that will eventually help to prevent the loss of peat through erosion. More locally, areas of high quality, intact blanket bog are present within the event area. These comprise vegetation with a high proportion of Sphagnum mosses on deep peat with limited evidence of peat erosion and gulley formation.
- Disturbance of recovering blanket bog by runners churning through the peat hags has the potential to trigger further peat erosion by de-stabilising the peat surface. Wherever possible, route choices in these areas should try to link the strips and patches of surviving moorland vegetation between the peat hags. These are often quite well-drained, providing areas of relatively robust vegetation and resistant to the trampling effects of running. If crossing peat hags is unavoidable, routes should try to link cushions of remnant moorland vegetation as ‘stepping stones’ across the bare peat surfaces. In some situations, the extent of peat erosion has been sufficient to expose the bedrock and glacial material underlying the peat. Running on this material is unlikely to cause significant harm to recovering peat surfaces.
- Limestone pavement is present at locations to the west of the event area, providing features of considerable nature conservation importance. The main ecological interest within this area is associated with communities of mosses, ferns and other plants that utilise the special microclimate of deep cracks (grykes) within the limestone pavement. Their location deep within the limestone pavement will ensure that they are protected from disturbance by runners. Occasionally, patches of limestone grassland are present on the surface of the pavement and these are vulnerable to fragmentation by disturbance from runners, and should be avoided if possible when selecting routes across limestone pavement areas. In addition to their botanical interest, limestone pavements are of considerable geological interest. Weathering the limestone surface has formed a variety of finely sculpted rock flutings and runnels with friable edges that could be easily snapped off when running across the pavements. This risk should be considered when selecting routes in the limestone pavement area.
- The event area contains a complex network of streams and rivers, some of which are potentially vulnerable to ecological disturbance from repeated crossing by runners. In particular, stream channels within the event area that cross limestone bedrock have the potential to support valuable populations of a highly protected aquatic invertebrate species called the White Clawed Crayfish. This animal is generally inactive during the day, and if present during the 2017 10Peaks™ Brecon Beacons event will be sheltering in burrows excavated into stream margins. Other important mammal species may be present along stream margins, including Otter and Water Vole. Wherever possible, stream crossings should avoid sliding down banks into streams to avoid the potential for disturbing the stream margin burrows and resting places of these animals.