Invasive Species Surveys of the SSSIs Cartland Craigs and Cleghorn Glen, Clyde Valley Woodlands NNR Undertaken by CSFT on behalf of SNH February 2014
Emilie Wadsworth Central Scotland Forest Trust Hillhouseridge Shottskirk Road Shotts ML7 4JS
Invasive Non-native Species Surveys Cartland Craigs and Cleghorn Glen 26th February 2014 Introduction CSFT secured some funding from CAVLP and SNH to undertake some preliminary work on Invasive Non-native species in early 2014 in order to produce a strategic plan for surveying, monitoring and controlling the main species of riparian INNS in South Lanarkshire from Spring 2014 onwards. Part of this involved the survey of two SSSIâ€™s within the CAVLP area for INNS and other exotic species which may have been escaping from neighbouring land. These were undertaken by CSFTâ€™s ecologist in late February 2014. Normally, this time of year is sub-optimal for undertaking plant surveys, but as the target species in these surveys were are evergreen, they are often easier to spot in the winter. The main target species were Rhododendron and Snowberry, though any other exotics found were also to be recorded. Site Descriptions Cartland Craigs Cartland Craigs is a SSSI within the Clyde Valley Woodlands NNR. It encompasses the gorge along the Mouse Water to the north and east of Lanark between Cartland Bridge and Mouse Bridge. The site is a deep, steep sided gorge with broadleaf woodland along the tops and sides. It is bordered to the south by the landownership of the Cartland Bridge hotel, which is made up of a conifer plantation woodland and the designed landscape associated with the hotel. A track leads up from the hotel car park, through the plantation, to a small burial ground at the top of the crags. On the ground, the boundary between the two areas is unclear. In the east of the site, the plantation woodland marks a fairly clear boundary, but on the west, the two areas of woodland are similar in characteristics, so some of the exotics found may not be within the SSSI itself. The woodland of the SSSI is predominantly Beech and Silver Birch, with some Holly. Ground flora is sparse, due to the topography, though Ferns and Giant Woodrush grow where they can, along with various moss species. Cleghorn Glen Cleghorn Glen is another area of SSSI within the Clyde Valley Woodlands NNR, to the east of Cartland Crags. It follows the path of the Mouse Water from Mouse Bridge to Cleghorn Bridge, north-west of Lanark. There is a well-used footpath running the length of this section of the NNR to the north of the Mouse Water The site is also a steep sided gorge, but has gentler slopes and wider areas of woodland in places. The woodland here is predominately Beech, Ash, Oak and Holly, with a ground flora of Ferns, Ivy and Giant Woodrush. Near to Cleghorn itself, there is an old burial ground and private garden that falls partly within the SSSI boundary, but is of private ownership. On the ground, the boundary between these areas is quite clear by the use of paths and signs. The Burial ground is separated from the rest of the SSSI by a dry stone wall.
Results Walkover surveys of both sites were conducted on 26th February 2014 with the express intention of looking for exotic or non-native species within the SSSI boundaries. The main species targeted were Rhododendron and Snowberry, both of which are easy to survey for at this time of year. Both of the sites have some steep sided gorges, and they were examined using binoculars from the top, as far as was possible. Cartland Craigs Map 1 shows the records of INNS found at Cartland Crags. The target notes for the map are in Table 1. Photos taken during the survey can be seen in Appendix 1. The main areas of Rhododendron are around the burial ground and to the east of the site, along an old wall line. At the burial ground, there are some very large plants within the plantation to the south as well as a dense clump in the ground itself, which is thought to be on the hotel owned land (Photos d & e, Appendix 1). There is a dense stand of Rhododendron behind the burial ground wall at the top of the crags, though the plants are younger and are potentially regeneration from some previously treated plants (see Photo h, Appendix 1). There are one or two small plants down the gorge itself which have probably been missed during any earlier eradication programme and some very small regeneration coming up on the path to the burial ground (see Photos b, c & g, Appendix 1). To the east of where the track meets the crags, there are a couple of old and straggly plants and one or two regenerating plants back in the woodland itself (Photos a & l). Approximately 100m to the east, there is a large and dense stand of Rhododendron with a mix of both mature and regenerating plants (see Photos m & n, Appendix 1) growing around an old wall line. Around 10m east of this is another cluster of approximately 5 regenerating plants (see Photo o, Appendix 1). Another 4/5 regenerating plants could be seen within the woodland to the south of this, but no more were found to the east. No Rhododendron was found to the west of the burial ground.
Map 1: Cartland Craigs
Table 1: Target notes from Cartland Craigs Number Species Description 1 Rhododendron Scraggly plant at end of track at top of gorge 2 Rhododendron Small plant on crags 3 Rhododendron Small regeneration on path 4 Rhododendron Larger plants in the woodland 5 Rhododendron Small plants covering the burial ground 6 Rhododendron Dead plants lining old fencing rails 7 Rhododendron Single plant down crags 8 Rhododendron Large patch of small plants 9 Rhododendron Scraggy plant away from crag edge 10 Rhododendron Large patch of mature plants 11 Rhododendron Small patch of c. 5 small plants 12 Rhododendron 2 or 3 small plants in the woodland 13 Rhododendron Single plant in woodland 14 Rhododendron Single plant in woodland
Cleghorn Glen Map 2 shows the records of INNS found at Cleghorn Glen. The target notes for the map are in Table 2. Photos taken during the survey can be seen in Appendix 2. The exotic plants found in Cleghorn Glen were confined to a much smaller area and consisted of one or two individual plants that appear to have escaped over the wall from the burial ground, and one larger area of Rhododendron close to the boundary with the private garden which appears to have been there for some time but isn’t spreading rapidly (see Photos h, I & j, Appendix 2). The other plants found are species of Berberis and Mahonia and do not appear to be spreading further in to the SSSI themselves as yet (see Photos b, c & f, Appendix 2). Map 2 shows an “area of Rhododendron”. On the ground, there is a clear “private garden” sign to the east of the small burn at this point, but nothing except a finger post showing the NNR footpath route on the western side. It wasn’t clear if this ground was private, so the footpath up the western side of the burn was walked. About a dozen large Rhododendron plants were found on both sides of the path (Photo l, Appendix 2), and nearer the top of the area on the map, the Rhododendron became denser and was clearly regenerating. At the top of the slope, the path opened onto a formal garden, which was clearly not part of the area to be surveyed, but it was thought to be worth noting the plants on the map as it may impact on eradication proposals. Only one photo was taken at the bottom of this area, due to potential sensitivity over land ownership. In addition, there were several clumps of Snowdrops beginning to appear along the path around the burial ground. It was not possible to tell if these are the native variety or potentially invasive species spreading from the gardens.
Map 2: Cleghorn Glen
Table 2: Target notes from Cleghorn Glen Number Species Description 1 Mahonia, Berberis Single plants south of path 2 Berberis Single plant south of path 3 Rhododendron Large plant north of bridge 4 Rhododendron Cluster of large plants and regeneration to south 5 Berberis Single plant at corner of path 6 Rhododendron At least a dozen large plants
Conclusions/Recommendations Cartland Craigs The ideal situation here would be to remove all the Rhododendron in the area, and to either treat any stumps left with herbicide, or keep on top of any regeneration for 3-4 years until the plants stop re-growing. There are potentially landowner restrictions on this, as this survey hasnâ€™t been able to determine exactly which landholding each Rhododendron plant is on. It is therefore recommended that as much Rhododendron as possible is removed (preferably by the root base) and treated/managed in the longer term, whilst the remaining plants are monitored to prevent further colonisation of the SSSI. The hotel might agree to the removal of the Rhododendron in the immediate vicinity of the SSSI (i.e. the plants found in this survey) as it is unlikely that the integrity of the designed landscape would be affected by the removal of such a small amount of Rhododendron. In fact, the removal of the Rhododendron from the burial ground itself will help to preserve its integrity as the plant maybe damaging the stone work. Cleghorn Glen The Mahonia and Berberis plants should be removed before they get the stage of spreading out into the SSSI. This will be a quick and easy process as there are only 4 individual plants. If possible, the plants should be removed by the root plate and completely removed from site. If this isnâ€™t possible, cutting as close to the ground as possible and treating the stumps with a herbicide to reduce chance of regeneration is recommended. The Rhododendron on the SSSI site should also be removed and either treated with herbicide, or be subject to regular visits to hand pull the regeneration. Unless an agreement can be made with the owners of the private garden to remove the Rhododendron back from the SSSI boundary by, say, 10m, it will be an on-going task to annually monitor the spread of the Rhododendron from this land into the SSSI and remove and new plants.