County Sligo Hedgerow Survey Report
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COUNTY SLIGO HEDGEROW SURVEY REPORT N. Foulkes 12th December 2008 Sligo County Council Hedgerow near Drumcliff, Crockauns to rear This Survey has been carried out on behalf of Sligo County Council, The Heritage Council and the County Sligo Heritage Forum © 2008 All rights reserved An Action of the County Sligo Heritage Plan 2007-2011 PAGE NO. CONTENTS i LIST OF TABLES iii LIST OF FIGURES iii ACKNOWLEDGEMENTS iv EXECUTIVE SUMMARY 1 1.0 INTRODUCTION 2 2.0 BACKGROUND 3 2.1 The history of hedgerows in County Sligo 3 2.2 The value of hedgerows for County Sligo 5 3.0 SURVEY RATIONALE AND OBJECTIVES 6 3.1 The need for a hedgerow survey in County Sligo 6 3.2 The objectives of the County Sligo Hedgerow Survey 7 3.3 Legislation and policy 7 4.0 METHODOLOGY AND FIELD SURVEY 9 4.1 Defining hedges 9 4.2 Selecting the sample 9 4.3 Maps and aerial photographs 11 4.4 Period of fieldwork 11 4.5 Access and permission 12 4.6 Structural recordings of hedges 12 4.7 Floristic recordings of hedges 13 4.8 Recording the extent of hedgerows in sample squares 13 4.9 Target notes 14 4.10 Photography 14 4.11 Data recording 14 5.0 RESULTS OF THE COUNTY SLIGO HEDGEROW SURVEY 15 5.1 Extent of hedgerows in County Sligo 15 5.2 Species composition of hedgerows in County Sligo 17 5.3 General ecological, historical, and agricultural context of 28 hedgerows in County Sligo. 5.4 Construction of hedges in County Sligo. 33 5.5 Structure and condition of hedges in County Sligo. 37 5.6 Management of hedges in County Sligo. 45 5.7 Quality of hedgerows in County Sligo 49 5.8 Hedgerow management and development control 51 5.9 Other observations 53 6.0 ANALYSIS AND DISCUSSION 55 i 7.0 RECOMMENDATIONS 72 7.1 Context 72 7.2 Recommendations 75 8.0 CONCLUSIONS 82 9.0 REFERENCES AND BIBLIOGRAPHY 83 10.0 APPENDICES 90 10.1 Example of aerial photograph 90 10.2 Example of vector map showing sample hedges 91 10.3 Example of Ordnance Survey map 92 10.4 Structural recording categories 93 10.5 Domin scale 94 10.6 DAFOR scale 94 10.7 Hedgerow related actions of the County Sligo Heritage Plan 94 2007-2011 10.8 Methodology review 95 10.9 Draft hedgerow conservation policies for County Sligo 98 10.10 List of species encountered during the survey 100 LIST OF TABLES Table 4.7.1 List of woody non-shrub species recorded. Table 5.1.1 Measurement of hedgerow extent in sample squares in County Sligo. Table 5.2.1 Frequency of woody shrub species occurrence and mean abundance in sampled County Sligo hedges. Table 5.2.2 Frequency of woody non-shrub species occurrence in sampled hedges. Table 5.2.3 Average number of shrub species per hedge (within the two 30m sample strips) Table 5.2.4 Comparison of average species diversity figures for townland boundary and roadside hedges. Table 5.2.5 Frequency of tree species occurrence in sampled County Sligo hedges. Table 5.3.1 Frequency of occurrence of sampled County Sligo hedges in CORINE land cover classes. Table 5.7.1 Comparison of the ‘favourable condition’ status of hedges County by County. Table 5.8.1 Summary of hedgerow-related planning conditions. Table 6.1 Comparison of average hedgerow density. Table 6.2 Comparison of shrub species diversity statistics. Table 6.3 Proportion of species rich hedges in County Hedgerow Surveys. Table 7.1 List of hedgerow stakeholder groups. LIST OF FIGURES Figure 4.2.1 Map of County Sligo showing the location of the 1 km² sample squares Figure 5.1.1 Distribution of sampled hedges in County Sligo. Figure 5.2.1 Frequency of occurrence of main woody shrub species in sampled hedges in County Sligo. Figure 5.2.2 Level of abundance of woody non-shrub species in sample strips in County Sligo. ii Figure 5.2.3 Distribution of main hedgerow species in sample squares. Figure 5.2.4 Distribution of species rich hedges in the sample squares. Figure 5.2.5 Percentage breakdown of domination of ivy at canopy level in sample 30m strips. Figure 5.3.1 Farm / property use of land adjacent to sampled hedgerows. Figure 5.3.2 Habitat category of land adjacent to sampled hedgerows. Figure 5.3.3 Links of sampled hedgerows with habitats in County Sligo. Figure 5.3.4 Historical context of sampled hedgerows. Figure 5.4.1 Boundary construction of sampled hedgerows. Figure 5.4.2 Proportion of sampled hedges in bank/wall/shelf size categories. Figure 5.4.3 Proportion of sampled hedges with adjacent drains and their associated drain size categories. Figure 5.5.1 Proportion of sampled hedges in hedge height categories. Figure 5.5.2 Proportion of sampled hedges in hedge width categories. Figure 5.5.3 Proportion of sampled hedges in ‘percentage gaps’ categories. Figure 5.5.4 Proportion of sampled hedges in basal density categories. Figure 5.5.5 Proportion of sampled hedges in profile categories. Figure 5.5.6 Proportion of sampled hedges in abundance level of hedgerow trees categories. Figure 5.5.7 Proportion of sampled hedges having degraded banks or walls. Figure 5.6.1 Types of hedgerow management recorded in hedges sampled. Figure 5.6.2 Proportion of managed sampled hedges in management method categories. Figure 5.6.3 Additional fencing of sampled hedgerows. Figure 5.7.1 Favourable condition status of sampled hedges in County Sligo. ACKNOWLEDGEMENTS Many people have contributed their time and support to this project. Thanks are primarily due to: County Sligo Heritage Forum for commissioning the project through the County Sligo Heritage Plan 2007-2011 and to Sligo County Council and The Heritage Council for funding this survey. Siobhán Ryan, Heritage Officer and Barbara Dobson in the Heritage Office, Sligo County Council. Members of the County Sligo Heritage Forum, in particular the members of the Natural Heritage Working Group who oversaw the delivering of the project: Ben Wilkinson; Brian McGarraghy; Caroline Sheil; Declan Feeney; Don Cotton; Jean Dunleavy; Martin Enright; Michael Archer; Michael Casey; Noel Raftery; Therisia Roddy; Tim Roderick; Will Woodrow and Gerard Scott. Cian Lundy for his assistance in providing Planning Application details. Theresa Gilligan and Billy Sommerville of the IFA, and the County Sligo Executive of the IFA. Caroline Conmy, GIS Office, Sligo County Council for back-up support in providing maps and aerial photographs: Anthony Byrne, Planning Section, for inputting ‘extent’ data into the Councils GIS database. Andy Booth and Robert Birtwistle who provided support with the fieldwork. My gratitude is also extended to all the landowners who allowed access to their land during this survey. If I had accepted all of the invitations to take tea I would still be out there. iii EXECUTIVE SUMMARY Sligo is a maritime county in the province of Connaught. It is bounded on the east by County Leitrim, on the north by the Atlantic Ocean, on the west and south by County Mayo and on the south-east by County Roscommon. It comprises an area of 1800 km² (695 miles²). County Sligo’s hedgerow network is an asset to the county, being valuable in terms of agriculture, landscape, wild flora and fauna, water quality, carbon sequestration and employment. In the summer of 2008, field recording of hedgerows was carried out using a standard methodology in 18 sample 1 km squares distributed evenly around the county, covering approximately 1% of its total area. The focus of the survey was to record information on the extent, species composition, structure, condition and management of hedgerows in County Sligo. At the request of the Natural Heritage Working Group compliance with recent hedgerow related planning consents was also investigated. Results from the County Sligo survey were compared with those from similar hedgerow surveys conducted in County Mayo in 2007, County Cavan, East Galway, Longford, Kildare and Leitrim in 2006, County Laois and County Offaly in 2005, and Counties Roscommon and Westmeath during 2004. Based on the results from the sample, the total length of hedgerow in County Sligo was estimated at 10449km, and the average figure for hedgerow density as 5.33 kilometres per square kilometre (km/km²). Examination of Ordnance Survey maps indicates that the majority of hedgerows in the county originated between 1837 and 1912. A total of 24 shrub and tree species, including 13 native species, were recorded in the sampled hedges. Whitethorn is the most frequently occurring shrub species found in 88% of hedges; Ash is the most common tree species, occurring in 47% of hedges in tree form. There was an average of 2.71 tree/shrub species per 30m sample strip. 73% of hedgerows sampled comprised solely of native species. Approximately 13% of hedges recorded were classed as ‘species rich’, with the majority of these found in the eastern half of the county. Hedges with drains were found, on average, to contain greater species diversity than those with no drains. Roadside hedges made up 17% of the sample, with Townland boundaries accounting for 8%. The majority of hedges were of a standard construction involving a single line of shrubs with a bank; whitethorn was the dominant species in 60% of hedges indicating a planted origin for much of the resource. Levels of management were found to be relatively low with 55% of hedges having no evidence of management within the last five years or more, although almost a quarter of hedges had been managed within the last year.