County Kildare Hedgerow Survey Report

Summary

County Kildare’s hedgerow network is a huge asset to the county, being valuable in terms of agriculture, landscape, wild flora and fauna, water quality, carbon sequestration and employment. Before this survey was carried out relatively little detailed information was known about the resource.

In the summer of 2006 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.

Results from the County Kildare survey were compared with those from similar hedgerow surveys conducted in County Longford in 2006, County Laois, County Offaly and East Galway in 2005, and Counties Roscommon and Westmeath during 2004.

Based on the results from the sample, the total length of hedgerow in County Kildare was estimated at 10305km, and the average figure for hedgerow density as 5.92 kilometres per square kilometre (km/km²).

There is a wide contrast in the structure and composition of hedgerows around the County, from the precisely managed hedges on stud farms and tightly managed tillage hedges to the less formal hedges on the less intensively managed lands further to the west.    

A very wide range of shrub and tree species were found in County Kildare’s hedges. A total of 45 shrub and tree species, including 20 native species, were recorded in the sampled hedges. Whitethorn is the most frequently occurring shrub species found in 93% of hedges, with Ash the most common tree species, occurring in 58% of hedges in tree form. Most hedges have young trees.

Approximately 19% of hedges recorded were classed as ‘species rich’, with the majority of these found in the north of the county.

County Kildare’s hedgerows show a higher degree of fragmentation than those of other counties, largely due to the high degree of development in rural areas. This information, coupled with the fact that two thirds of hedges adjoin intensively managed farmland, means that there are implications for the overall biodiversity potential of the resource.

Most hedges are of a standard construction with a single line of shrubs planted on the side of a hedge bank often with an associated drain. Stone walls are not a common feature of Kildare hedges. Over 80% of hedges are part of boundaries that have been in existence since at least the time of the first Ordnance Survey in 1837-8. This does not guarantee that the hedges themselves are of the same age. Some degree of field rationalisation has occurred since the second edition of the Ordnance Survey in 1912-13, but it is not possible to quantify hedgerow loss as there is no compatible benchmark to base the current results. 15% of hedges would now be classed as redundant boundaries in terms of the field division on farms.

County Kildare’s hedges compare favourably with those in other counties in terms of the structural characteristics of height, basal density, and extent of gaps. These qualities influence the agricultural and wildlife value of hedgerows. 65% of hedges showed evidence of some degree of management in the recent past.

23% of hedges met a series of ‘favourable condition’ criteria linked to structure and species composition. When species rich hedges alone were considered 41% met the criteria. Most of the assessed characteristics can be influenced by appropriate management.

Over half of the hedges had wire fixed to hedgerow stems and trees which is a negative feature that has implications for safety and hedgerow health.

Overall County Kildare has a varied, distinct, and interesting hedgerow resource, but appropriate efforts must be made by various bodies (and individuals) if the resource is to be improved and sustained into the future.

Recommendations have been made based on the Hedgerow Survey results, considered in the light of current best conservation practice. The relevance of the recommendations to each of the stakeholder groups, such as Kildare County Council, farmers and landowners, the various state bodies, research institutions and Teagasc, have been tabulated for easy reference.