Hartlepool Hedgerow survey reveals poor ecological condition
Monday, January 17th, 2011Survey work contributing to the ‘Hedgerows’ HAP continued in 2010 through a Defra-funded hedgerow survey in Hartlepool, carried out by The Wildflower Ark. A grant of £4,900 was awarded to the Ark in April last year allowing the field survey to be carried out over the summer and autumn.
The aim of the Hartlepool Hedgerow Survey was to establish the extent, character, condition and management requirements of hedgerows in the borough of Hartlepool by carrying out a random survey of hedgerows following the method given in Defra’s Hedgerow Survey Handbook. Using this standardised method allows the data to be collated nationally as well as locally, thus contributing to both the local and national HAPs. In addition to collecting information on extent and character, the survey method also allows the condition of hedgerows to be assessed. This will allow future hedgerow management to be targeted appropriately in order to increase the number of hedgerows in the borough that are in favourable condition for biodiversity.
The Wildflower Ark were assisted in the hedgerow survey by 23 volunteers who were trained in the survey method and contributed over 30 days of field work. In total, 183 hedges were surveyed, equating to 41.53km. The character of the hedgerows was similar across the borough. Almost all of them (86%) were shrubby hedgerows consisting predominantly of Hawthorn (present in 97% of the hedgerows) with additional species such as Dog Rose (47%), Bramble (41%), Elder (40%), Blackthorn (28%), Ash (21%) and Sycamore (13%). In total there were 76 isolated hedgerow trees, predominantly Ash (43) or Sycamore (21). Over half of the hedgerows were mixed (i.e. not dominated by one species) and over a quarter of the hedgerows (27%) were also species-rich, meaning they contained four or more native woody species in the 30m section that was surveyed.
Of the 183 hedgerows surveyed, only 5% were found to be in favourable condition. Favourable condition is assessed on six different attributes: hedgerow dimensions, percentage of gaps along the hedgerow length, basal canopy height, width of undisturbed ground at the base of the hedgerow, herbaceous vegetation cover at the base of the hedgerow, and presence of introduced species. Each attribute has an acceptable threshold and a hedgerow must be within this threshold for all six attributes in order to be classified as in favourable condition. Of the 95% of hedgerows that were not in favourable condition, the majority of them failed on the basal canopy height, meaning the gap between the ground and the bottom of the hedgerow canopy was too great.
The survey data has been collated onto both Defra’s online database and a GIS database and will be distributed to local statutory and non-statutory conservation bodies, the regional record centre, and Defra. A full report of the survey will be available to download in February on this website as well as at www.wildflowerark.org.uk













