Mapping for healthy hedgerows: one Tree Warden’s account
August 25, 2020
Leicestershire Tree Warden Richard Ellison shares his journey mapping his local hedgerows, inspired by a passion to see healthier hedgerows for all the ecological benefits they bring.
Having lived in Wymeswold, a small village in North Leicestershire, for 30 years I am well aware of the inexorable environmental deterioration of the surrounding countryside. My wife and I have always recorded birds, butterflies and dragonflies, and the start of concern over ash dieback disease in the area coincided with me becoming village Tree Warden some 5 years ago. This event in turn led me to look more closely at the hedgerows in the parish, the hedgerow trees, and the best areas of good value for wildlife. Most of the hedges are flailed once or twice a year and many have almost no environmental value.
In early spring of 2019, I decided to attempt to record the state of the hedgerows and hedgerow trees in the Parish. In the main they date from the enclosure of the village open fields in 1757 when ash and English elm were the standards, along with mostly hedgerow hawthorn. The elm is no more (except a few seemingly resistant ones). That leaves the ash trees which, if they succumb, will have a detrimental effect on the character of the countryside. Many are already in a poor state because of, among other things, ploughing close to the hedges, and herbicide spray drift. So, the survey I hoped ultimately would serve to focus on areas where tree planting and hedge improvement might take place for visual improvement, particularly on the skyline as seen from public access routes, and as the basis for establishing wildlife corridors.
Mapping the hedges one by one
In recording the hedges, I simplified the classification recommended by HedgeLink which is particularly appropriate as it was designed to be applicable to the English Midlands. By combining several of the 10 categories in the HedgeLink scheme I came up with three hedge types that I could usefully record covering the ground at a reasonable pace.
Poor hedges: over-trimmed, many with gaps and with hard knuckles at a trim line (HedgeLink types 1 and 2).
Good hedges: healthy looking, may be over trimmed but have frequent stems and may be up to 4m high (HedgeLink types 3,5,6,7).
Mature hedges: tall (more than 4m) many with healthy stems and in places with trees 20 or more years old (HedgeLink types 8, 9 and 10).
In addition, I plotted all woodlands, copses, spinneys, wide verges of wildlife value, conservation meadows and linear, largely wooded, valleys.
Hedgerow trees greater than 30cm girth at chest height were plotted and the species noted (about 90% of these trees are Ash)
All information was plotted on a paper OS map in the field and then transferred onto Google Earth. The exact location of the hedgerow trees was also plotted on Google Earth, particularly useful as tree shadows clearly show on an image with a low sun angle. The best image was taken in 2010 and therefore allowance had to be made for trees that had since died or had increased in size. Files of the information plotted on Google Earth were exported to QGIS, open access software, and viewed onscreen with the OS 1;25,000 scale maps in the background.
It takes time and perseverance
All in all, I carried out about 25 visits, with each field visit taking me a few hours at a time. I have completed approximately 80% of the parish, which in total is about 3200 acres or about 13 square kilometres!
For the survey I visited almost every hedge. Those not easily accessible from public rights of way or from land for which the owner had given permission were assessed using binoculars. At the time of writing about 20% of the Parish hedges are inaccessible and have not been surveyed.
If I was starting again, I would take more photographs during the course of the survey.
There is much more to do in terms of looking in more detail at specific hedges and determining more of those that date from before the enclosure. Also, to encourage local land managers/owners to support the establishment of corridors, to plant trees and widen hedges and the change to management of at least some hedges to a 3 year cutting cycle.
Thank you to Richard for sharing with us about your hard work!