Our principal ecologist, Barry Wright, recently led two field training workshops for the Yorkshire and Humberside branch of the Chartered Institute of Ecology and Environmental Managment (CIEEM). Taking place near Wetherby at the begining of March, the workshops were devised to help CIEEM members to identify tree and shrub species in winter, including studying twigs from 19 different species, and learn the methods available for surveying hedgerows.
As well as describing existing survey methods, Barry also gave a demonstration of his own survey method, HEDGES (Hedgerow Ecological Description, Grading and Evaluation System). This is based on Barry’s own research, can be tailored to individual project needs and enables more hedgerow information to be gathered. As well as being a principal ecologist at Baker Consultants, Barry is currently completing his research for a PhD at Sheffield Hallam University in the study of hedgerows and the species that can indicate their origins and age.
An assessment of the ‘importance’ of a hedgerow under the Hedgerows Regulations 1997 can be required at any time of year, but surveying hedgerows in winter can be a cold, wet and daunting task especially with no leaves in the trees and bushes to make identification easier. This increases the importance for ecologists in having skills in winter tree and shrub species identification. If ecological surveys miss hedgerow species due to ecologists being unable to correctly identify trees and shrubs during winter, this could lead to the removal of a hedgerow incorrectly deemed not to meet the minimum criteria of woody species presence.
Despite these problems, surveying hedgerows in winter has its benefits. Without leaves to get in the way, it is easier to see the structure of a hedge, such as evidence of laying, and ground flora is more clearly visible. This is beneficial, as woodland ground flora species like Bluebell, Dog’s Mercury and Lords-and-Ladies can add to the scoring for a hedgerow to be assessed as ‘important’ under the regulations. Ground flora species such as these and Ivy are often hidden under foliage in summer, unless there is vigorous growth emerging on the outside of a hedge.
Even if winter surveying of a hedgerow is not specifically required, carrying out a winter survey is still desirable, so as to complete the picture following a summer survey to record the frequency and abundance of trees and shrubs along the hedge.