Ms Shirley Clerkin:

Yes, actual gaps, that is, the basal layer is no longer dense such that you can see right through the hedge right the way across it. That would be an impact of a lack of the right type of management, which can be addressed.

Another impact is nutrient enrichment. This can occur where there is possibly excessive use of fertiliser or slurry. The hedge acts as a nutrient barrier in some senses, but it gets to a point where it is too much, it cannot take any more and the species diversity starts to decline. That is when a shift is noticed in the amount and type of species growing in a hedge. That can be directly related to nutrient enrichment. It is like any habitat; you can continue to do something for a while and it is not always noticed, then you reach an environmental threshold and something shifts. That is what we found in the hedges in County Monaghan. Approximately 40% of the hedges that were in poor condition had nutrient enrichment. Some of them even had slurry spread directly onto them, affecting their ability to photosynthesise. Nobody would welcome such a practice. All of those are management issues. There is also the issue of poaching, which involves cattle getting onto the banks of hedges and affecting and taking out all of the undergrowth. The soil is then exposed and can run off into any ditch that is there. That then has a downstream impact with sedimentation. Farmers also lose a very valuable resource, namely, the soil, in this process. We found that 75% of hedges in Monaghan were affected by poaching. Hedgerows can be fenced off temporarily during the growing season and cows can be allowed back on later in the season, in late summer and autumn, to graze the understory and prevent brambles and blackthorn from growing out too far into the field. That is all about making a shift in hedgerow management. Many of the issues are about management.