Trees play an important role in shaping and defining the landscapes of Denbighshire. From veteran parkland trees to woodland saplings, and from upland whitebeams to lowland poplars, they all contribute to the fabric of the county.
Generally, trees can live for a long time in Wales i.e. decades through to centuries. Through the course of a long lifetime trees provide numerous benefits to the wider environment and other species, including us. Benefits include provision of oxygen, carbon sequestration, home to other species, landscape character, cultural heritage, and the list goes on. However, the majority of these benefits are provided when a tree is in good health with vigorous growth.
Being living organisms, trees are susceptible to disease. Causes and presence of disease are an important element of the natural world but there is a fine balance to be struck in a healthy environment.
As humans have moved further and faster around the world, carried materials such as timber and soil to and from locations beyond natural ranges, and eroded natural systems, some species have exploited niches previously unavailable to them.
Hymenoscyphus fraxineus commonly known as ash dieback is a fungus that nowadays has spread well beyond its native range of parts of Asia. Ash (Fraxinus species) trees in such areas are able to cope with the presence of H. fraxineus as they have co-evolved. However, the native ash Fraxinus excelsior of the UK is more vulnerable as they have evolved independently.
Ash trees are one of the most common trees in Denbighshire. They dominate some woodlands, line many highways, stand proud in parks, and provide habitat for many associated species. However, as a tree declines in condition it is more likely to shed limbs therefore posing a potential risk to people. Although deadwood is a very important habitat feature and is retained where possible, we have a duty of care to the general public.
The health and safety of residents and visitors is of paramount importance. Therefore, we now have a team of Tree Inspectors dedicated to the task of mapping, surveying, inspecting, and risk assessing ash trees across the county. This is a challenging task and not only important for health and safety of people but also for purposes relating to the declaration of a climate change and ecological emergency. Trees that are recorded on our tree management system will be monitored closely to determine if and when any physical works are required.
Michelle Brown, Tree Inspector, says: “My favourite part of the job is being in the outdoors and enjoying Denbighshire’s nature and countryside. I also really enjoy meeting the public and trying to foster a positive relationship between us all.” She goes on to note that there is hope, saying “I’m most interested by the variable response of trees to ash dieback, not just in mature trees but also in a sizeable percentage of juvenile trees. The varied nature of Fraxinus excelsior gives hope that favourable (possibly resistant) mutations are already potentially being seen in young healthy trees and these must be protected as carefully as the surviving mature trees.”
Data gathered on ash trees during 2021 will feed into an Ash Dieback Action Plan. This document will provide a strategy to manage ash trees infected with ash dieback. It will also include a wider approach to protecting associated species, promote suitable tree species for planting as replacements, and consider locations where we can encourage natural regeneration of trees.
Unfortunately, ash dieback is not the only threat to our local trees. Other notable pests and diseases include Dutch elm disease Ophiostoma novo-ulmi, larch disease Phytophthora ramorum, and oak processionary moth Thaumetopoea processionea. These and some other species pose real threats but you can help reduce such pressures. The TreeAlert website from Forest Research is a good starting point should you wish to learn more and submit a report for tree pests and diseases.
Tom Hiles, Tree Inspector, notes how he stays positive in light of the growing number of tree pests and diseases: “It’s good to be proactive. We are able to do something about the environmental challenges of our time, albeit as small players in a vast game. There is always something to learn and explore further. Trees and their biology, how they interact with other species and their history in the landscape is fascinating.”
We can all make a positive difference and help reduce the spread of pests and diseases by practising good biosecurity. The simplest of which is to clean your footwear of mud after every walk, run, or exploration. Not only are you minimising the spread of spores and seeds, you’re also protecting your money as you won’t need to buy new shoes as regularly. More information on biosecurity can be found on the Natural Resources Wales website: https://naturalresources.wales/guidance-and-advice/business-sectors/forestry/tree-health-and-biosecurity/how-to-practise-biosecurity-in-woodlands-keep-it-clean/?lang=en
Andrew Cutts (County Tree Officer)