Branching out - Protecting our trees

An introduction to this damaging fungal plant disease to help understand how to recognise it, how does it spread and what can we all do to help reduce further plant health issues

Ash dieback disease, caused by the fungal pathogen Hymenoscyphus fraxineus, is now widespread in the UK, and killing huge numbers of our native ash trees. Despite high mortality rates, a small proportion of ash trees appear resistant to the disease, remaining healthy for many years. I will describe how we can use the latest genetic tools to understand more about why some trees survive, and to identify genes which may be important in the race to breed more resilient trees.

Grey squirrels are native to North America, but were introduced to a number of sites in the late 19th century . Their population is now at around 2.7 million individuals with populations across the UK. As well as out competing our native red squirrel serious grey squirrels are a major pest of trees with their bark stripping behaviour causing significant damage and tree fatalities. I will describe how at APHA we are currently looking at alternative methods of squirrel management to mitigate the effect of this non-native species on our woodlands. In particular, I will talk about new traps that have come on the market and the work APHA has been doing on the development of an oral fertility drug for grey squirrels.

Non-native insects pose a serious risk to tree health and if an incursion cannot be eradicated the only option is to manage the risk and reduce the spread on the invasive species. I will discuss the work we’re undertaking on managing an established populations of oak processionary moth using mating disruption and biological control and how we are preparing for a potential invasion of emerald ash borer.