Chalara – lessons learned

Ash dieback has become a continent-wide problem in a relatively short period of time which has generated a significant amount of research within and across countries.  To consider what lessons have been learned, this project convened a workshop of researchers and government and non-governmental representatives from 10 EU countries to describe the impact of the disease, research undertaken and underway, and management responses.  From the workshop and following work, it was identified that whilst there was much ongoing research which had the potential to deliver long term benefits, a lack of immediately useable information for land managers risks ash being lost from the landscape before long-term research outputs are available for use.  The Awareness, Planning, Action and Recovery framework developed with Defra funding (and subsequently published, Stokes and Jones, 2019) was used to explore this issue.

Given the research backgrounds of the attendees there was a strong emphasis on the search for resistant or tolerant species.  This line of research, by its nature, is uncertain and long term.  There appeared to be a number of potential interesting options but none of them were particularly close to offering a solution to the large-scale loss of ash from the landscape.  Outputs of resistance/tolerance research (resistant/tolerant ash) will most likely be available after then period of high impact and mortality of ash dieback has passed.  As such, this research may be more pertinent to the post invasion stage of Ash dieback.  Land managers may demonstrate low acceptance/uptake of resistant/tolerant ash if they are unsupported during the high mortality phase of ash dieback.  In the short term, adopting planting strategies to maintain/increase high genetic diversity may offer more immediate solutions for land managers and may also have a positive effect across multiple threats. 

Research into more immediate response options (e.g. silviculture) were mentioned.  However, there was limited discussion of how the outputs of this research have been, or should be, translated practical/usable solutions for those responsible for management at a local level.  The creation of a toolkit for local authority managers in the UK was an example of an attempt to achieve this.  The creation of a toolkit reflected the need to get information to those who have to manage the impacts of the disease whilst the longer-term research is ongoing.

The time for different strands of research to provide useable outputs to land managers emerged as a key theme.  It has been documented that responses in plant health can lag outbreaks (Ward, 2016), resulting in missed opportunities to limit the total impact of an outbreak.  This problem can be understood by considering the behaviour of local managers.  The Awareness, Planning, Action and Recovery framework sets out four phases which local managers need to oversee for a successful outcome. The research described at the workshop was more focussed upon the latter phases of action and recovery.  Overlooking the earlier phases risks local managers being unsupported during the early period of an outbreak and risks slow uptake of the outputs of long term research.  This situation may be worsened where local managers have had a poor, unsupported experience of managing ash which results in a reluctance to plant resistant/tolerant material.

Two options are to address this issue are: 1) to provide local managers with more immediate solutions and engagement; and 2) to take a pre-emptive approach to long term research, beginning before the threat arrives (as per New Zealand’s pre-emptive licensing of biological control agents for brown marmorated stink bug).