Sad to say, there is little that can now be done for Britain's ash trees. The rapid spread of the Chalara fraxinea fungus – confirmed at just two sites in the wild, two weeks ago, and now found at 61 – only emphasises the impossibility of confining it, and there is no cure. The impact on the countryside, and on all manner of flora and fauna that thrive in the ash's shade, is set to be as devastating as it is heart-breaking.
While it is too late to protect our 80 million ashes, we can make it harder for pathogens to take hold in the first place. Ash dieback came to Britain via two different routes. It was first found in saplings brought over from the Netherlands, where the disease was already rampaging. Subsequent outbreaks in the wild appear to have started with spores carried from the Continent on the wind. We can do nothing to block the sea breezes. But we can take control of imports.
Shutting the stable door after the horse has bolted? Hardly. In the past 12 years, Britain's trees have suffered more than twice as many outbreaks of foreign infection than in the whole of the previous century. The problem is not only not going away, it is getting markedly worse.
Much attention must focus on Europe. The EU Plant Health regime is now – finally – being significantly revised, for the first time since 1978. Such reforms must be expedited. But Britain's own border controls must also be tightened up, with "plant passports" to guarantee the health of all imports and keep track of what is coming in and from where.
Cumbersome as such a system may be, it is also vital. Although Britain does have a Non-native Species Secretariat, conservationists' attention has, until now, focused more on preserving the countryside from developers and mitigating the effects of pollution and climate change. The tragedy of Chalara fraxinea and its uncontrollable spread tells us that the biggest threat to British wildlife in the 21st century might be pathogens brought in from abroad. We cannot continue to be so unprepared.