Thanks to shocking failures of government, every tree, almost everywhere, is now threatened by killer plagues
By George Monbiot, published in the Guardian 14th August 2019
As Dutch elm disease spread across Britain in the 1970s, the country fell into mourning. When the sentinel trees that framed our horizons were felled, their loss was a constant topic of sad and angry conversation. Today, just a few years into the equally devastating ash dieback epidemic, and as the first great trees are toppled, most of us appear to have forgotten all about it. I’ve travelled around much of Britain this summer, and seen the disease almost everywhere. A survey published this spring found infected trees across roughly three-quarters of England and Wales: the spread has been as rapid and devastating as ecologists predicted. But in this age of hypernormalisation, only a few people still seem to care. Ash to ashes: our memories wither as quickly as the trees.
And almost nothing has been learnt. Our disease prevention rules,
whose scope is restricted by the European Union and the World Trade Organisation,
and whose enforcement is restricted by the British government’s austerity, do
little to prevent similar plagues afflicting our remaining trees. Several
deadly pathogens are marching across Europe. While it is hard to prevent some
of these plagues from spreading across land, there is a simple measure that
would stop most of them from spreading across water: a ban on the import of all
live plants except those grown from tissue cultures, in sterile conditions.
But bans are more or less banned. Nothing must be allowed to
obstruct free trade. Instead, the world’s governments rely on hand flapping.
Take, for example, a lethal
plague called Xylella, that is ravaging
olive groves in Italy, and threatens a remarkable variety of trees
and shrubs, including oak, sycamore, plane and cherry. The system for
preventing its spread depends on inspections of random consignments
of known host plants, and a passport scheme to ensure they aren’t imported from
This system is likely to be useless. The EU keeps a list of
plants that can carry Xylella. It has been updated 12 times
in four years, as new carriers emerge. No one knows how many more host species
there might be. Visual inspections won’t reveal plants that carry the disease without
symptoms. Random sampling won’t protect us from a plague that can be introduced
by a single plant.
Nor do we know whether Xylella is the most urgent risk to
our remaining trees, or whether an entirely new contagion will hit them
instead. Many plant pathogens evolve at extraordinary speed, jump unexpectedly
from one host to another, suddenly hybridise with each other, and behave in
radically different ways in different environments. A system that regulates
only known risks is bound to fail.
Even in economic terms, the live plant trade is senseless. Ash
dieback alone, according to a paper in
Current Biology, will cost this country around £15 billion. But the UK’s import
and export of all live plants amounts to £300 million a year – 2% of the costs
of this disease. The paper estimates that another 47 major tree pests and
diseases now threaten to arrive in this country, and these are just the known
In ecological terms, this legislative failure is a total disaster.
For the sake of deregulatory machismo, we face the prospect of tree species
everywhere eventually meeting their deadly pathogens. Where logging and climate
breakdown have so far failed to eliminate the world’s forests, imported
diseases threaten to complete the job.
What will come next? Will our beech trees succumb to
Phytophthora kernoviae, a disease that appears to have been imported
to Cornwall on infected shrubs from New Zealand? Will Sitka spruce, on which
commercial forestry in this country relies to
an extraordinary extent, be hammered by the larger
eight-toothed spruce bark beetle, found for the first time this year
in a Kent woodland? Will it be hit by another marvellously-named plague, Neonectria
fuckeliana? Or by something else entirely? As the trade in live plants
reaches almost every corner of the earth, nothing and nowhere is safe.
Just as we need a precautionary approach, every lid is being
ripped off, every barrier smashed, facilitating trade in everything, including
pathogens. In response
to a parliamentary question about Xylella, the environment
minister Therese Coffey claimed that Brexit creates an opportunity to introduce
“stricter biosecurity measures”. It does, but will it be used? Given that, for
the monomaniacs who now run this country, the main purpose of leaving the EU is
to escape its public protections, the chances of Brexit leading to the stricter
regulation of plant imports seem remote.
Never mind that this trade makes neither ecological nor economic
sense. Our government, like many others, favours a global trade regime that
places the free movement of goods above all other values (while imposing ever
tighter restrictions on the free movement of people).
There’s nothing good about ash dieback, but there is one useful
thing that could be done: wherever possible, leave the dead trees to stand.
There is more life in a dead tree than in a living tree: around 2000 animal
species in the UK rely on
dead or dying wood for their survival. But (except in politics)
there’s a dearth of dead wood in this country. Many species, such as the lesser
spotted woodpecker, the pied flycatcher and the stag beetle, are severely
restricted by the shortage of decay, caused by our tidy-minded forestry.
And there’s another reason to let the dead giants stand: as
memorials to the repeated failures of government. Let us remember our losses,
and learn from them.