This week there’s still loads of stuff about ash die back in the media. Even with the BBC in its death throws as it lurks from scandal to scandal, they find time to talk of the end of our Ash woodlands based on a couple of nurseries and a newly planted ash woodland showing up an imported variety of an indigenous fungus. Was there ever “death” or was it all just “die back” followed by “bonfire of the panic-trees”.
Anyway, in their Science slot, the New Statesman had an article by Michael Brooks on the topic this week, prompting this as my reply to it’s drifts:
I am so in favour of an “Arts and humanities” mag such as yourselves having at least some science input but Michael Brooks piece on Ash die back – “A deadly trade” 9-15/11/2012 – lacks both clarity and accuracy, both seemingly sacrificed in seeking journalistic clout.
Ash is a native tree adapted to its environment and co-habitants in said location. This includes fungal types well adjusted to a little changing ecosystem. Unlike the bacterial mutations witnessed in hospitals and on farms in recent decades giving rise to antibiotic resistance then shared between bacterial species with total and reckless promiscuity and multiplied by half hourly division, fungal evolution is very different and far, far slower. In fact they seem to evolve more by mycologists changing their names than by altering their genetic constitutions.
However, raising native woodland trees of local provenance on my nursery, I have always found the product performs well when transplanted to its final growing position. I regard importing of growing plants as anathema as they will inevitably be ill suited to the location and will introduce alien fungi, bacteria, plants and animal species like nematodes. Furthermore centralized production usually reduces employment and industrializes it, rendering it dull, monotonous and boring.
But, look, most of the species moved around the Globe fail in their new found niches – they don’t “swap genes and evolve into forms for which native species have no resistance”. In farms and hospitals bacteria can do this because of gross use of antibiotics as a selective agent. There is no equivalent in our natural woodlands or even our “suburban gardens”. Where we are now finding fungal damage in Britain – as in Europe, I imagine – is where the local conditions are poor and unnatural. So newly lined out, imported Fraxinus excelsior woodlands, carrying foreign fungi which can prosper in the short term before perishing/being absorbed into the established ecosystem surrounding it.
There are plenty of other examples – BBC’s Countryfile has Larch forest in the West Country this week, being clear felled to create a barrier to spore transfer of a Larch targetting fungus. This tree is non-native and grown in cramped, unnatural conditions. Of course it’s ailing – the fungus just proliferates in already sick trees. That’s what fungi are for – “saprophytes” to recycle organic matter. They are not “pathogens” waging war on our landscape – they just clean up natural or man made failures.
“A huge microbiology experiment that is destroying the World’s forests”? No, Michael, it’s the inept and ill informed pursuit of profits playing against gullible, fashion driven consumers and short sighted forestry managers going for cheap imports over high quality local stock. But there’s no ecological disaster round the corner and, if we in future concentrate on using only locally grown, locally bred species we have a healthier future ahead of us.