ash tree disease

The whole idea of a spore is that it is a tough little mini seed thing that can survive a hostile period and then get going when conditions are right.
ella46 in the midlands the ash trees are all losing their leaves right now. Apparently vertical scars on the bark are diagnostic of the disease.

I shall inspect them again tomorrow!

This is a really good video showing exactly what to look for and the map shows where the disease has been confirmed.

www.forestry.gov.uk/chalara

Thanks, jodi. That's useful.

The woods here are due to be inspected this week, a few trees are showing signs of the disease

Thanks Jodi that will be helpful.

The disease has now spread into the North-east and I think there has been a further spread in the south.

Depressed! It is everywhere. But if you look at the distribution it looks like some blew over from Denmark (cluster in the top of the East Anglian bulge, not related to imports).
The environment secretary has had another meeting. Sigh. Talk of managing leaf litter as this will spread disease next year. Why do I think this is a hopeless notion - because the entire country is covered in dead ash leaves this week, that's why. Suspect there are more ash trees than people in UK.
I was walking past our local wood yesterday and trying to picture it without the ash. It would not be a wood. An area of scrub with a scattering of oak trees.

I understand that all cases found in Yorkshire so far are in nurseries.

I am sick of people bringing whatever foreign bodies (this does not include immigrant people, of course ) they like into the country. We have Japanese knotweed, Himalayan balsam, wels, signal crayfish, harlequin ladybirds, b**y beavers, coypu, mink etc. etc. etc. many out of control.
I am particularly sick of the people who claim to be 'experts' with regard to things which have not been tested (e.g. beavers again).

On the other hand, if it had never been allowed we would have very few garden flowers. Whether a new item, flora or fauna, is going to become a problem is simply not known until it is too late.

Beavers have been re-introduced. They are were a native species. I hope they thrive.

And me! But what are wels?

We need to check the ash trees on our land, but I suspect it may be too late in the season to be sure of anything. The worrying thing is that if you do find any diseased plants on your land it is your responsibility to remove and burn it! An expense for larger landowners but a total nightmare for individual gardeners!

There are two species of beaver: the North American beaver (Castor canadensis) and the Eurasian beaver (Castor fiber).

Beavers are total vegetarians and do not eat fish. They will only build dams in they can find no suitable habitat with conditions which meet their needs. Knapdale is ideal for them.

The beavers re-introduced in the controlled trial in Knapdale are Eurasian ones from Norway, and are genetically very similar to the original Scottish ones.

However, there are also possibly 20 - 50 illegal immigrant beavers in Tayside, probably brought in by private individuals and released independently and without the observation which the Knapdale ones are getting. These are from further south-east in Europe (I will pinpoint where tomorrow when I have checked with a friend), and are genetically different - messing up the native gene pool! Tayside beavers

BTW the "Highland Tiger" or Scottish wildcat can interbreed with feral domestic moggies, and its genes are being diluted too. A project has been going on to check the genetic makeup of all the wildcats that can be trapped and tested (not an easy task) to see just what the position is. There are many fewer Scottish wildcats in the wild than amur tigers, but conserving tigers has a far higher profile than studying a native species often confused with house pussycats that have gone awol. wildcat genetics

Getting back to the poor trees. There are indeed more of them than us. 80 million is the estimate!
Vertical scarring is supposed to be a way you can diagnose it.
I feel sad about the really old trees - the oldest are probably those that have been hacked back in hedge lines, so that they have re-sprouted from stumps at some stage. Apparently this greatly increases lifespan.
Those in charge of woodlands need to start planning now and planting:
Hornbeam
Beech
Small leaved lime
Spanish chestnut

and some of the smaller natives, field maple, cherry, rowan , yew
I have been noticing this week that due to our wonderful Parks Trust we have lots of field maple and norwegian maple - all brightly butter coloured this week - and not a sycamore in sight.

If anyone is wondering, the Tayside beavers came from Bavaria (cue drinking song as beavers in lederhosen and silly hats slap their tails against their bare thighs)

So are the Tayside beavers not Eurasian beavers as well as the ones from Norway that were taken to Knapdale?

Re beavers: 'were' native is right. In my opinion they have no place in the landscape that we have now. With a bit of luck, infected ash trees will turn out to be poisonous for beavers. I used to enjoy Knapdale. Now it is a playground for 'expert' hobbyists with a God complex.

Wels are a monstrous catfish which was introduced to some still waters quite a few years ago. They are reminiscent of a dustbin with teeth and a tail. There are several more recent aquatic aliens.

Same eurasian species but a different genetic population. The Norwegian ones are closer to the original Scottish ones, which is what they want to approximate to. Maybe the land bridge to Europe made them nearer relations. I am not well up on the details, but an animal geneticist was distinctly scathing about the random introduction of beavers by amateurs.

These days they are pretty careful about what strain of animals they introduce, or use for captive breeding programmes. For instance they used to allow breeding between African and Asian elephants but don't any more, and no zoo can keep African and Asiatic lions in the same establishment, let alone the same enclosure.

There are international stud books for all the species that are being bred in captivity, and individuals are matched up with suitable mates. Sometimes the best choice is from a zoo far away, and at the other extreme really successful breeders whose genes are in danger of being over-represented in the breeding population are put on the pill and not allowed to have any more offspring.

But! Surely a larger gene pool is a good thing?

This tends to remind me of a certain moustached bloke who advocated ' pure' genetic stock!
Nature thrives on mutations.

'

I think they want a large gene pool but within a geographical and subspecies limit. The Scottish wildcats are an example. "No angry tabby or feral the wildcat is a genuine wild species of cat; it was here long before we were and long before the domestic cat had even evolved." Unfortunately it can interbreed with domestic cats - the two species are not yet separate enough to make interbreeding impossible, and there a lot of feral cats about. So the dilution of its genes with moggy genes mean that it will become extinct, probably in the near future.

African and Asiatic lions are also distinct species, but are near enough to interbreed, as can the two types of elephants (and also lions and tigers, though in nature they would never meet up. Ligers and tions were a freak novelty once, but I think the hybrids were infertile.)

Yes, they do want genetic diversity when they breed animals in captivity, so that reintroduced populations are better able to survive. That is what the stud books are for, not to keep "pure" and inbreed, which loses the genetic characteristics which make strong flexible groups.

But they do not want populations which have completely separated to merge and lose their characteristics.

Take zebras. You would probably think a zebra is a zebra is a zebra, most useful as the last animal in an alphabet book.

But there are three species of zebras: the plains zebra, the Grévy's zebra and the mountain zebra. The plains zebra and the mountain zebra belong to the subgenus Hippotigris, but Grévy's zebra is the sole species of subgenus Dolichohippus . The latter resembles an ass, to which it is closely related, while the former two are more horse-like. All three belong to the genus Equus along with other living equids, but their lifestyles differ.

Like most members of the horse family, zebras are highly social. Their social structure, however, depends on the species. Mountain zebras and plains zebras live in groups, known as 'harems', consisting of one stallion with up to six mares and their foals. Bachelor males either live alone or with groups of other bachelors until they are old enough to challenge a breeding stallion. When attacked by packs of hyenas or wild dogs a zebra group will huddle together with the foals in the middle while the stallion tries to ward them off.

Unlike the other zebra species, Grevy's zebras do not have permanent social bonds. A group of these zebras rarely stays together for more than a few months. The foals stay with their mothers, while adult males live alone. Like the other two zebra species, bachelor male zebras will organize in groups. Plains and mountain zebra foals are protected by their mothers, as well as the head stallion and the other mares in their group. Grevy's zebra foals have only their mother as a regular protector, since Grevy's zebra groups often disband after a few months.

When they are promiscuously interbred in captivity, the offspring are not representative of their original populations, so are able neither to fit in if released nor to serve as examples if kept.

(A lot of this description of zebras came from Wikipedia - must remember to quote sources )

The govt. tried to sell off the forests, and all the time they knew about this disease. Not that I believe in conspiracy theory.

I agree, jeni. Nothing like a bit of hybrid vigour for helping evolution along.

If the hybrids are sterile like mules it doesn't help evolution along.