Biodiversity Planting Formula

[JonnyVine]

It worries me when people say things like this.

 

No species have shown themselves better adapted to our climate than the ones that have native status. Britain has been far warmer (6000 years ago the tree line was 300m higher than it is now) than it is now as well as far colder (the 'mini ice-age'), yet every native species survived.

 

This is perfectly true, however, the threat here is not the climate which usualy allows time for life to adapt.

 

The rapid rate at which new pests and disesaes are being imported can not be sustained by indigenous trees, or, clearly the trees in the countries where the pathogens originated!

 

Like you, I am also worried, by the lack of foresight by our countries arboricultural consultants that appear to be casual.

 

If we take a good look at history and what the schollars tell us, Then what happend to places like Christmas Island can be a little easier to understand

 

I can still remember what happened when Ophiostoma novo-ulmi almost eradicated the british Elm population! History is a valuable recording of events and an insight into how they unfold, unfortunately, I feel the horse has already bolted.

[HCR]

My text in bold.

 

The rapid rate at which new pests and disesaes are being imported can not be sustained by indigenous trees, or, clearly the trees in the countries where the pathogens originated!

 

So by implication, indigenous trees will all become extinct. When? Who gets to decide which new trees should replace them?

 

Like you, I am also worried, by the lack of foresight by our countries arboricultural consultants that appear to be casual.

 

That's a slightly sweeping statement and mildly insulting to boot.

 

If we take a good look at history and what the schollars tell us, Then what happend to places like Christmas Island can be a little easier to understand

 

What specific event on Christmas Island are you referring to?

 

I can still remember what happened when Ophiostoma novo-ulmi almost eradicated the british Elm population! History is a valuable recording of events and an insight into how they unfold, unfortunately, I feel the horse has already bolted.

 

The 'British' elms wiped out by DED (which I remember as well, not sure what credance is gained by having been there when it happened, but however...) were on the whole non-native species.

[Gary Prentice]

 

The rapid rate at which new pests and disesaes are being imported can not be sustained by indigenous trees, or, clearly the trees in the countries where the pathogens originated!

 

I understand that a lot, certainly not all, of the newer pathogens do live with the trees in their native environment. The trees without resistance or immunity perished. New pathogens/pests here meet trees with no natural immunity

 

Like you, I am also worried, by the lack of foresight by our countries arboricultural consultants that appear to be casual.

 

Much of the industry is complacent. In the last month I've visited a replanting site, 12 trees- ten of which were one species:confused1:, a local TO suggested ash as a suitable replant for a TPO removal FFS, I've seen hundres of examples over the last thirty years of ridiculus schemes by landscape architects

 

Like you I witnessed the decline of the elms, I fear that ash are going to go the same way. I know that less than 10% of the TPO trees we remove are never replaced. The system and manpower shortages means that the condition is never followed up. It's sad.

 

I feel the horse has already bolted.

 

Me too

[HCR]

^^ I think something's gone a little awry with the quoted text - it looks like I made a post that was in fact made by Jonny.

 

There is nothing stopping us from having greater control over what enters the country other than the government's inertia. EU law is a hurdle but the mechanisms for overcoming those restrictions exist.

 

DED is quite different to most new pathogens, in that the elms that succumbed were clonal - one susceptible = all susceptible.

 

Last week Queen Mary Univeristy received confirmation of funding for the sequencing of the Ash genome. If this work can identify the markers that are associated with resistance to Chalara, then identifying resistant trees in the wider countryside could be greatly speeded up and a crisis could even be averted entirely. Even left to natural selection, I don't see the evidence for a catastrophic wipeout of the ash tree. A major setback, yes, but one it can recover from.

 

A knee-jerk reaction to import Danish resistant trees is both unecessary and potentially hazardous. The two populations have been isolated from each other since the last ice age (our trees came from south west Europe, Denmark's from the south east) and no research has been done to investigate the closeness of the association between British ash monophages and British ash tree.

[JonnyVine]

HCR

 

My mistake, I was had allways been under the belief that Dutch Elm Disease, or DED as you refer had been widely spread by the scolytus beetle! Not a continual chain of cloning?

 

I feel much more unworried knowing that all is well and under controll.

 

I will use the forthcoming break to learn more

 

Festive greetings

Jonny

[Gary Prentice]

^^ I think something's gone a little awry with the quoted text - it looks like I made a post that was in fact made by Jonny.

 

My Bad

 

There is nothing stopping us from having greater control over what enters the country other than the government's inertia. EU law is a hurdle but the mechanisms for overcoming those restrictions exist.

 

 

DED is quite different to most new pathogens, in that the elms that succumbed were clonal - one susceptible = all susceptible.

 

I can agree with that, to a degree, but in urban plantings there should have been a lot more diversity.

 

Last week Queen Mary Univeristy received confirmation of funding for the sequencing of the Ash genome. If this work can identify the markers that are associated with resistance to Chalara, then identifying resistant trees in the wider countryside could be greatly speeded up and a crisis could even be averted entirely. Even left to natural selection, I don't see the evidence for a catastrophic wipeout of the ash tree. A major setback, yes, but one it can recover from.

 

 

A knee-jerk reaction to import Danish resistant trees is both unecessary and potentially hazardous. The two populations have been isolated from each other since the last ice age (our trees came from south west Europe, Denmark's from the south east) and no research has been done to investigate the closeness of the association between British ash monophages and British ash tree.

 

As I understand it, both epidemics of DED came into the UK in imported lumber. Chalara fraxina appears to have arrived naturally. ALB arrived in New York State in timber packaging/pallet wood, as is supposedly did here. I have no doubt that certain pathogens have come on imported plants, but with world travel and world trade we're going to struggle unless we become isolationists.

 

 

I was unaware of any intention to import Danish trees, but I think your arguement is flawed, in that the populations have been isolated since the last ice age. We don't know where any specific tree is from, seeds from the uk are going to Europe and coming back marked as British. Do we truthfully know what is from where anymore.

If chalara is from Japan, where it exists with little detriment to the native ash population - with which it has evolved - why should the provenence of any European species of ash really matter.

I'm sure Scandanavia thinks that a loss of 80-90% of their trees is more than a setback. Sure replanting will replace losses, but ecologically the loss of mature trees is a crisis. you can't replace two hundred year old trees, the ecological niche, with twenty ten year old trees.

The crowdsourcing that has been set up, with a view to share research and knowledge is great, just too late. Nature will run her course, she always has but we're seeing to many losses and changes to our landscape and this is only going to continue. Apparently more threats have surfaced in the last ten years than the last century. Why?

[HCR]

HCR

 

My mistake, I was had allways been under the belief that Dutch Elm Disease, or DED as you refer had been widely spread by the scolytus beetle! Not a continual chain of cloning?

 

I feel much more unworried knowing that all is well and under controll.

 

I will use the forthcoming break to learn more

 

Festive greetings

Jonny

 

Maybe start by learning how to read things properly.

[HCR]

As I understand it, both epidemics of DED came into the UK in imported lumber. Chalara fraxina appears to have arrived naturally. ALB arrived in New York State in timber packaging/pallet wood, as is supposedly did here. I have no doubt that certain pathogens have come on imported plants, but with world travel and world trade we're going to struggle unless we become isolationists.

 

 

I was unaware of any intention to import Danish trees, but I think your arguement is flawed, in that the populations have been isolated since the last ice age. We don't know where any specific tree is from, seeds from the uk are going to Europe and coming back marked as British. Do we truthfully know what is from where anymore.

If chalara is from Japan, where it exists with little detriment to the native ash population - with which it has evolved - why should the provenence of any European species of ash really matter.

I'm sure Scandanavia thinks that a loss of 80-90% of their trees is more than a setback. Sure replanting will replace losses, but ecologically the loss of mature trees is a crisis. you can't replace two hundred year old trees, the ecological niche, with twenty ten year old trees.

The crowdsourcing that has been set up, with a view to share research and knowledge is great, just too late. Nature will run her course, she always has but we're seeing to many losses and changes to our landscape and this is only going to continue. Apparently more threats have surfaced in the last ten years than the last century. Why?

 

No country has lost 80-90% of its ash trees from Chalara. That percentage may have been infected, but mature trees don't die - certainly not quickly - from this pathogen.

 

I don't know if there is any specific intent to import Danish trees, but there has certainly been talk of using the progeny of their resistant stock. The overwhelming majority of ash trees in mature woodlands are British autochthonous stock. Yes, of course trees in nurseries are of dubious origin. I've been arguing against the potential issues this raises for nearly 20 years. The fact that British and Danish trees are from evolutionary distinct populations is sufficient cause for a red flag and further investigation before mass imports occur (if this does end up being proposed).

 

I still say that Chalara will be a setback. It may take 50 years, or 1-200 years for a recovery, but it will happen.

 

I couldn't agree more about the value of veteran trees, and you are of course totally right about a higher number of younger trees not being an equivalent in ecological terms. But planting exotic trees is no better - in fact it is worse as unlike the young native trees, they will never become veteran native trees.

 

It should be fairly clear why the rate of new pathogen arrival has accelerated. I won't insult anyone's intelligence by suggesting an answer.

[Gary Prentice]

:hmmmm2:HTC, seasons greetings.

I stand corrected, I misunderstood the correlation between infection rates and mortality. I may be wrong, I often am, but aren't the Danish predicting that they will only retain as little as 10% of their Ash. Whether this is due simply to Chalara or opportunist successive secondary pathogens is unclear.

 

I'm in agreement that Chalara will be a setback, the landscape will change and evolve, (Shigo's dynamic equilibrium) as it has with the elms. I have a theory, with the elms, that as the host trees numbers fell, the vectors population should have declined thereby slowing the rates of re-infection of new sucker/coppice growth. I also think that even minor changes in climate could have an affect on future spread, due to the beetles requirements with regard to temp., windspeed and humidity.

 

Your thoughts on exotic trees are interesting, sure they will never become veteran native trees. But is that important? As time goes on, are all our flora and fauna going to be native? Globalization again suggests that more and more species will become naturalised here. It's always occurred to some degree but the rates increased.

 

I started my craft in Cambridge, working on many mature 'exotics' in the universities and the old family estates. These will become veterans, having their own ecological niche, albeit non-native.

 

Maybe in the end it is simply a question of time scales:hmmmm2:

 

I will say, this has been an interesting debate and conversations such as these are the reasons I joined this forum. I'll wish you and yours all the best for today and the New Year.

 

Kind regards, Gary

[JonnyVine]

Gary

Sorry I could not help with the original problem, if you find the link again, please do post it as I think a quite a number of people would be interested.

 

I have often wondered when a particular species becomes indigenous? And, like you say, does it realy matter? I would rather have none natives than no trees at all.

 

Todays climate is an ideal breeding environment for most pathogenic organisms, not just tree related, which can then hybridise and could take decades to evaluate the potential outcome, if at all.

 

Merry Christmas and a happy new Year

Jonny