Powdery mildew

[Tony Croft aka hamadryad]

good ones david, apart from the concrete/tarmac shot I would call these compacted though!

 

thats certainly a bad dose of powdery mildew you got there.

[Dan Curtis]

Latecomer to the thread and apologies if this has been mentioned.

 

Oliver Rackham's new (ish) book, Woodlands, directly blames powdery mildew on the decline, and possibly failure, of oak regen in woodlands since it was first recorded in 1908. He claims it has transformed oak from a woodland climax tree into a pioneer.

 

Personally, I've noticed loads in the last four weeks or so, though it seems to be declining now.

 

Also, without a derail, there's quite a bit in the book to do with modern agriculture being to blame for the decline in mycorrizal fungi in the UK

[David Humphries]

Latecomer to the thread and apologies if this has been mentioned.

 

Oliver Rackham's new (ish) book, Woodlands, directly blames powdery mildew on the decline, and possibly failure, of oak regen in woodlands since it was first recorded in 1908. He claims it has transformed oak from a woodland climax tree into a pioneer.

 

Personally, I've noticed loads in the last four weeks or so, though it seems to be declining now.

 

Also, without a derail, there's quite a bit in the book to do with modern agriculture being to blame for the decline in mycorrizal fungi in the UK

 

Good spot Dan.

A few of Professor Rackhams books elude to oak decline in woodlands and specifically highlight mildew as a culprit but also the loss of managed coppice and increased shade. He said this as far back as 1976 in 'trees and woodland in the british countryside'

 

 

Have you mainly noted it on oak or other species aswell Dan?

.

[Dan Curtis]

Been a while since I read that, can't say I recall it too well.

 

Only on oak but I haven't looked too hard for it to be honest, I'll have a look about and let you know if I find anything.

Edited September 11, 2012 by Dan Curtis

[Tony Croft aka hamadryad]

mmmm, interesting, Im going to have a read tonight and see if my overly dismissive view is in need of a review.

 

prsonaly I see it as a sporadic outbreak phenomina, and not like a constant battering as would be implied to cause radical changes in a trees ecological niche, and Oak IS a pioneer it cant stand climax forest! regen is at the forest edges not within, we all can go out and see this.

[Treecreeper1961]

Agree, oak is a pioneer species, light demanding, cannot realy regenerate under it,s own shade. Strange one because it is also a climax species but that is lagely due to land management I would guess.

[Dan Curtis]

Oak IS a pioneer it cant stand climax forest! regen is at the forest edges not within, we all can go out and see this.

 

Agree, oak is a pioneer species, light demanding, cannot realy regenerate under it,s own shade. Strange one because it is also a climax species but that is lagely due to land management I would guess.

 

That's pretty much what Rackham is getting at. It IS a pioneer now, and it will only survive to maturity on edges. Whereas pre powdery mildew (1908) oak DID produce successful regen within woodland. A sapling suffering from overshading is soon finished off by mildew.

[Tony Croft aka hamadryad]

That's pretty much what Rackham is getting at. It IS a pioneer now, and it will only survive to maturity on edges. Whereas pre powdery mildew (1908) oak DID produce successful regen within woodland. A sapling suffering from overshading is soon finished off by mildew.

 

I know Rackams calibre, but NO, im not buying it not one bit.

 

going to take this one to task for myself.

[Ben Ballard]

Today's talk at Windsor park said early man would of seen a setting of how the oak are set out there like a grazed parkland ,not the dense oak wood some people think, and oaks grown in woods is purely for mans needs,

There was a lots of american mildew on the oaks there but luckily some don't seem to be affected by it and wod be good to grow acorns from:001_smile:

[Treecreeper1961]

That sets the scene of the wildwood nicely. There must have been open grazed land for oaks to propagate.