Body language Quercus

[Fungus]

This morning I monitored about 300 60-80 years old Quercus rubra and Q. robur alongside old sand roads.

Photo 1 : Extreme buckling on Q. rubra after an infection with Laetiporus sulphureus brown rotting the central wood.

Photo 2 : Bark necrosis on Q. rubra caused by (rhizomorphs of) a parasitic Armillaria species.

Photo 3. Phytophthora on Quercus robur.

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[alliaria]

Hi Gerrit,

Would you say the adaptive growth in pic 1 has compensated for the internal decay?

[alliaria]

or is that not adaptive growth but the first stage of collapse?

[RobArb]

Thanks gerrit, nice and simple referencing:thumbup: (info and pics)

 

Sent from Rob's GalaxySII

[ScottF]

Great pics, Gerrit. Very clear and instructive.

 

Does photo 2 show successions of partial occlusion and then marginal necrosis?

 

Cheers

[Fungus]

adaptive growth has compensated for the internal decay

or is that not adaptive growth but the first stage of collapse?

 

Not compensated, but overcompensated to the extent of becoming vulnerable for wind throw (sideways) and/or collaps (weight of the tree).

Edited July 20, 2011 by Fungus

[Fungus]

Does photo 2 show successions of partial occlusion and then marginal necrosis?

 

Scott,

It does with the addition, that the marginal necrosis is of the wound tissue (callus), with which the tree tried to repair and close the shallow open wound in the sapwood and the cambium.

[Will Hinchliffe]

The buckling in photo 1 is great.

 

How did you decide that the bark necrosis was caused by the Armillaria ? If coming across the feature shown in photo two for the first time how would you tell it was bark necrosis rather than a mechanical injury that has been colonised by Armillaria.

 

Have you identified the Phytothera species in photo 3 or sent a sample of.

 

Will

[Fungus]

1. How did you decide that the bark necrosis was caused by the Armillaria ? If coming across the feature shown in photo two for the first time how would you tell it was bark necrosis rather than a mechanical injury that has been colonised by Armillaria.

2. Have you identified the Phytophthera species in photo 3 or sent a sample of.

 

Will,

1. I've monitored this tree for 4 years now and the assessment started with black Armillaria plaques being present in the vertical wound after the bark came off. Because of the position of the tree, it could not have been mechanically damaged and the diagnosis of bark necrosis followed after the tree had in vain tried to close the wound with callus from aside.

Besides, this is one of the several hundreds of oaks, both Q. rubra and Q. robur, infected by (the rhizomorphs of) a parasitic Armillaria species, with all oaks (and many other tree species) always starting with bleeding of soon blackening cambium fluid from leakage spots on the trunk before other symptoms become manifest.

The at first foamy whitish leakage of Q. robur is often visited by flies, wasps, hornets and butterflies (photo 1). It can be distinguished from Phytophthera by its acid smell and taste, the visits payed by the earlier mentioned insects and the typically shaped cracks in the bark and cambium from which its flows.

Every tree species has its own species specific reaction pattern. Photo 2 shows the pattern on Quercus robur, photo 3 on Acer and photo 4 the leakage spots on Aesculus.

2. No need, in The Netherlands on oak and beech it always is P. ramorum.

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[Will Hinchliffe]

Really interesting thanks I have observed similar exudates on Fagus, Betula and Acers colonised by Armilaria but I have never tasted them before. Why are the exudates associated with cambium necrosis caused by armilaria different from those associated with Phytothera ?

 

What Is the fate of the Quercus robur with Phytothera ramorum infection. Is there a policy of removing P.ramorum infected trees for control of the disease in the Netherlands.

 

Have you seen P.ramorum with the ability to colonise and kill healthy trees or have the infected trees been stressed or in decline already.

 

Sory lots of questions. Feel free to point me to other sources.

 

Thanks.