Decay images

[David Humphries]

and its pectin in the middle lamella?

 

yes, the middle lamella is a pectin layer which binds adjoining cells together.

 

What I was trying to get across (to myself, as I continue to learn about this stuff, as well as to others who pehaps like to learn along) is that the brown rot (due to its prefered food source) will be leaving the lignin chemically and physiologically unchanged.

 

Because of this, I don't believe that the xylem vessels (drinking straws in essence which are the large water transfering holes/tubes created in the early spring wood) being partly made up of lignin, will enlarge or shrink as the lignin will remain intact, (only the cellulose/hemi cellulose is altered/diminished)

 

If any one has reference that shows that the xylem vessels are altered in size due to the effect of brown rot, please feel free to post up

 

 

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[David Humphries]

here, the remnants of turkey oak that has been white rotted by Ganoderma resinaceum.

 

Pretty much just leaving the medullary rays intact.

The rays are formed with parenchyma cells which are predominantly made up of cellulose.

 

Fantastic invertebrate habitat, it literally crawled with millipedes, wood lice and beetles

 

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[Gray git]

We suspect originally hit by lightening but unfortunately in a location where it couldn't be left standing but will be left to do its own thing on the ground. Bottom was particularly soft which even with the winch pulling made felling of the pole a little interesting.

 

sent while pretending to do something important on my mobile.

[Tony Croft aka hamadryad]

cause could also have been a strip canker during the droughts of 2003

[Tony Croft aka hamadryad]

yes, the middle lamella is a pectin layer which binds adjoining cells together.

 

What I was trying to get across (to myself, as I continue to learn about this stuff, as well as to others who pehaps like to learn along) is that the brown rot (due to its prefered food source) will be leaving the lignin chemically and physiologically unchanged.

 

Because of this, I don't believe that the xylem vessels (drinking straws in essence which are the large water transfering holes/tubes created in the early spring wood) being partly made up of lignin, will enlarge or shrink as the lignin will remain intact, (only the cellulose/hemi cellulose is altered/diminished)

 

If any one has reference that shows that the xylem vessels are altered in size due to the effect of brown rot, please feel free to post up

 

 

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Im going to dig out a few books and find an answer to this great chalenge, I will say this though the very small amount of lignin in the hosepipes would probably just turn to dust, which would explain very well its lack of substance and the enlargement

[sloth]

I feel if the secondary cell wall layers contain very little lignin/pectin it will, as Tony says, crumble. Or maybe 'shrink back' toward whatever attachments or attractions it has to the middle lamella, effectively enlarging the diameter of the lumen.

If this was simply the size of the vessels, then freshly cut (or dried, un-decayed) oak would always show its vessels so obviously - it doesn't.

I may well be wrongly assuming though.

I'll try and look through some books later, and be interested in anyone elses views or findings

 

 

Oh, and great shots of those remaining rays David

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[David Humphries]

Early spring wood xylem vessels within annual rings of brown rotted native oak.

Two areas of differing levels of degradation shown.........

 

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[David Humphries]

Early spring wood xylem vessels within annual rings of partially white rotted Turkey oak.

Two areas of differing levels of degradation shown.........

 

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[Tony Croft aka hamadryad]

Early spring wood xylem vessels within annual rings of partially white rotted Turkey oak.

Two areas of differing levels of degradation shown.........

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and none as degraded as seans example, and none showing quiet as many and difficult to tell due to scale but yours look to be far lees open than the examples in Seans?

[David Humphries]

I suppose what we don't know is the scale of Sean's shot

 

I think seans annual rings are a lot narrower than either of the two examples above, which may account for how big they look.

 

 

 

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