Wind throw

Sean Freeman

Just took these today at local park/arboretum its a E. peltata sb dimorpha growing on a slope of about 10' blew over 2 nights ago.



Point of interest is the cause..girdling root.



The tree had an unusual crown in as much as it was very unbalanced, the wind seems to have caught this asymmetry and rotated the tree away from the girdling root snapping it at the stem. There being no well formed buttress roots on that side the tree has fallen away under the wind loading.



There is also clear signs of decay, nectrotic tissue, I dug around there to expose the fibres, and some very small white pocket rot which hasnt come out very well on the photo.





Shame to lose this tree was an attractive specimen, and one I had assessed, wish I could say I'd spotted the girdling root but I didn't

We've got another three windthrows to clean up tomorrow so will post some pics if they're of interest.

SF

Eric Frei

That trees flare is non existent ... bad planting, happens a lot.

What's the statistics say ... something like 2/3's of blow overs go back to poor planting. I know it's something high like that.

Can't say I've seen one of those gums either, rather odd looking bark.

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Sean Freeman

Common name's Yellowjacket, pretty sure you get E. watsoniana down your way Ekka another yellow jacket with the same rough loose flaky tessellated bark, normally they're very reliable trees but like you say they have to be properly planted and be good stock.

SF

TreeCo

Great shots Boa.

I agree. It sure looks like it was planted too deep.

Sean Freeman

Ok, this one from today at the Army barracks not as interesting as the girdling but deserves some comment.

E. Tereticornus with a pronounced lean (before falling over!) and again an asymmetrical canopy (not really uncommon in Eucs)





When we look at the exposed root plate its clear that there is something very important missing..roots on the tension side to the fall. There are three significant sinker roots on that side (red arrows) but no primary roots (red circle), there's a good healthy root on the left side as we look at it.



The answer? (isn't hindsight wonderful especially when you can see the root system) trenching for electrical supply on two sides of the tree (yellow lines) even though the trenching was done 10-15yrs ago the tree has not been able to produce roots of enough size to resist the wind loading after our heavy rain in the last week.





SF

Eric Frei

Seems odd that there's so many roots going downward compared to outward.

I suspect that it must be sandy there and perhaps some moisture lower.

Hard to tell with the tree on the ground but it looks like the canopy was weighted to the side it fell. Which if it is the case means the tree didn't react much to that with opposing roots.

I bet you don't get too many ficus blow overs.

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Sean Freeman

I think the lack of root growth generally could be down to the poor quality soil and the high levels of compaction at the surface, you might be right about the sandy base it likely it was fill of some sort but probably brought from the creek bed not too far away.

You're right very few ficus failures, though have seen bengalensis (banyan) loss sections after years of abusive lopping and removal of prop roots cause they're in the way!!!


SF