daltontrees

Here's the simplest set-up you can get for taking pictures under a microscope. It's a USB microscope, such as RobArb mentioned. I should explain and state an obvious point about microscopes generally. The way you look at a picture depends on how you use the light. In this case it uses reflected light. Light hits the object from the room or the sun or the lights in the room and bounces off it. Some of it hits the microscope lens and gets focused into a picture. Just as the eye does. More complicated set-ups use transmitted light, the light passes through the object and into the microscope. The object has to be therefore fairly thin and almost transparent. To take a picture you just need to put a camera where your eye would be. The USB microscope in the picture does it all. It has it's own LED light source right where it's needed above the object. It can be swivelled about and focused at most angles. Then it converts the picture in real time to a picture on the computer screen, like a mini CCTV. No need to look into the microscope, it's there 17"" across on the laptop. And to take a picture you just hit the 'capture' button on the computer. The picture I took was a Poinsetta leaf, the quality is limited but you can see it gets in nice and close to see the vein structures on the underside of the leaf. If anyone fancies getting into a bit of simple reflected light microscopy/photography, this is the way to go and not too late to email Santa knowing it won't break the Bank of Lapland.

It's pretty much the same as soft tissues, still taking thin slices. I am hoping Tony Croft will come along in due course and enlighten me as to how to do wood. Most of my slides have been bought prepared since my own efforts at thin sections have been a bit haphazard. Hopefully I can post pictures of preparation of a slide step-by-step.

Well, if I know you, and seeing as some conifers can only be reliably differentiated by counting vascular bundles in needles, you'll be wanting to get into transmitted light microscopy.

Eventually I will get round to explaining a bit about microscopes and how in theory anyone on Arbtalk can get into this at very little expense.

Ahh, petrology, my other obsession. I have around 500 slides, hence I have polarising microscopes. I have suggested elsewhere to Tony Croft that he gets one because it shows up celllose degradation in the s2 layer of cell walls under crossed nicols.

I can't remember which microscope I used, I have two. Probably a GX Optical JPL1350HBG for the pictures with the crosshairs. The others might be a Swift Model P. The quality is probably a product of the camera used. The poor ones are probably a Nikon Coolpix and the good ones a Nikon D3100

Off you go then and have a look. Tree care - trees under the microscope. Any words of encouragement will ensure an almost never-ending stream of additional posts.

Larch cross section showing why trees look like they have rings. Densely packed cells of winter wood between larger cells of rapidly growing spring wood.

Long section of Cistanthera papyvifera showing what I suspect are sieve plates. One of my favourite slides for this reason.

This thread is for any interesting pictures, discussion, techniques etc. for discovering more about trees by examining them under the microscope. I will kick off with a few random pictures of my own. First is the cross section of a conifer needle. If I find the slide again I will confirm the species. Please look in from time to time even if you are not participating. If nothing else the pictures can be very pretty.

Too late, I couldn't help myself I have started a thread in Tre ehealth care since it's not just for pictures and it's related to tree physiology. See you there.

Tony, you or I should start a thread on trees uinder the microscope. I would have done it a while ago but I thought I was the only saddo on Arbtalk who would look at it.

To refine the point made by others, in UK law if the harm or damaged caused by the tree's failure was reasonably foreseeable then the owner is negligent and liable. As ever the difficulty is foreseeing. Foreseeing a car being there might not be that hard. Foreseeeing that a tree falling on it would damage it isn't that hard either. Foreseeing the tree falling is the tricky bit. If the rot wouldn't have been apparent to a reasonably skilful inspector, liability would be hard to prove. If the rot was apparent, it still might not have been enough to cause concern. But if the rot was extensive and the tree's failure was inevitable (I think the ISA system uses the word 'imminent') the owner is liable. Somewhere in the middle is a degree of decay that takes the risk from acceptable to tolerable and then another degree that takes it to unacceptable. If the decay resulted in unacceptable risk the owner is liable. If it resulted in tolerable risk the owner would have to show why he tolerated it despite the risk. That's the UK situation anyway. No-one yet has mentioned t/r ratios. That might be a good way of trying to quantify the residual strength. After all, if one is approaching the assessment (even retrospectively) as a VTA, the third stage is estimating the strength of the remaining parts. t/r ratio is part of the toolbox.

I woudl justy add the possibility of viral infection, basically dysfunction due to mutation of cells and then rapid proliferation, very like cancer.

I am intrigied, sir. What are these scopes to which you refer? Do you mean microscopes? If so, I would be happy to swop notes with you as I am a dabbler myself but have hit the buffers on thin-sectioning due to lack of knowledge on how to soften woody structures without damaging their detail.

Ash plus height from ground equals likely I. hispidus and startts to rule out any Ganoderma.

The subject has been beaten to death, but I just want to add an obvious (to me) point. The figure of 8 is very very easy to tie on the bight (5 seconds), whereafter it can be clipped into a krab (another 5 seconds), but in rock climbing iw Ould always tie the figure of 8 as a single then pass the tail, through the harness bridge (not through the krab) then complete it as a follow-back to double it up. It makes for a super-safe knot as strong as the harness. Can explain with photos if anyone needs it, but it has little if any application in tree work.

One of the enduring attractions of the figure of 8 is that if it doesn't look right it isn't right. The same is harder to say of the Bowline and harder still of the Yosemite. And I was talking about rock climbing. If you are stuck in a freezing gully with spindrift everywhere and cold hands in thick mitts, the Yosemite is an unthinkable option but the figure of 8 can be tied and checked by the numbest hands and mind. Surely the same applies perhaps less extremely in tree work? And it IS stronger than the Bowline. The only attraction I can see in the Bowline over the figure of 8 is it's ease of undoing after loading. The Yosemite doesn't make it any easier or harder in my experience. I have never seen any tests on its strength relative to teh Bowline, but I expect it is stronger. Sorry, I am not clear on what you disagree with. That I will never use a Yosemite tie-off again?

It has the habit, bark, haws and leaves of Crataegus crus-galli (Cockspur Thorn). The species has vicious thorns that make ordinary Hawthorn look poofy by comparison. Does your trees have thorns that would rip your eyeball out like a sausage on a cocktail stick?

I am coming to appreciate very quickly that there may be few situations where the rules of thumb in the guidance can be relied upon without any further adjustment. As the document says "A simple technique cannot cover every situation...". I am trying to develop my technique with sky protractors so that as well as using the guidance I can check the results against the British Standard. Who knowsd how the scottish Act is going to produce guidance to deal with deciduous trees and shrubs in hedges? The 5%/25% rule is just about manageable for evergreens but it all goes to pot when deciduous hedges come into play.

3m of 8" wood is approximately 0.1m3. Multiply by the density of green wood, typically about 1 tonne per m3, so should be about 100kg. 3.5m would be 117kg. 3m of 10" wood is about 0.15 m3 so it's about 150kg. 3.5m of 10" would be 175kg. Manual handling regs suggest no more than 25kg lift per man, about the weight of a standard bag of sand. As wood gets seasoned it loses up to 40% of its weight in water. You can estimate from that how dry your wood is and what a length is likely to weigh. It depends on species too. Lighter wood like dunkeld larch is around 0.85 tonne/m3, denser wood like oak is up to 1.06 tonnes/m3.

Ach well, it has been looked at about 4600 times, so I suppose it passes for some sort of diversion for people.

I watched that video, will never use a Yosemite tie-off again... A quick look on Google showed up that this is the knot that nearly killed famous american climber Lynn Hill. For rock climbing I always use the figure of 8, it's stronger but seizes if it takes a fall. But if I peel off the first thing I care about is the knot not coming undone, then the rope not breaking, and way way down the list is how easy it will be to untie the knot.

I thought there would eb at least one. Anybody else from the bish-bosh end want to add their names to the subbie blacklist of the i'd-never-do-that end?