mrtree
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Everything posted by mrtree
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SIA- the tree pulling test/theory
mrtree replied to Tony Croft aka hamadryad's topic in Forestry and Woodland management
Good to see that people are already pulling out examples of why SIA and SIM are no good. They also show a complete lack of understanding of the test. So in this case why was a pull test done if there was no fear of the stem breaking? Who hired the consultant? For what test? If the consultant was hired to do the pull test and that is what he did, his job was done. The question of what is the most vulnerable part of the tree (the most likely to fail) was likely not made by the consultant. You also say you have done one bend test. Are you trained or did you just install the cable in the tree? "My friend is contracted in for test pulls on trees, he broke a perfectly good Oak tree once." Well something is not right here. How do you pull apart a perfectly good tree? Surely there were defects not in the tree and that is why the tree was subjected to a pull test. Further the person doing the test should not be applying forces that would break an oak. -
SIA- the tree pulling test/theory
mrtree replied to Tony Croft aka hamadryad's topic in Forestry and Woodland management
I have to go out but there is a variation in wood fibre strength, that is why there are tables for modulis of elasticity by species. How are defects manifested during the pull? Well they are not really. The idea is that the trained and knowledgable assessor finds the areas of the tree that needs to be assessed for strength. Thus you will likely pull at the thinnest part of a shell around a hollow, or very near a defect and measure the reaction of the tree. The movements are so small they are measured with a micrometer. -
SIA- the tree pulling test/theory
mrtree replied to Tony Croft aka hamadryad's topic in Forestry and Woodland management
The basic idea is that you pull such that you do not damage or weaken the tree. By measuring tilt of the root plate you never pull beyond a 0.25 degrees. Failure generally occurs between 2.5 and 4 degrees. When tensioning (or compressing) fibres a load of 1 to 2 tonnes (10 o 20 kn) is applied which is below the "specific elastic limit" of wood fibres. -
SIA- the tree pulling test/theory
mrtree replied to Tony Croft aka hamadryad's topic in Forestry and Woodland management
I can certainly talk about pulling but not much about shear vs. buckling. One thing to keep in mind is that that there is a huge issue of egos, hurt feelings and pride in the issue of Mattheck vs. the pulling guys. -
Oh my god, I have not done statistics in such a long time. If you are going to talk about actual risks in terms of numbers, go for it.
I am currently adding some comments to your fungus example pages.
Michael
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Whitish discharge from Silver Birch Pruning.
mrtree replied to Treeworld's topic in Tree health care
Have you smelt the discharge? Fermented? I also think it is likely bacteria (and a few other microorganisms). You may wish to wash the ooze down as it might stain the tree but I think that there will be no problem with the tree and flower beds. -
Unfortunately some employees will not, or cannot take responsible steps to ensure safety and this is where others must step in to ensure people literally live through the day.
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Company owners have a duty to protect workers, even if they must protect them from their own stupidity. After training and farmilizing employees with equipment the owner must supervise and watch employees and correct as necessary. I am willing to bet that this employee had already shown a number of bad habits that had not been dealt with. My favourite example is helmets. If you see somebody who consistently does not wear a helmet you can bet that they are taking short cuts and sidestepping safety procedures at every step. Employers must demand a safety culture and dismiss those that do not participate in all aspects of the job safely. Take the early clues such as helmets and safety glasses and change behaviour or dismiss the person (and maybe save their legs or life). An accident like this is going to have an impact on many people.
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What would you suggest that people look for when hiring an arborist/tree surgeon? The cheapest price? The nearest? Maybe you should try to determine who will provide the best training!
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Why not mow and burn? Seems alot faster than hand work? Or at least fell with F550 and then push up into piles with a tractor.
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Nothofagus antarctica covered large tracts of what is now South America, Australia, New Zealand, Antaracrtica, Tasmania, New Guinea, and New Caladonia in the Cenezoic (65mpa to present). The last Nothofagus was believed to have died on Antarctica approximately 10 to 24 mpa, about the time the gap between South America and the Antarctic peninsula opened and the circumpolar current effectively isolated Antarctica.
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What is the weight of the lightest self-propelled chipper?
mrtree replied to morten's topic in Large equipment
There are chippers from Belgium called Eliets that offer a range of self-propelled machines. -
Natural History Book Service, a bibliophiles worst nightmare. Thousands of incredible books.
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I will try to find some photos I have of petrified wood (Nothofagus) in Antarctica and the live genius in South America Perhaps one of the great experiences you can have is to visit the fossil beds in Eriksdal, Sweden. If you split the rock layers you can apparently find the leaves of ancient Gingkos. In this case you would have impressions on the rock as opposed to fossils where living material has been replaced with minerals.
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eight or ten times is the most common. Check out NHBS to start. Put a cord on it and never set it down or you will be buying another and another
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Get you hand lens out and start looking for clues. Also check under a microscope. Identifying algae is not an easy thing but certain genera are common and yes you may be seeing the same thing on other tree species.
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Trentepophlia is found as a free growing (green) algae and as a lichen photobiont. Chlorophyta Ulvophyceae Trentepohlia
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Nothofagus immediately comes to mind, I am sure that their occurence were part of the reasoning behind continental drift theory (as presented by Wegner). Off the top of my head,genera, families having fossil lineage include (but perhaps not extant species which are fossils): Proteaceae Araucaria Agathus Cycad Conifers Podacarps Casuarina Eucalypts Acacia Magnolia Brachiychiton Fagus Quercus Cinnamomum
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Canada, USA, Greenland, Faroes, Norway, Russia, Japan, Grenadine Islands, Phillipines and Indonesia still allow whaling in some form. Maybe a job if you look around.
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Bracing does not equal cabling. Bracing is with rods. You only brace if you are installing a cable (perhaps very small pears are an exception). I am curious why you say "... this limb has fail written all over it but without the signs to back up that view" , either the limb has signs or not. What have you done to investigate? Have you climbed to inspect the union, are there cracks or included bark, is there a reduced cross-secitonal area, have you installed a line and rocked the limb? If your client wants to remove the limb and you are supporting this in the application, do you not need to provide evidence for your proposal for such a drastic limb removal?
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If you cut the entire left lower limb you are putting a massive wound into the tree. Loss of photosynthetic area and decay are a concern then. Conversely leaving the limb is not going to happen because of the owners and I think there may be issues of the limb eventually subsiding or splitting off. In the second photo it is not clear to me if there is a split, with lots of callus growth, on the top of the limb or not. I think at the minimum a (considerable) reduction in length and maybe a cable. Reduced length will reduce the lever arm length and thus the movement and torqueing at the union resulting in a limb less susceptible to breakage. The cable can also be used to reduce breakage and as a method to catch a broken limb.
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I think canker is vastly underestimated as a defect, likely because very few actually examine cross sections as shown above.
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You are correct that things are wierd, but wait. Your lucky Broad is gone, won't be hit for 36 at least.
