So much talk. There is a reason that trees are designated as "hazard" trees. Sometimes, we have to take a tree down. I don't even know why there is a discussion about this. Chances are that there aren't more people killed/injured by falling trees because we REMOVE trees when they are deemed unsafe.
Talk to a good arborist sometime. They aren't all about removal... In fact it is a last resort. I think I may unsubscribe to this list. Jesse On Jan 20, 2013, at 8:02 PM, "Jane Shevtsov" <[email protected]> wrote: > The number of people killed by falling trees each year isn't really the > information we need. That number could be low because few decayed trees > kill (or severely injure) people or because there are few such trees in > populated areas. > > What we really want to know is the probability that a decayed tree will > fall on somebody (or come close) when it eventually falls, given that it is > in an area frequented by people. We can guesstimate this by finding out > what fraction of the time there are people in the tree's fall zone, > adjusting for any inaccessible areas/directions. (Yes, this ignores things > like weather, but that's what makes it a back-of-the envelope estimate.) > Suppose there are no inaccessible areas around the tree and there are > people near it about 1/4 of the time. Then the probability of a hit or near > miss when the tree eventually falls is 1/4 -- quite substantial in my eyes. > Adjusting for weather and time of day or treefall may reduce it to 5% or > 10%, which is not small considering the stakes. > > Some might object to this calculation, saying that it could be used to > justify the removal of any urban trees. But the chances of a randomly > chosen urban tree falling in the near future are very small and we can > generally detect the conditions that make a tree likely to fall. The > estimate above only makes sense for a tree that we know is likely to fall > in the near future. If you wanted to, you could multiply the probability by > an estimate of the probability of the tree falling in the next ten years > (or whatever the time horizon of interest is), which the calculation above > assumes to be 100%. > > Jane Shevtsov > > > On Sun, Jan 20, 2013 at 12:32 PM, Nirmalya Chatterjee > <[email protected]>wrote: > >> Sorry to contradict you here Wayne, but your argument is anecdotal and >> seems to be as straw-manly as GWPatton's - people who work in the Forest >> Service are likely to get injured by trees, (lethally or otherwise) from >> falling branches, trees etc. - there's a term for that - occupational >> hazard. That doesn't necessarily mean that the general populace has the >> same odds of facing such an injury. >> >> 2010 CDC data indicate 4.88% accidental deaths (at #5 reason), and ~80% of >> those were due to poisoning, accidental falling and motor vehicle related, >> that pushes other reasons to sub-1% levels. Wind related tree failures >> caused 31 deaths/year from 1995-2007. >> http://www.bama.ua.edu/~jcsenkbeil/gy4570/schmidlin%20tree%20fatalities.pdf >> . >> >> That's 407 people in 12 years, don't blame the trees here. Blame human >> carelessness, thoughtlessness and Nature's unmitigated fury (the last >> cannot be controlled). Trees would be the means here, not the cause. My >> point being, yes there are some activities which cause people to be injured >> - but this always begs the question of what the odds are. As for the >> irrational fear of urban people to dying from tree-related as related by >> GWPatton - in my anecdotal experience, yes such fears exist. And trees are >> easy to pin the blame on, they aren't vocal about it, and with urban areas >> heavily paved and a whole gamut of underground disturbances related to >> utility lines etc., it is expected trees don't really find the unfettered >> access to the soil to stabilize themselves as evolution and Nature >> intended. The solution lies in learning to think more holistically instead >> of knee-jerk reactions, which many tend to do. >> >> And talking to "victims" of tree-fall injuries or their family members to >> get your ideas about its dangers is not proper science, neither is hearing >> anecdotes from of the likes of you, both would be called biased sources. I >> am yet to hear families and victims of auto accidents stopping riding or >> driving cars (in significant numbers), post-accident. Or people stopping >> use of household poisons because some one they knew mistakenly drank rat >> poison. As scientists it behooves us to keep emotion out of science. >> >> NC >> >> On 19 January 2013 23:11, Wayne Tyson <[email protected]> wrote: >> >>> Ecolog: >>> >>> I know I won't convince "Me" that while public safety concerns about >>> falling trees (and dropping branches) might sometimes be exaggerated, the >>> truth is that trees do fall and break and people die from it, and it is >>> only prudent to get the dangerous ones down before they fall down. >> "Me's" >>> point is also irrational, on this basis, and using straw-man arguments >> does >>> not advance the issue, it only adds an emotional component. He knows >> damned >>> well I did not imply that every tree that falls is going to kill someone; >>> thankfully, even in heavily-used areas such deaths are somewhat rare, but >>> that does not mean that dangerous trees should not be removed. Talk to >> the >>> families of the victims and tell them you stopped the tree that killed >>> their loved one from being removed. In my area, a public protest >> prevented >>> a severely leaning large tree that showed clear signs of root failure >>> opposite the direction of the lean from being removed. Those people >> should >>> have to face the families of the victims, but "God" will be blamed, as >>> usual. What poppycock! >>> >>> WT >>> >>> PS: I have lost one friend to a falling tree, almost another, and several >>> people have been killed over the years in my community by falling trees >> and >>> branches. While running a tree survey strip when I was in the Forest >>> Service, I was narrowly missed by a big widowmaker, and I saw a logger's >>> body being carried out with his flattened hard hat where his head used to >>> be. A widowmaker. That's how frequently falling branches kill people in >> the >>> forest--there's even been a name for them for years. >>> >>> ----- Original Message ----- From: "Me" <[email protected]> >>> To: "Wayne Tyson" <[email protected]> >>> Cc: <[email protected]> >>> Sent: Saturday, January 19, 2013 8:20 PM >>> Subject: Re: [ECOLOG-L] Tree stump removal in sensitive area >>> >>> >>> >>> Omg. The moment it falls, someone is in the perfect position to be >> fatally >>> injured. That's the reason there is a war on trees in the Washington DC >>> area. There is this unreasonable perception that something that looms >> over >>> us is out to kill us. Parks here have trees near paths cut for the same >>> irrational fear. Yet you can go to other states like NY or ME and find >>> that there is no such rampant tree culling. There is a distorted >> perception >>> of risk to me versus averaged risk to populations. >>> >>> Geoff Patton >>> Wheaton, MD >>> >>> Sent from my iPhone >>> >>> On Jan 19, 2013, at 12:23 PM, Wayne Tyson <[email protected]> wrote: >>> >>> Good idea in the wild, but in a place where there are lots of people, >> one >>>> has to think of what it hits when it falls after the roots rot >> enough--it's >>>> just fine until that instant when the last bit of rot or burrowing >> rodent >>>> or whatever cuts the last bit of dead tissue--and BAM! Somebody's dead. >>>> Drawing birds and other creatures into the urban context is wonderful, >> but >>>> I worry about the populations of predators like domestic and feral cats >> and >>>> the lack of understory for laddering fledglings up off the ground when >> they >>>> make their first hard landing. Context is everything. >>>> >>>> WT >>>> >>>> ----- Original Message ----- From: "eann" <[email protected]> >>>> To: <[email protected]> >>>> Sent: Saturday, January 19, 2013 7:02 AM >>>> Subject: [ECOLOG-L] Tree stump removal in sensitive area >>>> >>>> >>>> Rather than worry about stump removal, why not cut the tree off higher >> up >>>>> and leave it for cavity birds? >>>>> >>>>> Ann >>>>> ~*~ ~*~ ~*~ ~*~ ~*~ ~*~ ~*~ >>>>> E. Ann Poole, NH-CWS >>>>> Poole Ecological Consultancy >>>>> PO Box 890, 741 Beard Rd >>>>> Hillsborough, NH 03244 >>>>> (603)478-1178 >>>>> [email protected] >>>>> www.eannpoole.com >>>>> ~*~ ~*~ ~*~ ~*~ ~*~ ~*~ ~*~ >>>>> >>>>> >>>>> ----- >>>>> No virus found in this message. >>>>> Checked by AVG - www.avg.com >>>>> Version: 10.0.1430 / Virus Database: 2639/5543 - Release Date: 01/19/13 >>> >>> ----- >>> No virus found in this message. >>> Checked by AVG - www.avg.com >>> Version: 10.0.1430 / Virus Database: 2639/5543 - Release Date: 01/19/13 > > > > -- > ------------- > Jane Shevtsov, Ph.D. > Mathematical Biology Curriculum Writer, UCLA > co-founder, www.worldbeyondborders.org > > “Those who say it cannot be done should not interfere with those who are > doing it.” --attributed to Robert Heinlein, George Bernard Shaw and others
