Level 1 tree assessment

matdand

Active Member
I have a municipality that have asked me to give them a proposition for risk assessment in three parks, roughly 1100 trees. They have no idea how to go about this, so I was thinking of doing it this way:

- Level 1 walk by assessment with a 360 degree observation of each tree. Note only major defects or areas of concern for safety (decay, conks, fungus, cracks, dead branches, lean, etc.) No notes about tree health or insect/disease problems.

- No recommendations on my part, the muni will decide which trees should be inspected further and we will make the a proposition at that point.

- They are providing inventory info with geolocalisation of each tree.

So, how much time per tree on average? I was thinking 4-5 minutes including prep and documenting/reporting. I kind of tried it out at one of the parks, lots of trees go quickly, then some take a little longer.

4 minutes per = 73 hours
5 minutes per = 92 hours
 

LimbLoppa

Well-Known Member
Don't sell yourself short. Remember, they have no idea how to go about this- make sure you take into account ample time for a proper assessment /report. If you are "setting the bar" don't rush . Do a thorough job and give them what they are paying for. Just my .02$ ( I don't do sh*t for .02)
 

GrahamS

Member
If you can try to work with the City staff requesting the proposal, and identify what they are looking for as the outcome of your assessments. Assuming they need help developing a work specification for you, try to use their desired outcome to build a solid scope of work / work specification for them. Along with their inventory, try to have them identify what their targets of concern are, and prioritize them. So if you have a 10 acre park, and 5 acres are woods, 1 acre heavy use playgrounds and picnic area, and 4 acres of low occupancy open areas, you can focus more on the target intense 1 acre, and move through the lower use areas at a quicker pace. If you stay within a level one scope, which is basically windshield survey, you should be able to keep it under a minute per tree. When I am doing similar work I can usually hit 80-100 trees an hour, updating inventory info on a tablet, grabbing a DBH and a quick visual assessment. My feeling is at a level one scope, your only looking for the obvious defects, and usually only from one perspective, if you think some areas need a more thorough assessment, why not bump up your scope and account however you need to so the $ work out.
 

matdand

Active Member
Thanks! I understand not selling myself short, but I don't want to be done in half the time either, that would seem odd.

I have been trying to squeeze what they want out of them. At first, they were talking about what seemed like a level 2 for each tree, but that is crazy. Really what they want is a risk assessment for all dangerous trees, but they also want an idea of budget. I can't give the the latter without defining the scope and knowing how many trees need a level 2/3, so I figured let's start from scratch with a quick level 1. I wouldn't be doing any mesurements and also I would need to do a 360 around each tree. Occupancy rate would be largely the same in all three parks, except maybe some areas closest to the street where there would be continous parked cars. Not much in terms of site change other than that, no wooded areas or less occupied zones. I don't think this is of valid concern at this point though because all I would be doing is documenting noticeable defects. At a level 2 stage it would be more important.

Graham, you say you can bang out 80-100 trees/hour with some data inputing. I'm thinking I could be doing 40-50 and have some time to make a nice report.

This is my first time doing such an extensive project of this nature. I'm pretty psyched as this is something I really want to fall back on in futur years. Any more input is appreciated!
 

mrtree

Well-Known Member
Is 4 to 5 minutes realistic for inspection, data entry, notes, move between trees and sites, down time, travel time etc.? What about a report? What about time to discuss with staff? What about time to compile trees needing further assessment?

Staff cannot understand your data without alot of back and forth, thus more time.

Further if you have geo data for the trees how are you going to find them? A cell phone does not have the precision or accuracy.

What is a major defect? How will you separate mushrooms that are decay organisms from mycos or soil borne organisms?
 

Mangoes

Well-Known Member
Also consider - Davey Resource group are doing what you describe for $2-$5 per tree

Not sure if they are pursueing Quebec. Their intentions in eng canada are clear ......
 
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matdand

Active Member
Trees are all close, maybe 10- 20 feet frome each other. Parks are within 5 minutes drive from each other and 10 minutes from my house. Paper maps are what I was going to use, with an excel spreadsheet. Major defects would be defined in scope of work (dead branch of more than 10cm), but because I wouldn't have to describe anything in great detail during the assessment, I would probably mention more than less in the report. At this stage I would note any fungus, if they want further inspection or confirmation, that would be for a level 2. I'm thinking of just putting colums with the most common defects that I could check and the briefly descibe. I would hve to put all that into a nice report after.

Mangoes, Davey isn't in Quebec and not many people are offering this service around here, I see this as a good way to break into a new potential market. 2$ would seem a little low to me, 4-5$ makes more sense.
 

flyingsquirrel25

Well-Known Member
We did a large project a couple years ago for a retirement community. They said they had 1500 trees. I tagged each tree with a number and assessed health, DBH and the needs of each tree and a priority level. I also gave them a ball park figure on a cost for any recommendations for care (I was not being contracted to do the work, just to assess it). We finished the project with just over 950 trees (they were amazed at how many they had taken down since their last inventory). If I remember correctly we had a total of 22.5 hrs of field work and 12 in the office inputting data, writing the report and printing the book. With 2 of us in the field it went amazingly fast. I did the measurements, my wife recorded the data via walkie talkies.
Doing it on your own could be significantly slower.
 

matdand

Active Member
So 45 hours man(person)/hours in the field and 24 (?) in the office for 950 trees. Good info! Thanks!
 

mrtree

Well-Known Member
Why would you give them an excel spread sheet if they already have data for the trees? Should your programs not match? A simple download of data that works is better than another step in the process.
 

matdand

Active Member
Sorry, that was unclear. I would print their spreadsheet after adding a few colums I could check. I have been advised by a couple of people against using tablets in the field; more potential mistakes, losing info, harder to use in the rain. Waterproof paper was what was suggested to me. Also, I was planning on making a written report afterwards anyway, so the data collecting would be for me.
 

flyingsquirrel25

Well-Known Member
Why not input the data in the field while you are there?
Why? It's a giant PIA! We wrote everything down and then typed it into a computer. We began the process with a tablet and only went about 10 trees before it got tossed in the truck and brought the clip board and paper out.
 

mrtree

Well-Known Member
So why is it that Davey uses tablets successfully? With paper you are writing, inputting and checking; more than doubling your work.
 

matdand

Active Member
Do you know what program they are using ? I can imagine if you're georefencing the trees and you can input eveeything all at once, that would be the best.
 

mrtree

Well-Known Member
That is exactly what is being done. You want to be able to add your info to that already available through the municipality's GIS/engineering systems
 

Mangoes

Well-Known Member
Sorry, that was unclear. I would print their spreadsheet after adding a few colums I could check. I have been advised by a couple of people against using tablets in the field; more potential mistakes, losing info, harder to use in the rain. Waterproof paper was what was suggested to me. Also, I was planning on making a written report afterwards anyway, so the data collecting would be for me.
Ermergersh!!!

There's a whole plethora of iOS apps for data acquisition via forms that are FREE! I use one in particular - after a brief training - junior, 2nd year college employee was able to harvest 200+ trees per day via iOS device.

- GPS coordinates
- 10-12 data fields incl DBH
- 3300 trees for condo corp

Data exported into numerous functional formats, including .xls.

4-5 pivot tables and formulae permitted the condo corp to easily budget tree care prescriptions for 5 years.

Same condo was inventoried 7 years ago with a ledger book. Took 3x the time with less data harvested.

DO NOT USE PAPER (21st century and all)
 

guymayor

Well-Known Member
The biggest downfall with inventories is having to make recommendations. Keep your scope to specifying management options, to minimize the transfer of liability from the city to YOU.

I've been underbid by Davey at their $3 rate, and cities are stuck with crazy recommendations for removing excellent trees because of dead branches etc. They send trainees to do a grown (wo)man's work.

The idea that we KNOW a defect when we see it is crazy. Overextension of limbs and crowns is the #1 predisposing condition to consider. Fungi and holes can be significant features, but many assessors lose their vision of the whole tree and site when they see a mushroom.
 

GrahamS

Member
Davey is using their own software, a program called treekeeper. Its definitely not something you would mess with unless your continuously managing large populations of trees. The City I work for has been using this program since the late 90's to manage our inventory data, I really like it, and I use the mobile version on the tablet daily.

To Guys point about crazy recommendations, there is some truth to that as it is usually pretty green employee's doing their inventory work, but it is really up to the municipality to define the info they want, and how they want it reported back to them. This should help focus those recommendations. While we can argue the semantics of knowing what is specifically a defect or the severity of that defect all day long my take on managing trees for a municipality dealing with thousands of trees is this type of assessment is primarily about triage, and finding the trees showing the more apparent problems. I would love to hear from Guy or some of the other municipal guys, what there suggestion would be for the best approach to performing risk assessments on large populations of trees. I know I personally find it unrealistic to do much more then a level one, and based on those findings, a few more focused level 2 assessments on more then about 20% of our inventory annually.
 
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