Topographical survey - which trees to pick up

I was once asked to offer to survey a tract of over 150 acres and show all trees thereon having a minimum trunk diameter of three inches.?ÿ I was quite familiar with the property and what the intended use was to be.?ÿ The potential client was told to "be realistic, you twit" because about two-thirds of the area was going to be stripped bare prior to construction and the remainder was going to be left as a "natural" area.?ÿ There was absolutely no need for so much detail.?ÿ The potential contractors for the stripping would not base their pricing on any such data in the first place.?ÿ The "natural" area had no need whatsoever to be documented as to the trees.?ÿ Of course, the twit wanted the exact location of every tree, the approximate diameter, the common name for the tree and the Latin name for the tree.?ÿ The potential client's goal was to run up the over all cost of the project so that his percentage fee would also grow.

8" DBH is pretty standard in most of the outlying districts around here. In the city its 6", and 3" for ornamental (non-native) trees. The city has an?ÿ arborist, and said arborist dictates that standard. Some nuisance (weed) varieties can be all but ignored, but I don't trust myself, let alone survey field crews, to accurately identify trees more selectively than deciduous, coniferous, ornamental.?ÿ

Urban:

4" and larger are shot w/ truck diameter and estimated drip line (it scales in C3D).?ÿ Saplings are a single shot next to the trunk.

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Rural:

Clearly defined, independent trees are shot w/ the above criteria, but no saplings.?ÿ Clusters of trees have the outline of their dripline shot.?ÿ If the client requests it (and pays for it), trees w/ a diameter of 12" and larger can be shot in the groups.?ÿ?ÿ

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Individual tree tagging:

Sure.?ÿ T&M.

Don't do what I did-twice:

I set up under a four foot diameter pine to locate about a hundred trees that were tagged with metal strips for identification.?ÿ Guess which tree I left out?

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I did a tree survey for an architect once. He was going to design medians for a new subdivision according to the sizes and tree types on the site. We used metal tags and scribed them with a number. Each tree circumference was then measured, converted into a diameter, and the tree was identified. This information was then entered into a field book. There were over three thousand trees! I think we located everything four inches and larger. I've never heard of an industry standard for tree diameters.

Typically the architects I work for don't care about anything less than 8" for some to 12" for others.

I used to work in UK ten years ago and did exactly this kind of topo. We surveyed trees at a hight of 1m above ground and with a minimal diameter 0,15m.?ÿ We recorded the trunk diameter and canopy spread. Processed in Liscad.

For Belgium 150 mm => each tree

smaller trees we TOPO the perimeter of a Group of these smaller trees.

but the only good answer is to talk to the R-K-tect.

christof

Good stuff - many thanks guys

RICS specify <150mm. You really should be consulting their guidelines if you are working in the UK.

Around here it takes all kinds of thoughts.

They come in and clear out most of the small trees and keep the towering oaks and majestic cedars and silver maples.

It all looks good for a while and within 2 years the ground gets saturated and the wind picks up and blows all the remaining big trees down because the clearing crew dug too close to the big trees and damaging the root system there is no longer the underground network of tree roots to hold them all up.

IMVHO, it is best to keep trees 6in to 12in and that have a nice crown and clear out the rest unless some of the others are to your liking and are in a place that needs shade.

A second clearing is much better than having a new farm with all your nice trees laying on the ground.

0.02

@totalsurv

Correct. I was on the panel which wrote the 1996 update and advised on the subsequent one.

The 150mm diameter is a generic spec. for when the document doesn't give a specific size to work to. However, common sense also comes into play and you should take into consideration :

a) typical tree size on the site - if not many are greater than 150mm then perhaps you should consider all over 100mm.

b) purpose of the survey - as has already been commented, if the area is being flattened then only those likely to cause effort to the dozer need recording - if it is for a conservation purpose then all might need recording (but the customer should have stated this).

c) health and quality of the tree - if it is a specimen tree then record, even if smaller than 150mm. - if it is dead then perhaps only over 230mm.

A Harris's comment below is pertinent. I've seen too many sites where "weed trees" have been removed from around the perimeter, only to allow the wind in and wreck the ones they wanted keeping. This smaller growth often acts as leg warmers. No need to survey them all - a foliage line around groups of the smaller stuff should be adequate with a note saying "20 smaller trees". Where larger ones are closely spaced so that the crowns intermingle I'll often just pick up the trunk positions (to size) and put an outer foliage ring line.

If in doubt, discuss with the customer - you know what the site "should" look like in advance, thanks or otherwise to Mr. Google.

That should be something that is clearly defined in your Scope of Services.

Assuming you have a written contract you need to do an addendum to that contract to spell out what diameter trees are required.?ÿ

Now go forth and sin no more.