Predicting tree growth

[csnoke]

I have a question and was hoping someone from this forum may be able to help me. I'm a surveyor primarily interested in airport obstructions and spend a lot of time measuring trees to determine if they're a threat to planes on approach into a runway. I was thinking this weekend if it's possible, given enough information, to accurately predict the growth of a tree (height) over a period of time.

I would think, given information like tree age, soil type, geographic location.. there would be a formula to estimate how much a tree will grow each year. Can anyone tell me if it's more complicated than that.. or maybe less? Are there published growth rates for certain types of trees? Is there other important information that is needed to make this estimate?

Basically, I want to be able to tell an airport "This tree isn't an obstruction today, but based on our estimates it will be in X years." Anyone have thoughts on if this is possible to do accurately?

Thanks for your help in advance!

 

[jefflovstrom]

I have a question and was hoping someone from this forum may be able to help me. I'm a surveyor primarily interested in airport obstructions and spend a lot of time measuring trees to determine if they're a threat to planes on approach into a runway. I was thinking this weekend if it's possible, given enough information, to accurately predict the growth of a tree (height) over a period of time.

I would think, given information like tree age, soil type, geographic location.. there would be a formula to estimate how much a tree will grow each year. Can anyone tell me if it's more complicated than that.. or maybe less? Are there published growth rates for certain types of trees? Is there other important information that is needed to make this estimate?

Basically, I want to be able to tell an airport "This tree isn't an obstruction today, but based on our estimates it will be in X years." Anyone have thoughts on if this is possible to do accurately?

Thanks for your help in advance!

Get a certified arborist out there and have him tell you what you want to know.
Jeff

 

[pdqdl]

Evaluate the age of other trees in the area, then extrapolate for your target area. Naturally, you will need to be working with the same species of trees.

I imagine that each runway has clearing zones beyond the pavement, and acceptable heights within those zones. Just look at the trees immediately outside those zones; you should get some pretty close estimates.

An arborist is not likely to have experience with your specific goals, but hiring one in as a consultant will sure give you better results. You will certainly save a lot of time figuring out each variety of tree you run into. Some species of trees are easy to determine the age, others will be quite problematic. Greater experience with trees will be a big help there.

 

[pdqdl]

I would think, given information like tree age, soil type, geographic location.. there would be a formula to estimate how much a tree will grow each year. Can anyone tell me if it's more complicated than that.. or maybe less? Are there published growth rates for certain types of trees? Is there other important information that is needed to make this estimate?
...

I certainly am not aware of any such formulas. Trees grow at much different rates according to species, climate, and local soil conditions. Each species of tree is pretty well known as to its mature height and it's relative growth rate. Example: Lombardy poplar=very fast. Rosehill columnar maple=rather slow. From a distance, an untrained observer might not notice the difference.

For a truly reliable prediction for your customers, you must evaluate the local growth rates and extrapolate.


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I am a bit stumped by this problem. All the airports I am familiar with have absolutely no trees at all in the areas they have control over. Outside their property limits, they have no choices as to what they can do with the trees. Are we discussing landscape trees that are desired for esthetic purposes, or are we talking about open ground filled with uncontrolled vegetation? I would think the airport would just clear-cut anything within their possible flight path or crash zone.

 

[csnoke]

All the airports I am familiar with have absolutely no trees at all in the areas they have control over. Outside their property limits, they have no choices as to what they can do with the trees. Are we discussing landscape trees that are desired for esthetic purposes, or are we talking about open ground filled with uncontrolled vegetation? I would think the airport would just clear-cut anything within their possible flight path or crash zone.

Thanks for the information and responses, I appreciate it.

To explain a little further, the FAA obstruction identification surfaces cover a very large area (almost 30,000 acres). Most of the surfaces are too high for trees to be a concern, but if there are a lot of hills or a steep terrain around an airport, there can be problems. Often, if an airport does not own the property that is of concern, they will seek to obtain an easement for the right to conduct tree topping. Airports prefer to clear cut everything, but in situations where private owners won't allow that, the easement and topping is the only solution. In this case, they would be best suited to obtain current heights of the tree, and then use a model to determine what the future heights will be.. making sure they have an easement that covers the entire problem area.

I would build a comprehensive geographic information system showing the airport property, adjoining properties, land elevations with contours, tree locations/types, and then forecast over the next 5, 10, 15, 20 years, what is going to happen to trees so that an airport can plan long term and identify future problems.. soon enough that they can begin planning for costs, arranging funding.. that type of thing.

If an airport cuts a tree today and take 10 feet off the top, how will that tree regrow and when will it be a problem again? Right now they have no clue.. and often they get a rude awakening a few years down the road when the FAA notifies them that there are problems and they have to use emergency funding to cut trees, or they'll lose their approach procedures. A little bit of knowledge could be very beneficial.. but I'm a surveyor, not an arborist. I'm trying to figure out if this idea is even possible.

 

[cnpser]

This thread reminds me of when the SV Pallada paid a visit to Dutch Harbor, Alaska

View attachment 245959

They first docked at the fuel dock that was at the end of the runway but they had to move it because the masts were too tall and interfered with the 737 that was trying to land.

 

[ATH]

Actually, I am not sure that you want an arborist, but rather a forester. (I am both...so I can say that )

There is a measurement of growing site quality (mostly dependent on soils) called "Site Index". Basically, this is a list by species of how tall a tree will be at age 50 (or 25, depending on which base you use....50 is most common). If you look in the Soil Survey, the soil types will list site index for selected species. If you want to be more accurate, measure and age trees of like species in similar conditions (find an area with the same soil types, slopes, aspect, stand history, etc... nearby), you should be able to at least have some strong data to stand on when you make recommendations.

 

[jefflovstrom]

Actually, I am not sure that you want an arborist, but rather a forester. (I am both...so I can say that )

There is a measurement of growing site quality (mostly dependent on soils) called "Site Index". Basically, this is a list by species of how tall a tree will be at age 50 (or 25, depending on which base you use....50 is most common). If you look in the Soil Survey, the soil types will list site index for selected species. If you want to be more accurate, measure and age trees of like species in similar conditions (find an area with the same soil types, slopes, aspect, stand history, etc... nearby), you should be able to at least have some strong data to stand on when you make recommendations.

Yeah, arborist's don't know all that smart stuff, ya'll!?
Jeff

 

[ATH]

Yeah, arborist's don't know all that smart stuff, ya'll!?
Jeff

Felling a little sensitive?

I did not imply that arborists aren't "smart enough". It is simply not part of the profession...so it only makes sense to go to the profession where it is a standard parctice. SI is a very common measurement in forest management, but it has little or no application in arboriculture, so it is not taught/used.

 

[jefflovstrom]

Felling a little sensitive?

Yeah, a little. I am a sensitive guy that wonders why you are trying to equate forest management to an airport.
Jeff

 

[ATH]

Yeah, a little. I am a sensitive guy that wonders why you are trying to equate forest management to an airport.
Jeff

Fair enough

I guess it is taking a forestry principle and applying it in the urban setting, so it is a crossover either way you go. Like I said, my thought is that sicne forestry is where it is used a forester may be able to better help. Having said that, and re-reading the second post by the OP...he was also talking about "height reduced" trees, so no question an arborist would be a better help there, but as far as I know there is not an 'official system' used to estimate that kind of growth that could go into an engineering report and offer significant sources of literature to cite.

Now I am curious...who else is familar with site index?

 

[jefflovstrom]

Fair enough

I guess it is taking a forestry principle and applying it in the urban setting, so it is a crossover either way you go. Like I said, my thought is that sicne forestry is where it is used a forester may be able to better help. Having said that, and re-reading the second post by the OP...he was also talking about "height reduced" trees, so no question an arborist would be a better help there, but as far as I know there is not an 'official system' used to estimate that kind of growth that could go into an engineering report and offer significant sources of literature to cite.

Now I am curious...who else is familar with site index?

I read the word 'Topping'. Not 'Height reduced.'
After that, I reacted. The research of tree growth is easily obtained. Like I said, a cert arb could do it.
Jeff

 

[jefflovstrom]

Thanks for the information and responses, I appreciate it.
Airports prefer to clear cut everything, but in situations where private owners won't allow that, the easement and topping is the only solution.
If an airport cuts a tree today and take 10 feet off the top, how will that tree regrow and when will it be a problem again? Right now they have no clue..

And an ISA Cert. Arborist cannot answer this? We live in the urban forest and know more than you are giving credit for.
Not to be a bully, but I did not think you should of said said that the OP would be best to listen tou you.
Jeff

 

[ATH]

My 'problem' is that I was responding to everything before the OP's second post. I read those, and thought "he simply needs a Site Index estimate" and I frankly skimmed the follow-up post where he explained the circumstances in more detail.

I do come here to learn. I post the few times I think I have something to add, so I don't want to come off as doubting the knowledge/intelligence/experience of others because I get too much from so many folks here. I appologize for implying anything to the contrary.

 

[jefflovstrom]

My 'problem' is that I was responding to everything before the OP's second post. I read those, and thought "he simply needs a Site Index estimate" and I frankly skimmed the follow-up post where he explained the circumstances in more detail.

I do come here to learn. I post the few times I think I have something to add, so I don't want to come off as doubting the knowledge/intelligence/experience of others because I get too much from so many folks here. I appologize for implying anything to the contrary.

Cool, I sometimes jump the gun and get the Bully label,
Sorry!
Jeff

 

[ROOTSXROCKS]

Severe cutting is going to cause reactive growth that will depending on the species be very rapid elongated and weak. the power line contractors would be the ones to hire for what you need. BUT I would think a more practical method would be a Growth Regulator treatment like Paclobutrazol.

 

[pdqdl]

...

If an airport cuts a tree today and take 10 feet off the top, how will that tree regrow and when will it be a problem again? ...

Deciduous trees that have only been topped by 10 feet rebound rather quickly. Conifers that have been topped pretty much stay where they are cut off.

I don't know what variety of trees you are talking about, but it is Ohio, right? That generally means deciduous trees. Count on knocking off 10' every 5 years.