Bs 5837 tree removal/ retention questions

[Tony Banner]

Am an arb student just trying to get my head around bs 5837 2012, an I've just been doing a couple of practice surveys and ive got a couple of questions about tree removal/retention.

 

 

I surveyed an area using bs 5837 recommendations, for an area for the development of a small car park or building surrounded by the exsisting trees

 

Two trees I surveyed both bs cat - C1,

T1 - sycamore +20 m tall Dbh- 2820, fair condition, 10-20 years remaining contribution

T2 - silver birch, +15 m tall Dbh 1750, fair condition, 10-20 years remaining contribution

 

These trees would require crown lifting if retained and be really close to the borders of any development.

 

My questions are. Is it justifiable to remove these trees to facilitate any proposed development, just because of there size, condition, remaining life and proximity to the site? If so what would you suggest as replacement trees to plant, I mean you would plant another sycamore would you?

 

These may be stupid questions but there just little things I could do with a little advice with.

 

Any thoughts

 

Cheers

[oslac]

I think you have a few errors creeping in there.

 

The trees cannot both be b's and then C1. They are either B or C.

 

The DBH quoted is too great. That is diameter and the tree will not be 2.8m and 1.75m Are you confusing circumfrence with diameter. Even then, 1.75m, circumfrence for a birch appears mighty big. From the DBH, you can determine the RPA's and the impact the development is likely to have on the trees

 

The BS sets out the need to allow room for future growth. You will need to decide what is more important, the new building or the retention of the trees bearing in mind that the trees appear to be pretty ropey as you have described than as fair condition C1.

 

If you decide to retain the trees, what about their future management in relation to the development. If you decide to replace the trees and space allows, look at the character of the site and choose a replacement tree accordingly. I would be doubtful about replanting a sycamore but that is your choice.

[Tony Banner]

Thanks for your reply

 

How do you work out the rpa's? I've been measuring around the trees at 1.5 m, which have me the measurements I've mentioned and then times 12 of that to give me the rpa size. Should I take my measurements and divide them by 3.14 to give the diameter then?

 

Thanks for your help

[sloth]

Circumference divided by 3.14 will give the diameter. Or look at buying a diameter/dbh tape to make it a little easier. Then that x12 is the rpa radius from the center of the tree, eg a 1.5m diameter tree would the rpa radius - 75cm from the tree surface. Does that make sense written down?

Multiple stem trees get interesting, you have access to the bs presumably? Can your tutor help clear things up?

[Tony Banner]

Yeah sloth that helps, I get what your saying.

 

So here's my example worked thru, just to check I've got it right now.

 

I measured round the tree and got 2820mm divide that by 3.142 = 897.5 do I round that up to 90. X12 =1080 an then divide that by 1000 =. 1.8 m is that right then, thats the rpa from the centre of the tree

[Tony Banner]

Sorry I've got that wrong

 

Round that up to 900 not 90 and end up 10.8m rpa

[oslac]

Why not go on line, check out a conversion site and input your circumfrence measurements to get the diameter. Quick easy and accurate.