Tree protection zones| Critical root zones| Critical Root Radius| AUSTRALIA

Eric Frei · 2nd October 2007, 01:35 PM

PDF dated 27th September 2005 for ACT Australia protection zones.

First I have heard/seen of it, could be adapted into your reports, there is no actual Australian Standard for this issue and I have been using the British Standard BS 5837. If anyone has that British Standard do they mind putting it in this thread.

This formula is drip line + 2m or where there's absence of drip line a distance of 4m from the trunk (radius) which ever is the greater. The diagram shows it. The downfall would be tall thin trees, Italian cypress, pencil pines etc.

Also new thread here AS4970 Draft| Australian Development Tree Protection

Eric Frei · 2nd October 2007, 01:48 PM

This document is from Campbelltown Council SA and uses the 10x method.

Sean Freeman · 2nd October 2007, 06:57 PM

This is the one I use and incorporate into reports, works for all species and permits you to have input based on your knowledge and experience of particular species tolerances.

Its also the table used by a number of better LGA's here in Qld.

Eric Frei · 2nd October 2007, 08:08 PM

Hey Sean

I have a Corymbia maculata (spotted gum) 830mm DBH and 30m tall (guessed) on a development site.

I'd call it Moderate Mature according to your chart, what would you call it?

Sean Freeman · 2nd October 2007, 08:20 PM

Generally with Eucs I'd place them in the poor tolerance to root damage/disturbance but its certainly fine to put a particular species that your experience tells you is moderately tolerant into that category. Providing the tree has not (to your knowledge) been damaged in the past the difference may not be critical, also remember that roots don't grow in symetrical circles evenly spaced so site specific soil/ground conditions play an important role here too TPZ or CRZ fencing can and should reflect any such anomalies...it can be to the great advantage of the long term health of the tree.

Eric Frei · 5th October 2007, 05:55 PM

I just spoke with ecologist at BCC and rule of thumb is 10x DBH.

I mentioned my concerns and she will notify other DA ecologists and forward treeworld on to them as resource also.

Sean Freeman · 9th October 2007, 07:44 PM

I hope she does and they do drop in...and if they feel that 10X DBH is an acceptable one size fits all, that will provide sufficient protection for older sensitive significant trees to the community down there that they present their reasoning....looking forward to the justification.

As you abley pointed out even 1 or 2m difference in radius makes a big difference in volume of roots and soil protected.

1m diameter at breast hieght = 10m radius (I'm presuming its radius not diameter!) thats 314 square metres

1m dbh of a tree intolerant of root damage in mature age class = 15m radius....thats 707 square metres.....big difference eh?

Eric Frei · 9th October 2007, 07:58 PM

Big difference yes.

Keep getting the message out, hey Sean, maybe link those pics in here of the Hospital trees that died!

Steve Tipton · 9th October 2007, 09:16 PM

I think TPZ requirements vary greatly with regard to species, soil type and suitability of the tree to the particular site and available microclimate.
Each case should be assessed on it's individual situation.
Steve

redstree · 18th October 2007, 04:40 AM

I was on the Tree Commission for my city for about 15 years an done of the things that we accomplished was the creation of a series of regulations regarding trees. Section 5.14 of our city regulations covers most tree issues. Here is a link http://www.ci.milford.ct.us/Public_D...%202-21-06.pdf

I will post the link to our regulations to protect trees from consturction damage when I find it again. The city has changed their web site and I am having trouble locating it.

Eric Frei · 15th December 2007, 04:04 PM

Dr Kim D Coder's 1996 PDF, also covers structural root plate from Mattheck's work.

treeseer · 15th December 2007, 10:57 PM

and this

2nd October 2007, 06:57 PM	#3
Sean Freeman Monument Status Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland Posts: 1,985	Re: Tree protection zones\| Critical root zones\| Critical Root Radius\| AUSTRALIA This is the one I use and incorporate into reports, works for all species and permits you to have input based on your knowledge and experience of particular species tolerances. Its also the table used by a number of better LGA's here in Qld. Attached Thumbnails

2nd October 2007, 08:08 PM	#4
Eric Frei Admin - Razor sharp and independent 2 X Diploma Level 5 qualified arborist Join Date: Jan 2007 Location: Brisbane Posts: 12,820	Re: Tree protection zones\| Critical root zones\| Critical Root Radius\| AUSTRALIA Hey Sean I have a Corymbia maculata (spotted gum) 830mm DBH and 30m tall (guessed) on a development site. I'd call it Moderate Mature according to your chart, what would you call it? __________________ Protect your rights to work - Join Australian Tree Association My businesses:- Qualified Brisbane Tree Lopping \| Stump Grinding Brisbane \| Brisbane - Gold Coast Consulting Arborist

2nd October 2007, 08:20 PM	#5
Sean Freeman Monument Status Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland Posts: 1,985	Re: Tree protection zones\| Critical root zones\| Critical Root Radius\| AUSTRALIA Generally with Eucs I'd place them in the poor tolerance to root damage/disturbance but its certainly fine to put a particular species that your experience tells you is moderately tolerant into that category. Providing the tree has not (to your knowledge) been damaged in the past the difference may not be critical, also remember that roots don't grow in symetrical circles evenly spaced so site specific soil/ground conditions play an important role here too TPZ or CRZ fencing can and should reflect any such anomalies...it can be to the great advantage of the long term health of the tree.

5th October 2007, 05:55 PM	#6
Eric Frei Admin - Razor sharp and independent 2 X Diploma Level 5 qualified arborist Join Date: Jan 2007 Location: Brisbane Posts: 12,820	Re: Tree protection zones\| Critical root zones\| Critical Root Radius\| AUSTRALIA I just spoke with ecologist at BCC and rule of thumb is 10x DBH. I mentioned my concerns and she will notify other DA ecologists and forward treeworld on to them as resource also. __________________ Protect your rights to work - Join Australian Tree Association My businesses:- Qualified Brisbane Tree Lopping \| Stump Grinding Brisbane \| Brisbane - Gold Coast Consulting Arborist

9th October 2007, 07:44 PM	#7
Sean Freeman Monument Status Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland Posts: 1,985	Re: Tree protection zones\| Critical root zones\| Critical Root Radius\| AUSTRALIA I hope she does and they do drop in...and if they feel that 10X DBH is an acceptable one size fits all, that will provide sufficient protection for older sensitive significant trees to the community down there that they present their reasoning....looking forward to the justification. As you abley pointed out even 1 or 2m difference in radius makes a big difference in volume of roots and soil protected. 1m diameter at breast hieght = 10m radius (I'm presuming its radius not diameter!) thats 314 square metres 1m dbh of a tree intolerant of root damage in mature age class = 15m radius....thats 707 square metres.....big difference eh? Last edited by Sean Freeman; 9th October 2007 at 08:09 PM. Reason: removed reference to Eucs to adhere to the table posted previously

9th October 2007, 07:58 PM	#8
Eric Frei Admin - Razor sharp and independent 2 X Diploma Level 5 qualified arborist Join Date: Jan 2007 Location: Brisbane Posts: 12,820	Re: Tree protection zones\| Critical root zones\| Critical Root Radius\| AUSTRALIA Big difference yes. Keep getting the message out, hey Sean, maybe link those pics in here of the Hospital trees that died! __________________ Protect your rights to work - Join Australian Tree Association My businesses:- Qualified Brisbane Tree Lopping \| Stump Grinding Brisbane \| Brisbane - Gold Coast Consulting Arborist

9th October 2007, 09:16 PM	#9
Steve Tipton Over mature heritage tree Join Date: Jun 2007 Location: Sydney Posts: 823	Re: Tree protection zones\| Critical root zones\| Critical Root Radius\| AUSTRALIA I think TPZ requirements vary greatly with regard to species, soil type and suitability of the tree to the particular site and available microclimate. Each case should be assessed on it's individual situation. Steve

18th October 2007, 04:40 AM	#10
redstree Sappling Join Date: Oct 2007 Location: USA Posts: 25	Re: Tree protection zones\| Critical root zones\| Critical Root Radius\| AUSTRALIA I was on the Tree Commission for my city for about 15 years an done of the things that we accomplished was the creation of a series of regulations regarding trees. Section 5.14 of our city regulations covers most tree issues. Here is a link http://www.ci.milford.ct.us/Public_D...%202-21-06.pdf I will post the link to our regulations to protect trees from consturction damage when I find it again. The city has changed their web site and I am having trouble locating it. __________________ Drive a MINI, the most fun you can have with your trousers on.

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