AS4970 Draft| Australian Development Tree Protection

just starting

Eric thanks for another good example.

Of course we can use irrigation and on clay soil we may be able to rely on some lateral movement of soil moisture. I accept Sean's comment that what we are doing is trying to exploiting the survival capacities of particular species so some one can make more money through covering more ground with more concrete..... The alternative is more urban sprawl or fewer trees. The standard is not supposed to consider esoteric issues such as the density of the development that is a function of town planning.

I guess there are two different questions that are being considered.

The standard is answering the question ... What is the ideal distance to keep from a tree to ensure that there is no impact on the trees no matter what. I think it does a good job of this and it in fact says that if we keep that distance from the tree you don't need to seek the advice of an arborist. Our roll then is only to deal with the next question.

The question we are looking at is ... How close can we get to a tree and keep the tree as a safe and healthy specimen and what sort of design and arboricultural input is required to achieve this? This is a question that the standard largely ignores. Unfortunately the British Standard has been used here to stop many developments because it doesn’t consider this question either, so I suspect that we may often see the response “Does not comply with the Standard”.

When real estate costs millions of dollars then I guess trying to maximise yield or trying to build a suitably sized building seems somewhat understandable. As an arborist I would love to see more clients spend reasonable sums of money protecting and caring for trees.

I would hope that we all agree that it would be a shame to see trees removed because the council approves an appropriate sized building and the Owner then says well then we can’t keep this tree, this tree and this tree because they are closer than is provided for in the Australian Standards

Sean Freeman

I repeat read the standard and understand when Arboricultural input is required...at what stage...This is EXACTLY what the UK experience tells us.

Trees are a constraint just like any other physical constraint to development, with the additional proviso that they can deliver enormous benefits not only to the immediate local area but to the wider region as well

Most of the developers I get to deal with come to understand this (some find it harder to shift their perspective than others) and have no drama with the role a qualified professional Arborist plays in the design team

Personally I am very tired of living and working in environments where (to be kind) ill informed decisions about tree retention result in tree decline death and huge cost to the local community capital environmental cultural and ecological.

just starting

So am I Sean. So now we will protect a Phoenix palm with an area 1600% more soil than is taken to move it. We sterilise more of site and perpetuate the myth that trees can't be retained close to buildings. I find it odd that we can't retain a tree close to a building but we can plant it close to a building.

What we seem to be doing is requiring greater sterilisation of a site rather than environmentally sensitive construction techniques. When I was a kid we built on peers and kept the natural ground below the house and retained and planted trees. Now we rape the site and keep further away from trees and I hear they are currently looking at a standard now about how close we are allowed to plant a tree from a building.

When the lot sizes are getting smaller it is desirable to keep trees that are close to the building otherwise we end up with house lots and no trees or trees on the boundary with the inherent disputes. We also perpetuate the myth that it is dangerous to have a big tree overhang a house.

Remember a house lot without a tree is not fit for a dog.

just starting

How many times do you see a tree planted in the middle of the rear yard of a small lot. If we dont retain trees in those sort of places they will seldom be planted there.

Sean Freeman

This maybe true dependant on the way some move them

Whilst I am perrfectly willing to acknowlege that future grow considerations are poorly recognised and allowed for in many landscape designs AS4970 is specifically aimed at addressing existing trees on development sites...its in the text describing scope I believe.......I find it a little odd if you don't see there is some significant difference in the requirements of a sapling, and a mature oak?????

Strange turn of phrase...I clearly approach my work quite differently than the way you would.

Some might......I very much doubt anyone who has ever heard me speak or read anything I have written would ever consider that I fall into that category

just starting

Sean,

I do see that there is a difference in the requirement for a small tree and a mature tree. I also see small trees planted in highly confined spaces becoming big mature trees. Inner city areas worldwide are full of examples. Palm Cove shows that you can keep mature trees and build bloody close. A project like that would not likely be approved in Sydney. If you look at the standard it implies that is less achievable because the trees are large mature trees.

It makes you wonder how those guys transplant big old trees like they do … these contractors certainly cause more damage to the tree and come a lot closer than is suggested.

I was not intending to suggest that you thought that big trees near a house is a problem but when it is something that is seldom seen on new developments it is an understandable perception.

Picture this situation. To do a development you need to put an easement past a Phoenix palm. You don't need to go any closer than 2 metres from the palm but you are told the development cannot proceed because it does not comply with the standards. This sort of thing is a regular occurrence in Sydney using the British Standard. It could be overcome by simply having an arborist make decisions rather than a standard dictate them.

Or you want to build a resort in a grove of old Melaleucas and you are told that none of the trees within x metres can be retained because they are closer than provided for in the Australian Standards and as a result should be removed.

A client of mine just purchased a waterfront here for $20.8 million. Wants to build a nice house but is restricted because of the distance he needs to keep from the trees because "The British Standard" says .... (This is site sterilisation when you can only build on 20% of your site).

Now if you read the British Standard it doesn’t say that. What it says is consult an arborist. Unfortunately it is misused because it is poorly conceived and I suspect that this new standard may end up being similarly misused.

What I am suggesting is that the table should not be a guide for an arborist but a guide as to when an arborist is required. That being the case it would be best set at 15 times for each and every tree then made smaller under consultation.

Most my clients would spend inordinately more on tree protection and environmentally sensitive development if they were permitted and rewarded for doing so.

Sean Freeman

Seems like I have to keep writing the same thing .... please read what the Draft standard says......it does NOT stipulate that development cannot occur at distances closer than the multiples of the DBH.

I do think that Palm Cove is a great example of an incredibly resiliant tree species growing on ancient swamp and hind dune soil profiles, should it be held up as a bench mark for the majority of developments that occur on marginal ground often verging on anthropogenic soils with what little they have to offer to the established trees in grave danger of being destroyed by the necessities of construction to have stabalised substrates.

The DRAS4970 would not necessarily prevent the development in your scenario.....please read the standard.

This is something a number of us are continually arguing with the LGA's to achieve.

just starting

Sorry Sean I have read it! The British Standard is identical in concept and frequently misused to curtail development because the table suggests that this is the acceptable limit. What stops the level of misuse increasing when we have an Australian standard?

It may not but I suspect that it will. My sugestion is simple, remove the table and provide a single multiplier that becomes the point at which an arborist is required. Essentially this is what the standard says except that the user has to asses the age and health of the tree which implies they are an arborist or need an arborist to determine if they need an arborist ...

Sean Freeman

No document can prevent indivduals taking money off others for actions that could be described as malpractice.

There is a range of abilities across those who describe themselves as Arborists, just like any other profession.

Some like to make money out of providing less than best practice, arguing that the "market" will not support the "costs" of best practice.

I am not someone who supports such a position, nor do I have much time for those that promote such behaviour, be it in development reports, transplant specifications or pruning recommendations.

Most of what should inform our advice to clients, and our own actions has been well established for more than 10yrs.

just starting

Sean, My doubts about the standard neither reflect my view of your professionalism or my own but rather about significant problems that I percieve wheter real or imagined.

It is interesting that you move trees!

When you are moving trees do you move them with a root plate the size recomended by the Australian Standards? If not do you do a root mapping exercise to determine if transplanting will work or how do you go about the decission making process? if you do map the roots how do you process or interprate the data you obtain?

Abe

Sean Freeman

Which Australian Standard would that be????? The one specifically written for the protection of trees on development sites...or some other?????

Please read the standard and its scope....it does not extend to making recommendations about transplantation.

My hands on transplant experience is not as great as some, certainly not as great as some would imply theirs might be....however some of my limited experience is recorded on this forum in words and pictures.

I spend 95% of my working life writing these days, I write a great many specifications including those for proposed transplants, I try hard not to encourage the exploitation of the short term tolerances of trees to enable others to make profits at the expense of what is well known in Arboriculture to be best practice.

TrevMcRev

Full respect to that Sean Well said.

just starting

You will have to excuse me for being confused. I understand the standard is for trees on development site but it surely has some arboricultural basis. In order to get closer than 8.1 times DBH to the tree we need to do this root mapping stuff. I am simply asking if that same science is applied to transplanting and how accurate it is. If it is not applied why not and how come you can cut much closer all the way around and underneath tree to transplant it but we cant come that close on one side.

You keep on talking about exploiting a tree but if it comes down to being able to save the tree or cutting it down I am not sure how that is exploitive.

Sean Freeman

You are excused

DRAS4970 does NOT state that, please read it again, an encroachment into the TPZ of greater than 10% or impacting the CRZ requires the supervising Arborist to provide justification for that damage.

Such a specification is not tied to your figure of 8.1 times the DBH.


If and when an Australian Standard is ever developed for the transplantation of trees, perhaps you will provide input?

There is almost 25yrs of easily www accessable peer reviewed empirical scientific study to support the acknowledged best practices for tree transplantation, much of it within the Journnal of Arboriculture, and other texts.

You seem to have a good grasp of the internet, and your computer I suggest you apply yourself to tracking down some of that research.

If you want to discuss transplanting then I suggest you begin your own thread, if you want ot discuss my advice and recommendations (things I earn a living from providing) then you should contact me directly..its not hard....my contact details are easily available...Sean Freeman is my name, I don't use some pseudonym.

If you actually read what I have written you might see that my use of the term exploitative refers to those who make profit out of providing less than best practice, presenting it as best practice, or by implication or direct assertion state there are no best practices to apply.

We all of us have to operate within the practical limits imposed on us no matter what area of Arboriculture we are working in, DRAS4970 recognises those real constraints and makes some allowances for them IMO effectively, yes perhaps it could be improved in some areas, it will be over time.

Eric Frei

Seems the same merry-go-round Mark Hartley was spinning.
Ficus virens transplant.

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just starting

Sean, I again appologise. I was refering to the normal sort of tree that might be transplanted: a medium aged tree in good health. In this instance it would require a TPZ of 9 times DBH (according to table 2). Furthermore this can be reduce in size by an aborist generally without detailed investiagtion (as per 3.2.2.3.2). 10% of 9 times results in 8.1 times DBH as quoted ... hope that makes more sense




We all of us have to operate within the practical limits imposed on us no matter what area of Arboriculture we are working in, DRAS4970 recognises those real constraints and makes some allowances for them IMO effectively, yes perhaps it could be improved in some areas, it will be over time.

just starting

Sean, I again apologise. I was trying to keep things brief referring to the normal sort of tree that might be transplanted: a medium aged tree in good health. In this instance it would require a TPZ of 9 times DBH (according to table 2). Furthermore this can be reduced in size by an arborist generally without detailed investigation (as per 3.2.2.3.2). 10% of 9 times results in 8.1 times DBH as quoted ... hope that makes more sense

Let me say I am not trying to argue with you I am trying to understand the rationale behind what seems rather new and relatively unpublished research and the clear contrast that exists between your expertise as a transplanter. I am also trying to get a handle on a process that seems highly subjective by thinking aloud. I tried to find your number but I have been unable to find it … what is the name of your business?

I was not asking about transplanting but rather the relationship between what seems to be a generally recommended radius of 4 to 6 times for transplanting which involves the cutting of all roots generally without any form of investigation as outlined in 3.2.2.3.3. This is based as you say on extensive peer reviewed research over the last 25 years. I suggest since Sir Henry Steuart's "Planters Guide" (published in 1828 along with the published peer review by Sir Walter Scott et el dated the same year although Steuart’s work had been reviewed in print prior to his book being published). On this basis it is fairly well supported by almost 200 years of research.

This existing and extensive body of research appears to be at odds with this standard because it clearly demonstrates that you can cut ALL the roots at say 5 times trunk diameter without investigation in order to transplant a tree. This new science states that you cannot cut the roots along a tangent that hits 5 times from the base of the tree and leaving all other roots in tact, without investigation and it provides no scientific and reproducible process for evaluation the data collected during the investigation. I am sure that this is called an opinion by very definition and is NOT a standard.

I agree that I am probably not as good as you at trees but I can do basic maths so that may be the source of my confusion.. To protect a 1 metre diameter tree normally is 81 pi metres square and with investigation it may be possible to make a tangential cut 5 metres from the trunk that results in approximately 60 pi square metres (75%) of the "ideal " TPZ. With a 1 metre DBH it can be moved with a 25 pi metre squared root plate. This means that cutting a tangent 5 metres from a tree with a 1 metre diameter trunk will give more than twice the volume of soil that is required for a transplant that needs no investigation and substantially more if the works are limited to only one side of the tree.

I do accept that we are provided some important items to consider. Are we to assume that if the tree was suitable to be transplanted with a 5 metre root plate that cutting a portion of the roots 5 metres from the tree is also appropriate? I cant see why not. If this is the case I think I understand things .. if not I am definately confused becuse these two processes would seem to be at odds scientifically and mathematically.

I am having problems trying to reconcile the new process of root mapping and how I apply that scientifically and mathematically in any objective way. Producing a map of the roots will not help the tree and unless there is a clear process for handling the information it is pointless. Obviously we are not mapping absorbing roots but woody roots and using air or water to map roots will certainly damage the woody roots and destroy absorbing roots.

Is there some program or formula that we use to process the results of our investigation or is it just left to our own experience and knowledge in which case why not use 200 years of science and data. The standard is silent, the research is not clear or in fact even referenced in the standard and it is contrary to a huge body of tried and tested arboriculture. The only thing I have seen that makes any sense of it all was a formula by Thyer that was submitted to SA but not adopted.

I reiterate the concerns of at least one committee member that "if we make the retention of trees far more difficult than it needs to be then it will surely result in the unnecessary loss of trees".

My experiences clearly different to yours Sean! I do not need a standard to tell me what is an appropriate sized TPZ. The problem for most arborists in Sydney is not the size of the TPZ it is ensuring that the work recommended is performed. In this regard an Australian Standard has far less weight than the consent document, the DCP and the EPA act.

I support the standard, even if it makes mistakes, for the very reason you have clearly stated and for the very reasons you have stated I believe we need to be very clear about the fault and limits of this document particularly if we are to continue to grow in credibility as a scientific profession. Unfortunately this portion of the standard takes us back to a period before 1828. That may be progress in the minds of some but I have to disagree.

Hope that makes things clearer though I fear I may have only confused the situation further.

I remain respectfully

Abe

Eric Frei

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TrevMcRev

Sean Freeman

Really???? I did not think it so hard to track down a Certified Arborist listed in both the National and International Society of Arboricultural websites.

That I am fairly we can certainly agree on, however I think it is important to concentrate on the standard rather than what seems to me to be a game of point scoring

Trees that are present on a proposed development site are not really analagrous to trees that would be suitable candidates for transplantation. The kind of massive negative impacts even the best methodology imposes on the trees moved is precisely what many of us wish to avoid during development.

There are I suspect a significant number of Arborists who may well feel the same, some certainly voiced such opinions at the conference.

My feeling is this, where the LGA has an existing operational set of tree protection rules/regulations/local laws this draft (when it becomes a full standard) will provide the framework into which Arborists should be included at the concept stage of planning.

It will not happen smoothly and it will undoubtably take time.

(In areas where there are effectively no planning tools that properly address the requirement to manage vegetation having a standard is an essential first step it seems to me)

I personally think that for all its weaknesses the standard can help us have an impact on the clients who engange with us, we can I think, given enough lead in time demonstrate to the other professions intimately concerned with the nuts and bolts of development and construction that trees are first and foremost valuable assets, and that as constraints they can and do fit into development planning just like any other constraint.

Each LGA has adopted slightly different methods of incorporating the declared objectives within the legislation passed at state and federal level to address environmental protection, some appear far more effective at times than others.

My own experience has been that the biggest obstacle to achieving long term positive outcomes (besides possibly personalities) is that we rarely get to inform the concept planning stage of developments.

It seems to me that this is one of the strengths of the draft standard.

just starting

Really Sean, try inserting you name and arborist into Google. No luck. How was I supposed to know that you were ISA certified and to look in that directory? You talk about point scoring and indeed you are right it certainly seems to be your focus, rather than making things easy. I now fear that when I call you I will be treated with contempt. I think I have agreed to my errors along with your authority and expertise enough in these posts but you appear to see that as point scoring ... Be gentle and I'll call


We can agree to disagree on several counts.

Many large transplants are simply moved on site simply to allow for the retention of the trees on development sites.

Whilst I accept that transplanting does cause damage, when
combined with appropriate aftercare such tree can often be a long term part of the landscape. The trees at Allanton Estate in Bonkle were moved by Steuart almost 200 years ago and most of them survive to this day ... this is certainly a lot better than what happens on many development sites... even those with beautifully written documentation by some of the most talented arborists. I am sure that we agree that it is one thing to produce an appropriated design ... it is another thing altogether to ensure that trees are appropriately protected and cared for.

We agree (This has never been an issue of contention. I have not suggested throwing the baby out with the bath water ... I have just suggested we remove the brown floaty stuff and use some fresh water Considering trees once the plans are drawn is a major problem in the design process and the standard addresses this well. In NSW the law already covers this and in spite of this it is not common practice. In part this falls back to town planning issues (DCP's). I am confident that this will improve with time and the Australian Standard will be an important part of this evolution.

Abe

Sean Freeman

If you care to ask around I'm reasonably confident you will find that I treat very few with contempt, and certainly not based on the weak evidence of written posts on an internet forum.

Everyone makes errors, me more than most.....my authority is strictly circumscribed by my incomplete level of understanding.

As I have written on a great many occaisions here and in other places I NEVER write with an angry "voice". my main intention in contributing is to provide what information I might have that I think is relevant and promote the adoption of improved methods and increase understanding ....not least my own.

Sean Freeman

ATTENTION....Full Standard now released....very strongly advise all those involved in managing trees on development sites, or offering advice to those engaged in anyway with the protection/retention of trees on development sites, to purchase this standard, read and apply it.

http://infostore.saiglobal.com/store...AS0733792294AT

Eric Frei

Great, I have been waiting because I have a genius idea to market.

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TrevMcRev

Thanks Sean

MTS247

Any changes from the draft version?

Eric Frei

Yeah, a one size fits all 12X DBH TPZ!

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MTS247

So they changed the formula?

I cant download it till monday

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"Just cause i don't use it, don't make it wrong!"

Sean Freeman

What they have done is remove the table from the draft in relation to calculating TPZ that had (from memory) 9XDBH and 10XDBH and 12XDBH for different "classifications of trees" and replaced it with 12 X DBH for all trees, reflects what was apparently one of the most common issues raised during the public comment on the draft.

MTS247

Ok little help please,
12x DBH is the TPZ "Diameter"
The SRZ is expressed as "Radius"

please let me know if i have the wrong end of the stick

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"Just cause i don't use it, don't make it wrong!"