Perhaps not the most thrilling of topics, unless of course you’re subject to one or more on trees in your garden and in this case they may not be thrilling but rather, slightly annoying or you’re a designer working within spaces where trees might be subject to them or you’re a Tree Officer with the local council and this is you’re bread and butter, in which case please note this is a very general blog post and a full reading list lies below!

A Tree Preservation Order, or TPO, is a piece of legislation instigated in 1947 as part of the establishment of the modern Town and Country Planning system.
What it means in reality is that a TPO’d tree is protected from being cut down, being uprooted, topped, lopped, wilfully damaged, wilfully destroyed by anyone, the council included. That’s not to say it can never have work done to it or be removed but as a general rule there are quite a few hoops to be jumped through if you want to make any changes to such a tree.
Legislation has kept up momentum and there have been a number of amendments and reissues of it with The Town and Country Planning Act – 1990, The Planning and Compensation Act 1991, The Town and Country (Trees) Regulations – August 1999 and the most recent being 6th April 2012.
Like any legislation is has many ins and outs, special clauses for specific types of land and tree groups but the basic principle is to protect trees and woodland of outstanding or special amenity value.
Who decides on a tree being TPO’d?
Well the local planning authority usually makes the actual order although a plethora of bodies and authorities have the capactity under certain circumstances – the Secretary of State, National Parks authority, The Broads (Norfolk and Suffolk) authority, Enterprise and Urban Development associations and so on. Unsurprisingly the Forestry commission have a final say in TPO’s being applied to trees on land they have in interest in!
Though the LPA makes the decision and probably many of the suggestions in fact, any member of the public can ask for a tree to be considered for a TPO.

How do they decide?
There are many reasons for protection of a woodland or a tree though the main scope is to protect publicly visible resources. Screening, ecology, wildlife habitat, benefits for the future, intrinsic beauty, contribution to the landscape, scarcity, rarity and so on are all considerations. There are also rules of thumb :-
1.) All trees in a Conservation Area are protected – it’s a blanket protection for any tree whether on public or private land.
2.) Trees should have a trunk girth of 75mm and above at 1m from the ground are eligible for protection, though in woodland protection can apply to any tree of any age and size.
3) It is considered inappropriate to TPO a dead, dying or diseased tree!
Then what?
The person making the TPO visits the tree or tree group to consider if a TPO is required and appropriate. A TPO form is completed showing a map reference and boundaries, a description of why the tree(s) are suitable for a TPO, photographs and other relevant information. There is a lot of work that goes into assigning a TPO.
All the information is ‘served’ on the owner of the tree or land affected as well as being kept as a matter of public record.
What if I have a tree in the garden with a TPO on it, can I do anything to it?
Well YES and NO.
YES if the tree, or part of it, is dangerous or dead you can do necessary works on it without consent, though it’s advisable to notify your Tree Officer, in writing, 5+ days in advance if you are planning to do such work.
NO in that any remedial work to the tree or entire removal requires permission, plenty of form filling and written consent from, you guessed it, the LPA! To do it without is not a case of whoops we didn’t know or any such platitudes.
The simplest route is to call your local tree officer and ask him. The fines are substantial (up to £20,000) and per tree and it can happen to the best of us!
http://www.bbc.co.uk/news/uk-england-oxfordshire-12663088

Key changes from 6th April 2012:-
It must be said that this set of consolidating regulations supersedes all previous ones. Nice!
1.) Immediate (provisional) protection for the tree – there’s no waiting about the tree is protected immediately, whilst all the information gathering, discussions, challenges and representation take place (up to 6 months). Then full protection is, or is not, issued.
2.) Notification of anyone other than the owner/occupier of land upon which the tree/woodland sits is now discretionary. No more reams of paper being sent to occupants in a block of flats for a TPO’d tree round the corner.
3.) Exemptions used to include ‘dying trees’ but this is such a moveable feast it’s been removed. Removal without consent of dead branches in a living tree are however now allowed.
4.) Consents for work last for a default 2 years but can be individualised by the issuing LPA.
5.) Prior to 1999 the issuing authority could issue an ‘article 5 certificate’ which removed their liability to pay compensation under the order (!) this has been revoked. There is a standard scale of compensation if removals or works consent is refused.
http://www.communities.gov.uk/documents/planningandbuilding/pdf/tposguide.pdf
http://www.legislation.gov.uk/uksi/2012/605/introduction/made
Main changes at 6th April 2012
http://www.communities.gov.uk/documents/planningandbuilding/pdf/2127685.pdf