TPOs: Go to this page and you will find a link to a list of trees with TPOs.
Conservation areas: The Conservation Area designation automatically confers blanket protection to every tree within its parameters. A tree in this instance is defined as anything with a stem diameter above 75mm when measured at 1.5 metres. This does not apply to hedges in Conservation Areas.
A person wishing to carry out work to a tree (as defined above) that falls in a Conservation Area must send the local planning authority a notice of their intention to do so. This is referred to as a Section 211 Notice, and its purpose is to allow the LPA six weeks in which to evaluate the tree and respond, if necessary, with a TPO to prevent the work or control the extent of the work proposed.
Go to this page to find conservation areas