When to select "individual trees"
When determining the baseline
You should use "Individual trees" when there is a tree (or a group or stand of trees) over 7.5cm in diameter at breast height (DBH). You should also use "individual tree" to show lines, blocks or groups of trees found within and around the perimeter of urban land.
You should use your judgement whether or not does not meet or contribute towards the definition of another broad habitat type (e.g. orchards, lines of trees or wood-pasture and parkland).
E.g if there is a tree in a sports pitch, then it should be recorded as an individual tree in a field of modified grassland. But if it's woodland, then the right type of woodland habitat should be selected and no individual trees should be recorded.
There are some exceptions to the above is
if there are ancient or veteran trees these must always be recorded individually, regardless of what habitat they appear in.
If the tree is over 30cm DBH and in a private garden you should follow the rules set out below
If the tree is over 30cm DBH and in a hedgerow / line of tree you should follow the rules set out below
If the tree is over 30cm DBH and in orchard and wood-pasture and parkland, you should follow the rules set out below
When determining future works
Most newly planted trees should be categorised as ‘small’. You should provide evidence to justify the input of larger size classe
How to place trees with the Biodiversity Net Gain Tool
On the map screen you will be able to select between the different tree sizes. These sizes are determined by the diameter of the trunk at breast height
Size Class | Diameter at breast height (DBH) (cm) |
Small | greater than 7.5cm and less than or equal to 30cm |
Medium | greater than 30cm and less than or equal to 60cm |
Large | greater than 60cm and less than or equal to 90cm |
Very Large | greater than 90cm |
If the tree is multi-stemmed you should record the largest stem.
You should select the right size and place the tree. You should record the habitats that are under the canopy (i.e. draw any habitat as if the tree wasn't there and then place the tree on top of it). Do not
The difference between "urban" trees and "rural" trees
Individual trees may be classed as ‘urban’ or ‘rural’. Typically, urban trees will be bound by (or near) hardstanding surface and rural trees are likely to be found in open countryside. You should make a judgement based on the degree of ‘urbanisation’ of habitats around the tree and assign the best fit for the location.
Special rules with gardens
If you are creating a private garden as part of your development, any tree planting within the created garden should not be included within post-development sheets of the metric. The habitat type ‘Urban – Vegetated garden’ should be used.
When you are recording the baseline for a garden, if there are trees in a vegetated garden, you should not include them if the tree is 30cm DBH or less.
Special rules with hedgerows and lines of trees
If you are planning to remove any trees that are 30cm DBH or greater, record these as individual trees.
Ancient Trees and Veteran Trees
Ancient and veteran trees can be found as individual trees or collections of trees in any setting.
Ancient trees have passed beyond maturity into an ancient life stage or are old in comparison with other trees of the same species which exhibit one or more of the following—
(i) demonstrably great age relative to others of the same species
(ii) changes to their crown and trunk development indicative of the ancient life stage
Veteran trees are mature trees that share physical and other characteristics in common with ancient trees, due to their life or environment, but are neither developmentally nor chronologically ancient. All ancient trees are veteran trees, but not all veteran trees are ancient. Veteran and ancient trees which have died are still recognised as such because they retain significant biodiversity value for many decades.
Veteran trees exhibit one or more of the following—
(i) significant decay features such as deadwood, hollowing or signs of advanced decay in the trunk or major limbs
(ii) a large girth, depending on and relative to species, site and management history
(iii) a high value for nature, especially in hosting rare or specialist fungi, lichens and deadwood invertebrates
Useful Resources (open in new window)
You can read more about the law regarding ancient and veteran trees here
See Appendix 10 and Appendix 2 for how to determine if a tree is veteran or ancient