The criteria set out in the Statutory biodiversity metric condition assessments table must be used to decide on the condition of Individual trees habitat, which is scored as follows:
| Condition | Score |
| Good | 3 |
| Moderate | 2 |
| Poor | 1 |
There are six criteria for assessing a tree’s condition. If a tree passes five or six of the criteria, it is in good condition. If it passes three or four of the criteria, it is in moderate condition. If it passes two or fewer of the criteria, it is in poor condition.
These are the six criteria to consider:
A – The tree is a native species (or at least 70% of the block are native species).
B – The tree canopy is predominantly continuous, with gaps in canopy cover making up <10% of total area and no individual gap being >5 m wide (individual trees automatically pass this criterion).
C – The tree is mature (or more than 50% of the block are mature).
D – There is little or no evidence of an adverse impact on tree health by human activities (such as vandalism, herbicide or detrimental agricultural activity). And there is no current regular pruning regime, so the trees retain >75% of expected canopy for their age range and height.
E – Natural ecological niches for vertebrates and invertebrates are present, such as deadwood, cavities, ivy and loose bark.
F – More than 20% of the tree canopy area is oversailing vegetation beneath.
The ‘Fairly Good’ and ‘Fairly Poor’ condition categories are not available for this habitat type.
Enhancement of this habitat is only possible by improving it so that it meets the criteria B, D and F. It is not possible or appropriate to enhance individual tree/s through meeting just one or two of these criteria, nor by meeting only A or C or E.
It is important that the species of each tree on site is properly listed by the developer. Here is the list of the native species defined by the Statutory Metric:
Bristol Tree Forum 