Ash dieback management plan

A random sample of ash trees at various locations within the borough was made in 2019 and 2020. A survey of the extent of dieback was recorded with 4 stages of dieback:

1. 100% of the crown remains (meaning the tree not infected),
2. 75% of crown remains (meaning the tree is infected and up to 25% of the crown has died back - Stage 1)
3. 50% of crown remains (meaning the tree is infected and up to half the crown is dead - Stage 2)
4. 25% of crown remains (meaning the tree is infected and up to 75% of the crown is dead - Stage 3)
5. 0% (meaning the tree is virtually or totally dead - Stage 4)

These surveys were undertaken during mid-September when the full extent of dieback is apparent but before leaves have naturally fallen.

Survey results

The table below summarises the last sample assessment of the councils Ash tree population.

Assuming this random sample of surveyed ash trees is representative of the total a number of important points can be made:

1. Most ash trees (excluding Leckhampton Hill) did not show signs of ash die back.
2. No trees had yet actually died as a result of dieback.
3. Approximately 2/3 of trees had at least 75% of their crown remaining and 10% of trees have up to 50% of their crowns intact.
4. Worst affected trees were on Leckhampton Hill have only 25% or less of their crowns intact.
5. Excluding Leckhampton Hill, the rate of deterioration of the ash tree crowns was slow.
6. The severity of contamination of ash dieback on Leckhampton Hill was considerably worse than other surveyed areas.
7. The rate of deterioration of ash crowns on Leckhampton Hill is faster than elsewhere

Observation, appear to show significant contamination of trees and associated deterioration on Leckhampton Hill which reflects the picture of roadside and other rural ash trees in the south of England. Non-empirical evidence suggests that the same lower-degree of intensity of ADB is being experienced in other urban areas in the south of Britain.

Again, observation appears to show that dead trees do not readily fail prior to significant deterioration of structurally supporting roots. However, the mechanism for felling of advanced decay trees will likely require vehicular machinery (unless tree work contractors can identify other methods of self-preservation).

Further, smaller surveys were undertaken in 2021 and 2022. However, such surveys have not demonstrated they are adding value to the overall management of the Ash tree population assets of the council. The approach therefore is the ongoing observations outlined earlier in this management plan supported by the record of works (to address ash die-back) being recorded.

The felling of ash trees has primarily been adjacent to (or within 10 metres of) the busiest foot paths along Leckhampton Hill and within falling distance of Cirencester Road.