Self-funded MRes – A spectral assessment of ash dieback in a managed woodland

Self-funded MRes – A spectral assessment of ash dieback in a managed woodland

The study site is Bradfield Woods in Suffolk, eastern England. Bradfield Woods is a rare example of managed mixed species coppice, dominated by common ash (Fraxinus excelsior), hazel (Corylus avellana), birch (Betula spp.) and alder (Alnus glutinosa) which is typically cut on a rotation of 20 to 25 years. Scattered standard trees (non-coppiced, mature trees) are present in all coppice compartments, and there are some areas of mature woodland.

By 2017 Bradfield Woods had been infected by ‘ash dieback’, caused by the fungus Hymenoscyphus fraxineus. This was having particularly notable effects on the coppiced ash stools, often leading to the death of the ash plants (see Fuller et al., 2019). Field survey in 2017 recorded the status of 85 ash trees under various states of infection, whilst hand-held spectroscopy data covering the visible to short-wave infrared parts of the spectrum were recorded for leaves in neighbouring Ager Fen. This can be compared with UAV-derived photogrammetry data and satellite data from PlanetScope and Sentinel-2 from the same period.

The research questions to be addressed will be:

• Which parts of the spectrum most clearly distinguish affected canopy and is there an optimum band index that can be used or developed?

• Can the more suitable band indices be applied to satellite data to successfully map ash dieback distribution and infection level?

• If so, can the extent of ash dieback spread be monitored in satellite data from 2021 for Bradfield Woods or other woods in East Anglia (e.g. Monks Wood)?

In addition to our main entry requirements the applicant for this MRes project must have good remote sensing knowledge in order to interpret the various data sets. The candidate will also need experience with remote sensing or GIS software and be prepared to learn statistics and modelling using R.

Closing date for applications 31 October 2021.

Further reading:

Fuller, R.J., Casey, D., Melin, M., & Hill, R.A. (2019). Ash dieback and associated vegetation changes in the coppice of Bradfield Woods. Quarterly Journal of Forestry, 113, 102-108.

Chan , A.H.Y., Barnes , C., Swinfield, T., & Coomes, D.A. (2020). Monitoring ash dieback (Hymenoscyphus fraxineus) in British forests using hyperspectral remote sensing. Remote Sensing in Ecology and Conservation, doi: 10.1002/rse2.190