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School of Geography

Understanding underground biomass in Japanese knotweed

Supervisors: Dr Karen Bacon ( and Dr Mark Smith

Understanding the extent of the underground biomass and rhizome/seed longevity in the soil is crucial to managing invasive non-native species. Japanese knotweed (Fallopia japonica) is suspected to have a large rhizome network that remains viable in the soil long after herbicide treatment has ceased. This has led to the frequently cited 7 m rule being used as a reason to deny mortgage applications on properties with infestations. However, this distance is not based on experimentation and requires further investigation. Depending on student’s interests, the project could (i) use ground penetrating radar to determine the extent of the rhizome network across a range of soil types and stand maturities; (ii) investigate the rate at which Japanese knotweed rhizome extends using historical and current satellite imagery and site investigation across a range of habitat types; (iii) investigate the longevity of buried rhizome material using herbicide treatment, burial and exhumation experiments; (iv) calculate cell death rate microscopically over the period of the research project to determine half-life and to model longevity; (v) investigate the depth that seeds/rhizomes of the each species are found across a range of soil types and conditions for a range of distances from parent plants.

Dr Bacon is happy to supervise projects relating to plant functional ecology; palaeoecology; plant–atmosphere interactions; invasive plants