Impact of large woody debris used for flood mitigation on in-stream nutrient cycling and benthic macroinvertebrates.

Numerous recent flooding events in the UK have highlighted the need for flood mitigation measures. These include large scale engineering solutions and smaller scale natural attenuation methods such as the introduction of large woody debris (LWD) into streams. The latter have received increasing interest due to their low cost and visual appeal. Whilst research has shown that LWD can potentially be effective in preventing flooding, little work has been undertaken on its wider environmental impact, despite the fact that it may alter habitats and nutrient cycling.

This PhD project will look at the impact of LWD on in-stream nutrient cycling and benthic macroinvertebrate communities. Understanding the fate of nutrients in rivers is important because they receive inputs from both agricultural run-off and sewage treatment works, which can lead to degradation of the aquatic environment. Bed sediments are often the sites of most intensive nutrient cycling and they some natural capacity for rivers to self-cleanse. Macroinvertebrates living on and in these sediments also impact nutrient cycling. Addition of LWD to streams changes the hydrology, which impacts the sediments and macroinvertebrates, and consequently the nutrient cycling.

The project will use the existing natural flood attenuation scheme at our Brackenhurst campus, which is part of an ongoing project with the Environment Agency and Southwell Flood Forum to look at the effectiveness of LWD for flood prevention in the local agricultural catchment. A range of biogeochemical and macroinvertebrate sampling methods will be used. Sites upstream and downstream of LWD will be compared to analogous control sites in reaches without LWD. The findings will provide the first detailed understanding of the impact of LWD on habitats and nutrient cycling, which is essential for policy makers and catchment managers to make informed decisions about future deployment of such measures.

Specific qualifications/subject areas required of the applicants for this project
Entrants must have a first/undergraduate Honours degree, with an Upper Second Class or a First Class grade, in Environmental Science, Geoscience, Microbiology, or related subjects. Entrants with a Lower Second Class grade at first degree must also have a postgraduate Masters Degree at Merit.

This studentship competition is open to applicants who wish to study for a PhD on a full-time basis only. The studentship will pay UK/EU fees (currently set at £4,195 for 2017/18 and are revised annually) and provide a maintenance stipend linked to the RCUK rate (this is revised annually and is currently set at £14,553 for the academic year 2017/18) for up to three years. Applications from non-EU students are welcome, but a successful non-EU candidate would be responsible for paying the difference between non-EU and UK/EU fees. (Fees for 2017/18 are £12,900 for non-EU students and £4,195 for UK/EU students). The studentships will be expected to commence in October 2018.