My research develops and applies knowledge and tools for improving delivery of integrated catchment management across issues of water quality, flooding, resource use efficiency and water-energy links. My remit includes the lead of the Scottish Government five-year programme on Water and Renewable Energy. My background as a catchment biogeochemist gives an understanding across disciplines of hydrology, chemistry and ecosystems and I specialise in environmental pollution, especially relating to nutrient management.
My research aims to understand catchment biogeochemical processes affecting the interactions between landscapes, their management and the resulting impacts on water quality and quantity. My studies involve examining how biological, physical and chemical processes interact to determine the fate and impacts of nutrients and other potential pollutants, such as sediments and particulate bound contaminants.
It is increasingly important that we understand coupled factors of biogeochemistry to allow us to better predict and potentially control catchment processes to our benefit. Coupled nutrient cycling is a central theme to my research and provides a good example of ‘systems thinking’ at a process level.
However, catchment ‘systems thinking’ has to cross multiple scales to involve processes from surface interactions between soils and flowing waters to the decisions that land managers make at field to farm scales, to regional and national policy drivers.
This remains a key challenge in my work as theme leader for Managing Catchments and Coasts to provide the critical fine scale knowledge necessary to inform real world decision making at larger management and regulation scales.
As land use and environmental change pressures accumulate we will be looking increasingly to sound scientific principles of biogeochemistry to help manipulate catchment systems to function more efficiently.
This means learning to enhance natural biogeochemical function or understanding constraints of where to act in catchments to optimise growing demands for biodiversity, farming, energy, places to live and economic gain. Some highlights of my recent and ongoing work are given below.
I have sought to link understanding from nutrient and sediment monitoring in catchments with laboratory based experimentation and characterisation of soils, sediments and their reactions with water. This has been targeted to issues such as reducing nutrient losses from farmland and explaining rising DOC concentrations in upland soils.
I use novel combinations of analytical methods to study the dynamics of different nutrient forms (dissolved, particulate and organically-complexed) from sources, transport to in-river cycling. This feeds into the design of diffuse pollution mitigation methods aiming to reduce key sources and interrupt transport pathways.
Through upscaling I have then examined the cumulative effectiveness of these mitigation measures at field and catchment scales including appraisals of costs and other practicalities. My ‘systems biogeochemical approach’ has allowed me to address constraints of mitigation such as pollutant swapping between dissolved nutrient to gas release and between particulate to dissolved nutrient forms.
My work has shown that we cannot adopt riparian buffer strips to minimise nutrient delivery from farmland to waters without proper consideration of their management. Initial chemical studies showed high P solubility in buffer soils and further biogeochemical exploration then suggested an accelerated turnover of upslope P inputs by microbial processes.
Our improved biogeochemical process knowledge suggests a need for vegetative P mining to offset buffer P accumulation. These studies highlight riparian buffers as a critical interface for attaining multiple benefits for habitat, erosion trapping, bank stabilisation, tree shading and woody debris and wider recreational benefits.
This work aims to show that by coupling bank side and stream channel ecosystem services we can promote a more heterogeneous and resilient system against future coupled stressors of pollution and climate.
An efficient use of the P resource is crucial to sustaining agricultural production and minimising pollution of waters. My work unites aspects of promoting efficient crop acquisition of applied P, minimising losses from the field edge and recovering beneficial resources such as P from materials previously viewed as ‘wastes’ (such as sewage or anaerobic digestate).
This biogeochemical understanding is working to understand mechanisms such as how crops may compete with soils for sequestered soil P and how waste processing may optimise nutrient recovery. Read more details on the nutrient cycles page [2].
An improved knowledge of soil phosphorus concentrations is key to better management in matching agronomic inputs to crop requirements to minimise losses such as by soil P leaching. We are doing this with in partnership with the farming community, who are actively taking part in sampling to learn more about this resource. Learn about this project and how to get involved on the farmer led phosphorus sampling page [3].
Links:
[1] https://orcid.org/0000-0003-1483-376X
[2] https://www.hutton.ac.uk/research/themes/managing-catchments-and-coasts/nutrient-cycles
[3] https://www.hutton.ac.uk/research/themes/managing-catchments-and-coasts/farmer-led-phosphorus-sampling
[4] https://www.hutton.ac.uk/research/themes/managing-catchments-and-coasts
[5] http://www.theriverdee.org
[6] http://www.crew.ac.uk
[7] http://macronutrient-cycles.ouce.ox.ac.uk/
[8] http://www.evo-uk.org
[9] http://www.watercap.eu/WaterCAP.htm
[10] http://www.sniffer.org.uk/files/3013/4183/7999/ER18_Final_Project_Report.pdf
[11] http://a0768b4a8a31e106d8b0-50dc802554eb38a24458b98ff72d550b.r19.cf3.rackcdn.com/scho0612buwh-e-e.pdf
[12] http://www.cost869.alterra.nl