About the project
The UK supports 85% of the World's chalk streams, but a long history of human modification has resulted in their decline. River and floodplain restoration can deliver a range of societal benefits, but to date our understanding of natural chalk stream ecosystems is limited. This PhD will use a suite of novel approaches to reconstruct natural chalk river and floodplain ecosystems in support of their restoration.
Chalk rivers and streams are highly diverse and novel freshwater ecosystems, deriving most of their flow regime from groundwater. The challenge is that centuries of human modifications have largely obliterated the evidence for the habitats, morphology and processes that define the natural range of chalk streams. Nevertheless, it is essential to restoration practice to be able to articulate the potential range of habitats and services that future communities can expect from restored channel and floodplain restoration projects in chalk catchments. This studentship will deploy a suite of approaches to reconstruct past chalk stream and floodplain environments. This will help better inform and define potential reference conditions for chalk streams.
GIS based spatial analysis will be used to identify the broad range of chalk river and floodplain types, from which case studies will be selected for detailed analysis. Channel morphology will be reconstructed from palaeohydrological methods using LiDAR, topographic survey, floodplain coring and Ground Penetrating Radar (GPR). Palaeoecology will utilise a suite of proxy and palaeoecological analyses, including pollen, macrofossil, diatom and chironomid fossil counts possibly supported by ancient DNA analysis. Dating of sediment cores will utilise radioisotope methods (137Cs, 210Pb, 14C) to identify time periods before, during and after major human modification to the landscape and to the river and floodplain systems. Site specific modelling of flood storage and c-storage might also be possible. Together, these lines of evidence can provide evidence for natural channel morphology biodiversity and carbon sequestration.
This research project forms part of the implementation plan for the National Chalk Streams Strategy and will support future restoration planning and actions in chalk rivers of the UK.
