Dr A Smith
No more applications being accepted
Funded PhD Project (European/UK Students Only)
About the Project
The population of the World is expected to grow from 7.2 billion to 9.6 billion by 2050. Such rapid increases in population, changes in food consumption patterns, urbanisation and environmental degradation represent an unprecedented challenge to food and agricultural systems1. Intensively managed agricultural systems, such as on many livestock farms in Wales, can become less resilient to extreme events, such as drought or floods, as a result of the erosion of ecosystem functioning. In contrast, the presence of hedgerows and trees in pasture can increase livestock productivity through the provision of shelter, whilst creating a multifunctional landscape where synergies in agricultural or ecological niches may be exploited to sustainably intensify farming practices.
Typically, rainfall intercepted by the landscape is transferred to river channels and tributaries as both surface runoff and subsurface flow. However, land use and management practices driven by economic pressures to increase productivity can reduce water infiltration rates into soil and negatively impact upon the resilience of the landscape to flooding2. Evidence from small catchment (<10 km2) studies have shown that increasing agricultural intensity can result in larger peak flows in rivers increasing flooding potential3.
The inclusion of shelterbelts on improved pasture used for sheep production has been shown to have a significant impact on soil hydrological processes, increasing infiltration rates by 60 times when compared to non-sheltered areas up to 5 m from the shelterbelt edge; rates of surface runoff were also reduced3. However, major questions of hydrological function in silvopastoral systems remain to be addressed, in particular there is a serious gap in knowledge of how the behaviour of livestock influences the impact of trees. This project will use a chronosequence of strategically located shelterbelts across Wales to answer the following questions:
• How does the concentration of livestock adjacent to shelterbelts impact upon soil compaction, sward composition, productivity and root growth parameters that determine the key hydrological parameters of hydraulic conductivity and infiltration?
• At the hillslope scale, how does the position of trees influence the impact of livestock on hydrology and associated macronutrient cycling?
• Does the livestock compaction and the common placement of riverine trees at the bottom of hillslopes increase the risk of nutrient runoff into adjacent water-courses?
• How does the benefit of shelterbelts change with different soil type and depth profiles?
• How can the effectiveness of shelterbelts be optimised by identifying functional traits of trees that maximise water infiltration and soil hydraulic conductivity to reduce peak flows?
The successful candidate will be registered at Bangor University and be part of the Multi-Land (Enhancing Agricultural Productivity and Ecosystem Service Resilience in Multifunctional Landscapes) project funded by the Sêr Cymru National Research Network for Low Carbon Energy and the Environment (NRN-LCEE). The project is a collaboration between Aberystwyth and Bangor Universities, and NERCs Centre for Ecology and Hydrology. The network also benefits from input from Coed Cymru, Snowdonia National Park Authority and Natural Resources Wales as partners.
The project will be supervised by: Dr Andy Smith (Bangor University) and Dr Miles Marshall (Centre for Ecology and Hydrology, Bangor).
Funding Notes
Eligibility: Applicants should hold a minimum of a 2:1 classification UK Honours degree, or preferably a Master’s degree in subjects such as Forestry, Environmental Science or Natural Sciences. For further details please contact: Dr Andy Smith; [Email Address Removed]; 01248 382297 or Dr Miles Marshall; [Email Address Removed]; 01248 374500.
References
1Godfray et al. (2014) Food security and sustainable intensification. Phil. Trans. R. Soc. B, 369, 20120273.
2Pattison et al. (2014). The role of tributary relative timing and sequencing in controlling large floods. Water Resources Research, 50 (7), 5444-5458.
3Marshall et al. (2013). The impact of rural land management changes on soil hydraulic properties and runoff processes: results from experimental plots in upland UK. Hydrological Processes, 28 (4), 2617-2629.