Date/Time: 1st March 2016

Deborah Brady, School of Biology

Invasive alien species - the sustainability of the UK red squirrel population

Invasive alien species pose a huge threat to biodiversity across the globe. Here in the UK an iconic invasive species, the grey squirrel, is continuing to expand at the expense of our native red squirrel population. Across the UK, and at the forefront of the grey invasion in Northumberland, there has been continued effort to protect the remaining red squirrel populations.

Co-ordinated activity has monitored distribution changes over the last few years. These changes will be briefly described giving context for my research. To compliment these landscape scale surveys I have been investigating population responses to culling at a much smaller woodland habitat scale.

We had the unique opportunity to study a grey squirrel population in a recently invaded woodland. The cull process within this woodland was then closely monitored, creating a ‘cleared’ area into which the nearby red squirrel populations could potentially move. The surrounding red populations were tracked to detect any exploratory movements. Fieldwork has just recently been completed and so early findings can be described.

Uchenna Eqwu, School of Civil Engineering and Geosciences

The use of biomass extracts as low-cost additive supplements to improve the anaerobic digestion of lignocellulosic biomass

Lignocellulosic biomass comes from multicellular plants composed of lignin, hemicellulose and cellulose. These are the most abundant renewable materials suitable for sustainable biogas production. The nutrients required for plants growth are absorbed in trace concentrations from the soil by their roots. The addition of ‘expensive’ commercial trace elements to anaerobic digesters utilizing plant biomass for biogas (methane) production has been shown to increase the quantity of methane gas produced. These nutrients increase the activities of methane-producing bacteria in the anaerobic digesters.

In this research, the extraction of trace elements from empty cocoa pod and empty palm bunch was carried out. These extracts were used as supplements in 42-day batch anaerobic digestion experiments utilizing grass biomass as the lignocellulosic feedstock for methane production. A range of conditions were tested in triplicate according to the German standard protocol VDI 4630. The results showed that the biochemical methane potential (BMP) of the grass was 346, 408, 357, 379, 393 nmL CH4/gVS for the control, palm ash, cocoa ash, palm ash extract, cocoa ash extract, respectively.

Further experiments to confirm the sustainability of cocoa extract supplements in continuously stirred tank reactors (CSTRs), feed daily over 3 hydraulic residence times ( HRT) of 25 days each (total 75 days), showed that the cumulative volume of methane gas produced in the reactor supplemented with 2% (w/v) cocoa pod extract was 6% higher than the control. Conversely, cumulative volume of CH4 in the reactor dosed with commercial trace element actually decreased by 7% due to inhibition.  Therefore, the addition of biomass extracts to anaerobic digesters could potentially promote sustainable and more efficient biomethanation of lignocellulose biomass, and contribute to improved bioenergy recovery form wastes and energy crops.

Mhari Barnes, Eleanor Starkey and Liz Lewis, School of Civil Engineering and Geosciences

Flooding: What’s the solution?

The UK has experienced a number of flood events over the last decade. This includes the recent devastations caused by Storm Desmond, Eva and Frank this winter across the north of England, when record precipitation totals and river levels were observed in a number of locations.

Climate change projections also indicate that we are likely to experience wetter winters and heavier storms during summer. Due to the complexity of the environment, hydrologists and catchment scientists are continually trying to understand how each river system responds, develop sustainable flood risk management solutions and use computer models to predict future scenarios.

Three PhD researchers from the School of Civil Engineering and Geosciences will provide an overview of how their innovative projects are contributing to this process in order to provide a better understanding of the solutions to flooding. This includes:

• carrying out fieldwork to collect rainfall, river flow and flood related observations
• involving local communities who are at risk of flooding themselves through a ‘community-based’ or ‘citizen science’ approach
• understanding how natural flood risk management features perform during heavy rainfall events. These features can provide an alternative or be used alongside traditional or ‘hard’ defences
• using national scale modelling to understand catchment behaviour and assess likely changes to river flows and flood frequency under climate chang
• developing new visualisation tools for effectively communicating flood research