Aquatic and gaseous carbon exchanges in managed land-systems in the British Uplands
Prof R C Chiverrell, University of Liverpool
Dr Joshua Dean, University of Liverpool
- External Supervisors:
Prof R C Chiverrell, University of Liverpool, firstname.lastname@example.org
- CASE Partner: Confirmed CASE Partner: Dr Siân Whitehead, Research Scientist, Game & Wildlife Conservation Trust
Application deadline: 10 January 2020
The British Uplands combines a range of uses, providing hill-sheep grazing, managed moorlands for grouse shooting and sustaining commercial forestry, all provoking often-heated debate. Prescribed burning, typically as a series of regular low intensity cool burns, maintains mosaics of differing aged heather and other plants on some moorlands. The effects of high stock grazing pressure led to the terms ‘wet desert’ and ‘sheep-wrecked’ widely coined for the species-poor British uplands. Climate warming has also increased the wildfire threat augmented by availability of old growth biomass. These moorlands also sustain extensive upland peat and significant carbon (C) stores, 3.8m km2 in the boreal – northern temperate region alone storing 500 ± 100 Gt of global Carbon. Rewilding initiatives by reducing stock densities and reducing or restricting the use of prescribed burning, means that these are very much times of change for the British uplands. Research has targeted the solid phase measuring C accumulation (Marrs et al., 2019), water-borne DOC/POC (Li et al., 2019) and gaseous (Dinsmore et al. 2010). Knowledge gaps include a lack of geographical spread and integrated quantification of the solid, aquatic and gaseous C cycle phases for these moorlands. This research will draw on a range of peat moorlands, including the long-term grazed/ungrazed Hard Hill plot experiments at Moor House National Nature Reserve (Pennines). Other sites would cross gradients of land management to quantify C and other nutrient cycling for these value landscapes to explore the controls over these critical Carbon stores.Project Summary:
The project would:
1. Liaise and engage, via the Game & Wildlife Conservation Trust (GWCT), with landowners to identify an appropriate variety of moorlands, with a range of current and past land management that sustain thicknesses of peat. Knowledge exchange activities facilitated with the GWCT over C cycle implication of land management practices.
2. Undertake comprehensive solid phase inventories for the peat deposits at these sites. This would involve multiple and replicate coring, C and other nutrient analyses, peat chronologies from Spheroidal Carbonaceous Particles (SCPs), 210Pb dating, airfall stable Pb profiles and 14C dating. The product would be C inventories for these peatlands and millennial time-scale reconstructions of peat accumulation.
3. Develop cost effective (Arduino-based) continuous monitoring of DOC/POC aquatic fluxes from managed peatlands. Support the automated monitoring with campaign style sampling and laboratory analysis for DOC and the sources of water-borne carbon (14C analyses).
4. Install Arduino based Greenhouse Gas (GHG) flux chamber systems that we have developed to monitor CO2 and CH4 fluxes from selected peatlands. Support these continuous automated monitoring with campaign-based mobile flux measurements using a high resolution and high precision Los Gatos Microportable greenhouse gas analyser.
5. Use experimental 14C isotope analysis and dating to identify the source of C flux from these peatlands e.g. old carbon from deep peats (Dean et al., 2018).
6. The aim is to quantify existing and new empirical models for the fluxes and exchanges in C for differing land managements for upland British moorlands to better inform future land management strategies.References:
Dean, J.F., van der Velde, V., Garnett, M.H., Dinsmore, K.J., Lessels, J.S., Street, L., Subke, J.-A., Washbourne, I., Wookey, P.A., Billett, M.F. (2018). Abundant pre-industrial carbon detected in Canadian Arctic headwaters: implications for the permafrost carbon feedback. Environmental Research Letters, 13(3), 034024.
Dinsmore, K.J., Billett, M.F., Skiba, U.M., Rees, R.M., Drewer, J., Helfter, C. (2010) Role of the aquatic pathway in the carbon and greenhouse gas budgets of a peatland catchment. Global Change Biology, 16, 2750-2762.
Li C, Holden J, Grayson R. 2019. Sediment and fluvial particulate carbon flux from an eroding peatland catchment. Earth Surface Processes and Landforms.
Marrs, R.H., Marsland, E.-L., Lingard, R., Appleby, P.G., Piliposyan, G.T., Rose, R.J., O’Reilly, J., Milligan, G., Allen, K.A., Alday, J.G., Santana, V., Lee, H., Halsall, K., Chiverrell, R.C. (2019) Experimental evidence for sustained carbon sequestration in fire-managed, peat moorlands. Nature Geoscience, 12 (2), pp. 108-112.
Marrs, R.H., Sánchez, R., Connor, L., Blackbird S., Rasa, J. & Rose, R.J. (2018). Effects of removing sheep grazing on soil chemistry, plant nutrition and forage digestibility: lessons for rewilding the British uplands. Annals of Applied Biology, 173, 294–301.
Monbiot, G. (2013). Feral: Searching for enchantment on the frontiers of Rewilding. Allen Lane, London, UK.