Tel: +44 (0)1355 270024 (direct dial) +44(0)1355 223332 (Reception)
- Development and application of methods to recover samples of carbon dioxide for 14C analysis from different environments for understanding the source and rates of carbon cycling (e.g. soil respiration, deep peat CO2, evasion CO2 from surface waters, atmospheric CO2)
- Radiocarbon analysis of methane
- Carbon cycling and accumulation in soils/peats
- Applications of bomb-14C, e.g. to age the surface layers of peats
- Application of radiocarbon analysis for establishing chronologies and investigating the terrestrial carbon cycle
- Ramped combustion of samples for radiocarbon analysis
- Application of 14C analysis in soil meso-fauna studies
I joined the NERC Radiocarbon Facility in 2000 after completing a PhD investigating organic carbon storage in a British moorland ecosystem. My research interests have continued to be in the field of carbon cycling, but have expanded from terrestrial environments to other areas such as aquatic ecosystems. Understanding the carbon cycle is immensely important in order for us to exist sustainably on Earth, and a large part of my research concerns the use of radiocarbon methods for determining the age, source and rate of turnover of different forms of carbon within the carbon cycle. These measurements have particular importance for helping us understand how ecosystems will respond to climate change.
A particular focus of mine has been the development of novel radiocarbon methods that allow either new types of samples to be collected, or improve the collection of existing sample types. For example, I have led the development of a range of different methods to collect the greenhouse gases carbon dioxide and methane for radiocarbon analysis, from both terrestrial and aquatic environments. These methods have usually been developed in response to requests from Facility users, and have been applied to undertake some ground-breaking research with our collaborators (see Publications).
I have been fortunate to work with some great scientists from across the UK and beyond, but am always keen to establish new collaborations and deploy our methods to answer important scientific questions.
1998 PhD Newcastle University
1992 BSc Newcastle University (Anson Memorial prize)
Dean JF, Van Der Velde Y, Garnett MH et al. (2018) Abundant pre-industrial carbon detected in Canadian Arctic headwaters – implications for the permafrost carbon feedback. Environmental Research Letters, 13, 034024.
Cooper MDA, Estop-Aragones C, Fisher JP et al. (2017) Limited contribution of permafrost carbon to methane release from thawing peatlands. Nature Climate Change, 7, 507-511.
Garnett MH, Billett MF, Gulliver P, Dean JF (2016) A new field approach for the collection of samples for aquatic 14CO2 analysis using headspace equilibration and molecular sieve traps: The Super Headspace Method. Ecohydrology, 9, 1630-1638.
Garnett MH, Gulliver P, Billett MF (2016) A rapid method to collect methane from peatland streams for radiocarbon analysis. Ecohydrology, 9, 113-121.
Moore S, Evans CD, Page SE et al. (2013) Deep instability of deforested tropical peatlands revealed by fluvial organic carbon fluxes. Nature, 493, 660-664.
Hartley IP, Garnett MH, Sommerkorn M et al. (2012) A potential loss of carbon associated with greater plant growth in the European Arctic. Nature Climate Change, 2, 875-879.
Examples of current projects
I am currently collaborating on PRIMETIME, a large NERC-funded project led by Professor Phil Wookey at the University of Stirling. PrimeTime is examining the potential impact of global warming on Arctic ecosystems, and whether this will lead to less carbon being held in the soil. My role is to oversee the radiocarbon analytical aspects of the project, which involves measurements on respired carbon dioxide and dissolved organic carbon and are central to the project. For more details, please see our Projects page, and the PRIMETIME website.
Understanding fluvial carbon cycling in karst landscapes
I am a co-investigator on a NERC-funded project led by Professor Susan Waldron (University of Glasgow) entitled: “Addressing a significant knowledge gap in fluvial system atmospheric CO2 efflux: the contribution from karst landscapes”. Karst landscapes contain vast stores of carbon, but the role of fluvial systems in these landscapes and their contribution to atmospheric carbon dioxide has been largely overlooked. In this project we are quantifying the emission of carbon dioxide from rivers draining a karst landscape in southern China, and measuring the radiocarbon concentration in order to investigate the sources, age and rates of carbon cycling.
Plant growth chamber
My in-house research currently includes the development of an automated plant growth chamber for the production of fresh organic matter that is depleted in radiocarbon. The material produced by the plant growth chamber will be used as an isotopic tracer in experiments investigating the fate and turnover of carbon in different environments. For instance, we have previously used 14C-depleted charcoal in order to investigate the rate of decay of biochar. We discovered a “negative priming effect” associated with the biochar, which has implications for the turnover of this material in soils. The use of a 14C-depleted tracer has significant advantages over other methods, in that is relatively cheap to undertake, and the processes being examined are im
mune to isotopic fractionation effects (since radiocarbon results are corrected for fractionation).
Automation of molecular sieve carbon dioxide sampling methods
A large part of my role involves overseeing the Facility’s molecular sieve carbon dioxide sampling programme. Working with Josanne Newton, we continuously strive to improve our methods in order to provide the best possible results. Recent improvements mean that smaller samples can now be dated reliably.
We are currently part-way through a programme to automate our methods, having custom-built a rig for the automatic recharging of our molecular sieve traps (increasing the number that can be prepared per day, and greatly freeing up operator time for other activities).
We have also recently built a prototype system for automatic field sample collection using the molecular sieve traps, and an automated rig for recovering the sample carbon dioxide from the traps which is in the final phase of development.
2003-2007 Susie ML Hardie (Fawley). Isotopic (13C and 14C) tracers in ecosystem respiration. University of Glasgow
Full publication list
- Soulet G, Hilton R, Garnett MH, Dellinger M, Croissant T, Ogrič M, Klotz S (In press) Technical note: in situ measurement of flux and isotopic composition of CO2 released during oxidative weathering of sedimentary rocks. Biogeosciences:
- Gavazov K, Albrecht R, Buttler A, Dorrepaal E, Garnett MH, Gogo S, Hagedorn F, Mills RTE, Robroek BJM, Bragazza L (In press) Vascular plant-mediated controls on atmospheric carbon assimilation and peat carbon decomposition under climate change. Global Change Biology:
- Newsham KK, Garnett MH, Robinson CH, Cox F (2018) Discrete taxa of saprotrophic fungi respire different ages of carbon from Antarctic soils. Scientific Reports 8(1): 7866
- Estop-Aragones C, Cooper MDA, Fisher JP, Thierry A, Garnett MH, Charman DJ, Murton JB, Phoenix GK, Treharne R, Sanderson NK, Burn CR, Kokelj SV, Wolfe SA, Lewkowicz AG, Williams M, Hartley IP (2018) Limited release of previously-frozen C and increased new peat formation after thaw in permafrost peatlands. Soil Biology & Biochemistry 118: 115-129
- Dean JF, van der Velde Y, Garnett MH, Dinsmore KJ, Baxter R, Lessels J, Smith P, Street L, Subke J-A, Tetzlaff D, Washbourne I, Wookey PA, Billett MF (2018) Abundant pre-industrial carbon detected in Canadian Arctic headwaters – implications for the permafrost carbon feedback. Environmental Research Letters 13: 034024
- Bordy EM, Bowen DA, Moore J, Garnett MH, Tsikos H (2018) A Holocene "frozen accident": Sediments of extreme paleofloods and fires in the bedrock-confined upper Huis River, Western Cape, South Africa. Journal of Sedimentary Research 88: 696-716
- Andresen LC, Domínguez MT, Reinsch S, Smith AR, Schmidt IK, Ambus P, Beier C, Boeckx P, Bol R, de Dato G, Emmett BA, Estiarte M, Garnett MH, Kröel-Dulay G, Mason SL, Nielsen CS, Peñuelas J, Tietema A (2018) Isotopic methods for non-destructive assessment of carbon dynamics in shrublands under long-term climate change manipulation. Methods in Ecology and Evolution 9: 866-880
- Dean JF, Billett MF, Murray C, Garnett MH (2017) Ancient dissolved methane in inland waters revealed by a new collection method at low field concentrations for radiocarbon (14C) analysis. Water Research 115: 236-244
- Cooper MDA, Estop-Aragones C, Fisher JP, Thierry A, Garnett MH, Charman DJ, Murton JB, Phoenix GK, Treharne R, Kokelj SV, Wolfe SA, Lewkowicz AG, Williams M, Hartley IP (2017) Limited contribution of permafrost carbon to methane release from thawing peatlands. Nature Climate Change 7: 507-511
- Campeau A, Bishop K, Billett MF, Garnett MH, Laudon H, Leach JA, Nilsson MB, Öquist MG, Wallin MB (2017) Aquatic export of young dissolved and gaseous carbon from a pristine boreal fen: implications for peat carbon stock stability. Global Change Biology 23: 5523-5536
- Walker TN, Garnett MH, Ward SE, Oakley S, Bardgett RD, Ostle NJ (2016) Vascular plant presence promotes ancient peatland carbon loss under climate warming. Global Change Biology 22: 1880-1889
- Tilston EL, Ascough PL, Garnett MH, Bird MI (2016) Quantifying charcoal degradation and negative priming of soil organic matter with a radiocarbon-dead tracer. Radiocarbon 58: 905-919
- Garnett MH, Gulliver P, Billett MF (2016) A rapid method to collect methane from peatland streams for radiocarbon analysis. Ecohydrology 9: 113-121
- Garnett MH, Billett MF, Gulliver P, Dean JF (2016) A new field approach for the collection of samples for aquatic 14CO2analysis using headspace equilibration and molecular sieve traps: The Super Headspace Method. Ecohydrology 9(8): 1630-1638
- Muir GKP, Hayward S, Tripney BG, Cook GT, Naysmith P, Herbert BMJ, Garnett MH, Wilkinson M (2015) Determining the biomass fraction of mixed waste fuels: a comparison of existing industry and 14C-based methodologies. Waste Management 35: 293-300
- Hill PW, Garnett MH, Farrar J, Iqbal Z, Khalid M, Soleman N, Jones DL (2015) Living roots magnify the response of soil organic carbon decomposition to temperature in temperate grassland. Global Change Biology 21: 1368-1375
- Billett MF, Garnett MH, Dinsmore KJ (2015) Should aquatic CO2 evasion be included in contemporary carbon budgets for peatland ecosystems? Ecosystems 18: 471-480
- Vihermaa L, Waldron S, Garnett MH, Newton J (2014) Old carbon contributes to aquatic emissions of carbon dioxide in the Amazon. Biogeosciences 11: 3635-3645
- Leith FI, Garnett M, Dinsmore KJ, Billett M, Heal K (2014) Source and age of dissolved and gaseous carbon in a peatland–riparian–stream continuum: a dual isotope (14C and d13C) analysis. Biogeochemistry 119: 415-433
- Evans CD, Page SE, Jones TH, Moore S, Gauci V, Laiho R, Hruška J, Allott TEH, Billett MF, Tipping E, Freeman C, Garnett MH (2014) Contrasting vulnerability of drained tropical and high-latitude peatlands to fluvial loss of stored carbon. Global Biogeochemical Cycles 28: 1215-1234
- Barlow NLM, Long AJ, Saher MH, Gehrels WR, Garnett MH, Scaife RG (2014) Salt-marsh reconstructions of relative sea level change in the North Atlantic during the last 2000 years. Quaternary Science Reviews 99: 1-16
- Moore S, Evans CD, Page SE, Garnett MH, Jones TG, Freeman C, Hooijer A, Wiltshire AJ, Limin SH, Gauci V (2013) Deep instability of deforested tropical peatlands revealed by fluvial organic carbon fluxes. Nature 493: 660-664
- Hartley IP, Garnett MH, Sommerkorn M, Hopkins DW, Wookey PA (2013) The age of CO2released from contrasting ecosystems during the Arctic winter. Soil Biology & Biochemistry 63: 1-4
- Garnett MH, Murray C (2013) Processing of CO2 samples collected using zeolite molecular sieve for 14C analysis at the NERC Radiocarbon Facility (East Kilbride, UK). Radiocarbon 55(2-3): 410-415
- Garnett MH, Hardie SML, Murray C, Billett MF (2013) Radiocarbon dating of methane and carbon dioxide evaded from a temperate peatland stream. Biogeochemistry 114: 213-223
- Hartley IP, Garnett MH, Sommerkorn M, Hopkins DW, Fletcher BJ, Sloan VL, Phoenix GK, Wookey PA (2012) A potential loss of carbon associated with greater plant growth in the European Arctic. Nature Climate Change 2: 875-879
- Gehrels WR, Callard SL, Moss PT, Marshall WA, Blaauw M, Hunter J, Milton JA, Garnett MH (2012) Nineteenth and twentieth century sea-level changes in Tasmania and New Zealand. Earth and Planetary Science Letters 315-316: 94-102
- Garnett MH, Hardie SML, Murray C (2012) Radiocarbon analysis of methane emitted from the surface of a raised peat bog. Soil Biology & Biochemistry 50: 158-163
- Garnett MH, Dinsmore KJ, Billett MF (2012) Annual variability in the radiocarbon age and source of dissolved CO2 in a peatland stream. Science of the Total Environment 427-428: 277-285
- Billett MF, Garnett MH, Dinsmore KJ, Dyson KE, Harvey F, Thomson AM, Piirainen S, Kortelainen P (2012) Age and source of different forms of carbon released from boreal peatland streams during spring snowmelt in E. Finland. Biogeochemistry 111: 273-286
- Billett MF, Dinsmore KJ, Smart RP, Garnett MH, Holden J, Chapman P, Baird AJ, Grayson R, Stott AW (2012) Variable source and age of different forms of carbon released from natural peatland pipes Journal of Geophysical Research 117: G02003, doi:02010.01029/02011JG001807.
- Subke J-A, Voke NR, Leronni V, Garnett MH, Ineson P (2011) Dynamics and pathways of autotrophic and heterotrophic soil CO2 efflux revealed by forest girdling Journal of Ecology 99: 186-193
- Hardie SML, Garnett MH, Fallick AE, Rowland AP, Ostle NJ, Flowers TH (2011) Abiotic drivers and their interactive effect on the flux and carbon isotope (14C and δ13C) composition of peat-respired CO2. Soil Biology & Biochemistry 43: 2432-2440
- Garnett MH, Hardie SML, Murray C (2011) Radiocarbon and stable carbon analysis of dissolved methane and carbon dioxide from the profile of a raised peat bog. Radiocarbon 53(1): 71-83
- Garnett MH, Bol R, Bardgett RD, Wanek W, Bäumler R, Richter A (2011) Natural abundance radiocarbon in soil microbial biomass: results from a glacial foreland. Soil Biology & Biochemistry 43: 1356-1361
- Ball T, Smith KA, Garnett MH, Moncrieff JB, Zerva A (2011) An assessment of the effect of Sitka Spruce (Picea sitchensis Bong. Carr) plantation forest cover on carbon turnover and storage in a peaty gley soil, using radiocarbon tracing. European Journal of Soil Science 62: 560-571
- Heinemeyer A, Croft S, Garnett MH, Gloor E, Holden J, Lomas MR, Ineson P (2010) The MILLENNIA peat cohort model, predicting past, present and future soil carbon budgets and fluxes under changing climates in peatlands. Climate Research 45: 207-226
- Hardie SML, Garnett MH, Fallick AE, Stott AW, Rowland AP, Ostle NJ (2010) Testing the use of septum-capped vials for 13C isotope abundance analysis of carbon dioxide. Rapid Communications in Mass Spectrometry 24: 1805-1809
- Garnett MH, Hartley IP (2010) A passive sampling method for radiocarbon analysis of atmospheric CO2 using molecular sieve. Atmospheric Environment 44: 877-883
- Garnett MH, Harkness DD, Miller BF, Fallick AE, Bryant CL (2010) NERC radiocarbon age measurements determined by radiometric counting 1996-2005. Radiocarbon 52(4): 1553-1555
- Garnett MH, Bradwell T (2010) Use of bomb-14C to investigate the growth and carbon turnover rates of a crustose lichen. Geografiska Annaler 92 A: 53-63
- Garnett MH (2010) The carbon age. In: NERC Planet Earth. p 20-21
- Briones MJI, Garnett MH, Ineson P (2010) Soil biology and warming play a key role in the release of 'old C' from organic soils. Soil Biology & Biochemistry 42: 960-967
- Billett MF, Garnett MH (2010) Isotopic composition of carbon dioxide lost by evasion from surface water to the atmosphere: Methodological comparison of a direct and indirect approach Limnology and Oceanography: Methods 8: 45-53
- Hartley IP, Hopkins DW, Garnett MH, Sommerkorn M, Wookey PA (2009) No evidence for compensatory thermal adaptation of soil microbial respiration in the study of Bradford et al. (2008). Ecology Letters 12: E12-E14
- Hardie SML, Garnett MH, Fallick AE, Ostle NJ, Rowland AP (2009) Bomb-14C analysis of ecosystem respiration reveals that peatland vegetation facilitates release of old carbon. Geoderma 153: 393-401
- Garnett MH, Hartley IP, Hopkins DW, Sommerkorn M, Wookey PA (2009) A passive sampling method for radiocarbon analysis of soil respiration using molecular sieve. Soil Biology & Biochemistry 41: 1450-1456
- Garnett MH, Hardie SML (2009) Isotope (14C and 13C) analysis of deep peat CO2> using a passive sampling technique. . Soil Biology & Biochemistry 41: 2477-2483
- Hartley IP, Hopkins DW, Garnett MH, Sommerkorn M, Wookey PA (2008) Soil microbial respiration in arctic soil does not acclimate to temperature Ecology Letters 11: 1092-1100
- Newnham RM, Vandergoes MJ, Garnett MH, Lowe DJ, Prior C, Almond PC (2007) Test of AMS 14C dating of pollen concentrates using tephrochronology. Journal of Quaternary Science 22(1): 37-51
- Marshall W, Gehrels R, Garnett MH, Freeman SPHT, Maden C, Xu S (2007) The use of 'bomb spike' calibration and high-precision AMS 14C analyses to date salt-marsh sediments deposited during the past three centuries. Quaternary Research 68: 325-337
- Hardie SML, Garnett MH, Fallick AE, Rowland AP, Ostle NJ (2007) Spatial variability of bomb-14C in an upland peat bog. Radiocarbon 49(2): 1055-1063
- Garnett MH, Billett MF (2007) Do riparian plants fix CO2 lost by evasion from surface waters? An investigation using carbon isotopes. Radiocarbon 49(2): 993-1001
- Evans CD, Freeman C, Cork LG, Thomas DN, Reynolds B, Billett MF, Garnett MH, Norris D (2007) Evidence against recent climate-induced destabilisation of soil carbon from 14C analysis of riverine dissolved organic matter. Geophysical Research Letters 34: L07407
- Briones MJI, Ostle NJ, Garnett MH (2007) Invertebrates increase the sensitivity of non labile soil carbon to climate change. Soil Biology & Biochemistry 39(3): 816-818
- Bradford MA, Tordoff GM, Black HIJ, Cook R, Eggers T, Garnett MH, Grayston SJ, Hutcheson KA, Ineson P, Newington JE, Ostle N, Sleep D, Stott A, Jones TH (2007) Carbon dynamics in a model grassland with functionally different soil communities. Functional Ecology 21: 690-697
- Billett MF, Garnett MH, Harvey F (2007) UK peatland streams release old carbon dioxide to the atmosphere and young dissolved organic carbon to rivers Geophysical Research Letters 34: L23401, doi:23410.21029/22007GL031797.
- Bardgett RD, Richter A, Bol R, Garnett MH, Bäumler R, Xu X, Lopez-Capel E, Manning D, Hobbs PJ, Hartley IR, Wanek W (2007) Heterotrophic microbial communities use ancient carbon during primary succession on deglaciated terrain. Biology Letters 3: 487-490
- Billett MF, Garnett MH, Hardie SML (2006) A Direct Method to Measure 14CO2 Lost by Evasion From Surface Waters Radiocarbon 48(1): 61-68
- Karltun E, Harrison AF, Alriksson A, Bryant C, Garnett MH, Olsson MT (2005) Old organic carbon in soil solution DOC after afforestation - evidence from 14C analysis. Geoderma 127: 188-195
- Hardie SML, Garnett MH, Fallick AE, Rowland AP, Ostle NJ (2005) Carbon dioxide capture using a zeolite molecular sieve sampling system for isotopic studies (13C and 14C) of respiration. Radiocarbon 47(3): 441-451
- Garnett MH (2005) Use of 'bomb' radiocarbon as a tracer in studies of carbon cycling. Bulletin of the British Ecological Society 36(2): 28-30
- Charman DJ, Garnett MH (2005) Chronologies for recent peat deposits using wiggle-matched radiocarbon ages: problems with old carbon contamination. Radiocarbon 47(1): 135-145
- Briones MJI, Garnett MH, Piearce TG (2005) Earthworm ecological groupings based on 14C analysis. Soil Biology & Biochemistry 37: 2145-2149
- Bol R, Eriksen J, Smith P, Garnett MH, Coleman K, Christensen BT (2005) The natural abundance of 13C, 15N, 34S and 14C in archived (1923-1996) plant and soil samples from the Askov long-term experiments on animal manure and mineral fertiliser. Rapid Communications in Mass Spectrometry 19: 3216-3226
- Garnett MH, Stevenson AC (2004) Testing the use of bomb radiocarbon to date the surface layers of blanket peat. Radiocarbon 46(2): 841-851
- Garnett MH, Ineson P, Stevenson AC, Howard DC (2001) Terrestrial organic carbon storage in a British moorland. Global Change Biology 7: 375-388
- Garnett MH, Ineson P, Stevenson AC (2000) Effects of burning and grazing on carbon sequestration in a Pennine blanket bog, UK. Holocene 10(6): 729-736
- McTiernan KB, Garnett MH, Mauquoy D, Ineson P, Couteaux M-M (1998) Use of near-infrared reflectance spectroscopy (NIRS) in palaeoecological studies of peat. Holocene 8(6): 729-740
- Garnett MH (1998) Carbon storage in Pennine moorland and response to change. In: Department of Geography. University of Newcastle-Upon-Tyne, Newcastle-Upon-Tyne. p 302
- Garnett M, Adamson JK (1997) Blanket mire monitoring and research at Moor House National Nature Reserve. In: Tallis JH, Meade R & Hulme PD (eds) Blanket Mire Degradation: Causes, Consequences and Challenges. MLURI, Aberdeen.
- Garnett, M. H., Ineson P, Adamson JK (1997) A long-term upland temperature record: No evidence for recent warming. Weather 52: 342-351.