Aberdeen Mycorrhiza Research Group

Dr Dave Johnson

Lecturer

University of Aberdeen

&

Macaulay Institute

Tel: 01224 273857 or 01224 4395340

E-mail: D.Johnson@abdn.ac.uk

Research interests

Quantifying carbon flux to external mycorrhizal fungal mycelium.
Understanding the functional diversity of microorganisms in the mycorrhizosphere.
Impacts of climate change and atmospheric nitrogen deposition on nutrient cycling and microbial communities in peatland, upland and arctic ecosystems.
Interactions between mycorrhizal fungi and soil invertebrates.
The role of genotypic and species diversity for terrestrial ecosystem functioning.

Research Grants

Can plant genotypic diversity select for mycorrhizal fungal diversity in grasslands? Royal Society. June 2006-May 2007. Value: £7700.
“Mycorrhizal interactions in native pinewoods: are ericoid and ectomycorrhizal fungi genetically and functionally distinct?” Oct. 2005-Sept. 2009. funding: NERC. Value: £291,000. [more info].
“Influence of soil mesofaunal communities on carbon flux to ectomycorrhizal fungi and saprotrophic microorganisms” July 2004-July 2006. funding: NERC. Value: £50,483. NE/C507510/1.[more info]
NERC Advanced Fellowship. “Does below ground carbon allocation drive soil biodiversity in Boreal forests?” Sept. 2003-Sept 2008. Value: £243,604.[more info]
Ecological implications of elevated CO2 for soil carbon fluxes as mediated by the mycorrhizal symbioses. ESF Short Visit Grant with Dr PMA Fransson. Value: €1575.
" The significance of ericoid mycorrhizal mycelium for carbon turnover in heathland". NERC Open CASE (with Dr RRE Artz). Oct. 2008-2012. Value: £67,173. NE/F013760/1.
Royal Society Conference Grant. Value: £700.

Research students

Miranda T Prendergast-Miller, NERC funded. Does carbon flux from mycorrhizal fungi stimulate N2O production in soils? (With Dr EM Baggs) 2005-2008.
Pauline Currey , 6th Century/Macaulay funded. Carbon cycling in cutover peatbogs. (With Dr RRE Artz, Macaulay Institute). 2005-2008.
Eleni Siasou, 6th Century/Greek Government. Interactions between Take-all fungus, soil bacteria and arbuscular mycorrhizal fungi. (With Prof K Killham). 2006-2009.
Anna Wilkinson, NERC funded. Quantifying the contribution of external mycorrhizal mycelium to soil respiration: Does diversity matter? (with Prof I Alexander) 2007-2010.
Ully Kritzler, NERC CASE. The significance of ericoid mycorrhizal mycelium for carbon turnover in heathland (with Dr Rebekka Artz (Macaulay Institute), Dr Gwen Grelet and Prof Ian Alexander). 2008-2011.
Sunday Popoola. Do mycorrhizal and pathogenic fungi regulate phosphorus uptake by tropical agroforestry species? With Dr S Woodward. 2008-2011.
Faizal Mohd. Phosphorus cycling in Sago palm peatlands (With K Killham and D Standing). Malaysian Goverment funded. 2008-2011
Rosnida Tajuddin.

Past Research students

Clare Trinder, BBSRC funded. Carbon cycling in regenerating peatlands. (With Dr RRE Artz, Macaulay Institute)
Niki Papanikolaou DEFRA/Macaulay Institute. Impacts of increased nitrogen deposition on carbon and nutrient dynamics in montane ecosystems (with Drs R Helliwell and A Britton)

Publications

Johnson D. (2008) Resolving uncertainty in the carbon economy of mycorrhizal fungi. New Phytologist 180: 3-5.
Johnson D, Phoenix GK and Grime JP (2008) Plant community composition regulates soil respiration in grasslands. Biology Letters 4:345-348.
Trinder CJ, Johnson D & Artz, RRE (2008) Interactions between fungal community structure, litter decomposition and depth of water-table in a cutover peatland. FEMS Microbiology Ecology 64: 433-448.
Phoenix GK, Johnson D, Grime JP & Booth RE (2008). Sustaining ecosystem services in ancient limestone grassland: importance of major component plants and community composition. Journal of Ecology In Press.
Trinder CJ, Artz RRE & Johnson D (2008) Contribution of plant photosynthate to soil respiration and dissolved organic carbon in a naturally recolonising cutover peatland. Soil Biology & Biochemistry 40:1622-1628.
Trinder CJ, Artz, RRE and Johnson D (2008). Temporal patterns of litter production by vascular plants and its decomposition rate in cut-over peatlands. Wetlands 28:245-250.
Yan W, Artz RRE and Johnson D (2007) Species-specific effects of plants colonising cutover peatlands on patterns of carbon source utilisation by soil microorganisms. Soil Biology and Biochemistry doi:10.1016/j.soilbio.2007.09.001
Phuyal M, Artz RRE, Sheppard L, Leith ID and Johnson D (2007) Long-term nitrogen deposition increases phosphorus limitation of bryophytes in an ombrotrophic bog. Plant Ecology 196:111-121.
Foereid B, Dawson LA, Johnson D & Rangel-Castro JI (2006) Fate of carbon in upland grassland subjected to liming using in situ 13CO2 pulse-labelling. Plant & Soil 287: 301-311.
Leake JR, Ostle NJ, Rangel-Castro JI & Johnson D (2006) Carbon fluxes from plants through soil organisms determined by field 13CO2 pulse-labelling in an upland grassland. Applied Soil Ecology 33: 152-175.
Johnson D, Krsek M, Wellington EMH, Stott AW, Cole L, Bardgett RD, Read DJ, Leake JR (2005) Soil invertebrates disrupt carbon flow through fungal networks. Science 309: 1047-1047.
Johnson D (2005) Underworld Connections. Biologist 52, 155-160.
Johnson D, IJdo M, Genney DR, Anderson IC & Alexander IJ (2005) How do plants regulate the function, community structure and diversity of mycorrhizal fungi? Invited paper for Journal of Experimental Botany 56, 1751-1760.
Pilkington MG, Caporn SJM, Carroll JA, Cresswell N, Lee JA, Ashenden TW, Brittain SA, Emmett BA & Johnson D (2005) Effects of increased deposition of atmospheric nitrogen on an upland Calluna moor: N and P transformations. Environmental Pollution 135,469-480.
Johnson D, Leake JR & Read DJ (2005) Liming and nitrogen fertilisation affects phosphatase activities, microbial biomass and mycorrhizal colonisation in upland grassland. Plant & Soil 271, 157-164.
Leake JR, Johnson D, Donnelly DP, Muckle G, Boddy L & Read DJ. (2004) Networks of power and influence-the role of mycorrhizal mycelium in controlling plant communities and agroecosystem functioning. Canadian Journal of Botany82, 1016-1045.
Johnson D, Vandenkoornhuyse PJ, Leake JR, Gilbert LA, Booth RE, Grime JP, Young JPW & Read DJ. (2004) Plant communities affect arbuscular mycorrhizal fungal diversity and community composition in grassland microcosms. New Phytologist 161, 503-516.
Johnson D,Campbell CD, Lee JA, Callaghan T & Gwynn-Jones D. (2003) Elevated UV-B radiation affects Arctic soil microbial communities. Nature 423, 138.
Johnson D. (2003) Response of terrestrial microorganisms to ultraviolet-B radiation in ecosystems. Invited paper for Research in Microbiology 154, 315-320.
Carroll JA, Caporn SJM, Johnson D, Morecroft MD & Lee JA. (2003) The interactions between plant growth, vegetation structure and soil processes in semi-natural acidic and calcareous grasslands receiving long-term inputs of simulated pollutant nitrogen deposition. Environmental Pollution 121, 363-376.
Johnson D, Booth RE, Whiteley AS, Bailey MJ, Read DJ, Grime, JP & Leake JR. (2003) Plant community composition affects the biomass, activity and diversity of soil microorganisms in reconstituted calcareous grassland. European Journal of Soil Science54, 671-678.
Johnson D, Leake JR & Read DJ. (2002). Transfer of recent photosynthate into mycorrhizal mycelium of an upland grassland: short-term respiratory losses and accumulation of ¹⁴C. Soil Biology & Biochemistry 34, 1521-1524.
Johnson D, Campbell CD, Lee JA, Callaghan T & Gwynn-Jones D. (2002) Arctic microorganisms respond more to elevated UV-B radiation than CO₂. Nature 416, 82-83.
Johnson D,Leake JR, Ostle N, Ineson P & Read DJ. (2002). In situ ¹³CO₂ pulse-labelling of upland grassland demonstrates a rapid pathway of carbon flux from arbuscular mycorrhizal mycelium to the soil. New Phytologist 153, 327-334.
Johnson D,Leake JR & Read DJ. (2001). Novel in-growth core system enables functional studies of grassland mycorrhizal mycelial networks. New Phytologist 152, 555-562.
Carroll JA, Johnson D, Morecroft M, Taylor AFS, Caporn SJM & Lee JA (2000) The effect of long-term nitrogen additions on bryophyte cover of upland acidic grasslands. Journal of Bryology 22, 83-91.
Johnson D, Leake JR & Lee JA (1999). The effects of quantity and duration of simulated pollutant nitrogen deposition on root-surface phosphatase activities in calcareous and acid grasslands: a bioassay approach. New Phytologist 141, 433-442.
Lee JA, Caporn SJM, Carroll J, Foot JP, Johnson D, Potter L, Taylor AFS & Carroll JA (1998). Effects of ozone and atmospheric nitrogen deposition on bryophytes. In: JW Bates, NW Ashton, JG Duckett eds. Bryology for the twenty-first Century. The Centenary Symposium of the British Bryological Society. pp.331-341.
Johnson D, Leake JR, Lee JA & Campbell CD (1998). Changes in soil microbial biomass and microbial activities in response to seven years simulated pollutant nitrogen deposition on a heathland and two grasslands. Environmental Pollution 103, 239-250
Green N, Johnson D & Wilkins BT (1996). Factors affecting the transfer of radionuclides to sheep grazing on pastures reclaimed from the sea. Journal of Environmental Radioactivity 30, 173-183.

BOOK CHAPTERS:

Leake JR, Johnson D, Donnelly DP, Boddy L & Read DJ. Is diversity of mycorrhizal fungi important for ecosystem functioning? (2005). In: Biological Diversity and Function in Soils (Eds. D Hopkins, M Usher and R Bardgett). Cambridge University Press. pp216-235.
Johnson, D, Leake JR and Read DJ. Roles of arbuscular mycorrhizal fungi in carbon and nutrient cycling. In: Fungi in Biogeochemical Cycles (Ed GM Gadd). pp129-150. Cambridge.

Selected poster presentations

"Collembola disrupt carbon flux from mycorrhizal mycelium to the atmosphere". International Conference on Mycorrhizas 4, Montreal, Canada.
"In situ ¹³CO₂ pulse-labelling of upland grassland to measure carbon flux from plants through external mycelium of arbuscular mycorrhizal fungi" International Conference on Mycorrhizas 3, Adelaide 2001; British Society of Soil Science 2001 & 2002.
"Changes in soil microbial biomass and microbial activities in semi-natural ecosystems from simulated pollutant nitrogen deposition" Nitrogen deposition workshop, MLURI, 1996 and British Society of Soil Science Golden Jubilee, Newcastle, 1997.

Invited presentations

ICOM5, Granada, Spain July 2006. “Does carbon flux to mycorrhizal fungi drive soil biodiversity?”
Mycorrhiza: Systems Research from Genes to Communities. Monte Verita, Switzerland. March 2006. “Carbon flow through mycorrhizal networks and the impact of Collembola”
Society for General Microbiology, Barcelona, July 2005. “How do plants regulate the function, composition and diversity of soil microorganisms?”
Society for General Microbiology, April 2004. “The role of arbuscular mycorrhizal fungi in carbon and nutrient cycling”.
University of Stirling, March 2004. “Functioning of microorganisms in semi-natural ecosystems and their response to perturbations”.
University of Aberdeen, November 2003. “Functioning of microorganisms in semi-natural ecosystems and their response to perturbations”.
Swedish University of Agricultural Sciences, Umeå, 1998. “Effects of nitrogen deposition on U.K. semi-natural grasslands and heathlands".

Research experience

2003-2008. NERC Advanced Fellow, School of Biological Sciences, University of Aberdeen. “Does below ground carbon allocation drive soil microbial diversity in boreal forests?”
2001-2003. Post Doctoral Research Associate, Department of Animal and Plant Sciences, University of Sheffield. “Carbon flow through mycorrhizal mycelial systems to soil microbial populations-the impact of microarthropod diversity” (NERC Soil Biodiversity). With Dr Jonathan Leake and Prof David Read.
1998-2001. Post Doctoral Research Associate, Department of Animal and Plant Sciences, University of Sheffield. “The effect of mycorrhizal mycelium on the diversity, biomass and functioning of soil microbial communities and its role in carbon and nutrient cycles” (NERC Soil Biodiversity). With Dr Jonathan Leake and Prof David Read.
1997-1998. Research Assistant, Department of Animal and Plant Sciences, University of Sheffield. With Prof. John Lee.

Education & Background

PhD 1995-1998. Alfred Denny Scholarship studying “Soil microbial biomass and activity and plant nutrition in semi-natural ecosystems subjected to pollutant nitrogen deposition”, University of Sheffield.
MSc 1993-1994. Soil Science, University of Aberdeen (awarded prize for best class thesis)
BSc 2i (Hons) 1989-1993. Environmental Technology, University of Sunderland.