The University of Sheffield
Department of Animal and Plant Sciences

Dr Gareth Phoenix

Image of Gareth Phoenix

Tel: +44 (0)114 222 0082
Fax: +44 (0)114 222 0002

email :

Phoenix Lab home page


BSc, University of Edinburgh (1996)
PhD, University of Sheffield (2000)
NERC post-doctoral research associate, University of Sheffield (2000-2003)
Departmental research associate and teaching fellow, University of Sheffield (2003-2004)
RCUK academic fellow, University of Sheffield (2005-2009)
Lecturer, University of Sheffield (2010-2011)
Senior Lecturer, University of Sheffield (2011-present)

Key Research Interests

image of growth chambers

My research focuses on the impacts of environmental change on vegetation and ecosystem processes (particularly nutrient cycling and fluxes) and on how these ecosystem processes are affected by plant community structure

Current key questions include:

• Effects of environmental change on Arctic vegetation and biogeochemical cycling
• Effects of Arctic plants, parasitic plants and biodiversity on ecosystem function
• Effects of pollutant nitrogen deposition on plant biodiversity, nutrient cycling and plant nutrient acquisition

Professional Activities

Editorial Advisory Board - Global Change Biology (2007 onwards)
Associate Editor - Functional Ecology (2005 – 2011)
Member of Council - British Ecological Society (2005 – 2009)
University Representative - British Ecological Society (2004 – 2009)
Steering Committee member, CAPER (Committee on Air Pollution Effects Research) (2006 onwards)
NERC peer review college (2008 onwards)


Dr Gareth Phoenix is APS liaison for the Environmental Science degree, ad-hoc member of the Teaching Committee and co-ordinates APS118 tutorials for Environmental Science students.

At level 1, I teach APS124 (Ecosystems and Environmental Change). My main research interests are the impacts of global change on ecosystems, and this course gives me a chance to teach this fascinating area to new students. I cover a diversity of topics, from how past climates have influenced the development of ecosystems in the UK, to the threats of contemporary climate change. The latter includes findings from some of our own work undertaken here in APS. The APS118 and APS222 tutorials are also an excellent opportunity to develop discussion and debate on these topics as well as helping students develop generic skills in writing, critical analysis, experimental design and oral communication.

My own research includes work on Peak District ecosystems, and at level 2, we use this area to study the interaction between ecosystems and the environment in APS246 (Plant Habitats and Distributions). Here we use a combination of lectures, laboratory classes and field visits. These ideas are expanded further in APS273 (Population and Community Ecology 2) where I teach how plant diversity and the composition of species influence how an ecosystem functions (for instance, the ecosystem’s capacity to sequester carbon from the atmosphere, cycle nutrients or trap pollutants).

My key area of research – Arctic ecosystems and environmental change – informs my teaching at level 3. Here, in addition to lecturing on plant adaptations to arctic environments in APS325 (Life in Extreme Environments), I teach on the Arctic Ecosystems field course (APS343) to Abisko in northern Sweden. The research station we use is also the home to many of my field experiments and so in addition to teaching more generally about Arctic ecosystems, this course offers students the opportunity to learn about, and work on, on-going Arctic research experiments.

The topics of global change, biodiversity and ecosystem functioning are also covered in research projects and dissertations at level 3 (APS330 and 331) and at level 4 (APS402 & 406), where my students address questions concerning the impacts of pollution and climate change (e.g. drought, warming) on plant diversity and ecosystem functioning.

Recent Invited Lectures

International Botanical Congress, Melbourne, Australia (July 2011)

Department of Biology, University of York, UK (March 2011)

College of Life and Environmental Sciences, University of Exeter, UK (Feb 2011)

University of Illinois, Urbana-Champaign, USA (Sept 2010)

Kansas State University, Manhattan, USA (Sept 2010)

Oak Ridge National Laboratory, Knoxville, USA (Sept 2010)

School of Bioscience, University of Nottingham, UK (2010)

EURECO conference, Leipzig, Germany (September 2008)

Dept Geography, University of Sheffield (November 2008)

Polar Environment Centre, Tromsø, Norway (May, 2006)

Vrije Universiteit Amsterdam, Department of Systems Ecology (January 2006)

University of Aberdeen, School of Biological Sciences (November, 2004)

Research Group

Thomas Young
Green roof technologies for sustainable urban energy and water management (E-futures and Bonigale Ltd funded PhD, jointly supervised with Duncan Cameron and Jeff Sorrill)

Steffi Till
Engineering and functional mycorrhizosphere for agro-ecosystems (University funded PhD, jointly supervised with Duncan Cameron and Jonathan Leake)

Steven Lees
Impacts of atmospheric nitrogen deposition in grasslands (Defra funded PhD. Jointly supervised with Jonathan Leake)

James Fisher
Mechanisms of parasitic plant impacts on communities (NERC funded PhD studentship, jointly supervised with Duncan Cameron and Malcolm Press)

Aimeric Blaud
Impacts of acute nitrogen deposition events on Arctic soil microbial communities (NSINK Marie Curie Fellow - staff PhD candidate. Jointly supervised with Mark Osborn)

Sonal Choudhary
Impacts of acute nitrogen deposition events on Arctic tundra (NSINK Marie Curie Fellow - staff PhD candidate. Jointly supervised with Malcolm Press, University of Birmingham)

Recent Members

Dr Maria Arroniz-Crespo
Impacts of atmospheric nitrogen deposition on bryophytes in grassland ecosystems (Spanish Ministry funded)

Dr Victoria Sloan
The role of plant roots in Arctic carbon dynamics (NERC PhD studentship)

Dr Eva Koller
Carbon dynamics in an Arctic catchment: plant scale dynamics (MULTIARC Marie Curie Fellow - staff candidate. Jointly supervised with Malcolm Press)

Dr Nils Ohlanders
Carbon dynamics in an Arctic catchment: hydrology (MULTIARC Marie Curie Fellow - staff PhD candidate. Jointly supervised with Andrew Hodson, Dept Geography)

Dr Catherine Preece
Impacts of extreme winter warming and icing events on sub-Arctic heathland (NERC PhD studentship, jointly supervised with Terry Callaghan)

Dr Stef Bokhorst
Impacts of extreme winter warming events in the Arctic (Leverhulme Trust, joint with Terry Callaghan).

Dr Ben Fletcher
Arctic Biosphere-Atmosphere Coupling at Multiple Scales (NERC, joint wiht Malcolm Press. See

Dr Mike Pilkington
Impacts of root hemiparasitic plants: regulation of community structure and function (NERC, joint with Malcolm Press and Jonathan Leake)

Dr Jill Edmondson
N pollution impacts on plant P acquisition, and impacts of hemiparasitic plants on nutrient cycling (technician, NERC funded)

Recent Publications (2001 to date)

Phoenix GK, Emmett BA, Britton AJ, Caporn SJM, Dise NB, Helliwell R, Jones MLM, Leake JR, Leith ID, Sheppard LJ, Sowerby A, Pilkington MG, Rowe EC, Ashmore MR, Power SA (2011). Impacts of atmospheric nitrogen deposition: responses of multiple plant and soil parameters across contrasting ecosystems in long-term field experiments. Global Change Biology (in press)

Bokhorst S, Phoenix GK, Bjerke JW, Callaghan TV, Huyer-Brugman F, Berg MP (2011) Extreme winter warming events more negatively impact small rather than large soil fauna: shift in community composition explained by traits not taxa. Global Change Biology (in press)

Fletcher BJ, Gornall JL, Poyatos R, Press MC, Stoy PC, Huntley B, Baxter R, Phoenix GK (2011). Photosynthesis and productivity in heterogeneous arctic tundra: consequences for ecosystem function of mixing vegetation types at stand edges. Journal of Ecology (in press)

Bokhorst S, Bjerke JW, Street LE, Callaghan TV & Phoenix GK (2011). Impacts of multiple extreme winter warming events on sub-Arctic heathland: phenology, reproduction, growth, and CO2 flux responses. Global Change Biology (in press)

Bjerke JW, Bokhorst S, Zielke M, Callaghan TV, Bowles FW & Phoenix GK (2011). Contrasting sensitivity to extreme winter warming events of dominant sub-Arctic heathland bryophyte and lichen species. Journal of Ecology (in press)

Dise NB & Phoenix GK (2011). Peatlands in a Changing World. New Phytologist 191: 309–311

Payne RJ, Stevens CJ, Dise NB, Gowing DJ, Pilkington MG, Phoenix GK, Emmett BA &Ashmore MR (2011). Impacts of atmospheric pollution on the plant communities of British acid grasslands. Environmental Pollution 159, 2602-2608

Arróniz-Crespo M, Gwynn-Jones D, Callaghan TV, Núñez-Olivera E, Martínez-Abaigar J, Horton P & Phoenix GK (2011). Impacts of long-term enhanced UV-B radiation on bryophytes in two sub-Arctic heathlands of contrasting water availability. Annals of Botany 108: 557-565

O´Sullivan OS, Horswill P, Phoenix GK, Lee JA and Leake JR (2011). Recovery of soil nitrogen pools in species rich grasslands after 12 years of simulated pollutant nitrogen deposition: a 6 year experimental analysis. Global Change Biology 17,2615-2628

Bokhorst S, Bjerke JW, Davey MP, Taulavuori K, Taulavuori E, Laine K, Callaghan TV & Phoenix GK. (2010) Impacts of extreme winter warming events on plant physiology in a sub-Arctic heath community. Physiologia Plantarum 140, 128–140

Fletcher BJ, Press MC, Baxter R & Phoenix GK. (2010) Transition zones between vegetation patches in a heterogeneous Arctic landscape: how plant growth and photosynthesis change with abundance at small scales. Oecologia 163, 47–56

Bokhorst S, Bjerke JW, Melillo J, Callaghan TV & Phoenix GK. (2010) Impacts of extreme winter warming events on litter decomposition in a sub-Arctic heathland. Soil Biology and Biochemistry 42, 611-617

Bokhorst S, Bjerke JW, Tømmervik H, Callaghan TV, Phoenix GK. (2009). Winter warming events damage sub-Arctic vegetation: consistent evidence from an experimental manipulation and a natural event. Journal of Ecology 97, 1408-1415 (featured in Nature´s science highlights)

Bokhorst S, Bjerke JW, Bowles FW, Melillo JM, Callaghan TV, Phoenix GK. (2008). Impacts of extreme winter warming in the sub-Artic: growing season responses of dwarf-shrub heathland. Global Change Biology. 14, 2603-2612.

Arroniz-Crespo M, Leake JR, Horton P, Phoenix GK. (2008) Bryophyte physiological responses to, and recovery from, long-term nitrogen deposition and phosphorus fertilisation in acidic grassland. New Phytologist. 180, 864-874.

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. 96, 894-902.

Johnson D, Phoenix GK, Grime JP (2008). Does plant species diversity regulate soil respiration in grasslands? Biology Letters 4, 345-348

Horswill P, O'Sullivan O, Phoenix GK, Lee JA, Leake JR (2008) Base cation depletion, eutrophication and acidification of species-rich grasslands in response to long-term simulated nitrogen deposition. Environmental Pollution (in press)

Arróniz-Crespo M, Phoenix G, Núñez-Olivera E Martínez-Abaigar (2008). Age-specific physiological responses to UV radiation in the aquatic liverwort Jungermannia exsertifolia subsp. Cordifolia. Cryptogamie Bryologie (in press)

Pilkington MG, Caporn SJM, Carroll JA, Cresswell N, Phoenix GK, Lee JA, Emmett BA, Sparks T (2007). Impacts of burning and increased nitrogen deposition on nitrogen pools and leaching in an upland moor. Journal of Ecology 95, 1195–1207.

Phoenix GK, Hicks WK, Cinderby S, Kuylenstierna JCI, Stock WD, Dentener FJ, Giller KE, Austin AT, Lefroy RDB, Gimeno BS, Ashmore MR & Ineson P (2006). Atmospheric Nitrogen Deposition in World Biodiversity Hotspots: the need for a greater global perspective in assessing N deposition impacts. Global Change Biology 12, 470-476.

Phoenix GK. & Press MC. (2005). Linking physiological traits to impacts on community structure and function: the role of root hemiparasitic Orobanchaceae (ex-Scrophulariaceae). Journal of Ecology 93, 67-78.

Press MC. & Phoenix GK. (2005) Tansley review: Impacts of parasitic plants on natural communities. New Phytologist. 166, 737-751

Phoenix GK. & Press MC. (2005). Effects of climate change on root hemiparasitic plants. Folia Geobotanica. 40, 205-216.

Phoenix, G.K, Booth R.E, Leake, J.R, Read, D.J., Grime, J.P. & Lee, J.A. (2004) Simulated pollutant nitrogen deposition increases P stress and enhances root-surface phosphatase activities of three plant functional types in a calcareous grassland. New Phytologist 161, 279-289.

Phoenix, G.K, Leake, J.R, Read, D.J., Grime, J.P. & Lee, J.A. (2004) Accumulation of pollutant nitrogen in calcareous and acidic grasslands: evidence from N flux and 15N tracer studies. Water, Air and Soil Pollution, Focus 4, 159–167.

Phoenix, G.K. & Lee, J.A. (2004) Predicting impacts of Arctic climate change: past lessons and future challenges. Ecological Research 19, 65-74.

Phoenix, G.K, Booth R.E, Leake, J.R, Read, D.J., Grime, J.P. & Lee, J.A. (2003) Effects of enhanced nitrogen deposition and phosphorus limitation on nitrogen budgets of semi-natural grasslands. Global Change Biology 9, 1309-1321.

Semerdjieva, S.I., Sheffield, E., Phoenix, G.K., Gwynn-Jones, D., Callaghan, T.V. &. Johnson, G.N (2003). Contrasting strategies for UV-B screening in sub-Arctic dwarf shrubs. Plant, Cell and Environment 26, 957-964.

Phoenix, G.K., Gwynn-Jones, D., Lee, J.A. & Callaghan, T.V. (2003) Ecological importance of ambient solar ultraviolet radiation to a sub-Arctic heath community. Plant Ecology 165, 263-273.

Semerdjieva, S.I., Phoenix, G.K., Hares, D., Gwynn-Jones, D., Callaghan, T.V. & Sheffield E. (2003) Surface morphology, leaf and cuticle thickness of four dwarf shrubs from a sub-Arctic heath following long-term exposure to enhanced levels of UV-B. Physiologia Plantarum 117, 289-294.

Phoenix, G.K., Gwynn-Jones, D., Callaghan, T.V., Sleep, D. & Lee, J.A. (2001) Effects of global change on a sub-arctic heath: effects of enhanced UV-B radiation and increased summer precipitation. Journal of Ecology 89, 256-267.

Cornelissen, J.H.C., Callaghan, T.V. …Phoenix, G.K.,…et al. (2001) Global change and arctic ecosystems: is lichen decline a function of increases in vascular plant biomass?. Journal of Ecology 89, 984-994.

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