About the Authors


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Prof. Steve Long

Main current research interests are in:

  1. The effects of rising tropospheric carbon dioxide and ozone levels on photosynthesis in natural vegetation and in crops; 
  2. Low temperature C4 photosynthesis. 

Research projects concern the following areas:  

The mechanistic basis of the effects of rising tropospheric levels of carbon dioxide and ozone concentrations on photosynthesis in wheat, ryegrass, and a range of native UK herbaceous species. 
Low temperature tolerance of C4 photosynthesis in temperature grasses of the genera Miscanthus and Spartina 
Development of process-based mathematical models of photosynthesis, to relate changes at the biochemical level to changes at the canopy level. 
the mechanistic basis of ozone damage to leaves 

My research group is using a suite of high-light controlled environments to test hypotheses under closely controlled and repeatable conditions and then test applicability to the field via our collaborative links with a series of large-scale field experiments - including those established in the GCTE- FACE experiments in the USA and Switzerland. My research at the University of Essex is funded by grants from BBSRC, EU, and NERC; and in the USA by the US-DoE.  

Other research interests are:

limits on the photosynthetic productivity of terrestrial vegetation 
mechanistic mathematical models of photosynthesis 
primary productivity of tropical grasslands 
salt tolerance in plants and saltmarsh ecophysiology 

Research interests:

My main interests are the effects of atmospheric changes in carbon dioxide and ozone on photosynthesis in crops and native vegetation. This scales from studies of changes at the level of gene expression, through leaf photosynthesis to changes in canopy gas exchange and crop growth. My atmospheric change research uses both the large controlled environment facility recently established at the University of Essex and, through my collaboration with Brookhaven National Laboratory, the three major Free Air Carbon dioxide Enrichment (FACE) experiments.

Other Activities:

Editor of the Plants and Climate Change Section of the journal Plant Cell and Environment
Editor-in-Chief of the journal Global Change Biology
Co-ordinator of the TIGER IV.1 consortium: Ecophysiological Responses of Organisms to Changes in Carbon Dioxide and Climate.
Chairperson of the Working Group on Photosynthetic Responses of Vegetation to Atmospheric Change for EC COST ACTION 619.

Research Papers 

NIE, G.-Y., LONG, S.P., GARCIA, R.L., KIMBALL, B.A., LaMORTE, R.L., PINTER, P.J., WALL, G.W., & WEBBER, A.N. (1995) Effects of free-air CO2 enrichment on the development of the photosynthetic apparatus in wheat, as indicated by leaf proteins. Plant Cell & Environment 18, 855-864.  
NIE, G.-Y., HENDRIX, D. & WEBBER, A.N. & LONG, S.P.(1995) Free-air CO2 enrichment effects on the expression of photosynthetic genes and accumulation of carbohydrate in Wheat. Does decreased expression of specific photosynthetic genes correspond to increased accumulation of soluble carbohydrates? Plant Physiology 108, 975-983.  
FARAGE, P.K. & LONG, S.P. (1995) The effects of acute ozone exposure on photosynthesis in contrasting species: An in vivo analysis. Photosynthesis Research 43, 11-18.  
HUMPHRIES, S.W. & LONG, S.P. (1995) WIMOVAC: a software package for modelling the dynmaics of plant leaf and canopy photosynthesis. CABIOS 11, 361-371  
BEALE, C.V. & LONG, S.P. (1995) Can perennial C4 grasses attain high efficiencies of radiant energy conversion in cool climates? Plant Cell & Environment 18, 641-650.  
POTTER, L., BINGHAM, M.J., BAKER, M.G. & LONG, S.P. (1995) The potential of two perennial C4 grasses and a perennial C4 sedge as ligno-cellulosic fuel crops in N.W. Europe. Crop establishment and yields in E. England. Annals of Botany 76: 513-520.  
MCKEE, I.F., FARAGE, P.K. & LONG, S.P. (1995) The interactive effects of elevated CO2 and O3 concentration on photosynthesis in spring wheat. Photosynthesis Research 45: 111-119.  
PÉREZ-LEROUX, H.A.J. & LONG, S.P. (1994) Growth analysis of contrasting Zea mays L. cultivars at different rates of nitrogen supply. Annals of Botany 73, 503-515.  
PIEDADE, M.T., LONG, S.P. & JUNK, W.J. (1994) Leaf and canopy photosynthetic CO2 uptake of a stand of Echinochloa polystachya on the Central Amazon floodplain. Are the high potential rates associated with the C4 syndrome realized under the near-optimal conditions provided by this exceptional natural habitiat? Oecologia 97, 193-201.  
STIRLING, C.M., AGUILERA, C., BAKER, N.R., LONG, S.P. (1994) Changes in the photosynthetic light response curve during leaf development of field grown maize with implications for modelling canopy photosyntheis. Photosynthesis Research 42, 217-225.  
LONG, S.P., POSTL, W.F. & BOLHÁR-NORDENKAMPF, H.R. (1993) Quantum yields for CO2 uptake in C3 vascular plants of contrasting habitats and taxonomic groupings. Planta 189, 219-226.  
LONG, S.P., BAKER, N.R. & RAINES, C.A. (1993) Analysing the responses of photosynthetic CO2 assimilation to long-term elevation of atmospheric CO2 concentration. Vegetatio 104, 33-45.  
NIE, G.-Y., LONG, S.P. & BAKER, N.R. (1992) The effect of development at sub-optimal temperatures on photosynthetic capacity and susceptibility to photoinhibition of Zea mays. Physiologia Plantarum 85, 554-560.  
FARAGE, P.K. & LONG, S.P. (1991) The occurrence of photoinhibition in an over- wintering oil-seed rape crop (Brassica napus) and its correlation with changes in crop growth. Planta 185, 279-285.  
FARAGE, P.K., LONG, S.P., LECHNER, E.G. & BAKER, N.R. (1991) The sequence of change within the photosynthetic apparatus of wheat following short-term exposure to ozone. Plant Physiology 95, 529-535.
GROOME, Q., BAKER, N.R. & LONG, S.P. (1991) Photoinhibition in holly (Ilex aquifolium) in the field in S. England. Physiologia Plantarum 83, 585-590.  
JAHNKE, L.S., HULL, M.R. & LONG, S.P. (1991) Chilling and oxygen metabolising enzymes in Zea mays and Zea diploperennis. Plant Cell and Environment 14, 97- 104.  
LONG, S.P. (1991) Modification of the response of photosynthetic productivity to rising temperature by atmospheric CO2 concentrations. Has its importance been underestimated? - Opinion. Plant Cell and Environment 14, 729-739.  
LONG, S.P. & DRAKE, B.G. (1991) Effect of the long-term elevation of CO2 concentration in the field on the quantum yield of photosynthesis of the C3 sedge, Scirpus olneyi. Plant Physiology 96, 221-226.  
LONG, S.P. & HUTCHIN, P.B. (1991) Primary production in grasslands and coniferous forests in relation to climate change: An overview. Ecological Applications 1, 139-156.  
PIEDADE, M.T., JUNK, W.J. & LONG, S.P. (1991) The productivity of the C4 grass Echinochloa polystachya in the Amazon floodplain. Ecology 72, 1456-63.  
SHEN, Y.-G., QIU, G.-X., XU, D.-Q., HUANG, Q.-M., YANG, D.-D., GAO, A.-X., LONG, S.P. & HALL, D.O. (1991) Studies on the Photosynthesis of Bamboo. Chinese Journal of Botany 3, 116-121.  
STIRLING, C.M., NIE, G.-Y., AGUILERA, C., NUGAWELA, A., LONG, S.P. & BAKER, N.R. (1991) Photosynthetic productivity of an immature maize crop: changes in quantum yield of CO2 assimilation, coversion efficiency and thylakoid proteins. Plant Cell and Environment 14, 947-954.  

Recently published reviews:

LONG, S.P., HUMPHRIES, S. & FALKOWSKI, P.G. (1994) Photoinhibition of photosynthesis in nature. Annual Reviews of Plant Physiology and Plant Molecular Biology 45, 633-662.  
WEBBER, A., NIE, G.-Y. & LONG, S.P. (1994) Effects of rising CO2 concentration on expression of photosynthetic proteins. Photosynthesis Research 39, 413-425.  
LONG, S.P. AND J.-E. HÄLLGREN (1993) Measurement of CO2 assimilation by plants in the field and laboratory. In: Photosynthesis and Production in a Changing Environment: A Field and Laboratory Manual, (D.O. Hall, J.M.O. Scurlock, H.R. Bolhŕr-Nordenkampf, R.C. Leegood, and S.P. Long, eds.). Chapman & Hall, London, pp. 129-167. LONG, S.P. & DRAKE, B.G. (1992) Photosynthetic CO2 assimilation and rising atmospheric CO2 concentrations. In: Crop Photosynthesis: Spatial and Temporal Determinants. Topics in Photosynthesis Research Vol. 12 (N.R. Baker and H. Thomas eds.) Elsevier, Amsterdam. pp. 69-104. JONES, M.B., LONG, S.P., ROBERTS, M.J. (1992) Synthesis of tropical grasslands productivity. In: Primary Productivity of Tropical Ecosystems. (Long, S.P., Roberts, M.J. & Jones, M.B., eds.) Chapman & Hall, London, pp. 212-255.. LONG, S.P. & JONES, M.B. (1992) Introduction and general methods. In: Primary Productivity of Tropical Ecosystems. (Long, S.P., Roberts, M.J. & Jones, M.B., eds.) Chapman & Hall, London, pp. 1-24.  

Recently edited books:

HALL, D.O., SCURLOCK, J.M.O., BOLHAR-NORDENKAMPF, H.O., LEEGOOD, R.C. & LONG, S.P. (1993) Photosynthesis and Production in a Changing Environment: a Field and Laboratory Manual. Chapman & Hall, London. 464 pp. LONG, S.P., ROBERTS, M.J. & JONES, M.B. (1992) Primary Productivity of Tropical Ecosystems. Chapman & Hall, London, 267 pp. LONG, S.P., WOODWARD, F.I. (1988) Plants and Temperature, Symposium of the Society for Experimental Biology, Cambridge University Press. 406 pp.  


Dr. Marion Martin

My main input for WIMOVAC has been the construction of the model to simulate the effects of ozone exposure on wheat photosynthesis. This formed part of my PhD thesis, together with a proposed mechanistically-rich model for isoprene emission. I am currently involved in work for the European Sorghum Group adapting the wheat growth module of WIMOVAC to form a crop growth model for sorghum. In addition, as part of the preliminary work on the new FACE project based in Michigan, USA, I am investigating a process-based model to simulate the effects of ozone on aspen photosynthesis.

Recent Publications: MARTIN M.J. (1997) Models of the interactive effects of rising ozone, carbon dioxide and temperature on canopy carbon dioxide exchange and isoprene emission. PhD. Thesis, University of Essex. MARTIN M.J., HUMPHRIES S.W., FARAGE P.K., McKEE, I.F. & LONG S.P. (1995) in: Photosynthesis: From Light to Biosphere, Vol 5, ed. Mathis P., pp. 829-832.


Mr. Steve Humphries

I am chiefly responsible for the technical aspects of development for WIMOVAC, WOFTS and this web site. Questions relating to these issues should be addressed to me directly by e-mail at: the address given below.

Research Papers 

HUMPHRIES, S.A. & LONG, S.P. (1995) WIMOVAC: a software package for modelling the dynmaics of plant leaf and canopy photosynthesis. CABIOS 11, 361-371

Humphries, S.W., Jones, M.B., Long, S.P. & Morison, J.I.L.(1998) Development and Testing of a Mechanistic Model of Papyrus (Cyperus papyrus L.) Canopy Carbon Exchange using Eddy Covariance. Submitted to Biosphere/Geosphere Sciences.

Martin, M. J. & Humphries, S.W. (1995) A Mechanistic Model For the Prediction Of the Effects Of Rising Tropospheric Ozone Concentration On Wheat Photosynthesis. Photosynthesis: From Light to Biosphere, Vol. 5. Mathis. P: 829-832.

Long, S.P., Osborne, C.P. & Humphries S.W. (1998) Photosynthesis, Rising Atmospheric Carbon Dioxide Concentration and Climate Change. In: Global Change Effects on Coniferous Forests and Grassland edited by A.I. Breymeyer, D.O.Hall, J.M. Mellilo and G.I. Agren. SCOPE 56 - John Wiley & Sons. New York.


Recently published reviews:

LONG, S.P., HUMPHRIES, S. & FALKOWSKI, P.G. (1994) Photoinhibition of photosynthesis in nature. Annual Reviews of Plant Physiology and Plant Molecular Biology 45, 633-662.  

Other published material:

Steensgard, J., Humphries, S.W. & Spragg, S.P. (1996) Measurement of Sedimentation Coefficients. In: Preparative Centrifugation edited by Rickwood D. The Practical Approach Series. IRL Press Ltd. New York.

Spragg, S.P., Steensgard, J. & Humphries, S.W. (1996) Theoretical Aspects of Practical Centrifugation. In: Preparative Centrifugation edited by Rickwood D. The Practical Approach Series. IRL Press Ltd. New York.

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Last modified: August 26, 1998