Progress 10/01/04 to 09/30/09
Outputs
OUTPUTS: Activities: By combining direct measurements of surface ozone over the past 30 years with yield data in the counties monitored we developed regression equations relating year-year variation in yield with year-year variation in growing season temperature, precipitation and surface ozone. This analysis showed that although temperature and precipitation accounted for much of the variation, that ozone accounted for a statistically significant proportion of the residual variation. Deconvolution showed that we could use actual data of regional crop yields coupled with measured ozone concentrations to quantify losses. The regressions predict that the growing season average [O3] of 48.6 ppb across the U.S. in 2006 resulted in average yield losses of 0.29, 0.47, and 1.02 tons per hectare (t ha-1) for soybean, rice and maize, respectively. In proportion to the total crop, these represent losses of 10%, 4.5%, and 10% for soybean, rice and maize respectively in 2006. The expected 20% increase in [O3] by 2050 would further lower the yields of these three crops by 0.44, 0.24, and 1.50 t ha-1, respectively. The predicted decrease in soybean yield by O3 (16%) agrees well with the observed yield loss (20%) in the field in response to a 20% experimental elevation of [O3] by 20% under fully open-air field conditions in SoyFACE as reported previously. During this period we have also shown that the standard laboratory method of assessing mechanisms of ozone damage produces very different effects in soybean to the chronic pollution which actually operates under field conditions. Events: These findings were presented in invited University departmental seminars at the Danforth Center, St. Louis, Rutgers University, Princeton University, Harvard University, Australian National University, Essex University (UK), Rothamsted Experimental Station (UK) and the Institutes of Computational Biology and of Plant Physiology (Shanghai); a Society of Experimental Biology workshop at the International University, Baeza, Spain; and by Dr. Xinguang Zhu in workshops to CIMMYT (Mexico) and IRRI (Phillipines). Tutoring: This study formed part of the training post-doctoral fellows of Dr. Shawna Naidu (now Senior Instructor, School of Molecular and Cell Biology, Illinois), Dr. Xinguang Zhu (now Laboratory Leader for the Max Plank-CAS Joint Institute of Computational Biology) and graduate student Charles Chen (now post-doctoral fellow with JISC/IRRI - Japan/Phillipines). PARTICIPANTS: These results were discussed with visitors from Monsanto who have been considering a collaboration with the SoyFACE project and with staff from EPA who are examining new ozone standards. A post-doctoral fellow and a graduate student received training working on this project. TARGET AUDIENCES: This information should reach: a) Farmers to understand the real costs of current levels of air pollution on their yields, and the fact that climate change will exacerbate losses. b) Plant breeding organizations, to understand the opportunity to increase yields by selecting for increased tolerance to yields. c) Regulators to understand that current target ozone concentrations for rural areas are inadequate. PROJECT MODIFICATIONS: Corn and rice have been added to the modeling effort, since preliminary analysis showed that they were also affected by ozone.
Impacts
A change in knowledge. Ozone pollution standards are based solely on the effect on human health. Evidence of direct effects on crops has been rejected until now, because it comes from chamber and greenhouse experiments of uncertain relevance to the situation in farm fields. Here by a regression approach, and after separating out related variables, that ozone is resulting today in about a 10% yield loss for soybean, and unexpectedly a similar proportionate loss for corn. At 2006 prices the losses across the nation amounted to $8.6Bn. This provides important evidence for the value of the work of others at Illinois, who are using the SoyFACE facility to understand the basis of genetic variation in ozone tolerance in soybean. A paper about these findings has been reviewed by the journal Nature twice, and a third submission has been invited. Our finding on laboratory vs. field impacts of ozone should have an important influence on experimental design for selecting soybeans for ozone tolerance.
Publications
- Chen, C.P., Frank, T.D. and Long, S.P. 2009. Is a short, sharp shock equivalent to long-term punishment? Contrasting the spatial pattern of acute and chronic ozone damage to soybean leaves via chlorophyll fluorescence imaging. Plant Cell and Environment 32: 327-335
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Activities include conducting and analyzing experiments or surveys, assessments, facilitating, teaching, or mentoring. This work resulted in invitations to present the findings in several invited seminars (cost paid by hosts), most importantly: 1) The 9th Woolhouse Lecturer and Plenary Speaker "Plants and Global Atmospheric Change - Threats, Challenges and Opportunities", Society for Experimental Biology Annual Meeting, Marseilles, France (July, 2008). 2) Featured Speaker, "Soybean and ozone SoyFACE and beyond." Plants and Climate Change Conference. Iowa State University, Ames, IA (April 2008). Other invited talks about this work in 2008 were to seminar series at Washington University, St. Louis; Tokyo University, Japan; Glasgow University, Scotland; and Essex University, England. Models have been made publicly available through Chen et al. (2008). Field site visits were conducted for two visiting groups from Japan and China, a growers group from Brazil, and interested attendees at the Annual UI Agronomy Day. PARTICIPANTS: Charles Chen, who conducted part of his training in this work, has obtained his Ph.D. and won an NIH/JSPP Fellowship to undertake physiological crop breeding work jointly between the University of Tsukuba and the International Rice Research Institute. Xinguang Zhu, who conducted part of his post-doctoral training in this work, has been appointed a Junior Laboratory Leader at the CAS/Max Plank Institute of Computational Biology. TARGET AUDIENCES: Bioengineering and plant breeding companies and environmental protection agencies. PROJECT MODIFICATIONS: An extension is requested to further develop these models and the novel screening opportunities that they represent.
Impacts
The research has explained, by model and direct field measurements, that loss of yield of soybean due to the elevation of surface ozone concentration is predominantly the result of decreased photosynthetic efficiency and not the result of decreased leaf area - see Dermody et al. (2008) for details. We have identified a means, via pattern analysis of leaf chlorophyll analysis, to diagnose efficiency loss due to ozone impacts - currently in preparation for publication. The methods developed have allowed extension of this work to other vegetation.
Publications
- Dermody, O., Long, S.P., McConnaughay, K. and DeLucia, E.H. 2008. How do elevated CO2 and O3 affect the interception and utilization of radiation by a soybean canopy Global Change Biology 14, 556-564.
- Chen, C.P., Xhu, X.G. and Long, S.P. 2008. The effect of leaf-level spatial variability in photosynthetic capacity on biochemical parameter estimates using the Farquhar model. A theoretical analysis. Plant Physiology 148, 1139-1147.
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Progress 01/01/07 to 12/31/07
Outputs
The results have been disseminated through invited research presentations to international audiences: ComBio - Combined Biological Sciences Congress, Brisbane, Australia, The 27th Blackman Lecture, Oxford, UK; through radio and press: BBC One World Too Hot to Feed BBC, Science Now NPR, and MSNBC TV; and through 230 Press articles including The Times, NY Times, Washington Post, Chicago Tribune.
Impacts
Peak daily ozone concentrations during the summer in central Illinois, and much of the state, average 60 ppb with higher levels in counties adjacent to Chicago and St. Louis (EPA AirNow); Illinois therefore accounts for a substantial portion of this predicted loss. Most models for forecasting current year yields and future yields under global climate change take no account of ozone. Those projections which have been made assume that the impact of ozone is fixed regardless of environmental conditions. However, ozone impacts are variable, damage being diminished by drought, rising CO2, low temperatures, low light, and growth stage (Morgan, Ainsworth and Long, 2003). Ozone elicits damage by entering via the stomata, the more open the stomata the greater the damage for a given ozone concentration. We have shown previously, for wheat, that mechanistic prediction of stomatal aperture can accurately simulate cumulative ozone damage (Martin, Farage, Humphries and Long, 2000).
Our work in this CRIS project is developing a model of soybean growth incorporating a physiologically based response to ozone and its interactions with temperature, light, humidity and CO2, to improve prediction of current and future damage to the soybean crop. This year we have focused on quantifyin the effects of ozone on soybean. From direct measurements in the field within the SoyFACE experiment we show that current elevation of ozone is decreasing photosynthesis and yield by about 15 - 20%, and a similar further decline for the further increases in surface ozone forecast for 2050 (Bernacchi, Leakey, Heady, Morgan, Dohleman, McGrath, Gillespie, Wittig, Rogers, Long and Ort, 2006, and Morgan, Mies, Bollero, Nelson and Long, 2006). These decreases in soybean parallel those that we have demonstrated in a separate study for tree production (Wittig, Ainsworth and Long, 2007). We have shown that while rising CO2 significantly increases the fecundity of western corn root worm variant
entering the late soybean crop, ozone does not affect this major pest (Schroeder, Gray, Ratcliffe, Estes and Long, 2006). In the context of global grain production these reductions in soybean yield due to ozone suggest a lower world supply than previously anticipated under global atmospheric change (Long, Ainsworth, Leakey, Nosberger and Ort, 2006, and Long, Ainsworth, Leakey, Ort, Nosberger and Schimel, 2007). SoyFACE tells us about soybean yield reduction at one location, but is ozone causing a reduction nation wide? To assess this we have examined year-year variation over the past 30 years for all U.S. counties in which surface ozone has been measured. A strong negative and significant correlation has been discovered. Yields decrease by about 2 bu/acre for every 1 part per billion increase in surface ozone, and vice-versa independently confirming the SoyFACE experiment, i.e. soybean yield is very sensitive to this pollutant. It also suggests that ozone is currently depressing
soybean yields nationally by about 20%. The work is currently in preparation for submission to Science.
Publications
- Bernacchi, C.J., Leakey, A.D.B., Heady, L.E., Morgan, P.B., Dohleman, F.G., McGrath, J.M., Gillespie, K.M., Wittig, V.E., Rogers, A., Long, S.P. and Ort, D.R. 2006. Hourly and seasonal variation in photosynthesis and stomatal conductance of soybean grown at future CO2 and ozone concentrations for 3 years under fully open-air field conditions. Plant Cell and Environment, 29, 2077-2090.
- Long, S.P., Ainsworth, E.A., Leakey, A.D.B., Nosberger, J. and Ort, D.R. 2006. Food for thought: Lower-than-expected crop yield stimulation with rising CO2 concentrations. Science, 312, 1918-1921.
- Long, S.P., Ainsworth, E.A., Leakey, A.D.B., Ort, D.R., Nosberger, J. and Schimel, D. 2007. Crop models, CO2, and climate change - Response. Science, 315, 460-460.
- Morgan, P.B., Mies, T.A., Bollero, G.A., Nelson, R.L. and Long, S.P. 2006. Season-long elevation of ozone concentration to projected 2050 levels under fully open-air conditions substantially decreases the growth and production of soybean. New Phytologist, 170, 333-343.
- Schroeder, J.B., Gray, M.E., Ratcliffe, S.T., Estes, R.E. and Long, S.P. 2006. Effects of elevated Co-2 and O-3 on a variant of the western corn rootworm (Coleoptera : Chrysomelidae). Environmental Entomology, 35, 637-644.
- Wittig, V.E., Ainsworth, E.A. and Long S.P. 2007. To what extent do current and projected increases in surface ozone affect photosynthesis and stomatal conductance of trees? A meta-analytic review of the last 3 decades of experiments. Plant Cell and Environment, 30, 1150-1162.
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Progress 01/01/06 to 12/31/06
Outputs
During the past 12 months several of the data studies needed to inform the modeling effort have been completed (see publications). This year a range of soybean germplasm lines were planted in soyface and monitored for ozone effects; this has supported observations in prior years of variation in ozone response, also critical to projections of long-term responses of ozone. We have established that ozone concentrations of the levels observed in central Illinois (40 - 80 ppb) decrease photosynthesis of leaves, but only as they age. Most affected are the leaves that remain at the top of the canopy during grain filling; this is linked to the decreased individual grain mass observed under elevated ozone. We have also begun monitoring and modeling 3-dimenstional canopy growth which is critical to modeling light interception and in turn photosynthesis, and how both are affected. At present we are able to predict affects of ozone on individual leaf photosynthesis. Our next
phase is to integrate this into the growing canopy and finally partitioning of photosynthate to grain.
Impacts
Soybean is the number two crop in the U.S. in terms of area planted. However, it is very vulnerable to ozone which likely lowers current yields by between 10 and 20%. The effect of ozone is also likely to be increased by global climate change. Although ozone has decreased in some parts of the U.S., it has continued to increase in many rural regions. The Intergovernmental Panel on Climate Change predict that these increases will continue through this century. Accurate forecasting of the future impacts of ozone and climate change on the soybean crop in different regions of the U.S. will be critical to planning and setting priorities for crop improvement.
Publications
- Bernacchi, C.J., Leakey, A.D.B., Heady, L.E. and Long, S.P. 2006. Hourly and seasonal variation in photosynthesis and stomatal conductance of soybean grown at future CO2 and ozone concentrations for three years under fully open-air field conditions. Pl. Cell Env. 29, 2077-90.
- Dermody, O., Long, S.P. and DeLucia, E.H. 2006 How does elevated CO2 or ozone affect the leaf-area index of soybean when applied independently? New Phytol. 169, 145-155.
- Morgan, P.B., Mies, T.A., Bollero, G.A., Nelson, R.L. and Long, S.P. 2006. Season-long elevation of ozone concentration to projected 2050 levels under fully open-air conditions substantially decreases the growth and production of soybean. New Phytol. 170, 333-343.
- Schroeder, J.B., Gray, M.E., Ratcliffe, S.T., Estes, R.E. and Long, S.P. 2006 Effects of elevated CO2 and O3 on a variant of the western corn rootworm (Coleoptera: Chrysomelidae). Env. Entomol. 35, 637-644.
- Long, S.P., Ainsworth, E.A., Leakey, A.D.B., Nosberger, J. and Ort, D.R. 2006. Food for thought: Lower than expected crop yield stimulation with rising carbon dioxide concentrations. Science. 312, 1918-1921.
- Ort, D.R., Ainsworth, E.A., Aldea, M., Allen, D.J., Bernacchi, C.J., Berenbaum, M.R., Bollero, G.A., Cornic, G., Davey, P.A., Dermody, O.C., Dohleman, F.G., Hamilton, J.G., Heaton, E.A., Leakey, A.B.D., Mahoney, J., Mies, T.A., Morgan, P.B., Nelson, R.L., Rogers, A., Zangerl, A.R., Zhu, X.-G., DeLucia, E.H. and Long, SP. 2006. SoyFACE: The effects and interactions of elevated [CO2] and [O3] on soybean. In: Managed Ecosystems and CO2: Case studies, processes and perspectives. (J. Noesberger, S.P. Long, R.J. Norby, M. Stitt, G.R. Hendrey, and H. Blum, Eds.) Ecological Studies Series, Vol. 187. Springer-Verlag. Pp. 71-86.
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Progress 01/01/05 to 12/31/05
Outputs
Peak daily ozone concentrations during the summer in central Illinois, and much of the state, average 60 ppb with higher levels in counties adjacent to Chicago and St. Louis. Illinois therefore accounts for a substantial portion of this predicted loss. Most models for forecasting current year yields and future yields under global climate change take no account of ozone. Those projections which have been made assume that the impact of ozone is fixed regardless of environmental conditions. Ozone elicits damage by entering via the stomata, the more open the stomata the greater the damage for a given ozone concentration. Our work in this project is developing a model of soybean growth incorporating a physiologically-based response to ozone and its interactions with temperature, light, humidity and CO2, to improve prediction of current and future damage to the soybean crop. This year we have focused on tracking effects on canopy development for parameterizing the model. We
have tracked leaf area index and developmental stage in control and elevated ozone plots within the SoyFACE experiment, and compiled results from previous years. Elevation of ozone to 20% above ambient levels has significantly decreased leaf area index by ca. 20%. This occurred both in each of the past 3 years, and largely reflects the decreased lifespan and size of leaves developed in elevated ozone. In 2004 background ozone levels were well below average, such that our treatment elevated levels to the normal background. This still lowered leaf area index and yield by about 20%, suggesting that ozone is not only a future, but also current problem. Information on leaf area index dynamics and distribution is being used to scale up effects on photosynthesis to the canopy level in the framework of our previous models (www.life.uiuc.edu/plantbio/wimovac).
Impacts
Soybean is the number two crop in the U.S. in terms of area planted. However, it is very vulnerable to ozone which likely lowers current yields by between 10 and 20%. The effect of ozone is also likely to be increased by global climate change. Although ozone has decreased in some parts of the U.S., it has continued to increase in many rural regions. The Intergovernmental Panel on Climate Change predict that these increases will continue through this century. Accurate forecasting of the future impacts of ozone and climate change on the soybean crop in different regions of the U.S. will be critical to planning and setting priorities for crop improvement.
Publications
- Long S.P., Ainsworth E.A., Leakey A.D.B. and Morgan P.B. 2005. Global food insecurity. Treatment of major food crops with elevated carbon dioxide or ozone under large-scale fully open-air conditions suggests recent models may have overestimated future yields. Philosophical Transactions Of The Royal Society B-Biological Sciences, 360, 2011-2020.
- Morgan P.B., Bernacchi C.J., Ort D.R. and Long S.P. 2004. An in vivo analysis of the effect of season-long open-air elevation of ozone to anticipated 2050 levels on photosynthesis in soybean. Plant Physiology, 135, 2348-2357.
- Dermody O., Long S.P. and DeLucia E.H. 2006. How does elevated CO2 or ozone affect the leaf-area index of soybean when applied independently? New Phytologist, 169, 145-155.
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Progress 01/01/04 to 12/31/04
Outputs
This project has only been in place for ten weeks so the report largely concerns our reasoning and planned work. Based on current ozone levels within the contiguous U.S. (EPA AirNow), it can be calculated that ozone induced decrease in soybean yield may cost U.S. agriculture some $2bn per year (Morgan et al., 2003). Peak daily ozone concentrations during the summer in central Illinois, and much of the state, average 60 ppb with higher levels in counties adjacent to Chicago and St. Louis (EPA AirNow), Illinois therefore accounts for a substantial portion of this predicted loss. Most models for forecasting current year yields and future yields under global climate change take no account of ozone. Those projections which have been made assume that the impact of ozone is fixed regardless of environmental conditions. However, ozone impacts are variable, damage being diminished by drought, rising CO2, low temperatures, low light and growth stage (Morgan et al., 2003). Ozone
elicits damage by entering via the stomata, the more open the stomata the greater the damage for a given ozone concentration. We have shown previously, for wheat, that mechanistic prediction of stomatal aperture can accurately simulate cumulative ozone damage (Martin et al., 2000). Our work in this CRIS project is developing a model of soybean growth incorporating a physiologically-based response to ozone and its interactions with temperature, light, humidity and CO2 to improve prediction of current and future damage to the soybean crop. A leaf level model of ozone uptake and damage to capacity for carbon assimilation by soybean is being developed, based on our previous approach for wheat (Martin et al., 2000). The model is being parameterized from prior chamber studies of stomatal and photosynthetic responses to ozone (reviewed: Morgan et al. 2003). These responses will be tested within SoyFACE (Ainsworth et al., 2004, Rogers et al., 2004). This leaf model is being incorporated into
our whole plant physiological model of partitioning and production (www.life.uiuc.edu/plantbio/wimovac, (Humphries & Long, 1995)). Partitioning coefficients will be derived from our surveys of prior soybean studies (Ainsworth et al., 2002, Morgan et al., 2003) and phenology following the methods used in the DSSAT crop modeling system, using responses of yield and biomass observed within SoyFACE (www.soyface.uiuc.edu). Finally the model will be used with current national ozone distributions and future projected distributions to assess the impact of ozone on future soybean production by region.
Impacts
Soybean is the number two crop of the U.S. in terms of area planted. However, it is very vulnerable to ozone which likely lowers current yields by between 10 and 20%. The effect of ozone is also likely to be increased by global climate change. Although ozone has decreased in some parts of the U.S., it has continued to increase in many rural regions. The Intergovernmental Panel on Climate Change predicts that these increases will continue through this century. Accurate forecasting of the future impacts of ozone and climate change on the soybean crop in different regions of the U.S. will be critical to planning and setting priorities for crop improvement.
Publications
- Ainsworth, E.A., Rogers, A., Nelson, R. and Long, S.P. 2004. Testing the "source-sink" hypothesis of down-regulation of photosynthesis in elevated CO2 in the field with single gene substitutions in Glycine max. Agricultural and Forest Meteorology, 122, 85-94.
- Rogers, A., Allen, D.J., Davey, P.A., Morgan, P.B., Ainsworth, E.A., Bernacchi, C.J., Cornic, G., Dermody, O., Dohleman, F.G., Heaton, E.A., Mahoney, J., Zhu, X.G., Delucia, E.H., Ort, D.R. and Long, S.P. 2004. Leaf photosynthesis and carbohydrate dynamics of soybeans grown throughout their life-cycle under Free-Air Carbon dioxide Enrichment. Plant Cell and Environment, 27, 449-458.
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