Skip to main content

The effect of timing of growing season drought on flowering of a dominant C4 grass


Timing of precipitation is equally important as amount for determining ecosystem function, especially aboveground net primary productivity (ANPP), in a number of ecosystems. In tallgrass prairie of the Central Plains of North America, grass flowering stalks of dominant C4 grasses, such as Andropogon gerardii, can account for more than 70 % of ANPP, or almost none of it, as the number of flowering stalks produced is highly variable. Although growing season precipitation amount is important for driving variation in flowering stalk production, it remains unknown whether there are critical periods within the growing season in which sufficient rainfall must occur to allow for flowering. The effect of timing of rainfall deficit (drought) on flowering of A. gerardii, was tested by excluding rainfall during three periods within the growing season (starting in mid-April, mid-May and mid-June). Mid-summer drought (starting in mid-June) strongly reduced the flowering rate (e.g., density and biomass) of A. gerardii (e.g., as high as 94 % compared to the control), suggesting flowering is highly sensitive to precipitation at this time. This effect appeared to be related to plant water status at the time of flowering stalk initiation, rather than an indirect consequence of reduced C assimilation. Our results suggest that increased frequency of growing season drought forecast with climate change could reduce sexual reproduction in this dominant grass species, particularly if it coincides with timing of flowering stalk initiation, with important implications for ecosystem functioning.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4


  • Benson E, Hartnett D (2006) The role of seed and vegetative reproduction in plant recruitment and demography in tallgrass prairie. Plant Ecol 187:163–178

    Article  Google Scholar 

  • Briggs J, Knapp A (1995) Interannual variability in primary production in tallgrass prairie: climate, soil moisture, topographic position, and fire as determinants of aboveground biomass. Am J Bot 82:1024–1030

    Article  Google Scholar 

  • Craine J (2013) The importance of precipitation timing for grassland productivity. Plant Ecol 214:1085–1089. doi:10.1007/s11258-013-0236-4

    Article  Google Scholar 

  • Craine JM, Towne EG, Nippert JB (2010) Climate controls on grass culm production over a quarter century in a tallgrass prairie. Ecology 91:2132–2140

    Article  PubMed  Google Scholar 

  • Craine JM, Nippert JB, Elmore AJ, Skibbe AM, Hutchinson SL, Brunsell NA (2012) Timing of climate variability and grassland productivity. Proc Natl Acad Sci 109:3401–3405. doi:10.1073/pnas.1118438109

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Curtis J, Partch MAX (1950) Some factors affecting flower production in Andropogon gerardi. Ecology 31:488–489

    Article  Google Scholar 

  • Hulbert L (1988) Causes of fire effects in tallgrass prairie. Ecology 69:46–58

    Article  Google Scholar 

  • Kelly D (2001) Evaluating the wind pollination benefits of mast seeding. Ecology 82:117–126

    Article  Google Scholar 

  • Knapp AK (1984) Water relations and growth of three grasses during wet and drought years in a tallgrass prairie. Oecologia 65:35–43. doi:10.1007/BF00384460

    Article  Google Scholar 

  • Knapp AK (1985) Effect of fire and drought on the ecophysiology of Andropogon gerardii and Panicum virgatum in a tallgrass prairie. Ecology 66:1309–1320

    Article  Google Scholar 

  • Knapp AK, Hulbert L (1986) Production, density and height of flower stalks of three grasses in annually burned and unburned eastern kansas tallgrass prairie: a 4 year record. Southwest Nat 31:235–241

    Article  Google Scholar 

  • Knapp AK, Seastedt TR (1986) Detritus accumulation limits productivity of tallgrass prairie. Bioscience 36:662–668

    Article  Google Scholar 

  • Knapp AK, Briggs JM, Koelliker JK (2001) Frequency and extent of water limitation to primary production in a mesic temperate grassland. Ecosystems 4:19–28

    Article  Google Scholar 

  • Knapp AK, Fay PA, Blair JM, Collins SL, Smith MD, Carlisle JD, Harper CW, Danner BT, Lett MS, McCarron JK (2002) Rainfall variability, carbon cycling, and plant species diversity in a mesic grassland. Science 298:2202–2205

    Article  CAS  PubMed  Google Scholar 

  • Kucera CL, Ehrenreich J (1962) Some effects on annual burning on Central Missouri Prairie. Ecology 43:334

    Article  Google Scholar 

  • La Pierre KJ, Yuan S, Chang CC, Avolio ML, Hallett LM, Schreck T, Smith MD (2011) Explaining temporal variation in above-ground productivity in a mesic grassland: the role of climate and flowering. J Ecol 99:1250–1262. doi:10.1111/j.1365-2745.2011.01844.x

    Article  Google Scholar 

  • McCune B, Grace J (2002) Analysis of ecological communities. MjM Software, Bleneden Beach

    Google Scholar 

  • Muller B, Pantin F, Génard M, Turc O, Freixes S, Piques M, Gibon Y (2011) Water deficits uncouple growth from photosynthesis, increase C content, and modify the relationships between C and growth in sink organs. J Exp Bot 62:1715–1729

    Article  CAS  PubMed  Google Scholar 

  • NRCS (2014) NRCS web soil survey. USDA National Resources Conservation Service

  • Owensby C, Hyde R, Anderson K (1970) Effects of clipping and supplemental nitrogen and water on loamy upland bluestem range. J Range Manage 23:341

    Article  Google Scholar 

  • Owensby CE, Coyne PI, Ham JM, Auen LM, Knapp AK (1993) Biomass production in a tallgrass prairie ecosystem exposed to ambient and elevated CO2. Ecol Appl 3:644–653

    Article  Google Scholar 

  • Robinson TMP, La Pierre KJ, Vadeboncoeur MA, Byrne KM, Thomey ML, Colby SE (2013) Seasonal, not annual precipitation drives community productivity across ecosystems. Oikos 122:727–738. doi:10.1111/j.1600-0706.2012.20655.x

    Article  Google Scholar 

  • Seastedt TR, Knapp AK (1993) Consequences of nonequilibrium resource availability across multiple time scales: the transient maxima hypothesis. Am Nat 141:621–633

    Article  CAS  PubMed  Google Scholar 

  • Selbo SM, Snow AA (2005) flowering phenology and genetic similarity among local and recently introduced populations of Andropogon gerardii in Ohio. Restor Ecol 13:441–447. doi:10.1111/j.1526-100X.2005.00055.x

    Article  Google Scholar 

  • Sheffield J, Wood EF (2008) Projected changes in drought occurrence under future global warming from multi-model, multi-scenario, IPCC AR4 simulations. Clim Dyn 31:79–105

    Article  Google Scholar 

  • Sherry RA, Zhou X, Gu S, Arnone JA III, Schimel DS, Verburg PS, Wallace LL, Luo Y (2007) Divergence of reproductive phenology under climate warming. Proc Natl Acad Sci 104:198–202. doi:10.1073/pnas.0605642104

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Smith M, Knapp A (2003) Dominant species maintain ecosystem function with non-random species loss. Ecol Lett 6:509–517

    Article  Google Scholar 

  • Smith C, Hamrick JL, Kramer C (1990) The advantage of mast years for wind pollination. Am Nat 136:154–166

    Article  Google Scholar 

  • Swemmer AM, Knapp AK, Smith MD (2006) Growth responses of two dominant C4 grass species to altered water availability. Int J Plant Sci 167:1001–1010. doi:10.1086/505611

    Article  Google Scholar 

  • Wang Y, Li L, Ye T, Lu Y, Chen X, Wu Y (2013) The inhibitory effect of ABA on floral transition is mediated by ABI5 in Arabidopsis. J Exp Bot 64:675–684

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  • Wilcox K, von Fischer J, Muscha J, Petersen M, Knapp A (2015) Contrasting above- and belowground sensitivity of three Great Plains grasslands to altered rainfall regimes. Glob Change Biol 21:335–344

    Article  Google Scholar 

Download references


We thank the many individuals who helped make this work possible. Fieldwork assistance was provided by Lauren Baur, Francis Chaves, Elsie Denton, Andrew Felton, Ava Hoffman, Brian Leinwetter, Whitney Mowll, and Mariah Patton. Laboratory assistance was provided by Brianna Magbual and Katie Michaels. Meghan Avolio and Sally Koerner provided help with the shelter design. Philip Turk’s advice on statistical analysis was very valuable. Alan Knapp and Troy Ocheltree provided many valuable insights on overall experimental design and plant physiology. None of this work would have been possible without the Konza Prairie Biological Station and the people who work there, especially Patrick O’Neal. Support was provided by the National Science Foundation Long-term Ecological Research program.

Author contribution statement

J. D. D. and M. D. S. conceived and designed the experiment. J. D. D. executed the study, analyzed the data, made all tables and figures, and wrote the first draft of the manuscript. J. D. D. and M. D. S. contributed to revisions.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Melinda D. Smith.

Additional information

Communicated by Rowan Sage.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Dietrich, J.D., Smith, M.D. The effect of timing of growing season drought on flowering of a dominant C4 grass. Oecologia 181, 391–399 (2016).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Andropogon gerardii
  • Aboveground net primary productivity
  • Ecophysiology
  • Precipitation timing
  • Tallgrass prairie