Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Herbivores and nutrients control grassland plant diversity via light limitation


Human alterations to nutrient cycles1,2 and herbivore communities3,4,5,6,7 are affecting global biodiversity dramatically2. Ecological theory predicts these changes should be strongly counteractive: nutrient addition drives plant species loss through intensified competition for light, whereas herbivores prevent competitive exclusion by increasing ground-level light, particularly in productive systems8,9. Here we use experimental data spanning a globally relevant range of conditions to test the hypothesis that herbaceous plant species losses caused by eutrophication may be offset by increased light availability due to herbivory. This experiment, replicated in 40 grasslands on 6 continents, demonstrates that nutrients and herbivores can serve as counteracting forces to control local plant diversity through light limitation, independent of site productivity, soil nitrogen, herbivore type and climate. Nutrient addition consistently reduced local diversity through light limitation, and herbivory rescued diversity at sites where it alleviated light limitation. Thus, species loss from anthropogenic eutrophication can be ameliorated in grasslands where herbivory increases ground-level light.

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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Figure 1: Geographic and climatic distribution of experimental sites.
Figure 2: Mixed-effects model parameters showing average response of plots (n = 360) to 3 years of nutrient addition and herbivore exclusion by fencing.
Figure 3: Effects of herbivore exclusion by fencing on mean grassland species richness and the mean proportion of PAR reaching ground level at 29 sites after 3 years of treatment.


  1. Foley, J. A., Monfreda, C., Ramankutty, N. & Zaks, D. Our share of the planetary pie. Proc. Natl Acad. Sci. USA 104, 12585–12586 (2007)

    Article  CAS  ADS  Google Scholar 

  2. Rockström, J. et al. A safe operating space for humanity. Nature 461, 472–475 (2009)

    Article  ADS  Google Scholar 

  3. Gibson, D. Grasses and Grassland Ecology (Oxford Univ. Press, 2009)

    Google Scholar 

  4. Neely, C., Bunning, S. & Wilkes, A. Review of Evidence on Drylands Pastoral Systems and Climate Change: Implications and Opportunities for Mitigation and Adaptation (Food and Agriculture Organization of the United Nations, 2009)

    Google Scholar 

  5. Foley, J. A. et al. Solutions for a cultivated planet. Nature 478, 337–342 (2011)

    Article  CAS  ADS  Google Scholar 

  6. Millennium Ecosystem Assessment Panel. Ecosystems and Human Well-being: Synthesis (Island Press, 2005)

  7. Wassenaar, T. et al. Projecting land use changes in the Neotropics: The geography of pasture expansion into forest. Glob. Environ. Change 17, 86–104 (2007)

    Article  Google Scholar 

  8. Harpole, W. S. & Tilman, D. Grassland species loss resulting from reduced niche dimension. Nature 446, 791–793 (2007)

    Article  CAS  ADS  Google Scholar 

  9. Holt, R. D., Grover, J. & Tilman, D. Simple rules for interspecific dominance in systems with exploitative and apparent competition. Am. Nat. 144, 741–771 (1994)

    Article  Google Scholar 

  10. Díaz, S., Fargione, J., Chapin, F. S. & Tilman, D. Biodiversity loss threatens human well-being. PLoS Biol. 4, e277 (2006)

    Article  Google Scholar 

  11. Hillebrand, H. et al. Consumer versus resource control of producer diversity depends on ecosystem type and producer community structure. Proc. Natl Acad. Sci. USA 104, 10904–10909 (2007)

    Article  CAS  ADS  Google Scholar 

  12. Proulx, M. & Mazumder, A. Reversal of grazing impact on plant species richness in nutrient-poor vs. nutrient-rich ecosystems. Ecology 79, 2581–2592 (1998)

    Article  Google Scholar 

  13. Worm, B., Lotze, H. K., Hillebrand, H. & Sommer, U. Consumer versus resource control of species diversity and ecosystem functioning. Nature 417, 848–851 (2002)

    Article  CAS  ADS  Google Scholar 

  14. Olff, H. & Ritchie, M. E. Effects of herbivores on grassland plant diversity. Trends Ecol. Evol. 13, 261–265 (1998)

    Article  CAS  Google Scholar 

  15. Milchunas, D. G. & Lauenroth, W. K. Quantitative effects of grazing on vegetation and soils over a global range of environments. Ecol. Monogr. 63, 327–366 (1993)

    Article  Google Scholar 

  16. Huisman, J. & Weissing, F. J. Light-limited growth and competition for light in well-mixed aquatic environments: an elementary model. Ecology 75, 507–520 (1994)

    Article  Google Scholar 

  17. Bakker, E. S., Ritchie, M. E., Olff, H., Milchunas, D. G. & Knops, J. M. H. Herbivore impact on grassland plant diversity depends on habitat productivity and herbivore size. Ecol. Lett. 9, 780–788 (2006)

    Article  Google Scholar 

  18. Weissing, F. J. & Huisman, J. Growth and competition in a light gradient. J. Theor. Biol. 168, 323–336 (1994)

    Article  Google Scholar 

  19. Dybzinski, R. & Tilman, D. Resource use patterns predict long-term outcomes of plant competition for nutrients and light. Am. Nat. 170, 305–318 (2007)

    Article  Google Scholar 

  20. Hautier, Y., Niklaus, P. A. & Hector, A. Competition for light causes plant biodiversity loss after eutrophication. Science 324, 636–638 (2009)

    Article  CAS  ADS  Google Scholar 

  21. Newman, E. I. Competition and diversity in herbaceous vegetation. Nature 244, 310 (1973)

    Article  ADS  Google Scholar 

  22. Chesson, P. Mechanisms of maintenance of species diversity. Annu. Rev. Ecol. Syst. 31, 343–366 (2000)

    Article  Google Scholar 

  23. Coley, P. D., Bryant, J. P. & Chapin, F. S. Resource availability and plant antiherbivore defense. Science 230, 895–899 (1985)

    Article  CAS  ADS  Google Scholar 

  24. Strauss, S. Y., Rudgers, J. A., Lau, J. A. & Irwin, R. E. Direct and ecological costs of resistance to herbivory. Trends Ecol. Evol. 17, 278–285 (2002)

    Article  Google Scholar 

  25. Lind, E. M. et al. Life-history constraints in grassland plant species: a growth-defence trade-off is the norm. Ecol. Lett. 16, 513–521 (2013)

    Article  Google Scholar 

  26. Grime, J. P. & Pierce, S. The evolutionary strategies that shape ecosystems (Wiley-Blackwell, 2012)

    Book  Google Scholar 

  27. Borer, E. T. et al. Finding generality in ecology: a model for globally distributed experiments. Methods Ecol. Evol. 5, 65–73 (2014)

    Article  Google Scholar 

  28. De Schrijver, A. et al. Cumulative nitrogen input drives species loss in terrestrial ecosystems. Glob. Ecol. Biogeogr. 20, 803–816 (2011)

    Article  Google Scholar 

  29. Crawley, M. J. Plant ecology (Blackwell Science, 1997)

    Google Scholar 

  30. Hijmans, R. J., Cameron, S. E., Parra, J. L., Jones, P. G. & Jarvis, A. Very high resolution interpolated climate surfaces for global land areas. Int. J. Climatol. 25, 1965–1978 (2005)

    Article  Google Scholar 

  31. The Oak Ridge National Laboratory Distributed Active Archive Center. (accessed (25 August 2011)

  32. Grueber, C. E., Nakagawa, S., Laws, R. J. & Jamieson, I. G. Multimodel inference in ecology and evolution: challenges and solutions. J. Evol. Biol. 24, 699–711 (2011)

    Article  CAS  Google Scholar 

Download references


This work uses data from the Nutrient Network ( experiment, funded at the site scale by individual researchers. Coordination and data management are supported by funding to E. Borer and E. Seabloom from the NSF Research Coordination Network (NSF-DEB-1042132) and Long Term Ecological Research (NSF-DEB-1234162 to Cedar Creek LTER) programs and the UMN Institute on the Environment (DG-0001-13). The Minnesota Supercomputer Institute hosts project data. We are grateful to F. Isbell for suggestions that improved the manuscript. Any use of trade names is for descriptive purposes only and does not imply endorsement by the US Government.

Author information

Authors and Affiliations



E.T.B., E.W.S., W.S.H. and E.M.L. are Nutrient Network coordinators. E.T.B., W.S.H., H.H. and D.S.G. developed and framed the research questions in this paper. All authors contributed data from this experiment. E.T.B. and E.W.S. analysed the data. D.S.G., W.S.H. and E.M.L. contributed to data analyses. E.T.B. wrote the paper with input from all authors. Supplementary Information Appendix S2 provides further information on author contributions.

Corresponding author

Correspondence to Elizabeth T. Borer.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 Regression parameters for treatment effects.

ac, All available data are shown for richness (a), total biomass (b) and ambient light reaching ground level (c). Error bars represent ±2 s.e.m. Treatment years and their associated sample sizes are shown in each panel. One- and two-year models represent greater spatial extent and replication, but reduced temporal extent compared to Fig. 2 in the main text. Four-year models represent longer temporal effects, but reduced spatial extent, particularly for light measurements. All models were fitted as in Extended Data Tables 2, 3, 4 and described in the Methods.

Extended Data Figure 2 Fertilization does not alter the relationship between ‘fence’ effects on light and diversity.

The log response ratio (LRR) model of the effect of fences (herbivore exclusion) on richness and light (year 3 data) demonstrates no additional effect of nutrient addition on the relationship shown in Fig. 3. The grey region indicates the 95% confidence interval around the regression. The effect of fences on ground-level light predicts changes in plot-scale species richness (P = 0.00254), whereas fertilization is not included in the final statistical model of this relationship (P > 0.05). Thus, the magnitude of the effect of grazers on richness is dependent on the magnitude of their effect on light regardless of whether a plot has been fertilized.

Extended Data Table 1 Sites contributing experimental data
Extended Data Table 2 Statistical model for treatment effects on richness after 3 years of treatment (n = 29) as a function of fertilization by N, P and K and micronutrients, herbivore exclusion by fencing, and their interaction
Extended Data Table 3 Statistical model for treatment effects on biomass after 3 years of treatment (n = 29) as a function of fertilization by N, P and K and micronutrients, herbivore exclusion by fencing, and their interaction
Extended Data Table 4 Statistical model for treatment effects on proportion of photosynthetically active radiation (PAR) reaching ground level after 3 years of treatment (n = 29) as a function of fertilization by N, P and K and micronutrients, herbivore exclusion by fencing, and their interaction
Extended Data Table 5 Statistical model for biomass effects on ground-level proportion of photosynthetically active radiation (PAR) after 3 years of treatment (n = 29) as a function of total plot-scale biomass
Extended Data Table 6 Effects of climate, nitrogen deposition, soil nitrogen and site productivity on change in ground-level light across experimental fencing treatments after 3 years of treatment
Extended Data Table 7 Effects of climate, nitrogen deposition, soil nitrogen and site productivity on site-level mean biomass change across experimental fencing treatments after 3 years of treatment
Extended Data Table 8 Effects of climate, nitrogen deposition, soil nitrogen, site productivity, and change in light on change in site-level mean plant species richness across experimental fencing treatments after three years of treatments

Supplementary information

Supplementary Information

This file contains Supplementary Appendices S1-S2. (PDF 159 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Borer, E., Seabloom, E., Gruner, D. et al. Herbivores and nutrients control grassland plant diversity via light limitation. Nature 508, 517–520 (2014).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing