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Community rescue in experimental phytoplankton communities facing severe herbicide pollution

Abstract

Community rescue occurs when ecological or evolutionary processes restore positive growth in a highly stressful environment that was lethal to the community in its ancestral form, thus averting biomass collapse in a deteriorating environment. Laboratory evidence suggests that community rescue is most likely in high-biomass communities that have previously experienced moderate doses of sublethal stress. We assessed this result under more natural conditions, in a mesocosm experiment with phytoplankton communities exposed to the ubiquitous herbicide glyphosate. We tested whether community biomass and prior herbicide exposure would facilitate community rescue after severe contamination. We found that prior exposure to glyphosate was a very strong predictor of the rescue outcome, while high community biomass was not. Furthermore, although glyphosate had negative effects on diversity, it did not influence community composition significantly, suggesting a modest role for genus sorting in this rescue process. Our results expand the scope of community rescue theory to complex ecosystems and confirm that prior stress exposure is a key predictor of rescue.

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Fig. 1: Experimental site, design and timeline.
Fig. 2: Phytoplankton biomass dynamics during the experiment.
Fig. 3: Effect of glyphosate on phytoplankton biodiversity.
Fig. 4: Effect of glyphosate on phytoplankton community composition.
Fig. 5: Predictors of final phytoplankton biomass.

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Data availability

The data necessary to reproduce figures and results in this study are publicly archived in Figshare: https://doi.org/10.6084/m9.figshare.11717361.v2.

Code availability

The R code necessary to reproduce figures and results in this study is available on GitHub: https://github.com/VFugere/LEAP2016_NEE.

References

  1. Ceballos, G., Ehrlich, P. R. & Dirzo, R. Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines. Proc. Natl Acad. Sci. USA 114, E6089–E6096 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Wake, D. B. & Vredenburg, V. T. Are we in the midst of the sixth mass extinction? A view from the world of amphibians. Proc. Natl Acad. Sci. USA 105, 11466–11473 (2008).

    Article  PubMed  PubMed Central  Google Scholar 

  3. Thomas, C. D. Rapid acceleration of plant speciation during the Anthropocene. Trends Ecol. Evol. 30, 448–455 (2015).

    Article  PubMed  Google Scholar 

  4. Cardinale, B. J. et al. Biodiversity loss and its impact on humanity. Nature 486, 59–67 (2012).

    Article  CAS  PubMed  Google Scholar 

  5. Hooper, D. U. et al. A global synthesis reveals biodiversity loss as a major driver of ecosystem change. Nature 486, 105–108 (2012).

    Article  CAS  PubMed  Google Scholar 

  6. Chevin, L.-M., Gallet, R., Gomulkiewicz, R., Holt, R. D. & Fellous, S. Phenotypic plasticity in evolutionary rescue experiments. Phil. Trans. R. Soc. Lond. B 368, 20120089 (2013).

    Article  Google Scholar 

  7. Kovach-Orr, C. & Fussmann, G. F. Evolutionary and plastic rescue in multitrophic model communities. Phil. Trans. R. Soc. B 368, 20120084 (2013).

    Article  PubMed  PubMed Central  Google Scholar 

  8. Bell, G. Evolutionary rescue. Annu. Rev. Ecol. Evol. Syst. 48, 605–627 (2017).

    Article  Google Scholar 

  9. Alexander, H. K., Martin, G., Martin, O. Y. & Bonhoeffer, S. Evolutionary rescue: linking theory for conservation and medicine. Evol. Appl. 7, 1161–1179 (2014).

    Article  PubMed  PubMed Central  Google Scholar 

  10. Carlson, S. M., Cunningham, C. J. & Westley, P. A. H. Evolutionary rescue in a changing world. Trends Ecol. Evol. 29, 521–530 (2014).

    Article  PubMed  Google Scholar 

  11. Gomulkiewicz, R. & Holt, R. D. When does evolution by natural selection prevent extinction? Evolution 49, 201–207 (1995).

    Article  PubMed  Google Scholar 

  12. Bell, G. & Gonzalez, A. Evolutionary rescue can prevent extinction following environmental change. Ecol. Lett. 12, 942–948 (2009).

    Article  PubMed  Google Scholar 

  13. Bell, G. & Gonzalez, A. Adaptation and evolutionary rescue in metapopulations experiencing environmental deterioration. Science 332, 1327–1330 (2011).

    Article  CAS  PubMed  Google Scholar 

  14. Ramsayer, J., Kaltz, O. & Hochberg, M. E. Evolutionary rescue in populations of Pseudomonas fluorescens across an antibiotic gradient. Evol. Appl. 6, 608–616 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Samani, P. & Bell, G. Adaptation of experimental yeast populations to stressful conditions in relation to population size. J. Evol. Biol. 23, 791–796 (2010).

    Article  CAS  PubMed  Google Scholar 

  16. Gonzalez, A. & Bell, G. Evolutionary rescue and adaptation to abrupt environmental change depends upon the history of stress. Phil. Trans. R. Soc. Lond. B 368, 20120079 (2013).

    Article  Google Scholar 

  17. Lachapelle, J. & Bell, G. Evolutionary rescue of sexual and asexual populations in a deteriorating environment. Evolution 66, 3508–3518 (2012).

    Article  PubMed  Google Scholar 

  18. Low-Décarie, E. et al. Community rescue in experimental metacommunities. Proc. Natl Acad. Sci. USA 112, 14307–14312 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  19. Bell, G. et al. Trophic structure modulates community rescue following acidification. Proc. R. Soc. B 286, 20190856 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Fussmann, G. F. & Gonzalez, A. Evolutionary rescue can maintain an oscillating community undergoing environmental change. Interface Focus 3, 20130036 (2013).

    Article  PubMed  PubMed Central  Google Scholar 

  21. Hillebrand, H. et al. Decomposing multiple dimensions of stability in global change experiments. Ecol. Lett. 21, 21–30 (2018).

    Article  PubMed  Google Scholar 

  22. Pimm, S. L. The complexity and stability of ecosystems. Nature 307, 321–326 (1984).

    Article  Google Scholar 

  23. McCann, K. S. The diversity–stability debate. Nature 405, 228–233 (2000).

    Article  CAS  PubMed  Google Scholar 

  24. Tsui, M. T. K. & Chu, L. M. Aquatic toxicity of glyphosate-based formulations: comparison between different organisms and the effects of environmental factors. Chemosphere 52, 1189–1197 (2003).

    Article  CAS  PubMed  Google Scholar 

  25. Saxton, M. A., Morrow, E. A., Bourbonniere, R. A. & Wilhelm, S. W. Glyphosate influence on phytoplankton community structure in Lake Erie. J. Gt. Lakes Res. 37, 683–690 (2011).

    Article  CAS  Google Scholar 

  26. Christy, S. L., Karlander, E. P. & Parochetti, J. V. Effects of glyphosate on the growth rate of Chlorella. Weed Sci. 29, 5–7 (1981).

    Article  CAS  Google Scholar 

  27. Wong, P. K. Effects of 2,4-D, glyphosate and paraquat on growth, photosynthesis and chlorophyll—a synthesis of Scenedesmus quadricauda Berb 614. Chemosphere 41, 177–182 (2000).

    Article  CAS  PubMed  Google Scholar 

  28. Benbrook, C. M. Trends in glyphosate herbicide use in the United States and globally. Environ. Sci. Eur. 28, 3 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Duke, S. O. & Powles, S. B. Glyphosate: a once-in-a-century herbicide. Pest Manag. Sci. 64, 319–325 (2008).

    Article  CAS  PubMed  Google Scholar 

  30. Hébert, M.-P., Fugère, V. & Gonzalez, A. The overlooked impact of rising glyphosate use on phosphorus loading in agricultural watersheds. Front. Ecol. Environ. 17, 48–56 (2019).

  31. Gilbert, N. A hard look at GM crops. Nature 497, 24–26 (2013).

    Article  CAS  Google Scholar 

  32. Hicks, H. L. et al. The factors driving evolved herbicide resistance at a national scale. Nat. Ecol. Evol. 2, 529–536 (2018).

    Article  PubMed  Google Scholar 

  33. Green, J. M. The rise and future of glyphosate and glyphosate-resistant crops. Pest Manag. Sci. 74, 1035–1039 (2018).

    Article  CAS  PubMed  Google Scholar 

  34. Kreiner, J. M., Stinchcombe, J. R. & Wright, S. I. Population genomics of herbicide resistance: adaptation via evolutionary rescue. Annu. Rev. Plant Biol. 69, 611–635 (2018).

    Article  CAS  PubMed  Google Scholar 

  35. Van Bruggen, A. H. C. et al. Environmental and health effects of the herbicide glyphosate. Sci. Total Environ. 616–617, 255–268 (2018).

    Article  CAS  PubMed  Google Scholar 

  36. Motta, E. V. S., Raymann, K. & Moran, N. A. Glyphosate perturbs the gut microbiota of honey bees. Proc. Natl Acad. Sci. USA 115, 10305–10310 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Annett, R., Habibi, H. R. & Hontela, A. Impact of glyphosate and glyphosate-based herbicides on the freshwater environment. J. Appl. Toxicol. 34, 458–479 (2014).

    Article  CAS  PubMed  Google Scholar 

  38. Helander, M., Saloniemi, I. & Saikkonen, K. Glyphosate in northern ecosystems. Trends Plant Sci. 17, 569–574 (2012).

    Article  CAS  PubMed  Google Scholar 

  39. Relyea, R. A. The impact of insecticides and herbicides on the biodiversity and productivity of aquatic communities. Ecol. Appl. 15, 618–627 (2005).

    Article  Google Scholar 

  40. Giroux, I. Présence de pesticides dans l’eau au Québec: Portrait et tendances dans les zones de maïs et de soya – 2011 à 2014 (MELCC, 2015); https://go.nature.com/2SfqYGc

  41. Dill, G. M. et al. in Glyphosate Resistance in Crops and Weeds: History, Development, and Management (ed. Nandula, V.) 1–33 (Wiley, 2010).

  42. Hove-Jensen, B., Zechel, D. L. & Jochimsen, B. Utilization of glyphosate as phosphate source: biochemistry and genetics of bacterial carbon-phosphorus lyase. Microbiol. Mol. Biol. Rev. 78, 176–197 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Gross, K. et al. Species richness and the temporal stability of biomass production: a new analysis of recent biodiversity experiments. Am. Nat. 183, 1–12 (2014).

    Article  PubMed  Google Scholar 

  44. Tlili, A. et al. Pollution‐induced community tolerance (PICT): towards an ecologically relevant risk assessment of chemicals in aquatic systems. Freshw. Biol. 61, 2141–2151 (2016).

    Article  CAS  Google Scholar 

  45. Blanck, H. & Wängberg, S.-Å. Induced community tolerance in marine periphyton established under Arsenate stress. Can. J. Fish. Aquat. Sci. 45, 1816–1819 (1988).

    Article  Google Scholar 

  46. Bérard, A. & Benninghoff, C. Pollution-induced community tolerance (PICT) and seasonal variations in the sensitivity of phytoplankton to atrazine in nanocosms. Chemosphere 45, 427–437 (2001).

    Article  PubMed  Google Scholar 

  47. Gustavson, K. et al. Pollution-induced community tolerance (PICT) in coastal phytoplankton communities exposure to copper. Hydrobiologia 416, 125–138 (1999).

    Article  Google Scholar 

  48. Millward, R. N. & Grant, A. Assessing the impact of copper on nematode communities from a chronically metal-enriched estuary using pollution-induced community tolerance. Mar. Pollut. Bull. 30, 701–706 (1995).

    Article  CAS  Google Scholar 

  49. Hua, J., Morehouse, N. I. & Relyea, R. Pesticide tolerance in amphibians: induced tolerance in susceptible populations, constitutive tolerance in tolerant populations. Evol. Appl. 6, 1028–1040 (2013).

    PubMed  PubMed Central  Google Scholar 

  50. Pizarro, H. et al. Glyphosate input modifies microbial community structure in clear and turbid freshwater systems. Environ. Sci. Pollut. Res. 23, 5143–5153 (2016).

    Article  CAS  Google Scholar 

  51. Thibodeau, G., Walsh, D. A. & Beisner, B. E. Rapid eco-evolutionary responses in perturbed phytoplankton communities. Proc. R. Soc. B 282, 20151215 (2015).

    Article  PubMed Central  Google Scholar 

  52. van Benthem, K. J. et al. Disentangling evolutionary, plastic and demographic processes underlying trait dynamics: a review of four frameworks. Methods Ecol. Evol. 8, 75–85 (2017).

    Article  Google Scholar 

  53. Govaert, L., Pantel, J. H., De Meester, L. & Coulson, T. Eco‐evolutionary partitioning metrics: assessing the importance of ecological and evolutionary contributions to population and community change. Ecol. Lett. 19, 839–853 (2016).

    Article  PubMed  Google Scholar 

  54. Cuhra, M., Traavik, T. & Bøhn, T. Clone- and age-dependent toxicity of a glyphosate commercial formulation and its active ingredient in Daphnia magna. Ecotoxicology 22, 251–262 (2013).

    Article  CAS  PubMed  Google Scholar 

  55. Lipok, J., Studnik, H. & Gruyaert, S. The toxicity of Roundup® 360 SL formulation and its main constituents: glyphosate and isopropylamine towards non-target water photoautotrophs. Ecotoxicol. Environ. Saf. 73, 1681–1688 (2010).

    Article  CAS  PubMed  Google Scholar 

  56. Vera, M. S. et al. New evidences of Roundup® (glyphosate formulation) impact on the periphyton community and the water quality of freshwater ecosystems. Ecotoxicology 19, 710–721 (2010).

    Article  CAS  PubMed  Google Scholar 

  57. Austin, A. P., Harris, G. E. & Lucey, W. P. Impact of an organophosphate herbicide (GlyphosateR) on periphyton communities developed in experimental streams. Bull. Environ. Contam. Toxicol. 47, 29–35 (1991).

    Article  CAS  PubMed  Google Scholar 

  58. Gaupp-Berghausen, M., Hofer, M., Rewald, B. & Zaller, J. G. Glyphosate-based herbicides reduce the activity and reproduction of earthworms and lead to increased soil nutrient concentrations. Sci. Rep. 5, 12886 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Harris, T. D. & Smith, V. H. Do persistent organic pollutants stimulate cyanobacterial blooms? Inland Waters 6, 124–130 (2016).

    Article  CAS  Google Scholar 

  60. Brennan, G. & Collins, S. Growth responses of a green alga to multiple environmental drivers. Nat. Clim. Change 5, 892–897 (2015).

    Article  Google Scholar 

  61. Zhang, C., Jansen, M., De Meester, L. & Stoks, R. Thermal evolution offsets the elevated toxicity of a contaminant under warming: a resurrection study in Daphnia magna. Evol. Appl. 11, 1425–1436 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  62. Kelly, M. W., DeBiasse, M. B., Villela, V. A., Roberts, H. L. & Cecola, C. F. Adaptation to climate change: trade-offs among responses to multiple stressors in an intertidal crustacean. Evol. Appl. 9, 1147–1155 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. Bell, G. Evolutionary rescue and the limits of adaptation. Phil. Trans. R. Soc. Lond. B 368, 20120080 (2013).

    Article  Google Scholar 

  64. Schiebelhut, L. M., Puritz, J. B. & Dawson, M. N. Decimation by sea star wasting disease and rapid genetic change in a keystone species, Pisaster ochraceus. Proc. Natl Acad. Sci. USA 115, 7069–7074 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  65. Whitehead, A., Clark, B. W., Reid, N. M., Hahn, M. E. & Nacci, D. When evolution is the solution to pollution: key principles, and lessons from rapid repeated adaptation of killifish (Fundulus heteroclitus) populations. Evol. Appl. 10, 762–783 (2017).

    Article  PubMed  PubMed Central  Google Scholar 

  66. Matz, M. V., Treml, E. A., Aglyamova, G. V. & Bay, L. K. Potential and limits for rapid genetic adaptation to warming in a Great Barrier Reef coral. PLoS Genet. 14, e1007220 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  67. Epstein, B. et al. Rapid evolutionary response to a transmissible cancer in Tasmanian devils. Nat. Commun. 7, 12684 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  68. Canadian water quality guidelines for the protection of aquatic life: Glyphosate. Canadian Environmental Quality Guidelines (Canadian Council of Ministers of the Environment, 2012); http://st-ts.ccme.ca/en/index.html

  69. Guidelines for Canadian Drinking Water Quality—Summary Table (Health Canada, 2017).

  70. Pérez, G. L. et al. Effects of the herbicide Roundup on freshwater microbial communities: a mesocosm study. Ecol. Appl. 17, 2310–2322 (2007).

    Article  PubMed  Google Scholar 

  71. Khadra, M., Planas, D., Girard, C. & Amyot, M. Age matters: submersion period shapes community composition of lake biofilms under glyphosate stress. FACETS 3, 934–951 (2018).

    Article  Google Scholar 

  72. Lund, J. W. G., Kipling, C. & Le Cren, E. D. The inverted microscope method of estimating algal numbers and the statistical basis of estimations by counting. Hydrobiologia 11, 143–170 (1958).

    Article  Google Scholar 

  73. Kremer, C. T., Gillette, J. P., Rudstam, L. G., Brettum, P. & Ptacnik, R. A compendium of cell and natural unit biovolumes for >1200 freshwater phytoplankton species. Ecology 95, 2984–2984 (2014).

    Article  Google Scholar 

  74. Patton, C. J. & Kryskalla, J. R. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory: evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water Water-Resources Investigations Report 2003-4174 (USGS, 2003); http://pubs.er.usgs.gov/publication/wri034174

  75. Wetzel, R. G. & Likens, G. Limnological Analyses (Springer Science & Business Media, 2000).

  76. R Core Team. R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, 2018).

  77. Wood, S. N. Generalized Additive Models: An Introduction with R (Chapman and Hall/CRC, 2017).

  78. Hothorn, T., Hornik, K. & Zeileis, A. Unbiased recursive partitioning: a conditional inference framework. J. Comput. Graph. Stat. 15, 651–674 (2006).

    Article  Google Scholar 

  79. Jost, L. Entropy and diversity. Oikos 113, 363–375 (2006).

    Article  Google Scholar 

  80. Hallett, L. M. et al. codyn: An r package of community dynamics metrics. Methods Ecol. Evol. 7, 1146–1151 (2016).

    Article  Google Scholar 

  81. Oksanen, J. et al. vegan: Community Ecology Package R package version 2.5-6 (2019); https://CRAN.R-project.org/package=vegan

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Acknowledgements

The Canadian Foundation for Innovation and the Liber Ero Chair in Biodiversity Conservation provided funding to A.G. to construct and operate the LEAP mesocosm facility. We acknowledge support and operating funds from the Natural Sciences and Engineering Research Council of Canada, the Fonds de Recherche du Québec—Nature et Technologies, the Canada Research Chair Program (R.D.H.B., A.G. and B.J.S.), the Quebec Centre for Biodiversity Science and the Groupe de Recherche Interuniversitaire en Limnologie et environnements aquatiques. We thank D. Maneli, C. Normandin, A. Arkilanian and T. Jagadeesh for assistance in the field, K. Velghe for nutrient analyses, P. Carrier-Corbeil and M. Rautio for phytoplankton identification and M. A. P. Castro for developing the LC–MS method for glyphosate measurements and for conducting chemical analyses.

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V.F., M.-P.H., R.D.H.B., B.E.B., G.B., G.F.F., B.J.S. and A.G. designed the study. V.F., M.-P.H. and N.B.C. collected the data. C.C.Y.X. and V.Y. contributed to the development of laboratory methods. B.E.B. provided a phytoplankton trait database for biovolume estimation. V.F. analysed data, made the figures and drafted the manuscript. All authors contributed significantly to data interpretation and commented on manuscript drafts.

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Correspondence to Vincent Fugère or Andrew Gonzalez.

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Extended data

Extended Data Fig. 1 Glyphosate and nutrient concentrations.

Time series of glyphosate concentration (a), total nitrogen (TN; b), and total phosphorus (TP; c) during the experiment. Lines are colour-coded by glyphosate treatment while symbols indicate nutrient treatment (a small offset on x axis values was introduced to better distinguish low and high nutrient ponds). In (a), low glyphosate concentrations in some control ponds in early Phase I are most likely the product of field contamination.

Extended Data Fig. 2 Other physicochemical parameters.

Time series of water depth (a), temperature (b), specific conductance (SPC; c), dissolved oxygen (DO; d), and pH (e) during the experiment. Lines are colour-coded by glyphosate treatment while symbols indicate nutrient treatment, as in Extended Data 1. (a,b) Depth and temperature varied over time but not across mesocosms. (c) Mean specific conductance increased slightly over Phase I (from 91 to 116 µS/cm), indicative of solute accumulation in the mesocosms due to evaporation. (d) Dissolved oxygen concentration tracked changes in phytoplankton biomass and was negatively affected by the first glyphosate pulse in the ponds exposed to the highest dose. (e) pH was mostly stable over time, although the highest glyphosate doses temporarily lowered pH by < 1 unit. In Phase II, biomass collapse in most communities decreased dissolved oxygen concentration (d), while specific conductance and pH respectively increased and decreased in all ponds that received the lethal dose irrespective of the response of their phytoplankton community (c,e).

Extended Data Fig. 3 Drivers of Phase I biomass dynamics.

Regression tree model of phytoplankton biomass over the course of Phase I as a function of date, nutrient treatment, and glyphosate and imidacloprid concentrations. Boxplots show the distribution of log-transformed chlorophyll a values in each group. Results (p value) of permutation tests of a correlation between the response and significant predictors are indicated. The tree demonstrates that at dates < 15 days, biomass is negatively affected only in ponds receiving more than 3 mg/L of glyphosate, while after day 15, biomass increases with glyphosate treatment but only in ponds receiving doses > 4 mg/L. This regression tree also shows that the positive effect of the nutrient treatment on biomass is only significant in low-glyphosate ponds, and it confirms that imidacloprid had no discernible effect on phytoplankton biomass.

Extended Data Fig. 4 Phosphorus data.

Relationship between total phosphorus (TP) and soluble reactive phosphorus (SRP) in 16 ponds on day 35 of the experiment, shortly after the second glyphosate dose was applied. Symbols indicate nutrient treatment while colours indicate glyphosate treatment. Note that ponds receiving the highest glyphosate dose also show the highest concentration of SRP. However, given that SRP was measured immediately after a glyphosate application but several weeks after the onset of the nutrient treatment, and given that SRP is often assimilated very quickly by phytoplankton, these measurements likely under-estimate the effect of the nutrient treatment on SRP. ppb = parts per billion (µg/L).

Extended Data Fig. 5 Final biomass vs. final glyphosate concentration.

Phytoplankton biomass at the end of Phase II as a function of Phase II glyphosate concentration. Although all ponds had a target in-pond concentration of 40 mg/L for the lethal dose in Phase II, residual glyphosate from past exposure, and/or potential error associated with glyphosate measurements for some ponds, led to unintended variance in measured concentrations at the beginning of Phase II. The effect of glyphosate concentration on phytoplankton biomass (log 1+x transformed) was statistically significant in a GAM (p = 0.007). However, the modelled relationship was positive (thus excluding the possibility that high-biomass ponds received less glyphosate in Phase II), driven by the high biomass of high-glyphosate ponds, and failed to capture the response of the two high-nutrient ponds that received the highest glyphosate dose in Phase I. Symbols indicate nutrient and glyphosate treatment as in Extended Data 4. chl. = chlorophyll.

Extended Data Fig. 6 Final biomass vs. zooplankton density.

Phytoplankton biomass at the end of Phase II as a function of crustacean zooplankton density at the end of Phase II. Symbol shape indicates nutrient treatment while symbol colour indicates Phase I glyphosate treatment, following the same nomenclature as all other figures. Note that the GAM testing for an effect of zooplankton density (log 1+x transformed) on phytoplankton biomass (log transformed) described in the main text (Fig. 5b) excluded the two control ponds (black symbols in this figure), as for all other predictor variables–hence the low explanatory power of the zooplankton GAM in Fig. 5b.

Extended Data Fig. 7 Correspondence between biomass and biovolume.

Relationship between community biovolume and biomass measured as chlorophyll a concentration. Each symbol represents a pond for which biovolume and biomass data were averaged across time points. The line and polygon indicate fitted values with confidence intervals from a GAM with biomass as the response and biovolume as the predictor. Biovolume was a significant predictor of biomass (p = 0.0004), and the adjusted R2 of this GAM was 0.54. The Pearson correlation coefficient between the two variables was 0.75 for the time-averaged data and 0.56 for the raw (unaveraged) data considering all pond by sampling occasion combinations as independent data points.

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Fugère, V., Hébert, MP., da Costa, N.B. et al. Community rescue in experimental phytoplankton communities facing severe herbicide pollution. Nat Ecol Evol 4, 578–588 (2020). https://doi.org/10.1038/s41559-020-1134-5

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