Chen, C., Riley, W. J., Prentice, I. C. & Keenan, T. F. CO2 fertilization of terrestrial photosynthesis inferred from site to global scales. Proc. Natl Acad. Sci. USA 119, e2115627119 (2022).
Forzieri, G., Dakos, V., McDowell, N. G., Ramdane, A. & Cescatti, A. Emerging signals of declining forest resilience under climate change. Nature 608, 534–539 (2022).
Jia, G. et al. in Climate Change and Land: an IPCC Special Report on Climate Change, Desertification, Land Degradation, Sustainable Land Management, Food Security, and Greenhouse Gas Fluxes in Terrestrial Ecosystems (eds Shukla, P. R. et al.) 131–242 (IPCC, 2019).
Hubau, W. et al. Asynchronous carbon sink saturation in African and Amazonian tropical forests. Nature 579, 80–87 (2020).
Grace, J., José, J. S., Meir, P., Miranda, H. S. & Montes, R. A. Productivity and carbon fluxes of tropical savannas. J. Biogeogr. 33, 387–400 (2006).
Lawrence, D. M. et al. The Community Land Model version 5: description of new features, benchmarking, and impact of forcing uncertainty. J. Adv. Model. Earth Syst. 11, 4245–4287 (2019).
Leakey, A. D., Bishop, K. A. & Ainsworth, E. A. A multi-biome gap in understanding of crop and ecosystem responses to elevated CO2. Curr. Opin. Plant Biol. 15, 228–236 (2012).
Pan, Y. et al. Contrasting responses of woody and grassland ecosystems to increased CO2 as water supply varies. Nat. Ecol. Evol. 6, 315–323 (2022).
Nowak, R. S., Ellsworth, D. S. & Smith, S. D. Functional responses of plants to elevated atmospheric CO2—do photosynthetic and productivity data from FACE experiments support early predictions? New Phytol. 162, 253–280 (2004).
Ainsworth, E. A. & Long, S. P. 30 Years of free-air carbon dioxide enrichment (FACE): what have we learned about future crop productivity and its potential for adaptation? Glob. Chang. Biol. 27, 27–49 (2021).
Bond, W. J. & Midgley, G. F. Carbon dioxide and the uneasy interactions of trees and savannah grasses. Phil. Trans. R. Soc. B 367, 601–612 (2012).
Buitenwerf, R., Bond, W. J., Stevens, N. & Trollope, W. S. W. Increased tree densities in South African savannas: >50 years of data suggests CO2 as a driver. Glob. Chang. Biol. 18, 675–684 (2012).
Staver, A. C., Botha, J. & Hedin, L. Soils and fire jointly determine vegetation structure in an African savanna. New Phytol. 216, 1151–1160 (2017).
Alvarado, S. T., Andela, N., Silva, T. S. F. & Archibald, S. Thresholds of fire response to moisture and fuel load differ between tropical savannas and grasslands across continents. Global Ecol. Biogeogr. 29, 331–344 (2020).
Leakey, A. D. et al. Photosynthesis, productivity, and yield of maize are not affected by open-air elevation of CO2 concentration in the absence of drought. Plant Physiol. 140, 779–790 (2006).
Wand, S. J. E., Midgley, G. F., Jones, M. H. & Curtis, P. S. Responses of wild C4 and C3 grass (Poaceae) species to elevated atmospheric CO2 concentration: a meta-analytic test of current theories and perceptions. Glob. Chang. Biol. 5, 723–741 (1999).
Morgan, J. A. et al. C4 grasses prosper as carbon dioxide eliminates desiccation in warmed semi-arid grassland. Nature 476, 202–205 (2011).
Reich, P. B., Hobbie, S. E., Lee, T. D. & Pastore, M. A. Unexpected reversal of C3 versus C4 grass response to elevated CO2 during a 20-year field experiment. Science 360, 317–320 (2018).
Spinoni, J., Naumann, G., Carrao, H., Barbosa, P. & Vogt, J. World drought frequency, duration, and severity for 1951–2010. Int. J. Climatol. 34, 2792–2804 (2014).
Chiang, F., Mazdiyasni, O. & AghaKouchak, A. Evidence of anthropogenic impacts on global drought frequency, duration, and intensity. Nat. Commun. 12, 2754 (2021).
Sala, O. E., Gherardi, L. A., Reichmann, L., Jobbágy, E. & Peters, D. Legacies of precipitation fluctuations on primary production: theory and data synthesis. Phil. Trans. R. Soc. B 367, 3135–3144 (2012).
Staver, A. C., Abraham, J. O., Hempson, G. P., Karp, A. T. & Faith, J. T. The past, present, and future of herbivore impacts on savanna vegetation. J. Ecol. 109, 2804–2822 (2021).
Smit, I. P., Peel, M. J., Ferreira, S. M., Greaver, C. & Pienaar, D. J. Megaherbivore response to droughts under different management regimes: lessons from a large African savanna. Afr. J. Range Forage Sci. 37, 65–80 (2020).
Stevens, C. J. et al. Anthropogenic nitrogen deposition predicts local grassland primary production worldwide. Ecology 96, 1459–1465 (2015).
Del Toro, I., Case, M. F., Karp, J., Slingsby, J. & Staver, A. C. Carbon isotope trends across a century of herbarium specimens suggest CO2 fertilization of C4 grasses. New Phytol. 243, 560–566 (2024).
Keeling, R. F., Morgan, E. J. & Keeling, C. D. Atmospheric monthly in situ CO2 data—Mauna Loa Observatory, Hawaii. In Scripps CO2 Program Data. UC San Diego Library Digital Collections https://doi.org/10.6075/J08W3BHW (2017).
Terrer, C. et al. Nitrogen and phosphorus constrain the CO2 fertilization of global plant biomass. Nat. Clim. Change 9, 684–689 (2019).
Fay, P. A. et al. Soil-mediated effects of subambient to increased carbon dioxide on grassland productivity. Nat. Clim. Change 2, 742–746 (2012).
Polley, H. W. et al. CO2 enrichment and soil type additively regulate grassland productivity. New Phytol. 222, 183–192 (2019).
Collatz, G. J., Ribas-Carbo, M. & Berry, J. A. Coupled photosynthesis-stomatal conductance model for leaves of C4 plants. Funct. Plant Biol. 19, 519–538 (1992).
Kennedy, D. et al. Implementing plant hydraulics in the Community Land Model version 5. J. Adv. Model. Earth Syst. 11, 485–513 (2019).
Medlyn, B. E. et al. Reconciling the optimal and empirical approaches to modelling stomatal conductance. Glob. Chang. Biol. 17, 2134–2144 (2011).
Lin, Y. S. et al. Optimal stomatal behaviour around the world. Nat. Clim. Change 5, 459–464 (2015).
Noy-Meir, I. Desert ecosystems: environment and producers. Annu. Rev. Ecol. Syst. 4, 25–52 (1973).
Piñeiro, J. et al. Effects of elevated CO2 on fine root biomass are reduced by aridity but enhanced by soil nitrogen: a global assessment. Sci. Rep. 7, 15355 (2017).
Purcell, C. et al. Increasing stomatal conductance in response to rising atmospheric CO2. Ann. Bot. 121, 1137–1149 (2018).
Scoffoni, C., Albuquerque, C., Buckley, T. N. & Sack, L. The dynamic multi-functionality of leaf water transport outside the xylem. New Phytol. 239, 2099–2107 (2023).
Márquez, D. A., Wong, S. C., Stuart-Williams, H., Cernusak, L. A. & Farquhar, G. D. Mesophyll airspace unsaturation drives C4 plant success under vapor pressure deficit stress. Proc. Natl Acad. Sci. USA 121, e2402233121 (2024).
Crafts-Brandner, S. J. & Salvucci, M. E. Sensitivity of photosynthesis in a C4 plant, maize, to heat stress. Plant Physiol. 129, 1773–1780 (2002).
Boyd, R. A., Gandin, A. & Cousins, A. B. Temperature responses of C4 photosynthesis: biochemical analysis of rubisco, phosphoenolpyruvate carboxylase, and carbonic anhydrase in Setaria viridis. Plant Physiol. 169, 1850–1861 (2015).
Yin, X., van der Putten, P. E. L., Driever, S. M. & Struik, P. C. Temperature response of bundle-sheath conductance in maize leaves. J. Exp. Bot. 67, 2699–2714 (2016).
Sonawane, B. V., Sharwood, R. E., von Caemmerer, S., Whitney, S. M. & Ghannoum, O. Short-term thermal photosynthetic responses of C4 grasses are independent of the biochemical subtype. J. Exp. Bot. 68, 5583–5597 (2017).
Raubenheimer, S. L., Simpson, K., Carkeek, R. & Ripley, B. Could CO2-induced changes to C4 grass flammability aggravate savanna woody encroachment? Afr. J. Range Forage Sci. 39, 82–95 (2022).
Reyes-Fox, M. et al. Elevated CO2 further lengthens growing season under warming conditions. Nature 510, 259–262 (2014).
Abreu, R. C. R. et al. The biodiversity cost of carbon sequestration in tropical savanna. Sci. Adv. 3, e1701284 (2017).
Zhou, Y. et al. Limited increases in savanna carbon stocks over decades of fire suppression. Nature 603, 445–449 (2022).
Poulter, B. et al. Contribution of semi-arid ecosystems to interannual variability of the global carbon cycle. Nature 509, 600–603 (2014).
Zhou, Y. et al. Soil carbon in tropical savannas mostly derived from grasses. Nat. Geosci. 16, 710–716 (2023).
Robinson, E. A., Ryan, G. D. & Newman, J. A. A meta-analytical review of the effects of elevated CO2 on plant–arthropod interactions highlights the importance of interacting environmental and biological variables. New Phytol. 194, 321–336 (2012).
Luo, X. et al. Mapping the global distribution of C4 vegetation using observations and optimality theory. Nat. Commun. 15, 1219 (2024).
Skowno, A. L. et al. Woodland expansion in South African grassy biomes based on satellite observations (1990–2013): general patterns and potential drivers. Glob. Chang. Biol. 23, 2358–2369 (2017).
Grames, E. M., Stillman, A. N., Tingley, M. W. & Elphick, C. S. An automated approach to identifying search terms for systematic reviews using keyword co-occurrence networks. Methods Ecol. Evol. 10, 1645–1654 (2019).
Rohatgi, A. WebPlotDigitizer. GitHub https://github.com/ankitrohatgi/WebPlotDigitizer (2023).
Abdalla, A. L. et al. Nutritive value and enteric methane production of Brachiaria spp. under elevated [CO2]. Int. J. Plant Prod. 14, 119–126 (2020).
Abdalla Filho, A. L. et al. Fiber fractions, multielemental and isotopic composition of a tropical C4 grass grown under elevated atmospheric carbon dioxide. PeerJ 7, e5932 (2019).
Abdalla Filho, A. L. et al. CO2 fertilization does not affect biomass production and nutritive value of a C4 tropical grass in short timeframe. Grass Forage Sci. 74, 670–677 (2019).
Adam, N. R., Owensby, C. E. & Ham, J. M. The effect of CO2 enrichment on leaf photosynthetic rates and instantaneous water use efficiency of Andropogon gerardii in the tallgrass prairie. Photosynth. Res. 65, 121–129 (2000).
Anderson, L. J., Maherali, H., Johnson, H. B., Polley, H. W. & Jackson, R. B. Gas exchange and photosynthetic acclimation over subambient to elevated CO2 in a C3–C4 grassland. Glob. Chang. Biol. 7, 693–707 (2001).
Barbehenn, R. V., Chen, Z., Karowe, D. N. & Spickard, A. C3 grasses have higher nutritional quality than C4 grasses under ambient and elevated atmospheric CO2. Glob. Chang. Biol. 10, 1565–1575 (2004).
Baruch, Z. & Jackson, R. B. Responses of tropical native and invader C4 grasses to water stress, clipping and increased atmospheric CO2 concentration. Oecologia 145, 522–532 (2005).
Bellasio, C., Quirk, J. & Beerling, D. J. Stomatal and non-stomatal limitations in savanna trees and C4 grasses grown at low, ambient and high atmospheric CO2. Plant Sci. 274, 181–192 (2018).
von Caemmerer, S., Ghannoum, O., Conroy, J. P., Clark, H. & Newton, P. C. D. Photosynthetic responses of temperate species to free air CO2 enrichment (FACE) in a grazed New Zealand pasture. Funct. Plant Biol. 28, 439–450 (2001).
Carter, D. R. & Peterson, K. M. Effects of a CO2-enriched atmosphere on the growth and competitive interaction of a C3 and a C4 grass. Oecologia 58, 188–193 (1983).
Carvalho, J. M. et al. Elevated CO2 and warming change the nutrient status and use efficiency of Panicum maximum Jacq. PLoS ONE 15, e0223937 (2020).
Clark, H., Newton, P. C. D. & Barker, D. J. Physiological and morphological responses to elevated CO2 and a soil moisture deficit of temperate pasture species growing in an established plant community. J. Exp. Bot. 50, 233–242 (1999).
de Oliveira, A. C. G., Rios, P. M., Pereira, E. G. & Souza, J. P. Growth and competition between a native leguminous forb and an alien grass from the Cerrado under elevated CO2. Austral Ecol. 46, 750–761 (2021).
Dijkstra, F. A., Blumenthal, D., Morgan, J. A., LeCain, D. R. & Follett, R. F. Elevated CO2 effects on semi-arid grassland plants in relation to water availability and competition. Funct. Ecol. 24, 1152–1161 (2010).
de Faria, A. P., Marabesi, M. A., Gaspar, M. & França, M. G. C. The increase of current atmospheric CO2 and temperature can benefit leaf gas exchanges, carbohydrate content and growth in C4 grass invaders of the Cerrado biome. Plant Physiol. Biochem. 127, 608–616 (2018).
Fravolini, A., Williams, D. G. & Thompson, T. L. Carbon isotope discrimination and bundle sheath leakiness in three C4 subtypes grown under variable nitrogen, water and atmospheric CO2 supply. J. Exp. Bot. 53, 2261–2269 (2002).
Ghannoum, O., Caemmerer, S. V., Barlow, E. W. R. & Conroy, J. P. The effect of CO2 enrichment and irradiance on the growth, morphology and gas exchange of a C3 (Panicum laxum) and a C4 (Panicum antidotale) grass. Funct. Plant Biol. 24, 227–237 (1997).
Ghannoum, O., von Caemmerer, S. & Conroy, J. P. Plant water use efficiency of 17 Australian NAD-ME and NADP-ME C4 grasses at ambient and elevated CO2 partial pressure. Funct. Plant Biol. 28, 1207–1217 (2001).
Gifford, R. M. & Morison, J. I. L. Photosynthesis, water use and growth of a C4 grass stand at high CO2 concentration. Photosynth. Res. 7, 77–90 (1985).
Hager, H. A., Ryan, G. D., Kovacs, H. M. & Newman, J. A. Effects of elevated CO2 on photosynthetic traits of native and invasive C3 and C4 grasses. BMC Ecol. 16, 28 (2016).
Hager, H. A., Ryan, G. D. & Newman, J. A. Effects of elevated CO2 on competition between native and invasive grasses. Oecologia 192, 1099–1110 (2020).
Hamerlynck, E. P., McAllister, C. A., Knapp, A. K., Ham, J. M. & Owensby, C. E. Photosynthetic gas exchange and water relation responses of three tallgrass prairie species to elevated carbon dioxide and moderate drought. Int. J. Plant Sci. 158, 608–616 (1997).
Hunt, H. W., Elliott, E. T., Detling, J. K., Morgan, J. A. & Chen, D.-X. Responses of a C3 and a C4 perennial grass to elevated CO2 and temperature under different water regimes. Glob. Chang. Biol. 2, 35–47 (1996).
Johnson, S. N., Lopaticki, G. & Hartley, S. E. Elevated atmospheric CO2 triggers compensatory feeding by root herbivores on a C3 but not a C4 grass. PLoS ONE 9, e90251 (2014).
Kellogg, E. A., Farnsworth, E. J., Russo, E. T. & Bazzaz, F. Growth responses of C4 grasses of contrasting origin to elevated CO2. Ann. Bot. 84, 279–288 (1999).
Kgope, B. S., Bond, W. J. & Midgley, G. F. Growth responses of African savanna trees implicate atmospheric [CO2] as a driver of past and current changes in savanna tree cover. Austral Ecol. 35, 451–463 (2010).
Knapp, A. K., Hamerlynck, E. P. & Owensby, C. E. Photosynthetic and water relations responses to elevated CO2 in the C4 grass Andropogon gerardii. Int. J. Plant Sci. 154, 459–466 (1993).
LeCain, D. R. et al. Root biomass of individual species, and root size characteristics after five years of CO2 enrichment on native shortgrass steppe. Plant Soil 279, 219–228 (2006).
LeCain, D. R. & Morgan, J. A. Growth, gas exchange, leaf nitrogen and carbohydrate concentrations in NAD-ME and NADP-ME C4 grasses grown in elevated CO2. Physiol. Plant. 102, 297–306 (1998).
LeCain, D. R., Morgan, J. A., Mosier, A. R. & Nelson, J. A. Soil and plant water relations determine photosynthetic responses of C3 and C4 grasses in a semi-arid ecosystem under elevated CO2. Ann. Bot. 92, 41–52 (2003).
Lee, T. D., Barrott, S. H. & Reich, P. B. Photosynthetic responses of 13 grassland species across 11 years of free-air CO2 enrichment is modest, consistent and independent of N supply. Glob. Chang. Biol. 17, 2893–2904 (2011).
Lee, T. D., Tjoelker, M. G., Ellsworth, D. S. & Reich, P. B. Leaf gas exchange responses of 13 prairie grassland species to elevated CO2 and increased nitrogen supply. New Phytol. 150, 405–418 (2001).
Maherali, H., Reid, C. D., Polley, H. W., Johnson, H. B. & Jackson, R. B. Stomatal acclimation over a subambient to elevated CO2 gradient in a C3/C4 grassland. Plant Cell Environ. 25, 557–566 (2002).
Manea, A., Leishman, M. R. & Downey, P. O. Exotic C4 grasses have increased tolerance to glyphosate under elevated carbon dioxide. Weed Sci. 59, 28–36 (2011).
Marks, S. & Clay, K. Effects of CO2 enrichment, nutrient addition, and fungal endophyte-infection on the growth of two grasses. Oecologia 84, 207–214 (1990).
McGranahan, D. A. & Yurkonis, K. A. Variability in grass forage quality and quantity in response to elevated CO2 and water limitation. Grass Forage Sci. 73, 517–521 (2018).
Morgan, J. A., Knight, W. G., Dudley, L. M. & Hunt, H. W. Enhanced root system C-sink activity, water relations and aspects of nutrient acquisition in mycotrophic Bouteloua gracilis subjected to CO2 enrichment. Plant Soil 165, 139–146 (1994).
Morgan, J. A., LeCain, D. R., Read, J. J., Hunt, H. W. & Knight, W. G. Photosynthetic pathway and ontogeny affect water relations and the impact of CO2 on Bouteloua gracilis (C4) and Pascopyrum smithii (C3). Oecologia 114, 483–493 (1998).
Morgan, J. A., Lecain, D. R., Mosier, A. R. & Milchunas, D. G. Elevated CO2 enhances water relations and productivity and affects gas exchange in C3 and C4 grasses of the Colorado shortgrass steppe. Glob. Chang. Biol. 7, 451–466 (2001).
Morgan, J. A. et al. CO2 enhances productivity, alters species composition, and reduces digestibility of shortgrass steppe vegetation. Ecol. Appl. 14, 208–219 (2004).
Newman, Y. C., Sollenberger, L. E., Boote, K. J., Allen, L. H. & Littell, R. C. Carbon dioxide and temperature effects on forage dry matter production. Crop Sci. 41, 399–406 (2001).
Pallett, N. The Effects of Elevated CO2 on C4 Panicoid Grass Drought Tolerance. MSc Thesis, Rhodes Univ. (2018).
Pastore, M. A., Lee, T. D., Hobbie, S. E. & Reich, P. B. Strong photosynthetic acclimation and enhanced water-use efficiency in grassland functional groups persist over 21 years of CO2 enrichment, independent of nitrogen supply. Glob. Chang. Biol. 25, 3031–3044 (2019).
Pastore, M. A., Lee, T. D., Hobbie, S. E. & Reich, P. B. Interactive effects of elevated CO2, warming, reduced rainfall, and nitrogen on leaf gas exchange in five perennial grassland species. Plant Cell Environ. 43, 1862–1878 (2020).
Paterson, E., Rattray, E. A. S. & Killham, K. Effect of elevated atmospheric CO2 concentration on C-partitioning and rhizosphere C-flow for three plant species. Soil Biol. Biochem. 28, 195–201 (1996).
Polley, H. W., Johnson, H. B., Mayeux, H. S. & Brown, D. A. Leaf and plant water use efficiency of C4 species grown at glacial to elevated CO2 concentrations. Int. J. Plant Sci. 157, 164–170 (1996).
Quirk, J., Bellasio, C., Johnson, D. A., Osborne, C. P. & Beerling, D. J. C4 savanna grasses fail to maintain assimilation in drying soil under low CO2 compared with C3 trees despite lower leaf water demand. Funct. Ecol. 33, 388–398 (2019).
Reich, P. B. et al. Do species and functional groups differ in acquisition and use of C, N and water under varying atmospheric CO2 and N availability regimes? A field test with 16 grassland species. New Phytol. 150, 435–448 (2001).
Rudmann, S. G., Milham, P. J. & Conroy, J. P. Influence of high CO2 partial pressure on nitrogen use efficiency of the C4 Grasses Panicum coloratum and Cenchrus ciliaris. Ann. Bot. 88, 571–577 (2001).
Runion, G. B., Prior, S. A., Capo-chichi, L. J. A., Torbert, H. A. & van Santen, E. Varied growth response of cogongrass ecotypes to elevated CO2. Front. Plant Sci. 6, 1182 (2016).
Seneweera, S. P., Ghannoum, O. & Conroy, J. High vapour pressure deficit and low soil water availability enhance shoot growth responses of a C4 grass (Panicum coloratum cv. Bambatsi) to CO2 enrichment. Funct. Plant Biol. 25, 287–292 (1998).
Seneweera, S. P., Ghannoum, O. & Conroy, J. P. Root and shoot factors contribute to the effect of drought on photosynthesis and growth of the C4 grass Panicum coloratum at elevated CO2 partial pressures. Aust. J. Plant Physiol. https://doi.org/10.1071/PP01007 (2001).
Sionit, N. & Patterson, D. T. Responses of C4 grasses to atmospheric CO2 enrichment. Oecologia 65, 30–34 (1984).
Smith, S., Strain, B. & Sharkey, T. Effects of CO2 enrichment on four Great Basin grasses. Funct. Ecol. 1, 139–143 (1987).
Tooth, I. M. & Leishman, M. R. Post-fire resprouting responses of native and exotic grasses from Cumberland Plain Woodland (Sydney, Australia) under elevated carbon dioxide. Austral Ecol. 38, 1–10 (2013).
Tooth, I. M. & Leishman, M. R. Elevated carbon dioxide and fire reduce biomass of native grass species when grown in competition with invasive exotic grasses in a savanna experimental system. Biol. Invasions 16, 257–268 (2014).
Volin, J. C., Reich, P. B. & Givnish, T. J. Elevated carbon dioxide ameliorates the effects of ozone on photosynthesis and growth: species respond similarly regardless of photosynthetic pathway or plant functional group. New Phytol. 138, 315–325 (1998).
Wand, S. J. E. & Midgley, G. F. Effects of atmospheric CO2 concentration and defoliation on the growth of Themeda triandra. Grass Forage Sci. 59, 215–226 (2004).
Wand, S., Midgley, G. & Stock, W. Response to elevated CO2 from a natural spring in a C4-dominated grassland depends on seasonal phenology. Afr. J. Range Forage Sci. 19, 81–91 (2002).
Wand, S. J. E., Midgley, G. F. & Musil, C. F. Physiological and growth responses of two African species, Acacia karroo and Themeda triandra, to combined increases in CO2 and UV-B radiation. Physiol. Plant. 98, 882–890 (1996).
Wand, S. J. E., Midgley, G. F. & Stock, W. D. Growth responses to elevated CO2 in NADP-ME, NAD-ME and PCK C4 grasses and a C3 grass from South Africa. Funct. Plant Biol. 28, 13–25 (2001).
Watling, J. R. & Press, M. C. How does the C4 grass Eragrostis pilosa respond to elevated carbon dioxide and infection with the parasitic angiosperm Striga hermonthica? New Phytol. 140, 667–675 (1998).
Weller, S. L., Florentine, S. K., Mutti, N. K., Jha, P. & Chauhan, B. S. Response of Chloris truncata to moisture stress, elevated carbon dioxide and herbicide application. Sci. Rep. 9, 10721 (2019).
Wilsey, B. J., Coleman, J. S. & McNaughton, S. J. Effects of elevated CO2 and defoliation on grasses: a comparative ecosystem approach. Ecol. Appl. 7, 844–853 (1997).
Wilsey, B. J., McNaughton, S. J. & Coleman, J. S. Will increases in atmospheric CO2 affect regrowth following grazing in C4 grasses from tropical grasslands? A test with Sporobolus kentrophyllus. Oecologia 99, 141–144 (1994).
Xiao, L., Liu, G. & Xue, S. Elevated CO2 concentration and drought stress exert opposite effects on plant biomass, nitrogen, and phosphorus allocation in Bothriochloa ischaemum. J. Plant Growth Regul. 35, 1088–1097 (2016).
Xu, Z. et al. Effects of elevated CO2, warming and precipitation change on plant growth, photosynthesis and peroxidation in dominant species from North China grassland. Planta 239, 421–435 (2014).
Yu, J., Sun, L., Fan, N., Yang, Z. & Huang, B. Physiological factors involved in positive effects of elevated carbon dioxide concentration on Bermudagrass tolerance to salinity stress. Environ. Exp. Bot. 115, 20–27 (2015).
Ziska, L. H., Hogan, K. P., Smith, A. P. & Drake, B. G. Growth and photosynthetic response of nine tropical species with long-term exposure to elevated carbon dioxide. Oecologia 86, 383–389 (1991).
Hedges, L. V., Gurevitch, J. & Curtis, P. S. The meta-analysis of response ratios in experimental ecology. Ecology 80, 1150–1156 (1999).
Bracken, M. B. in Effective Care of Newborn Infants (eds Sinclair, J. C. & Bracken M. B.) 13–20 (Oxford Univ. Press, 1992).
Hadfield, J. D. MCMC methods for multi-response generalized linear mixed models: the MCMCGLMM R package. J. Stat. Softw. 33, 1–22 (2010).
R Core Team. R: a Language and Environment for Statistical Computing https://www.R-project.org/ (R Foundation for Statistical Computing, 2023).
Forrestel, E. J. Biogeographic Influences on Grassland Community Structure and Function. PhD Thesis, Yale Univ. (2015).
Plummer, M., Best, N., Cowles, K. & Vines, K. CODA: convergence diagnosis and output analysis for MCMC. R News 6, 7–11 (2006).
Lenth, R. emmeans: Estimated marginal means, aka least-squares means. R package version 1.9.0 https://CRAN.R-project.org/package=emmeans (CRAN, 2023).
Walker, A. P. et al. Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO2. New Phytol. 229, 2413–2445 (2021).
Jacob, V. et al. High safety margins to drought-induced hydraulic failure found in five pasture grasses. Plant Cell Environ. 45, 1631–1646 (2022).
Osborne, C. P. & Sack, L. Evolution of C4 plants: a new hypothesis for an interaction of CO2 and water relations mediated by plant hydraulics. Phil. Trans. R. Soc. B 367, 583–600 (2012).
Wei, C., Tyree, M. T. & Steudle, E. Direct measurement of xylem pressure in leaves of intact maize plants. A test of the cohesion-tension theory taking hydraulic architecture into consideration. Plant Physiol. 121, 1191–1206 (1999).
Staver, A. C., Wigley-Coetsee, C. & Botha, J. Grazer movements exacerbate grass declines during drought in an African savanna. J. Ecol. 107, 1482–1491 (2019).
Trollope, W. S. W. & Potgieter, A. L. F. Estimating grass fuel loads with a disc pasture meter in the Kruger National Park. J. Grassl. Soc. S. Afr. 3, 148–152 (1986).
Wigley-Coetsee, C. & Staver, A. Grass community responses to drought in an African savanna. Afr. J. Range Forage Sci. 37, 43–52 (2020).
Clayton, W. D., Vorontsova, M. S., Harman, K. T. & Williamson, H. GrassBase—the online world. Kew http://www.kew.org/data/grasses-db.html (2006).
Kattge, J. et al. TRY plant trait database—enhanced coverage and open access. Glob. Chang. Biol. 26, 119–188 (2020).
Adler, P. B. et al. Functional traits explain variation in plant life history strategies. Proc. Natl Acad. Sci. USA 111, 740–745 (2014).
Atkin, O. K. et al. Global variability in leaf respiration in relation to climate, plant functional types and leaf traits. New Phytol. 206, 614–636 (2015).
Baruch, Z. & Goldstein, G. Leaf construction cost, nutrient concentration, and net CO2 assimilation of native and invasive species in Hawaii. Oecologia 121, 183–192 (1999).
Catford, J. A., Morris, W. K., Vesk, P. A., Gippel, C. J. & Downes, B. J. Species and environmental characteristics point to flow regulation and drought as drivers of riparian plant invasion. Diversity Distrib. 20, 1084–1096 (2014).
Craine, J. M. et al. Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability. New Phytol. 183, 980–992 (2009).
Craine, J. M., Lee, W. G., Bond, W. J., Williams, R. J. & Johnson, L. C. Environmental constraints on a global relationship among leaf and root traits of grasses. Ecology 86, 12–19 (2005).
Craine, J. M. et al. Global diversity of drought tolerance and grassland climate-change resilience. Nat. Clim. Change 3, 63–67 (2013).
Diaz, S. et al. The plant traits that drive ecosystems: evidence from three continents. J. Veg. Sci. 15, 295–304 (2004).
Domingues, T. F., Martinelli, L. A. & Ehleringer, J. R. Ecophysiological traits of plant functional groups in forest and pasture ecosystems from eastern Amazônia, Brazil. Plant Ecol. 193, 101–112 (2007).
Fonseca, C. R., Overton, J. M., Collins, B. & Westoby, M. Shifts in trait-combinations along rainfall and phosphorus gradients. J. Ecol. 88, 964–977 (2000).
Fortunel, C. et al. Leaf traits capture the effects of land use changes and climate on litter decomposability of grasslands across Europe. Ecology 90, 598–611 (2009).
He, J.-S. et al. Leaf nitrogen:phosphorus stoichiometry across Chinese grassland biomes. Oecologia 155, 301–310 (2008).
Kattge, J., Knorr, W., Raddatz, T. & Wirth, C. Quantifying photosynthetic capacity and its relationship to leaf nitrogen content for global-scale terrestrial biosphere models. Glob. Chang. Biol. 15, 976–991 (2009).
Kazakou, E., Vile, D., Shipley, B., Gallet, C. & Garnier, E. Co-variations in litter decomposition, leaf traits and plant growth in species from a Mediterranean old-field succession. Funct. Ecol. 20, 21–30 (2006).
Kerkhoff, A. J., Fagan, W. F., Elser, J. J. & Enquist, B. J. Phylogenetic and growth form variation in the scaling of nitrogen and phosphorus in the seed plants. Am. Nat. 168, E103–E122 (2006).
Kleyer, M. et al. The LEDA Traitbase: a database of life-history traits of the Northwest European flora. J. Ecol. 96, 1266–1274 (2008).
Maire, V. et al. Global effects of soil and climate on leaf photosynthetic traits and rates. Global Ecol. Biogeogr. 24, 706–717 (2015).
McDonald, P. G., Fonseca, C. R., Overton, J. M. & Westoby, M. Leaf-size divergence along rainfall and soil-nutrient gradients: is the method of size reduction common among clades? Funct. Ecol. 17, 50–57 (2003).
Meziane, D. & Shipley, B. Interacting components of interspecific relative growth rate: constancy and change under differing conditions of light and nutrient supply. Funct. Ecol. 13, 611–622 (1999).
Onoda, Y. et al. Physiological and structural tradeoffs underlying the leaf economics spectrum. New Phytol. 214, 1447–1463 (2017).
Pakeman, R. J. et al. Relative climatic, edaphic and management controls of plant functional trait signatures. J. Veg. Sci. 20, 148–159 (2009).
Peco, B., de Pablos, I., Traba, J. & Levassor, C. The effect of grazing abandonment on species composition and functional traits: the case of dehesa grasslands. Basic Appl. Ecol. 6, 175–183 (2005).
Prentice, I. C. et al. Evidence of a universal scaling relationship for leaf CO2 drawdown along an aridity gradient. New Phytol. 190, 169–180 (2011).
Reich, P. B., Oleksyn, J. & Wright, I. J. Leaf phosphorus influences the photosynthesis-nitrogen relation: a cross-biome analysis of 314 species. Oecologia 160, 207–212 (2009).
Shipley, B. & Vu, T.-T. Dry matter content as a measure of dry matter concentration in plants and their parts. New Phytol. 153, 359–364 (2002).
Tucker, S. S., Craine, J. M. & Nippert, J. B. Physiological drought tolerance and the structuring of tallgrass prairie assemblages. Ecosphere 2, art48 (2011).
Wang, H. et al. The China Plant Trait Database: toward a comprehensive regional compilation of functional traits for land plants. Ecology 99, 500 (2018).
Wright, I. J. et al. The worldwide leaf economics spectrum. Nature 428, 821–827 (2004).
Bates, D., Mächler, M., Bolker, B. & Walker, S. Fitting linear mixed-effects models using lme4. J. Stat. Softw. 67, 1–48 (2015).
Liu, Y. et al. Evaluating the responses of net primary productivity and carbon use efficiency of global grassland to climate variability along an aridity gradient. Sci. Total Environ. 652, 671–682 (2019).
Simpson, K. J. et al. C4 photosynthesis and the economic spectra of leaf and root traits independently influence growth rates in grasses. J. Ecol. 108, 1899–1909 (2020).
Danabasoglu, G. et al. The Community Earth System Model version 2 (CESM2). J. Adv. Model. Earth Syst. 12, e2019MS001916 (2020).
Levis, S., Badger, A., Drewniak, B., Nevison, C. & Ren, X. CLM crop yields and water requirements: avoided impacts by choosing RCP 4.5 over 8.5. Clim. Change 146, 501–515 (2018).
Portmann, F. T., Siebert, S. & Döll, P. MIRCA2000—global monthly irrigated and rainfed crop areas around the year 2000: a new high-resolution data set for agricultural and hydrological modeling. Global Biogeochem. Cycles https://doi.org/10.1029/2008GB003435 (2010).
Bonan, G. B. et al. Improving canopy processes in the Community Land Model (CLM4) using global flux fields empirically inferred from FLUXNET data. J. Geophys. Res. 116, G02014 (2011).
De Kauwe, M. G. et al. A test of an optimal stomatal conductance scheme within the CABLE land surface model. Geosci. Model Dev. 8, 431–452 (2015).
Shi, M., Fisher, J. B., Brzostek, E. R. & Phillips, R. P. Carbon cost of plant nitrogen acquisition: global carbon cycle impact from an improved plant nitrogen cycle in the Community Land Model. Glob. Chang. Biol. 22, 1299–1314 (2016).
Li, F., Zeng, X. D. & Levis, S. A process-based fire parameterization of intermediate complexity in a dynamic global vegetation model. Biogeosciences 9, 2761–2780 (2012).
Li, F., Levis, S. & Ward, D. S. Quantifying the role of fire in the Earth system—part 1: improved global fire modeling in the Community Earth System Model (CESM1). Biogeosciences 10, 2293–2314 (2013).
Umair, M., Kim, D. & Choi, M. Impact of climate, rising atmospheric carbon dioxide, and other environmental factors on water-use efficiency at multiple land cover types. Sci. Rep. 10, 11644 (2020).
Lawrence, D. M., Koven, C. D., Swenson, S. C., Riley, W. J. & Slater, A. G. Permafrost thaw and resulting soil moisture changes regulate projected high-latitude CO2 and CH4 emissions. Environ. Res. Lett. 10, 094011 (2015).
Denager, T. et al. Point-scale multi-objective calibration of the Community Land Model (version 5.0) using in situ observations of water and energy fluxes and variables. Hydrol. Earth Syst. Sci. 27, 2827–2845 (2023).
Oloruntoba, B. J., Kollet, S., Montzka, C., Vereecken, H. & Hendricks Franssen, H.-J. High resolution land surface modelling over Africa: the role of uncertain soil properties in combination with temporal model resolution. Hydrol. Earth Syst. Sci. 29, 1659–1683 (2025).