Warming promotes growth of seedlings of a woody encroacher in grassland dominated by C₄ species

References

• Acharya BS, Kharel G, Zou CB, Wilcox BP, Halihan T. 2018; Woody plant encroachment impacts on groundwater recharge: A review. Water (Basel) 10: 1466. https://doi.org/10.3390/w10101466.
   Web of Science ®Google Scholar
• An J, Han S, Chang H, Park MJ, Kim S, Hwang J, Cho MS, Chung H, Son Y. 2017. Physiological and growth responses to experimental warming in first-year seedlings of deciduous tree species. Turkish Journal of Agriculture and Forestry 41: 175–182. https://doi.org/10.3906/tar-1611-106.
   Web of Science ®Google Scholar
• Armani M, Goodale UM, Charles-Dominique T, Barton KE, Yao X, Tomlinson KW. 2020. Structural defence is coupled with the leaf economic spectrum across saplings of spiny species. Oikos 129: 740–752. https://doi.org/10.1111/oik.06960.
   Web of Science ®Google Scholar
• Belayneh A, Tessema ZK. 2017. Mechanisms of bush encroachment and its inter-connection with rangeland degradation in semi-arid African ecosystems: a review. Journal of Arid Land 9: 299–312. https://doi.org/10.1007/s40333-016-0023-x.
   Web of Science ®Google Scholar
• Bond WJ, Midgley GF. 2012. Carbon dioxide and the uneasy interactions of trees and savannah grasses. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 367: 601–612. https://doi.org/10.1098/rstb.2011.0182.
   PubMed Web of Science ®Google Scholar
• Bowman DMJS, Brienen RJW, Gloor E, Phillips OL, Prior LD. 2013. Detecting trends in tree growth: not so simple. Trends in Plant Science 18: 11–17. https://doi.org/10.1016/j.tplants.2012.08.005.
   PubMed Web of Science ®Google Scholar
• Buhrmann RD, Ramdhani S, Pammenter NW, Naidoo S. 2016. Grasslands feeling the heat: The effects of elevated temperatures on a subtropical grassland. Bothalia 46: a2122. https://doi.org/10.4102/abc.v46i2.2122.
   Web of Science ®Google Scholar
• Butterly CR, Armstrong R, Chen D, Tang C. 2016. Free-air CO2 enrichment (FACE) reduces the inhibitory effect of soil nitrate on N2 fixation of Pisum sativum. Annals of Botany 117: 177–185. https://doi.org/10.1093/aob/mcv140.
   PubMed Web of Science ®Google Scholar
• Chung H, Muraoka H, Nakamura M, Han S, Muller O, Son Y. 2013. Experimental warming studies on tree species and forest ecosystems: a literature review. Journal of Plant Research 126: 447–460. https://doi.org/10.1007/s10265-013-0565-3.
   PubMed Web of Science ®Google Scholar
• Devine AP, McDonald RA, Quaife T, Maclean IM. 2017. Determinants of woody encroachment and cover in African savannas. Oecologia 183: 939–951. https://doi.org/10.1007/s00442-017-3807-6.
   PubMed Web of Science ®Google Scholar
• D’Odorico P, Okin GS, Bestelmeyer BT. 2012. A synthetic review of feedbacks and drivers of shrub encroachment in arid grasslands. Ecohydrology 5: 520–530. https://doi.org/10.1002/eco.259.
   Web of Science ®Google Scholar
• Edwards EJ, Osborne CP, Strömberg CAE, Smith SA, Bond WJ, Christin PA, Cousins AB, Duvall MR, Fox DL, Freckleton RP, et al. 2010. The origins of C4 grasslands: integrating evolutionary and ecosystem science. Science 328: 587–591. https://doi.org/10.1126/science.1177216.
   PubMed Web of Science ®Google Scholar
• February EC, Coetsee C, Cook GD, Ratnam J, Wigley B. 2020. Physiological traits of savanna woody species: Adaptations to resource availability. In: Scogings PF, Sankaran M (Eds), Savanna woody plants and large herbivores. Hoboken: John Wiley & Sons Ltd. pp 311–329.
   Google Scholar
• Fey M. 2010. Soils of South Africa. Cambridge: Cambridge University Press. https://doi.org/10.1017/CBO9780511782183.
   Google Scholar
• Fynn RWS, O’Connor TG. 2005. Determinants of community organization of a South African mesic grassland. Journal of Vegetation Science 16: 93–102. https://doi.org/10.1111/j.1654-1103.2005.tb02342.x.
   Web of Science ®Google Scholar
• Grellier S, Janeau J, Richard P, Florsch N, Ward D, Bariac T, Lorentz S. 2020. Water uptake plasticity of savanna trees in encroached grassland: small trees match the mature trees. African Journal of Range & Forage Science. https://doi.org/10.2989/10220119.2020.1834453.
   Google Scholar
• Gleason SM, Stephens AEA, Tozer WC, Blackman CJ, Butler DW, Chang Y, Cooke AM, Cooke J, Laws CA, Rosell JA, et al. 2018. Shoot growth of woody trees and shrubs is predicted by maximum plant height and associated traits. Functional Ecology 32: 247–259. https://doi.org/10.1111/1365-2435.12972.
   Web of Science ®Google Scholar
• Gunton RM, Boyes LJ, Griffiths ME, Lawes MJ. 2010. Regeneration niches and functional traits of three common species in subtropical dune forest. Forest Ecology and Management 260: 1490–1497. https://doi.org/10.1016/j.foreco.2010.07.047.
   Web of Science ®Google Scholar
• Hanley ME, Lamont BB, Fairbanks MM, Rafferty CM. 2007. Plant structural traits and their role in anti-herbivore defence. Perspectives in Plant Ecology, Evolution and Systematics 8: 157–178. https://doi.org/10.1016/j.ppees.2007.01.001.
   Web of Science ®Google Scholar
• Herms DA, Mattson WJ. 1992. The dilemma of plants: to grow or defend. The Quarterly Review of Biology 67: 283–335. https://doi.org/10.1086/417659.
   Web of Science ®Google Scholar
• Hoffmann WA, Poorter H. 2002. Avoiding bias in calculations of relative growth rate. Annals of Botany 90: 37–42.
   PubMed Web of Science ®Google Scholar
• Ibáñez I, Katz DSW, Lee BR. 2017. The contrasting effects of short-term climate change on the early recruitment of tree species. Oecologia 184: 701–713.
   PubMed Web of Science ®Google Scholar
• IPCC. 2014. IPCC Climate Change. 2014. Impacts, adaptation and vulnerability. Cambridge: Cambridge University Press.
   Google Scholar
• John GP, Scoffoni C, Buckley TN, Villar R, Poorter H, Sack L. 2017. The anatomical and compositional basis of leaf mass per area. Ecology Letters 20: 412–425. https://doi.org/10.1111/ele.12739.
   PubMed Web of Science ®Google Scholar
• Jolly WM, Running SW. 2004. Effects of precipitation and soil water potential on drought deciduous phenology in the Kalahari. Global Change Biology 10: 303–308. https://doi.org/10.1046/j.1365-2486.2003.00701.x.
   Web of Science ®Google Scholar
• Joshi AA, Ratnam J, Sankaran M. 2020. Frost maintains forests and grasslands as alternate states in a montane tropical forest– grassland mosaic; but alien tree invasion and warming can disrupt this balance. Journal of Ecology 108: 122–132. https://doi.org/10.1111/1365-2745.13239.
   Web of Science ®Google Scholar
• Ketter BL, Holdo RM. 2018. Strong competitive effects of African savanna C4 grasses on tree seedlings do not support rooting differentiation. Journal of Tropical Ecology 34: 65–73. https://doi.org/10.1017/S0266467418000020.
   Web of Science ®Google Scholar
• Krab EJ, Roennefarth J, Becher M, Blume-Werry G, Keuper F, Klaminder J, Kreyling J, Makoto K, Milbau A, Dorrepaal E. 2018. Winter warming effects on tundra shrub performance are species-specific and dependent on spring conditions. Journal of Ecology 106: 599–612.
   Web of Science ®Google Scholar
• Kreyling J, Grant K, Hammerl V, Arfin-Khan MAS, Malyshev AV, Peñuelas J, Pritsch K, Sardans J, Schloter M, Schuerings J, Jentsch A, Beierkuhnlein C. 2019. Winter warming is ecologically more relevant than summer warming in a cool-temperate grassland. Scientific Reports 9: 14632. https://doi.org/10.1038/s41598-019-51221-w.
   PubMed Web of Science ®Google Scholar
• Lazarus BE, Castanha C, Germino MJ, Kueppers LM, Moyes AB. 2018. Growth strategies and threshold responses to water deficit modulate effects of warming on tree seedlings from forest to alpine. Journal of Ecology 106: 571–585. https://doi.org/10.1111/1365-2745.12837.
   Web of Science ®Google Scholar
• Lett S, Dorrepaal E. 2018. Global drivers of tree seedling establishment at alpine treelines in a changing climate. Functional Ecology 32: 1666–1680. https://doi.org/10.1111/1365-2435.13137.
   Web of Science ®Google Scholar
• Lie Z, Lin W, Huang W, Fang X, Huang C, Wu T, Chu G, Liu S, Meng Z, Zhou G, Liu J. 2019. Warming changes soil N and P supplies in model tropical forests. Biology and Fertility of Soils 55: 751–763. https://doi.org/10.1007/s00374-019-01382-7.
   Web of Science ®Google Scholar
• Luvuno L, Biggs R, Stevens N, Esler K. 2018. Woody encroachment as a social-ecological regime shift. Sustainability 10: 2221. https://doi.org/10.3390/su10072221.
   Web of Science ®Google Scholar
• Marion GM, Henry GHR, Freckman DW, Johnstone J, Jones G, Jones MH, Lévesque E, Molau U, Mølgaard P, Parsons AN, et al. 1997. Open-top designs for manipulating field temperature in high-latitude ecosystems. Global Change Biology 3: 20–32.
   Web of Science ®Google Scholar
• Mathew I, Shimelis H, Mutema M, Clulow A, Zengeni R, Mbava N, Chaplot V. 2019. Selection of wheat genotypes for biomass allocation to improve drought tolerance and carbon sequestration into soils. Journal Agronomy & Crop Science 205: 385–400. https://doi.org/10.1111/jac.12332.
   Web of Science ®Google Scholar
• Matyssek R, Kozovits AR, Wieser G, King J, Rennenberg H. 2017. Woody-plant ecosystems under climate change and air pollution – response consistencies across zonobiomes? Tree Physiology 37: 706–732. https://doi.org/10.1093/treephys/tpx009.
   PubMed Web of Science ®Google Scholar
• Moleele NM, Perkins JS. 1998. Encroaching woody plant species and boreholes: is cattle density the main driving factor in the Olifants Drift communal grazing lands, south-eastern Botswana? Journal of Arid Environments 40: 245–253. https://doi.org/10.1006/jare.1998.0451.
   Web of Science ®Google Scholar
• Mucina L, Rutherford MC (Eds). 2006. The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. Pretoria: South African National Biodiversity Institute.
   Google Scholar
• O’Connor TG, Puttick JR, Hoffman MT. 2014. Bush encroachment in southern Africa: changes and causes. African Journal of Range & Forage Science 31: 67–88. https://doi.org/10.2989/10220119.2014.939996.
   Web of Science ®Google Scholar
• Pallardy SG. 2008. Physiology of woody plants. Burlington: Academic Press.
   Google Scholar
• Parmesan C, Hanley ME. 2015. Plants and climate change: complexities and surprises. Annals of Botany 116: 849–864. https://doi.org/10.1093/aob/mcv169.
   PubMed Web of Science ®Google Scholar
• Quirk J, Bellasio C, Johnson DA, Osborne CP, Beerling DJ. 2019. C4 savanna grasses fail to maintain assimilation in drying soil under low CO2 compared with C3 trees despite lower leaf water demand. Functional Ecology 33: 388–398. https://doi.org/10.1111/1365-2435.13240.
   Web of Science ®Google Scholar
• Russell J, Ward D. 2014. Vegetation change in northern KwaZulu-Natal since the Anglo-Zulu War of 1879: local or global drivers? African Journal of Range & Forage Science 31: 89–105. https://doi.org/10.2989/10220119.2013.827740.
   Web of Science ®Google Scholar
• Scogings PF, Sankaran M. 2020. Woody plants and large herbivores in savannas: ancient past–uncertain future. In: Scogings PF, Sankaran M (Eds), Savanna woody plants and large herbivores. Hoboken, USA: John Wiley & Sons Ltd. pp 683–712.
   Google Scholar
• Sinclair MN, Woods NN, Zinnert JC. 2020. Seasonal facilitative and competitive trade-offs between shrub seedlings and coastal grasses. Ecosphere 11: e02995. https://doi.org/10.1002/ecs2.2995.
   Web of Science ®Google Scholar
• Slot M, Winter K. 2018. High tolerance of tropical sapling growth and gas exchange to moderate warming. Functional Ecology 32: 599–611. https://doi.org/10.1111/1365-2435.13001.
   Web of Science ®Google Scholar
• Stevens N, Seal CE, Archibald A, Bond W. 2014. Increasing temperatures can improve seedling establishment in arid-adapted savanna trees. Oecologia 175: 1029–1040. https://doi.org/10.1007/s00442-014-2958-y.
   PubMed Web of Science ®Google Scholar
• Stevens N, Erasmus BFN, Archibald S, Bond WJ. 2016. Woody encroachment over 70 years in South African savannahs: overgrazing, global change or extinction aftershock? Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 371: 20150437. https://doi.org/10.1098/rstb.2015.0437.
   PubMed Web of Science ®Google Scholar
• Stevens N, Lehmann CER, Murphy BP, Durigan G. 2017. Savanna woody encroachment is widespread across three continents. Global Change Biology 23: 235–244. https://doi.org/10.1111/gcb.13409.
   PubMed Web of Science ®Google Scholar
• Sweet RJ, Mphinyane W. 1986. Preliminary observations on the ability of goats to control post-burning regrowth in Acacia nigrescens/Combretum apiculatum savanna in Botswana. Journal of the Grassland Society of Southern Africa 3: 79–84. https://doi.org/10.1080/02566702.1986.9648040.
   Google Scholar
• Swemmer A, Ward D. 2020. Patterns and determinants of woody plant growth in savannas. In: Scogings PF, Sankaran M (Eds), Savanna woody plants and large herbivores. Hoboken: John Wiley & Sons Ltd. pp 331–438.
   Google Scholar
• Tedder M, Morris C, Fynn R, Kirkman K. 2012. Do soil nutrients mediate competition between grasses and Acacia saplings? Grassland Science 58: 238–245. https://doi.org/10.1111/grs.12003.
   Web of Science ®Google Scholar
• Tedder M, Kirkman K, Morris C, Fynn R. 2014 Tree–grass competition along a catenal gradient in a mesic grassland, South Africa. Grassland Science 60: 1–8. https://doi.org/10.1111/grs.12034.
   Web of Science ®Google Scholar
• Tobita H, Yazaki K, Harayama H, Kitao M. 2016. Responses of symbiotic N2 fixation in Alnus species to the projected elevated CO2 environment. Trees (Berlin) 30: 523–537. https://doi.org/10.1007/s00468-015-1297-x.
   Web of Science ®Google Scholar
• Tomlinson KW, Sterck FJ, Barbosa ER, de Bie S, Prins HH, van Langevelde F. 2019. Seedling growth of savanna tree species from three continents under grass competition and nutrient limitation in a greenhouse experiment. Journal of Ecology 107: 1051–1066. https://doi.org/10.1111/1365-2745.13085.
   Web of Science ®Google Scholar
• Venter ZS, Cramer MD, Hawkins H. 2018. Drivers of woody plant encroachment over Africa. Nature Communications 9: 2272. https://doi.org/10.1038/s41467-018-04616-8.
   PubMed Web of Science ®Google Scholar
• Vetter S, Goodall VL, Alcock R. 2020. Effect of drought on communal livestock farmers in KwaZulu-Natal, South Africa. African Journal of Range & Forage Science 37: 93–106. https://doi.org/10.2989/10220119.2020.1738552.
   Web of Science ®Google Scholar
• Volder A, Briske DD, Tjoelker MG. 2013. Climate warming and precipitation redistribution modify tree–grass interactions and tree species establishment in a warm-temperate savanna. Global Change Biology 19: 843–857. https://doi.org/10.1111/gcb.12068.
   PubMed Web of Science ®Google Scholar
• Wagner TC, Richter J, Joubert DF, Fischer C. 2018. A dominance shift in arid savanna: an herbaceous legume outcompetes local C4 grasses. Ecology and Evolution 8: 6779–6787. https://doi.org/10.1002/ece3.4188.
   PubMed Web of Science ®Google Scholar
• Wakeling JL, Cramer MD, Bond WJ. 2012. The savanna- grassland ‘treeline’: why don’t savanna trees occur in upland grasslands? Journal of Ecology 100: 381–391. https://doi.org/10.1111/j.1365-2745.2011.01921.x.
   Web of Science ®Google Scholar
• Ward D, Wiegand K, Getzin S. 2013. Walter’s two-layer hypothesis revisited: back to the roots! Oecologia 172: 617–630. https://doi.org/10.1007/s00442-012-2538-y.
   Google Scholar
• Ward D, Hoffman MT, Collocott SJ. 2014. A century of woody plant encroachment in the dry Kimberley savanna of South Africa. African Journal of Range & Forage Science 31: 107–121. https://doi.org/10.2989/10220119.2014.914974.
   Web of Science ®Google Scholar
• Wigley BJ, Slingsby JA, Díaz S, Bond WJ, Fritz H, Coetsee C. 2016. Leaf traits of African woody savanna species across climate and soil fertility gradients: evidence for conservative versus acquisitive resource-use strategies. Journal of Ecology 104: 1357–1369. https://doi.org/10.1111/1365-2745.12598.
   Web of Science ®Google Scholar
• Wilcox BP, Birt A, Fuhlendorf SD, Archer SR. 2018. Emerging frameworks for understanding and mitigating woody plant encroachment in grassy biomes. Current Opinion in Environmental Sustainability 32: 46–52. https://doi.org/10.1016/j.cosust.2018.04.005.
   Web of Science ®Google Scholar
• Yang L, Yang Z, Peng Y, Lin Y, Xiong D, Li Y, Yang Y. 2019. Evaluating P availability influenced by warming and N deposition in a subtropical forest soil: a bioassay mesocosm experiment. Plant and Soil 444: 87–99. https://doi.org/10.1007/s11104-019-04246-z.
   Web of Science ®Google Scholar
• Yuan Y, Ge L, Yang H, Ren W. 2018. A meta-analysis of experimental warming effects on woody plant growth and photosynthesis in forests. Journal of Forestry Research 29: 727–733. https://doi.org/10.1007/s11676-017-0499-z.
   Web of Science ®Google Scholar