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Research Papers

Does defoliation frequency and severity influence plant productivity? The role of grazing management and soil nutrients

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References

  • Ali I, Cawkwell F, Dwyer E, Barrett B, Green S. 2016. Satellite remote sensing of grasslands: from observation to management. Journal of Plant Ecology 9: 649–671. doi:10.1093/jpe/rtw005.
  • Anderson TM, Kumordzi BB, Fokkema W, Fox HV, Olff H. 2013. Distinct physiological responses underlie defoliation tolerance in African lawn and bunch grasses. International Journal of Plant Sciences 174: 769–778. doi:10.1086/670237.
  • Avenant P. 2016. Grazing capacity map of South Africa 2016. South Africa: Department of Agriculture, Forestry and Fisheries.
  • Avery DJ, Lacey HJ. 1968. Changes in the growth-regulator content of plum infested with fruit tree red spider mite, Panonychus ulmi (Koch). Journal of Experimental Botany 19: 760–769. doi:10.1093/jxb/19.4.760.
  • Baddeley A, Rubak E, Turner R. 2015. Spatial point patterns: methodology and applications with R. New York: CRC Press. doi:10.1201/b19708.
  • Baker JN, Hunt OJ. 1961. Effects of clipping treatments and clonal differences on water requirement of grasses. Journal of Range Management 14: 216–219. doi:10.2307/3895153.
  • Bardgett RD, Wardle DA. 2003. Herbivore-mediated linkages between aboveground and belowground communities. Ecology 84: 2258–2268. doi:10.1890/02-0274.
  • Barnes DL. 1990. A survey of grazed and ungrazed grassland in the south-eastern Transvaal highveld 1. Palatability composition and grazing capacity. Journal of the Grassland Society of southern Africa 7: 217–222.
  • Bates D, Mächler M, Bolker B, Walker S. 2014. Fitting linear mixed-effects models using lme4. arXiv preprint arXiv:1406.5823.
  • Bateson CA, Asner GP, Wessman CA. 2000. Endmember bundles: A new approach to incorporating endmember variability into spectral mixture analysis. IEEE Transactions on Geoscience and Remote Sensing 38: 1083–1094. doi:10.1109/36.841987.
  • Beeri O, Phillips R, Hendrickson J, Frank AB, Kronberg S. 2007. Estimating forage quantity and quality using aerial hyperspectral imagery for northern mixed-grass prairie. Remote Sensing of Environment 110: 216–225. doi:10.1016/j.rse.2007.02.027.
  • Belsky AJ. 1986. Does herbivory benefit plants? A review of the evidence. American Naturalist 127: 870–892. doi:10.1086/284531.
  • Blanco L, Aguilera M, Paruelo J, Biurrun F. 2008. Grazing effect on NDVI across an aridity gradient in Argentina. Journal of Arid Environments 72: 764–776. doi:10.1016/j.jaridenv.2007.10.003.
  • Bork EW, Broadbent TS, Willms WD. 2017. Intermittent growing season defoliation variably impacts accumulated herbage productivity in mixed grass prairie. Rangeland Ecology and Management 70: 307–315. doi:10.1016/j.rama.2016.10.007.
  • Bransby DI, Tainton NM. 1977. The disc pasture meter: possible applications in grazing management. Proceedings of the Annual Congresses of the Grassland Society of Southern Africa 12: 115–118. doi:10.1080/00725560.1977.9648818.
  • Briske D. 1996. Strategies of plant survival in grazed systems: a functional interpretation. Rangeland Ecology and Management 61: 3–17. doi:10.2111/REM-D-10-00084.1.
  • Briske D, Sayre NF, Huntsinger L, Fernandez-Gimenez M, Budd B, Derner J. 2011. Origin, persistence, and resolution of the rotational grazing debate: integrating human dimensions into rangeland research. Rangeland Ecology and Management 64: 325–334 doi:10.2111/REM-D-10-00084.1.
  • Briske DD, Derner J, Brown J, Fuhlendorf S, Teague W, Havstad K, Gillen RL, Ash AJ, Willms W. 2008. Rotational grazing on rangelands: reconciliation of perception and experimental evidence. Rangeland Ecology and Management 61: 3–17. doi:10.2111/06-159R.1.
  • Brockett G. 1983. The effect of defoliation on the persistence of Elionurus muticus (Spreng.) Kunth in the Highland Sourveld of Natal. Proceedings of the Annual Congresses of the Grassland Society of Southern Africa 18: 81–83. doi:10.1080/00725560.1983.9648989.
  • Bryant JP, Chapin FS, Klein DR.1983. Carbon/nutrient balance of boreal plants in relation to vertebrate herbivory. Oikos 40(3): 357–368. doi:10.2307/3544308.
  • Chapin FS, McNaughton SJ. 1989. Lack of compensatory growth under phosphorus deficiency in grazing-adapted grasses from the Serengeti Plains. Oecologia 79: 551–557. doi:10.1007/BF00378674.
  • Crider FJ. 1955. Root-growth stoppage resulting from defoliation of grass. Washington DC, USA: US Department of Agriculture.
  • Cromsigt JPGM, Olff H. 2008. Dynamics of grazing lawn formation: an experimental test of the role of scale-dependent processes. Oikos 117: 1444–1452. doi:10.1111/j.0030-1299.2008.16651.x.
  • Danckwerts J, Gordon A. 1990. Partitioning, storage and remobilization of 14C assimilated by Themeda triandra Forssk. Journal of the Grassland Society of southern Africa 7: 97–105.
  • Dawson LA, Thornton B, Pratt SM, Paterson E. 2004. Morphological and topological responses of roots to defoliation and nitrogen supply in Lolium perenne and Festuca ovina. The New Phytologist 161: 811–818. doi:10.1111/j.1469-8137.2004.00979.x.
  • Del-Val EK, Crawley MJ. 2005. Are grazing increaser species better tolerators than decreasers? An experimental assessment of defoliation tolerance in eight British grassland species. Journal of Ecology 93: 1005–1016. doi:10.1111/j.1365-2745.2005.01011.x.
  • Derner JD, Gillen RL, McCollum FT, Tate KW. 1994. Little bluestem tiller defoliation patterns under continuous and rotational grazing. Journal of Range Management 47(3): 220–225. doi:10.2307/4003020.
  • Detling JK, Dyer MI, Winn DT. 1979. Net photosynthesis, root respiration, and regrowth of Bouteloua gracilis following simulated grazing. Oecologia 41: 127–134. doi:10.1007/BF00344997.
  • Dunn JH, Engel RE. 1971. Effect of defoliation and root-pruning on early root growth from Merion Kentucky bluegrass sods and seedlings. Agronomy Journal 63: 659–663. doi:10.2134/agronj19 71.00021962006300050001x.
  • Ellison L. 1960. Influence of grazing on plant succession of rangelands. The Botanical Review 26: 1–78. doi:10.1007/BF02860480.
  • Food and Agriculture Organization (FAO). 2006. Chapter 4: Soil description. In: Guidelines for soil description (4th edn), FAO, Rome, pp 21–65, ISBN 92–5–105521–1. Rome, Italy: FAO.
  • Food and Agriculture Organization (FAO). 2010. Land degradation assessment in drylands (LADA): assessing the status causes and impact of land degradation. Rome, Italy: FAO.
  • Fernández RJ. 2002. Do humans create deserts? Trends in Ecology & Evolution 17: 6–7. doi:10.1016/S0169-5347(01)02366-7.
  • Ferraro DO, Oesterheld M. 2002. Effect of defoliation on grass growth. A quantitative review. Oikos 98: 125–133. doi:10.1034/j.1600-0706.2002.980113.x.
  • Fishe RA. 1921. Some remarks on the methods formulated in a recent article on “the quantitative analysis of plant growth”. Annals of Applied Biology 7: 367–372. doi:10.1111/j.1744-7348.1921.tb05524.x.
  • Foran BD, Tainton NM, Booysen PV. 1978. The development of a method for assessing veld condition in three grassveld types in natal. Proceedings of the Annual Congresses of the Grassland Society of Southern Africa 13: 27–33. doi:10.1080/00725560.1978.9648829.
  • Frank DA, Groffman PM. 1998. Ungulate vs. Landscape control of soil C and N processes in grasslands of Yellowstone National Park. Ecology 79: 2229–2241. doi:10.1890/0012-9658(1998)079[2229:UVLCOS]2.0.CO;2.
  • Fulkerson W, Donaghy D. 2001. Plant-soluble carbohydrate reserves and senescence-key criteria for developing an effective grazing management system for ryegrass-based pastures: a review. Animal Production Science 41: 261–275. doi:10.1071/EA00062.
  • Fuls E. 1992. Ecosystem modification created by patch-overgrazing in semi-arid grassland. Journal of Arid Environments 23: 59–69. doi:10.1016/S0140-1963(18)30541-X.
  • Fynn RW, O’Connor TG. 2005. Determinants of community organization of a South African mesic grassland. Journal of Vegetation Science 16: 93–102. doi:10.1111/j.1654-1103.2005.tb02342.x.
  • Fynn RWS, Morris CD, Kirkman KP. 2005. Plant strategies and trait trade-offs influence trends in competitive ability along gradients of soil fertility and disturbance. Journal of Ecology 93: 384–394. doi:10.1111/j.0022-0477.2005.00993.x.
  • Georgiadis NJ, Ruess RW, McNaughton SJ, Western D. 1989. Ecological conditions that determine when grazing stimulates grass production. Oecologia 81: 316–322 doi:10.1007/BF00377077.
  • Gifford R, Marshall C. 1973. Photosynthesis and assimilate distribution in Lolium multiflorum Lam. following differential tiller defoliation. Australian Journal of Biological Sciences 26: 517–526. doi:10.1071/BI9730517.
  • Gorelick N, Hancher M, Dixon M, Ilyushchenko S, Thau D, Moore R2017. Google Earth Engine: Planetary-scale geospatial analysis for everyone. Remote Sensing of Environment 202: 18–27. doi:10.1016/j.rse.2017.06.031.
  • Hamilton EW, Giovannini MS, Moses SA, Coleman JS, McNaughton SJ. 1998. Biomass and mineral element responses of a Serengeti short-grass species to nitrogen supply and defoliation: compensation requires a critical [N]. Oecologia 116: 407–418. doi:10.1007/s004420050604.
  • Harper JL. 1989. The value of a leaf. Oecologia 80: 53–58. doi:10.1007/BF00789931.
  • Harrison XA, Donaldson L, Correa-Cano ME, Evans J, Fisher DN, Goodwin CED, Robinson BS, Hodgson DJ, Inger R. 2018. A brief introduction to mixed effects modelling and multi-model inference in ecology. PeerJ 6: e4794. doi:10.7717/peerj.4794.
  • Hawkes CV, Sullivan JJ. 2001. The impact of herbivory on plants in different resource conditions: a meta-analysis. Ecology 82: 2045–2058. doi:10.1890/0012-9658(2001)082[2045:TIOHOP]2.0.CO;2.
  • Hawkins H-J. 2017. A global assessment of Holistic Planned Grazing™ compared with season-long, continuous grazing: meta-analysis findings. African Journal of Range & Forage Science 34: 65–75. doi:10.2989/10220119.2017.1358213.
  • Haynes RJ, Naidu R. 1998. Influence of lime, fertilizer and manure applications on soil organic matter content and soil physical conditions: a review. Nutrient Cycling in Agroecosystems 51: 123–137. doi:10.1023/A:1009738307837.
  • Heady HF. 1961. Continuous vs. specialized grazing systems: a review and application to the California Annual Type. Journal of Range Management 14: 182–193. doi:10.2307/3895147.
  • Hempson GP, Archibald S, Bond WJ, Ellis RP, Grant CC, Kruger FJ, Kruger LM, Moxley C, Owen-Smith N, Peel MJ, et al. 2015. Ecology of grazing lawns in Africa. Biological Reviews of the Cambridge Philosophical Society 90: 979–994. doi:10.1111/brv.12145.
  • Hengl T, Mendes de Jesus J, Heuvelink GBM, Ruiperez Gonzalez M, Kilibarda M, Blagotić A, Shangguan W, Wright MN, Geng X, Bauer-Marschallinger B, et al. 2017. SoilGrids250m: Global gridded soil information based on machine learning. PLoS One 12: e0169748. doi:10.1371/journal.pone.0169748.
  • Hijmans RJ, Cameron SE, Parra JL, Jones PG, Jarvis A. 2005. Very high resolution interpolated climate surfaces for global land areas. International Journal of Climatology 25: 1965–1978. doi:10.1002/joc.1276.
  • Hilbert DW, Swift DM, Detling JK, Dyer MI. 1981. Relative growth rates and the grazing optimization hypothesis. Oecologia 51: 14–18. doi:10.1007/BF00344645.
  • Hilker T, Natsagdorj E, Waring RH, Lyapustin A, Wang Y. 2014. Satellite observed widespread decline in Mongolian grasslands largely due to overgrazing. Global Change Biology 20: 418–428. doi:10.1111/gcb.12365.
  • Hobbs NT. 1996. Modification of ecosystems by ungulates. The Journal of Wildlife Management 60(4): 695–713. doi:10.2307/3802368.
  • Hodgkinson K. 1974. Influence of Partial Defoliation on Photosynthesis, Photorespiration and Transpiration by Lucerne Leaves of Different Ages. Functional Plant Biology 1: 561–578. doi:10.1071/PP9740561.
  • Iqbal N, Masood A, Khan NA. 2012. Analyzing the significance of defoliation in growth, photosynthetic compensation and sourcesink relations. Photosynthetica 50: 161–170. doi:10.1007/s11099-012-0029-3.
  • IUSS Working Group WRB. 2015. World Reference Base for Soil Resources 2014, update 2015 International soil classification system for naming soils and creating legends for soil maps. World Soil Resources Reports No. 106. Rome, Italy: FAO.
  • Jones CG, Hartley SE. 1999. A protein competition model of phenolic allocation. Oikos 86(1): 27–44. doi:10.2307/3546567.
  • LeBauer DS, Treseder KK. 2008. Nitrogen limitation of net primary productivity in terrestrial ecosystems is globally distributed. Ecology 89: 371–379. doi:10.1890/06-2057.1.
  • Lee JM, Sathish P, Donaghy DJ, Roche JR. 2011. Impact of defoliation severity on photosynthesis, carbon metabolism and transport gene expression in perennial ryegrass. Functional Plant Biology 38: 808–817. doi:10.1071/FP11048.
  • Levy EB, Madden EA. 1933. The point method of pasture analysis. New Zealand Journal of Agriculture 46: 267–279.
  • Machado RAR, Ferrieri AP, Robert CAM, Glauser G, Kallenbach M, Baldwin IT, Erb M. 2013. Leaf-herbivore attack reduces carbon reserves and regrowth from the roots via jasmonate and auxin signaling. The New Phytologist 200: 1234–1246. doi:10.1111/nph.12438.
  • Maschinski J, Whitham TG. 1989. The continuum of plant responses to herbivory: the influence of plant association, nutrient availability, and timing. American Naturalist 134: 1–19. doi:10.1086/284962.
  • McCormick AJ, Cramer MD, Watt DA. 2006. Sink strength regulates photosynthesis in sugarcane. The New Phytologist 171: 759–770. doi:10.1111/j.1469-8137.2006.01785.x.
  • McCosker T. 2000. Cell Grazing—the first 10 years in Australia. Tropical Grasslands 34: 207–218.
  • McNaughton S. 1979. Grazing as an optimization process: grass-ungulate relationships in the Serengeti. American Naturalist 113: 691–703. doi:10.1086/283426.
  • McNaughton S. 1983. Compensatory plant growth as a response to herbivory. Oikos: 329–336. doi:10.2307/3544305.
  • McNaughton SJ, Banyikwa FF, McNaughton MM. 1998. Root biomass and productivity in a grazing ecosystem: The Serengeti. Ecology 79: 587–592. doi:10.1890/0012-9658(1998)079[0587:RBAPIA]2.0.CO;2.
  • McNaughton SJ, Chapin FS. 1985. Effects of phosphorus nutrition and defoliation on C4 graminoids from the Serengeti Plains. Ecology 66: 1617–1629. doi:10.2307/1938024.
  • Morris CD. 2016. Is the grazing tolerance of mesic decreaser and increaser grasses altered by soil nutrients and competition? African Journal of Range & Forage Science 33: 235–245. doi:10.2989/10220119.2016.1264481.
  • Mucina L, Rutherford MC. 2006. The vegetation of South Africa, Lesotho and Swaziland. Pretoria, South Africa: South African National Biodiversity Institute.
  • Munyati C, Makgale D. 2009. Multitemporal Landsat TM imagery analysis for mapping and quantifying degraded rangeland in the Bahurutshe communal grazing lands, South Africa. International Journal of Remote Sensing 30: 3649–3668. doi:10.1080/01431160802592534.
  • O’Reagain P, Turner J. 1992. An evaluation of the empirical basis for grazing management recommendations for rangeland in southern Africa. Journal of the Grassland Society of southern Africa 9: 38–49.
  • Oosthuizen IB, Snyman HA. 2003. Impact of water stress on growth reserves and re-growth of Themeda triandra (Forssk) following defoliation. African Journal of Range & Forage Science 20: 41–45. doi:10.2989/10220110309485796.
  • Opperman DPJ, Roberts BR, van Rensburg WLJ. 1970. The influence of defoliation on the root weights, stubble weights and growth reserves of three perennial veld grasses (Themeda triandra, Eragrostis lehmanniana and Cymbopogon plurinodis). Agroplantae 2: 51–60.
  • Oswalt DL, Bertrand AR, Teel MR. 1959. Influence of nitrogen fertilization and clipping on grass roots. Soil Science Society of America Journal 23: 228–230. doi:10.2136/sssaj1959.03615995002300030022x.
  • Paul MJ, Foyer CH. 2001. Sink regulation of photosynthesis. Journal of Experimental Botany 52: 1383–1400. doi:10.1093/jexbot/52.360.1383.
  • Pettorelli N, Vik JO, Mysterud A, Gaillard J-M, Tucker CJ, Stenseth NC. 2005. Using the satellite-derived NDVI to assess ecological responses to environmental change. Trends in Ecology & Evolution 20: 503–510. doi:10.1016/j.tree.2005.05.011.
  • PlanetTeam. 2017. Planet Application Program Interface: In Space for Life on Earth. Available at: https://api.planet.com.
  • Porensky LM, Veblen KE. 2015. Generation of ecosystem hotspots using short-term cattle corrals in an African Savanna. Rangeland Ecology and Management 68: 131–141. doi:10.1016/j.rama.2015.01.002.
  • R CoreTeam. 2017. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing.
  • Richards J, Caldwell M. 1985. Soluble carbohydrates, concurrent photosynthesis and efficiency in regrowth following defoliation: a field study with Agropyron species. Journal of Applied Ecology 22(3): 907–920. doi:10.2307/2403239.
  • Roy DP, Kovalskyy V, Zhang HK, Vermote EF, Yan L, Kumar SS, Egorov A. 2016. Characterization of Landsat-7 to Landsat-8 reflective wavelength and normalized difference vegetation index continuity. Remote Sensing of Environment 185: 57–70. doi:10.1016/j.rse.2015.12.024.
  • Ryle GJA, Powell CE. 1975. Defoliation and regrowth in the graminaceous plant: the role of current assimilate. Annals of Botany 39: 297–310. doi:10.1093/oxfordjournals.aob.a084943.
  • Sampson AW. 1951. A symposium on rotation grazing in North America. Journal of Range Management 4: 19–24. doi:10.2307/3894427.
  • Savory A, Butterfield J. 2016. Holistic management: a commonsense revolution to restore our environment. Washinton DC, US: Island Press.
  • Snyman HA, Ingram LJ, Kirkman KP. 2013. Themeda triandra: a keystone grass species. African Journal of Range & Forage Science 30: 99–125. doi:10.2989/10220119.2013.831375.
  • Svoray T, Perevolotsky A, Atkinson PM. 2013. Ecological sustainability in rangelands: the contribution of remote sensing. International Journal of Remote Sensing 34: 6216–6242. doi:10.1080/01431161.2013.793867.
  • Tainton N, Booysen P De V, Scott J. 1970. Response of tall grassveld to different intensities, seasons and frequencies of clipping. Proceedings of the Annual Congresses of the Grassland Society of Southern Africa 5: 32–41.
  • Tainton NM, Edwards PJ, Mentis MT.1980. A revised method for assessing veld condition. Proceedings of the Annual Congresses of the Grassland Society of Southern Africa 15: 37–42. doi:10.1080/00725560.1980.9648882.
  • Thorne JH, Koller HR. 1974. Influence of assimilate demand on photosynthesis, diffusive resistances, translocation, and carbohydrate levels of soybean leaves. Plant Physiology 54: 201–207. doi:10.1104/pp.54.2.201.
  • Thurow TL. 1991. Hydrology and erosion. Grazing management: An ecological perspective. Portland, US: Timber Press. p 141–160.
  • Tiedeman J. 1986. Short duration grazing: proceedings of the short duration grazing and current issues in grazing management shortcourse, 21–23 January 1986. Kennewick, Washington: Pullman: Washington University. https://download-pdfs.com/v6/preview/?pid=6&offer_id=26&ref_id=16e1b1df42794468c3d1f2aaaYc65xTK_e6cef1e4_c28f910b&sub1=92654&keyword=Short%20Duration%20Grazing%20-%20Short%20Duration%20Grazing%20And%20Current%20Issues%20In%20Grazing%20Management%20Shortcourse%20(1986%20Kennewick,%20Wash.).
  • Tiffin P. 2000. Mechanisms of tolerance to herbivore damage: what do we know? Evolutionary Ecology 14: 523–536. doi:10.1023/A:1010881317261.
  • Tucker CJ. 1979. Red and photographic infrared linear combinations for monitoring vegetation. Remote Sensing of Environment 8: 127–150. doi:10.1016/0034-4257(79)90013-0.
  • Van Poollen HW, Lacey JR. 1979. Herbage Response to Grazing Systems and Stocking Intensities. Journal of Range Management 32: 250–253. doi:10.2307/3897824.
  • Veblen KE. 2013. Impacts of traditional livestock corrals on woody plant communities in an East African savanna. The Rangeland Journal 35: 349–353. doi:10.1071/RJ13001.
  • Venter A, Drewes R. 1969. A flexible system of management for sourveld in Natal. Proceedings of the Annual Congresses of the Grassland Society of Southern Africa 4: 104–107. doi:10.1080/00725560.1969.9648596.
  • Venter ZS, Cramer MD, Hawkins HJ. 2018. Drivers of woody plant encroachment over Africa. Nature Communications 9: 2272. doi:10.1038/s41467-018-04616-8.
  • Venter ZS, Hawkins HJ, Cramer MD. 2019a. Cattle don’t care: Animal behaviour is similar regardless of grazing management in grasslands. Agriculture, Ecosystems & Environment 272: 175–187. doi:10.1016/j.agee.2018.11.023.
  • Venter ZS, Cramer MD, Hawkins HJ. 2019b. Rotational grazing management has little effect on remotely-sensed vegetation characteristics across farm fence-line contrasts. Agriculture, Ecosystems & Environment 282: 40–48. doi:10.1016/j.agee.2019.05.019.
  • Vesk PA, Westoby M. 2001. Predicting plant species’ responses to grazing. Journal of Applied Ecology 38: 897–909. doi:10.1046/j.1365-2664.2001.00646.x.
  • Volesky JD. 1994. Tiller defoliation patterns under frontal, continuous, and rotation grazing. Journal of Range Management 47: 215–219. doi:10.2307/4003019.
  • Wardlaw IF. 1990. Tansley Review No. 27 The control of carbon partitioning in plants. The New Phytologist 116: 341–381. doi:10.1111/j.1469-8137.1990.tb00524.x.
  • White AC, Rogers A, Rees M, Osborne CP. 2016. How can we make plants grow faster? A source–sink perspective on growth rate. Journal of Experimental Botany 67: 31–45. doi:10.1093/jxb/erv447.
  • Wilson JB. 1988. A review of evidence on the control of shoot: root ratio, in relation to models. Annals of Botany 61: 433–449. doi:10.1093/oxfordjournals.aob.a087575.
  • Wise MJ, Abrahamson WG. 2005. Beyond the compensatory continuum: environmental resource levels and plant tolerance of herbivory. Oikos 109: 417–428.doi:10.1111/j.0030-1299.2005.13878.x.
  • Wise MJ, Abrahamson WG. 2007. Effects of resource availability on tolerance of herbivory: a review and assessment of three opposing models. American Naturalist 169: 443–454. doi:10.1086/512044.
  • Zhao W, Chen S-P, Lin G-H. 2008. Compensatory growth responses to clipping defoliation in Leymus chinensis (Poaceae) under nutrient addition and water deficiency conditions. Plant Ecology 196: 85–99. doi:10.1007/s11258-007-9336-3.