Functionally divergent growth, biomass allocation and root distribution of two xerophytic species in response to varying soil rock fragment content



Rock fragments are widespread in soil profiles. Despite direct effects of rock fragment content (RFC) on vegetation and soil properties, how plants respond to variations in RFC remains poorly understood. In this work, we investigated responses of two contrasting xerophytic species to varying RFC.


Root biomass allocation, vertical distribution and above-ground growth were measured in Artemisia vestita and Bauhinia brachycarpa after 2 years of growth in an experiment with four levels of RFC (0, 25, 50 and 75% ν ν−1).


The responses of above-ground growth and total biomass of both species showed a unimodal curve with values increasing up to intermediate RFC (25% and 50%) and then declining. Both species increased relative biomass allocation to roots at the highest RFC level (75%). A. vestita had a shallow rooting profile and greater declines in plant growth with high RFC compared with B. brachycarpa which had a deeper rooting profile.


We found that intermediate RFCs were beneficial for growth of both species and both species increased root-to-shoot ratios to compensate for high RFC. The higher overall root fraction and deeper rooting profile may make B. brachycarpa more suitable than A. vestita for areas with high RFC, enabling greater extraction of increasingly limited soil resources.

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Rock fragment content

R/S ratio (g g−1):

Root-to-shoot ratio

RMF (g g−1):

Root mass fraction

FRMF (g g−1):

Fine-root mass fraction


  1. Babalola O, Lal R (1977) Subsoil gravel horizon and maize root growth. I. Gravel concentration and bulk density effects. Plant Soil 46:337–346.

    Article  Google Scholar 

  2. Bao WK, Pang XY, Li FL, Zhou ZQ (2012) A study of ecological restoration and sustainable Management of the Arid Minjiang River Valley, China. Science Press, Beijing (in Chinese)

    Google Scholar 

  3. Bloom AJ, Chapin FS, Mooney HA (1985) Resource limitation in plants – an economic analogue. Annu Rev Ecol Syst 16:363–392.

    Article  Google Scholar 

  4. Ceacero CJ, Díaz-Hernández JL, del Campo AD, Navarro-Cerrillo RM (2020) Soil rock fragment is stronger driver of spatio-temporal soil water dynamics and efficiency of water use than cultural management in holm oak plantations. Soil Tillage Res 197:104495.

    Article  Google Scholar 

  5. Chow TL, Rees HW, Monteith JO, Toner P, Lavoie J (2007) Effects of coarse fragment content on soil physical properties, soil erosion and potato production. Can J Soil Sci 87:565–577.

    Article  Google Scholar 

  6. Clark LJ, Whalley WR, Barraclough PB (2003) How do roots penetrate strong soil? Plant Soil 255:93–104.

    CAS  Article  Google Scholar 

  7. Danalatos NG, Kosmas CS, Moustakas NC, Yassoglou N (1995) Rock fragments II. Their impact on soil physical properties and biomass production under Mediterranean conditions. Soil Use Manag 11:121–126.

    Article  Google Scholar 

  8. de Kroon H, Visser EJW (2003) Root ecology. In: Bengough AG (ed) Root growth and function in relation to soil structure, composition, and strength. Springer-Verlag, New York, pp 151–171

    Google Scholar 

  9. Freschet GT, Swart EM, Cornelissen JHC (2015) Integrated plant phenotypic responses to contrasting above- and below-ground resources: key roles of specific leaf area and root mass fraction. New Phytol 206:1247–1260.

    CAS  Article  PubMed  Google Scholar 

  10. Freschet GT, Violle C, Bourget MY, Scherer-Lorenzen M, Fort F (2018) Allocation, morphology, physiology, architecture: the multiple facets of plant above- and below-ground responses to resource stress. New Phytol 219:1338–1352.

    Article  PubMed  Google Scholar 

  11. Gargiulo L, Mele G, Terribile F (2016) Effect of rock fragments on soil porosity: a laboratory experiment with two physically degraded soils. Eur J Soil Sci 67:597–604.

    Article  Google Scholar 

  12. Grewal SS, Singh K, Dyal S (1984) Soil profile gravel concentration and its effect on rainfed crop yields. Plant Soil 81:75–83.

    Article  Google Scholar 

  13. Hanson CT, Blevins RL (1979) Soil-water in coarse fragments. Soil Sci Soc Am J 43:819–820.

    Article  Google Scholar 

  14. Iwasa Y, Roughgarden J (1984) Shoot/root balance of plants: optimal growth of a system with many vegetative organs. Theor Popul Biol 25(1):78–105

  15. Jian SQ, Zhao CY, Fang SM, Yu K (2015) The distribution of fine root length density for six artificial afforestation tree species in loess plateau of Northwest China. Forest Systems 24:1–15.

    Article  Google Scholar 

  16. Kosmas C, Moustakas N, Danalatos NG, Yassonglou N (1994) The effect of rock fragments on wheat biomass production under highly variable moisture conditions in Mediterranean environments. Catena 23:191–198.

    Article  Google Scholar 

  17. Li FL, Bao WK (2014) Elevational trends in leaf size of Campylotropis polyantha in the arid Minjiang River valley, SW China. J Arid Environ 108:1–9.

    Article  Google Scholar 

  18. Li FL, Bao WK, Wu N (2008) Growth, biomass partitioning, and water-use efficiency of a leguminous shrub (Bauhinia faberi var. microphylla) in response to various water availabilities. New For 36:53–65.

    Article  Google Scholar 

  19. Li FL, Bao WK, Wu N (2009) Effects of water stress on growth, dry matter allocation and water-use efficiency of a leguminous species, Sophora davidi. Agrofor Syst 77:193–201.

    Article  Google Scholar 

  20. Mi M, Shao MA, Liu B (2016) Effect of rock fragments content on water consumption, biomass and water-use efficiency of plants under different water conditions. Ecol Eng 94:574–582.

    Article  Google Scholar 

  21. Ogbonnaya CI, Nwalozie MC, Roy-Macauley H, Annerose DJM (1998) Growth and water relations of Kenaf (Hibiscus cannabinus L.) under water deficit on a sandy soil. Ind Crops Prod 8(1):65–76

  22. Poesen J, Lavee H (1994) Rock fragments in top soils: significance and processes. Catena 23:1–28.

    Article  Google Scholar 

  23. Poorter H, Jagodzinski AM, Ruiz-Peinado R, Kuyah S, Luo YJ, Oleksyn J, Usoltsev VA, Buckley TN, Reich PB, Sack L (2015) How does biomass distribution change with size and differ among species? An analysis for 1200 plant species from five continents. New Phytol 208:736–749.

    Article  PubMed  PubMed Central  Google Scholar 

  24. Poorter H, Niklas KJ, Reich PB, Oleksyn J, Poot P, Mommer L (2012) Biomass allocation to leaves, stems and roots: meta-analyses of interspecific variation and environmental control. New Phytol 193:30–50.

    CAS  Article  PubMed  Google Scholar 

  25. Qin Y, Yi SH, Chen JJ, Ren SL, Ding YJ (2015) Effects of gravel on soil and vegetation properties of alpine grassland on the Qinghai-Tibetan plateau. Ecol Eng 74:351–355.

    Article  Google Scholar 

  26. Qu LY, Wang ZB, Huang YY, Zhang YX, Song CJ, Ma KM (2017) Effects of plant coverage on shrub fertile islands in the upper Minjiang River valley. Sci China Life Sci 61:340–347.

    Article  PubMed  Google Scholar 

  27. Reich P (2002) Root–shoot relations: optimality in acclimation and adaptation or the “Emperor’s new clothes”? In: Waisel Y, Eshel A, Kafkafi U (eds) Plant roots, the hidden half, 3rd edn. Marcel Dekker, New York, pp 205–220

    Google Scholar 

  28. Rytter RM (2012) Stone and gravel contents of arable soils influence estimates of C and N stocks. Catena 95:153–159.

    CAS  Article  Google Scholar 

  29. Schenk HJ, Jackson RB (2002) Rooting depths, lateral root spreads and below‐ground/above‐ground allometries of plants in water‐limited ecosystems. J Ecol 90(3):480–494

  30. Suo GD, Xie YS, Zhang Y, Luo H (2019) Long-term effects of different surface mulching techniques on soil water and fruit yield in an apple orchard on the loess plateau of China. Sci Hortic 246:643–651.

    Article  Google Scholar 

  31. Tetegan M, Nicoullaud B, Baize D, Bouthier A, Cousin I (2011) The contribution of rock fragments to the available water content of stony soils: proposition of new pedotransfer functions. Geoderma 165:40–49.

    Article  Google Scholar 

  32. Van Wesemael B, Mulligan M, Poesen J (2000) Spatial patterns of soil water balance on intensively cultivated hillslopes in a semi-arid environment: the impact of rock fragments and soil thickness. Hydrol Process 14:1811–1828.<1811::aid-hyp65>;2-d

    Article  Google Scholar 

  33. Villagra PE, Carla G, Alvarez JA, Bruno Cavagnaro J, Guevara A, Sartor C, Passera CB, Greco S (2011) To be a plant in the desert: water use strategies and water stress resistance in the Central Monte desert from Argentina. Ecologia Austral 21:29–42.

    Article  Google Scholar 

  34. Wang L, Wang QJ, Wei SP, Shao MA, Li Y (2008) Soil desiccation for loess soils on natural and regrown areas. For Ecol Manag 255:2467–2477.

    Article  Google Scholar 

  35. Wang X, Taub DR (2010) Interactive effects of elevated carbon dioxide and environmental stresses on root mass fraction in plants: a meta-analytical synthesis using pairwise techniques. Oecologia 163:1–11.

    Article  PubMed  Google Scholar 

  36. Wei H, Shao MA, Wang QJ, Reichardt K (2009) Time stability of soil water storage measured by neutron probe and the effects of calibration procedures in a small watershed. Catena 79:72–82.

    CAS  Article  Google Scholar 

  37. Wijdenes DO, Poesen J, Vandekerckhove L, de Luna E (1997) Chiselling effects on the vertical distribution of rock fragments in the tilled layer of a Mediterranean soil. Soil Tillage Res 44(1-2):55–66

  38. Wu FZ, Bao WK, Li FL, Wu N (2008) Effects of water stress and nitrogen supply on leaf gas exchange and fluorescence parameters of Sophora davidii seedlings. Photosynthetica 46:40–48.

    CAS  Article  Google Scholar 

  39. Xu L, Shi Z, Wang Y, Chu X, Xiong W (2012) Contribution of rock fragments on formation of forest soil macropores in the stoney mountains of the loess plateau, China. Journal of food agriculture and environment 10: 1220-1226.

  40. Xu XL, Ma KM, Fu BJ, Song CJ, Liu W (2008a) Relationships between vegetation and soil and topography in a dry warm river valley, SW China. Catena 75:138–145.

    Article  Google Scholar 

  41. Xu XL, Ma KM, Fu BJ, Song CJ, Liu W (2008b) Influence of three plant species with different morphologies on water runoff and soil loss in a dry-warm river valley, SW China. For Ecol Manag 256:656–663.

    Article  Google Scholar 

  42. Zhang WH, Wei CF, Li Y, Wang GG, Xie DT (2011) Effects of rock fragments on infiltration and evaporation in hilly purple soils of Sichuan Basin, China. Environ Geol 62:1655–1665.

    CAS  Article  Google Scholar 

  43. Zhang YH, Zhang MX, Niu JZ, Li HL, Xiao R, Zheng HJ, Bench J (2016) Rock fragments and soil hydrological processes: significance and progress. Catena 147:153–166.

    Article  Google Scholar 

  44. Zhou BB, Shao MA, Shao HB (2009) Effects of rock fragments on water movement and solute transport in a loess plateau soil. Comptes rendus - Géoscience 341:462–472.

    Article  Google Scholar 

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This study was funded by the National Key R & D Program of China (No. 2017YFC0505105) and the Second Qinghai-Xizang Plateau Scientific Expedition and Research Program (STEP)(2019QZKK0301).

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Correspondence to Fang Lan Li or Wei Kai Bao.

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Fig. S1

Timeline of the experiment. (JPG 2375 kb)

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Hu, H., Li, F.L., McCormack, M.L. et al. Functionally divergent growth, biomass allocation and root distribution of two xerophytic species in response to varying soil rock fragment content. Plant Soil (2021).

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  • Biomass allocation
  • Dry ecosystem
  • Functional adaption
  • Gravel content
  • Root distribution
  • Soil structure