Advertisement

The fertile island effect collapses under extreme overgrazing: evidence from a shrub-encroached grassland

  • Yurong Cai
  • Yuchun YanEmail author
  • Dawei Xu
  • Xingliang Xu
  • Chu Wang
  • Xu Wang
  • Jinqiang Chen
  • Xiaoping Xin
  • David J Eldridge
Regular Article

Abstract

Background and aims

Woody plant encroachment is a phenomenon of global concern in drylands due to demonstrated reductions in livestock carrying capacity. However, shrubs are known to contribute to the development of patches of enhanced fertility that might offset any negative effects of increasing grazing. We measured soil physical and chemical characteristics within shrub and open patches across a gradient in livestock grazing to explore how the relative effect of shrubs might change with increasing grazing-induced disturbance.

Methods

Soil carbon, nitrogen phosphorus and bulk density were measured within 92 shrub patches and their paired interspaces at five sites ranging from long-grazed to long-ungrazed in a semiarid grassland encroached by the N-fixing shrub Caragana microphylla. We used a combination of linear and structural equation modelling to test whether shrubs might buffer any negative effects of overgrazing on soils.

Results

Shrub soils were more porous, and had more organic carbon, nitrogen and phosphorus than interspace soils. Within both microsites, however, soil bulk density increased, and soil organic carbon and nutrients declined, with increasing grazing intensity. Grazing reduced interspace plant cover and height and exacerbated the negative effects of bulk density on soil carbon, whereas shrubs had the opposite effect. The relative importance of shrubs for soil carbon and nutrients increased with increasing grazing intensity but collapsed under extreme overgrazing.

Conclusions

These findings highlight the effect of grazing in promoting shrub dominance, which can also prevent grassland degradation. However, any positive effects of grazing collapsed when sites were severely overgrazed.

Keywords

Fertile patch Overgrazing Shrub Soil nutrients Temperate grassland 

Notes

Acknowledgments

This study was funded by the National Natural Science Foundation of China (41671044), the National Key Research and Development Program of China (2016YFC0500603), a National Non-profit Institute Research Grant of CAAS (938-1), the International S & T Cooperation Project of China (2017YFE0104500), and the Special Funding for the Modern Agricultural Technology System of the Chinese Ministry of Agriculture.

Author’s contribution

Y. Y. designed the experiment; Y.C., Y.Y., D.X., C.W., and X.W. conducted the field work. Y.C., Y.Y. and D.J.E. performed the data analyses and wrote the manuscript, and all authors provided comments on the manuscript and the revisions and approved the final version.

Supplementary material

11104_2020_4426_MOESM1_ESM.docx (127 kb)
ESM 1 (DOCX 127 kb)

References

  1. Aguilera LE, Gutiérrez JR, Meserve PL (1999) Variation in soil micro-organisms and nutrients underneath and outside the canopy of Adesmia bedwellii (Papilionaceae) shrubs in arid coastal Chile following drought and above average rainfall. J Arid Environ 42:61–70.  https://doi.org/10.1006/jare.1999.0503 CrossRefGoogle Scholar
  2. Allington GRH, Valone TJ (2014) Islands of fertility: a byproduct of grazing? Ecosystems 17:127–141.  https://doi.org/10.1007/s10021-013-9711-y CrossRefGoogle Scholar
  3. Armas C, Ordiales R, Pugnaire FI (2004) Measuring plant interactions: a new comparative index. Ecology 85:2682–2686.  https://doi.org/10.1890/03-0650 CrossRefGoogle Scholar
  4. Asner GP, Elmore AJ, Olander LP, Martin RE, Harris AT (2004) Grazing systems, ecosystem responses, and global change. Ann Rev Environ Resour 29:261–299.  https://doi.org/10.1146/annurev.energy.29.062403.102142 CrossRefGoogle Scholar
  5. Bao SD (2000) Soil agrochemical analysis. China Agriculture Press, BeijingGoogle Scholar
  6. Bechtold HA, Inouye RS (2007) Distribution of carbon and nitrogen in sagebrush steppe after six years of nitrogen addition and shrub removal. J Arid Environ 71:122–132.  https://doi.org/10.1016/j.jaridenv.2007.02.004 CrossRefGoogle Scholar
  7. Bochet E, Poesen J, Rubio JL (2000) Mound development as an interaction of individual plants with soil, water erosion and sedimentation processes on slopes. Earth Surf Proc Land 25:847–867.  https://doi.org/10.1002/1096-9837(200008)25:83.0.CO;2-Q CrossRefGoogle Scholar
  8. Bolton JH, Smith JL, Link SO (1993) Soil microbial biomass and activity of a disturbed and undisturbed shrub-steppe ecosystem. Soil Biol Biochem 25:545–552.  https://doi.org/10.1016/0038-0717(93)90192-e CrossRefGoogle Scholar
  9. Bonell M, Coventry RJ, Holt JA (1986) Erosion of termite mounds under natural rainfall in semiarid tropical northeastern Australia. Catena 13:11–28.  https://doi.org/10.1016/S0341-8162(86)80002-9 CrossRefGoogle Scholar
  10. Colloff MJ, Pullen KR, Cunningham SA (2010) Restoration of an ecosystem function to revegetation communities: the role of invertebrate macropores in enhancing soil water infiltration. Restor Ecol 18:65–72.  https://doi.org/10.1111/j.1526-100x.2010.00667.x CrossRefGoogle Scholar
  11. Conforti M, Lucà F, Scarciglia F, Matteucci G, Buttafuoco G (2016) Soil carbon stock in relation to soil properties and landscape position in a forest ecosystem of southern Italy (Calabria region). Catena 144:23–33.  https://doi.org/10.1016/j.catena.2016.04.023 CrossRefGoogle Scholar
  12. Cournane FC, McDowell R, Littlejohn R, Condron L (2011) Effects of cattle, sheep and deer grazing on soil physical quality and losses of phosphorus and suspended sediment losses in surface runoff. Agric Ecosys Environ 140:264–272.  https://doi.org/10.1016/j.agee.2010.12.013 CrossRefGoogle Scholar
  13. Dean WRJ, Milton SJ, Jeltsch F (1999) Large trees, fertile islands, and birds in arid savanna. J Arid Environ 41:61–78.  https://doi.org/10.1006/jare.1998.0455 CrossRefGoogle Scholar
  14. Delgado-Baquerizo M, Maestre FT, Gallardo A, Bowker MA, Wallenstein MD, Quero JL, Ochoa V, Gozalo B, García-Gómez M, Soliveres S (2013) Decoupling of soil nutrient cycles as a function of aridity in global drylands. Nature 502:672–676.  https://doi.org/10.1038/nature12670 CrossRefPubMedGoogle Scholar
  15. Dougill AJ, Thomas AD (2002) Nebkha dunes in the Molopo Basin, South Africa and Botswana: formation controls and their validity as indicators of soil degradation. J Arid Environ 50:413–428.  https://doi.org/10.1006/jare.2001.0909 CrossRefGoogle Scholar
  16. Eldridge DJ, Wong VNL (2005) Clumped and isolated trees influence soil nutrient levels in an Australian temperate box woodland. Plant Soil 270:331–342.  https://doi.org/10.1007/s11104-004-1774-2 CrossRefGoogle Scholar
  17. Eldridge DJ, Wang L, Ruiz-Colmenero M (2015) Shrub encroachment alters the spatial patterns of infiltration. Ecohydrology 8:83–93.  https://doi.org/10.1002/eco.1490 CrossRefGoogle Scholar
  18. Eldridge DJ, Delgado-Baquerizo M, Travers SK, Val J, Oliver I (2017) Do grazing intensity and herbivore type affect soil health? Insights from a semi-arid productivity gradient. J Appl Ecol 54:976–985.  https://doi.org/10.1111/1365-2664.12834 CrossRefGoogle Scholar
  19. FAO (2014) Permanent meadows and pastures. III, Farmer Seed Co, ChicagoGoogle Scholar
  20. Fleischner TL (1994) Ecological costs of livestock grazing in western North America. Conserv biol l8: 629-644.  https://doi.org/10.2307/2386504
  21. García-Moya E, McKell CM (1970) Contribution of shrubs to the nitrogen economy of a desert-wash plant community. Ecology 51:81–88.  https://doi.org/10.2307/1933601 CrossRefGoogle Scholar
  22. Garner W, Steinberger Y (1989) A proposed mechanism for the formation of fertile islands in the desert ecosystem. J Arid Environ 16:257–262.  https://doi.org/10.2307/2409074 CrossRefGoogle Scholar
  23. Gherardi LA, Sala OE, Yahdjian L (2013) Preference for different inorganic nitrogen forms among plant functional types and species of the Patagonian steppe. Oecologia 173:1075–1081.  https://doi.org/10.1007/s00442-013-2687-7 CrossRefPubMedGoogle Scholar
  24. Grace JB (2006) Structural equation Modelling and natural systems. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  25. Han GD, Hao XY, Zhao ML, Wang MJ, Ellert BH, Willms WD, Wang MJ (2008) Effect of grazing intensity on carbon and nitrogen in soil and vegetation in a meadow steppe in Inner Mongolia. Agric Ecosys Environ 125:21–32.  https://doi.org/10.1016/j.agee.2007.11.009 CrossRefGoogle Scholar
  26. Hao L, Pan C, Fang D, Zhang XY, Zhou DC, Liu PL, Liu YQ, Sun G (2018) Quantifying the effects of overgrazing on mountainous watershed vegetation dynamics under a changing climate. Sci Total Environ 639:1408–1420.  https://doi.org/10.1016/j.scitotenv.2018.05.224 CrossRefPubMedGoogle Scholar
  27. Heggenes J, Odland A, Chevalier T, Ahlberg J, Berg A, Larsson H, Bjerketvedt DK (2017) Herbivore grazing—or trampling? Trampling effects by a large ungulate in cold high-latitude ecosystems. Ecol Evol 7:6423–6431.  https://doi.org/10.1002/ece3.3130 CrossRefPubMedPubMedCentralGoogle Scholar
  28. Hennessy JT, Gibbens RP, Tromble JM, Cardenas M (1985) Mesquite (Prosopis glandulosa Torr.) dunes and interdunes in southern New Mexico: a study of soil properties and soil water relations. J Arid Environ 9:27–38.  https://doi.org/10.1016/S0140-1963(18)31269-2 CrossRefGoogle Scholar
  29. Herman RP, Provencio KR, Herrera-Matos J, Torrez R (1995) Resource islands predict the distribution of heterotrophic bacteria in Chihuahuan Desert soils. Appl Environ Microb 61:1816–1821.  https://doi.org/10.1002/bit.260460313 CrossRefGoogle Scholar
  30. Kelly RH, Burke IC (1997) Heterogeneity of soil organic matter following death of individual plants in shortgrass steppe. Ecology 78:1256–1261.  https://doi.org/10.2307/2265875 CrossRefGoogle Scholar
  31. Li XY, Hu X, Zhang ZH, Peng HY, Zhang SY, Li GY, Li L, Ma YJ (2013) Shrub hydropedology: preferential water availability to deep soil layer. Vadose Zone J 12:1–12.  https://doi.org/10.2136/vzj2013.01.0006 CrossRefGoogle Scholar
  32. Liu ZL, Wang W, Hao DY, Liang CZ (2002) Probes on the degeneration and recovery succession mechanism of Inner Mongolia steppe. J Arid Land Res Environ 16:84–91 https://doi.org/ CNKI:SUN:GHZH.0.2002-01-014 Google Scholar
  33. Lynch JM, Whipps JM (1990) Substrate flow in the rhizosphere. Plant Soil 129:1–10.  https://doi.org/10.1007/BF00011685 CrossRefGoogle Scholar
  34. Mallen-Cooper M, Eldridge DJ, Delgado-Baquerizo M (2018) Livestock grazing and aridity reduce the functional diversity of biocrusts. Plant Soil 429:175–185.  https://doi.org/10.1007/s11104-017-3388-5 CrossRefGoogle Scholar
  35. Navarro-Cano JA, Verdú M, García C, Goberna M (2015) What nurse shrubs can do for barren soils: rapid productivity shifts associated with a 40 years ontogenetic gradient. Plant Soil 388:197–209.  https://doi.org/10.1007/s11104-014-2323-2 CrossRefGoogle Scholar
  36. Ochoa-Hueso R, Eldridge DJ, Delgado-Baquerizo M, Soliveres S, Bowker MA, Gross N, Bagousse-Pinguet YL, Quero JL, García-Gómez M, Valencia E, Arredondo T, Beinticinco L, Bran D, Cea A, Coaguila D, Dougill AJ, Espinosa CI, Gaitán J, Guuroh RT, Guzman E, Gutiérrez JR, Hernández RM, Huber-Sannwald E, Jeffries T, Linstädter A, Mau RL, Monerris J, Prina A, Pucheta E, Stavi I, Thomas AD, Zaady E, Singh BK, Maestre FT, Salguero-Gómez R (2018) Soil fungal abundance and plant functional traits drive fertile island formation in global drylands. J Ecol 106:242–253.  https://doi.org/10.1111/1365-2745.12871 CrossRefGoogle Scholar
  37. Reynolds JF, Virginia RA, Kemp PR (1999) Impact of drought on desert shrubs: effects of seasonality and degree of resource island development. Ecol Monogr 69:69–106.  https://doi.org/10.2307/2657195 CrossRefGoogle Scholar
  38. Román-Sánchez A, Vanwalleghem T, Peña A, Laguna A, Giráldez JV (2018) Controls on soil carbon storage from topography and vegetation in a rocky, semi-arid landscapes. Geoderma 311:159–166.  https://doi.org/10.1016/j.geoderma.2016.10.013 CrossRefGoogle Scholar
  39. Schlesinger WH, Pilmanis AM (1998) Plant-soil interactions in deserts. Biogeochemistry 42:169–187.  https://doi.org/10.1023/a:1005939924434 CrossRefGoogle Scholar
  40. Schlesinger WH, Reynolds JF, Cunningham GL, Huenneke LF, Jarrell WM, Virginia RA, Whitford WG (1990) Biological feedbacks in global desertification. Science 247:1043–1048.  https://doi.org/10.1126/science.247.4946.1043 CrossRefPubMedGoogle Scholar
  41. Seghieri J, Galle S (1999) Run-on contribution to a Sahelian two-phase mosaic system: soil water regime and vegetation life cycles. Acta Oecol 20:209–217.  https://doi.org/10.1016/s1146-609x(99)80033-2 CrossRefGoogle Scholar
  42. Smit C, Ruifrok J (2011) From protégé to nurse plant: establishment of thorny shrubs in grazed temperate woodlands. J Veg Sci 22:377–386.  https://doi.org/10.1111/j.1654-1103.2011.01264.x CrossRefGoogle Scholar
  43. Sparrow AD, Friedel MH, Tongway DJ (2003) Degradation and recovery processes in arid grazing lands of Central Australia part 3: implications at landscape scale. J Arid Environ 55:349–360.  https://doi.org/10.1016/s0140-1963(03)00027-2 CrossRefGoogle Scholar
  44. Su YZ, Zhao HL, Zhang TH, Zhao XY (2004) Soil properties following cultivation and non-grazing of a semi-arid sandy grassland in northern China. Soil Till Res 75:27–36.  https://doi.org/10.1016/s0167-1987(03)00157-0 CrossRefGoogle Scholar
  45. Su JH, Nan ZB, Ji WH (2016) Effects of livestock grazing on rodents in grassland ecosystems. Acta Prataculturae Sinic 2:136–148.  https://doi.org/10.11686/cyxb2015587 CrossRefGoogle Scholar
  46. Telles EDCC, Camargo PBD, Martinelli LA, Trumbore SE, Costa ESD, Santos J, Higuchi N, Junior RCO (2004) Influence of soil texture on carbon dynamics and storage potential in tropical forest soils of Amazonia. Global Biogeochem Cy 17:1–12.  https://doi.org/10.1029/2002gb001953 CrossRefGoogle Scholar
  47. Tengberg A (1995) Nebkha dunes as indicators of wind erosion and land degradation in the Sahel zone of Burkina Faso. J Arid Environ 3: 265–282.  https://doi.org/10.1016/S0140-1963(05)80002-3CrossRefGoogle Scholar
  48. Vaieretti MV, Iamamoto S, Harguindeguy NP, Cingolani AM (2018) Livestock grazing affects microclimate conditions for decomposition process through changes in vegetation structure in mountain grasslands. Acta Oecol 91:101–107.  https://doi.org/10.1016/j.actao.2018.07.002 CrossRefGoogle Scholar
  49. Weltzin JF, Coughenour MB (1990) Savanna tree influence on understory vegetation and soil nutrients in northwestern Kenya. J Veg Sci 1:325–334.  https://doi.org/10.2307/3235707 CrossRefGoogle Scholar
  50. Wezel A, Rajot JL, Herbrig C (2000) Influence of shrubs on soil characteristics and their function in Sahelian agro-ecosystems in semi-arid Niger. J Arid Environ 44:383–398.  https://doi.org/10.1006/jare.1999.0609 CrossRefGoogle Scholar
  51. Wiesmeier M, Steffens M, Kölbl A, Kögel-Knabner I (2009) Degradation and small-scale spatial homogenization of topsoils in intensively-grazed steppes of northern China. Soil Till Res 104:299–310.  https://doi.org/10.1016/j.still.2009.04.005 CrossRefGoogle Scholar
  52. Will M, Suter GW (1995) Toxicological benchmarks for potential contaminants of concern for effects on soil and litter invertebrates and heterotrophic process. Oak Ridge National Lab, TN (United States)CrossRefGoogle Scholar
  53. Yan YC, Xu XL, Xin XP, Yang GX, Wang X, Yan RR, Chen BR (2011) Effect of vegetation coverage on aeolian dust accumulation in a semiarid steppe of northern China. Catena 87:351–356.  https://doi.org/10.1016/j.catena.2011.07.002 CrossRefGoogle Scholar
  54. Yan YC, Xin XP, Xu XL, Wang X, Yang GX, Yan RR, Chen BR (2013) Quantitative effects of wind erosion on the soil texture and soil nutrients under different vegetation coverage in a semiarid steppe of northern China. Plant Soil 369:585–598.  https://doi.org/10.1007/s11104-013-1606-3 CrossRefGoogle Scholar
  55. Yan YC, Xin XP, Xu XL, Wang X, Yan RR, Philip J. Murray (2016) Vegetation patches increase wind-blown litter accumulation in a semi-arid steppe of northern China. Environ Res Lett 11: 124008.  https://doi.org/10.1088/1748-9326/11/12/124008 CrossRefGoogle Scholar
  56. Yan YC, Yan RR, Chen JQ, Xin XP, Eldridge DJ, Shao CL, Wang X, Lv SJ, Jin DY, Chen JQ, Guo ZJ, Chen BR, Xu LJ (2018) Grazing modulates soil temperature and moisture in a Eurasian steppe. Agric Forest Meteorol 262:157–165.  https://doi.org/10.1016/j.agrformet.2018.07.011 CrossRefGoogle Scholar
  57. Yan YC, Xu DW, Xu XL, Wang DL, Wang X, Cai YR, Chen JQ, Xin XP, Eldridge DJ (2019) Shrub patches capture tumble plants: potential evidence for a self-reinforcing pattern in a semiarid shrub encroached grassland. Plant Soil 422:1–11.  https://doi.org/10.1007/s11104-019-04189-5 CrossRefGoogle Scholar
  58. Yang ZP, Zhang Q, Wang YL, Zhang JJ, Chen MC (2011) Spatial and temporal variability of soil properties under Caragana microphylla shrubs in the northwestern Shanxi Loess Plateau, China. J Arid Environ 75:538–544.  https://doi.org/10.1016/j.jaridenv.2011.01.007 CrossRefGoogle Scholar
  59. Zhang PJ, Yang J, Zhao LQ, Bao S, Song BY (2011) Effect of Caragana tibetica nebkhas on sand entrapment and fertile islands in steppe–desert ecotones on the Inner Mongolia plateau, China. Plant Soil 347:79–90.  https://doi.org/10.1007/s11104-011-0813-z CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  • Yurong Cai
    • 1
  • Yuchun Yan
    • 1
    Email author
  • Dawei Xu
    • 1
  • Xingliang Xu
    • 2
  • Chu Wang
    • 1
  • Xu Wang
    • 1
  • Jinqiang Chen
    • 1
  • Xiaoping Xin
    • 1
  • David J Eldridge
    • 3
  1. 1.Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijingChina
  2. 2.Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources ResearchChinese Academy SciencesBeijingChina
  3. 3.Centre for Ecosystem Science, School of Biological, Earth and Environmental SciencesUniversity of New South WalesSydneyAustralia

Personalised recommendations