Symbiotic nitrogen fixation by legumes in two Chinese grasslands estimated with the 15N dilution technique

Original Article


Symbiotic nitrogen (N) fixation by legumes was investigated using the 15N dilution technique in two Chinese grasslands: one in the north-eastern Tibetan Plateau and the other in Inner Mongolia in China. A small amount (0.03 g N m−2) of 15N labelled (NH4)2SO4 fertilizer was evenly distributed in two soils. One month after the 15N addition, four legumes (Astragalus sp., Gueldenstaedtia diversifolia, Oxytropis ochrocephala and Trigonella ruthenica) in the alpine meadow and two legumes (Thermopsis lanceolata and Melissitus ruthenica) in the temperate steppe were collected. Several non-legume plant species were harvested as the reference. Above-ground biomass of legumes ranged from 8 to 24 g m−2 in the alpine meadow and from 11 to 35 g m−2 in the temperate steppe. The reference plants showed distinctly higher 15N atom% excess than legumes (0.08% vs. 0.02% in the alpine meadow, 0.10% vs. 0.02% in the temperate steppe). The N derived from atmosphere (%Ndfa) ranged from 50 to 90% N in the alpine meadow, while it ranged from 85 to 92% in the temperate steppe. Based on the legume above-ground biomass, total symbiotic N2-fixation rate was estimated to be 1.00 g N m−2 year−1 in the alpine meadow and 1.15 g N m−2 year−1 in the temperate steppe. These N inputs by legumes can account for 9% of the gap between the N demand and the seasonal N release by mineralization in the alpine Kobresia grassland and 20% in the temperate Leymus grassland, respectively. Considering additional contribution of the root biomass, we suggest that biological N2-fixation by legumes plays an important role in the cycling of N in both Kobresia and Leymus grasslands on an annual scale.


15N tracer Alpine meadow Temperate steppe Kobresia humilis Leymus chinensis 


  1. Arnone JA III (1999) Symbiotic N2 fixation in a high alpine grassland: effects of four growing seasons of elevated CO2. Funct Ecol 13:383–387CrossRefGoogle Scholar
  2. Bowman WD, Schardt JC, Schmidt SK (1996) Symbiotic N2 fixation in alpine tundra: ecosystem input and variation in fixation rates among communities. Oecologia 108:345–350Google Scholar
  3. Busse MD (2000) Suitability and use of the 15N-isotope dilution method to estimate nitrogen fixation by actinorhizal shrubs. For Ecol Manag 136:85–95CrossRefGoogle Scholar
  4. Cao GM, Wu Q, Li D, Hu QW, Li YM, Wang X (2004) Effects of nitrogen supply and demand status of soil and herbage system on vegetation succession and grassland degradation in alpine meadow. Chin J Ecol 23:25–28Google Scholar
  5. Carranca C, Varennes A, Rolston DE (1999) Biological nitrogen fixation estimated by 15N dilution, natural 15N abundance, and N difference techniques in a subterranean clover-grass sward under Mediterranean condition. Eur J Agron 10:81–89CrossRefGoogle Scholar
  6. Chalk PM (1991) The contribution of associative and symbiotic nitrogen fixation to the nitrogen nutrition of non-legumes. Plant Soil 132:29–39CrossRefGoogle Scholar
  7. Chapin FS, Vitousek PM, Vancleve K (1986) The nature of nutrient limitation in plant-communities. Am Nat 127:48–58CrossRefGoogle Scholar
  8. Chen ZZ, Wang SP (eds) (2000) Chinese typical grassland ecosystem. Science Press, BeijingGoogle Scholar
  9. Cusack DF, Silver W, McDowell WH (2009) Biological nitrogen fixation in two tropical forests: ecosystem-level patterns and effects of nitrogen fertilization. Ecosystems 12:1299–1315CrossRefGoogle Scholar
  10. Dart PJ, Day JM (1971) Effects of incubation temperature and oxygen-tension on nitrogenase activity of legume root nodules. Plant Soil 35:167–184CrossRefGoogle Scholar
  11. Gao CX, Su LJ, Song JH, Gong CN, Cheng W (2004) Relationship between distribution of frozen earth and soil temperature in northeast of Inner Mongolia. Meteorol J Inner Mongolia 19–22Google Scholar
  12. Haselwandter K, Hofmann A, Holzmann HP, Read DJ (1983) Availability of nitrogen and phosphorus in the nival zone of the Alps. Oecologia 57:266–269CrossRefGoogle Scholar
  13. Heimann M, Reichstein M (2008) Terrestrial ecosystem carbon dynamics and climate feedbacks. Nature 451:289–292PubMedCrossRefGoogle Scholar
  14. Holst J, Butterbach-Bahl K, Liu CY, Zheng XH, Kaiser AJ, Schnitzler JP, Zechmeister-Boltenstern S, Bruggemann N (2009) Dinitrogen fixation by biological soil crusts in an Inner Mongolian steppe. Biol Fert Soils 45:679–690CrossRefGoogle Scholar
  15. Holzmann HP, Haselwandter K (1988) Contribution of nitrogen fixation to nitrogen nutrition in an alpine sedge community (Caricetum curvulae). Oecologia 76:298–302CrossRefGoogle Scholar
  16. Jacot KA, Lüscher A, Nösberger J, Hartwig UA (2000a) Symbiotic N2 fixation of various legume species along an altitudinal gradient in the Swiss Alps. Soil Bio Biochem 32:1043–1052CrossRefGoogle Scholar
  17. Jacot KA, Lüscher A, Nösberger J, Hartwig UA (2000b) The relative contribution of symbiotic N2 fixation and other nitrogen sources to grassland ecosystems along an altitudinal gradient in the Alps. Plant Soil 225:201–211CrossRefGoogle Scholar
  18. Körner C (2003) Alpine plant life-functional plant ecology of high mountain ecosystems. Springer, New YorkGoogle Scholar
  19. Ledgard SF, Steele KW (1992) Biological nitrogen-fixation in mixed legume grass pastures. Plant Soil 141:137–153CrossRefGoogle Scholar
  20. Li YZ, Redmann RE, Zhu TC, Li JD (2002) Nitrogen fixation in Leymus chinensis grassland in Northeast China. Acta Agrestia Sin 10:164–166Google Scholar
  21. Li YN, Zhao XQ, Cao GM, Zhao L, Wang QX (2004) Analyses on climates and vegetation productivity background at Haibei alpine meadow ecosystem research station. Plateau Meteorol 23:558–567Google Scholar
  22. McAuliffe C, Chamblee DS, Uribe-Arango H, Woodhouse WW (1958) Influence of inorganic nitrogen on nitrogen fixation by legumes as revealed by 15N. Agron J 50:334–337CrossRefGoogle Scholar
  23. Meng X, Li X, Xin X, Zhou R (2009) Study on community characteristics and a diversity under different grazing intensity on Leymus chinensis (Trin.) Tzvel. meadow steppe of Hulunbeier. Acta Agrestia Sin 17:239–244Google Scholar
  24. Mulder CPH, Jumpponen A, Hogberg P, Huss-Danell K (2002) How plant diversity and legumes affect nitrogen dynamics in experimental grassland communities. Oecologia 133:412–421CrossRefGoogle Scholar
  25. WRB (1998) World reference base for soil resources. FAO/ISRIC/ISSS, RomeGoogle Scholar
  26. Song MH, Xu XL, Hu QW, Tian YQ, Ouyang H, Zhou CP (2007) Interactions of plant species mediated plant competition for inorganic nitrogen with soil microorganisms in an alpine meadow. Plant Soil 297:127–137CrossRefGoogle Scholar
  27. Vitousek PM, Cassman K, Cleveland C, Crews T, Field CB, Grimm NB, Howarth RW, Marino R, Martinelli L, Rastetter EB, Sprent JI (eds) (2002) Towards an ecological understanding of biological nitrogen fixation. Biogeochemistry (Kluwer Academic Publishers)Google Scholar
  28. Wojciehowski MF, Heimbrook ME (1984) Dinitrogen fixation in alpine tundra, Niwot Ridge, Front Range, Colorado, U.S.A. Arctic Alpine Res 16:1–10CrossRefGoogle Scholar
  29. Xu XL, Ouyang H, Cao GM, Pei ZY, Zhou CP (2004) Nitrogen deposition and carbon sequestration in alpine meadows. Biogeochemistry 71:353–369CrossRefGoogle Scholar
  30. Xu XL, Ouyang H, Cao GM, Richter A, Wanek W, Kuzyakov Y (2011a) Dominant plant species shift their nitrogen uptake patterns in response to nutrient enrichment caused by a fungal fairy in an alpine meadow. Plant Soil 341:495–504Google Scholar
  31. Xu XL, Wanek W, Cao GM, Richter A, Song MH, Zhou CP, Ouyang H, Kuzyakov (2011b) Effects of nitrogen addition on forliar N:P ratio and δ15N in an alpine meadow on the Tibetan Plateau. J Plant Nutr Soil Sci (submitted)Google Scholar
  32. Yang XH, Dong YS, Qi YC, Geng YB, Liu LX (2005) Soil net nitrogen mineralization in an aneulolepidium chinensis grassland, Inner Mongolia. Progr Geogr 24:30–37Google Scholar
  33. Zhang JX, Cao GM (1999) The nitrogen cycle in an alpine meadow ecosystem. Acta Ecol Sin 19:509–513Google Scholar
  34. Zhao QG (1998) Chinese soil resources. Nanjing university press, NanjingGoogle Scholar
  35. Zheng D (2000) Mountain geoecology and sustainable development of the Tibetan plateau. Kluwer, DordrechtGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Baijie Yang
    • 1
    • 2
  • Na Qiao
    • 2
    • 3
  • Xingliang Xu
    • 1
  • Hua Ouyang
    • 1
  1. 1.Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China
  2. 2.Graduate University of Chinese Academy of SciencesBeijingPeople’s Republic of China
  3. 3.Forest Ecosystem Research Center, Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesKunmingPeople’s Republic of China

Personalised recommendations