Journal of Integrative Agriculture ›› 2018, Vol. 17 ›› Issue (06): 1445-1453.DOI: 10.1016/S2095-3119(17)61881-1

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  • 收稿日期:2017-08-28 出版日期:2018-06-01 发布日期:2018-06-05

Long-term grazing exclusion influences arbuscular mycorrhizal fungi and their association with vegetation in typical steppe of Inner Mongolia, China

CHEN Xue-jiao1, LIN Qi-mei1, 2, ZHAO Xiao-rong1, 2, CHEN Hao1, WEN Jing1, LI Ying1, LI Gui-tong1, 2 
  

  1. 1 College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, P.R.China
    2 Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture/Key Laboratory of Plant-Soil Interactions, Ministry of Education, Beijing 100193, P.R.China
  • Received:2017-08-28 Online:2018-06-01 Published:2018-06-05
  • Contact: Correspondence ZHAO Xiao-rong, Tel: +86-10-62734258, E-mail: zhaoxr@cau.edu.cn
  • About author:CHEN Xue-jiao, E-mail: xjchen@cau.edu.cn
  • Supported by:
    This work was supported by the National Basic Research Program of China (2014CB138801) and the Program for Changjiang Scholars and Innovative Research Team in University of China (IRT0412).

Abstract:

It is not certain that long-term grazing exclusion influences arbuscular mycorrhizal (AM) fungi and their association with steppe vegetation.  In this study, soil and plant samples were collected from two sites of grazing exclusion since 1983 (E83) and 1996 (E96), and one site of free-grazing (FG) in the typical steppe of Xilinguole League, Inner Mongolia, China, and assayed for soil basic physicochemical properties, AM fungal parameters, aboveground biomass and shoot phosphorus (P) uptake as well.  The results showed that long-term grazing exclusion of E83 and E96 led to less drastic seasonal changes and significant increases in spore density, hyphal length density and root colonization intensity of AM fungi and even soil alkaline phosphatase activity, by up to 300, 168, 110 and 102%, respectively, compared with those of FG site.  In addition, the total aboveground biomass and shoot P uptake of E83 and E96 were 75–992% and 58–645%, respectively, higher than those of FG.  Generally, the root colonization intensity, spore density, and hyphal length density of AM fungi were all positively correlated with the aboveground biomass and even shoot P uptake of plant.  These results may imply that grazing exclusion play a critical role in increasing the growth of AM fungi, and subsequently, may increase plant P uptake and aboveground biomass production.  Moreover, the spore density could sensitively reflect the impacts of long-term grazing exclusion on AM fungi since survival strategy of spores in soil.
 

Key words: typical steppe ,  long-term grazing exclusion ,  arbuscular mycorrhizal fungi ,  aboveground biomass ,  shoot phosphorus uptake