REFERENCES
Adair, E. C., Reich, P. B., Hobbie, S. E., Knops, J. M. H. (2009). Interactive effects of time, CO2, N, and diversity on total belowground carbon allocation and ecosystem carbon storage in a grassland community. Ecosystems , 12 , 1037-1052. https://doi.org/10.1007/s10021-009-9278-9
Aye, N. S., Butterly, C. R., Sale, P. W. G., & Tang, C. X. (2018). Interactive effects of initial pH and nitrogen status on soil organic carbon priming by glucose and lignocelluloses. Soil Biology and Biochemistry , 123 , 33-44. https://doi.org/10.1016/j.soilbio.2018.04.027
Baumann, K., Marschner, P., Smernik, R. J., & Baldock, J. A. (2009). Residue chemistry and microbial community structure during decomposition of eucalypt, wheat and vetch residues. Soil Biology and Biochemistry , 41 , 1966-1975. https://doi.org/10.1016/j.soilbio.2009.06.022
Blagodatskaya, E. V., Blagodatsky, S. A., Anderson, T. H., Kuzyakov, Y. (2007). Priming effects in Chernozem induced by glucose and N in relation to microbial growth strategies. Applied Soil Ecology ,37 , 95-105. https://doi.org/10.1016/j.apsoil.2007.05.002
Blagodatskaya, E., & Kuzyakov, Y., 2008. Mechanisms of real and apparent priming effects and their dependence on soil microbial biomass and community structure: critical review. Biology and Fertility of Soils , 45 , 115-131. http:// doi.org/ 10.1007/s00374-008-0334-y
Blagodatskaya, E., Khomyakov, N., Myachina, O., Bogomolova, I., Blagodatsky, S., Kuzyakov, Y. (2014). Microbial interactions affect sources of priming induced by cellulose. Soil Biology and Biochemistry , 74 , 39-49. http:// doi.org/10.1016/j. soilbio.2014.02.017
Borer, E. T., Grace, J. B., Harpole, W. S., MacDougall, A. S., Seabloom, E. W. (2017). A decade of insights into grassland ecosystem responses to global environmental change. Nature Ecology and Evolution ,1 , 0118. https://doi.org/10.1038/s41559-017-0118
Chen, R., Senbayram, M., Blagodatsky, S., Myachina, O., Dittert, K., Lin, X., Blagodatskaya, E., Kuzyakov, Y. (2014). Soil C and N availability determine the priming effect: microbial N mining and stoichiometric decomposition theories. Global Change Biology ,20 , 2356-2367. http:// doi.org/10.1111/gcb.12475
Chen, Y. L., Chen, L. Y., Peng, Y. F., Ding, J. Z., Li, F., Yang, G. B., Liu, L., Fang, K., Zhang, B. B., Wang, J., Yang, Y. H. (2016). Linking microbial C:N:P stoichiometry to microbial community and abiotic factors along a 3500-km grassland transect on the Tibetan Plateau. Global Ecology and Biogeography , 25 , 1416-1427.  https://doi.org/10.1111/geb.12500
Cleveland, C. C., & Liptzin, D. (2007). C:N:P stoichiometry in soil: Is there a “Redfield ratio” for the microbial biomass?Biogeochemistry , 85 , 235-252. https://doi.org/10.2307/20456544
Craine, J. M., Morrow, C., & Fierer, N. (2007). Microbial nitrogen limitation increases decomposition. Ecology , 88 , 2105-2113.  https://doi.org/10.1890/06-1847.1
Crowther, T.W., Riggs, C., Lind, E.M., Borer, E.T., Seabloom, E.W., Hobbie, S.E., Wubs, J., Adler, P.B., Firn, J., Gherardi, L., Hagenah, N., Hofmockel, K.S., Knops, J. M.H., McCulley, R.L., McDougall, A., Peri, P.L., Prober, S.M., Stevens, C.J., & Routh, D. (2019). Sensitivity of global soil carbon stocks to combined nutrient enrichment. Ecology Letters , 22 , 936-945. https://doi.org/10.1111/ele.13258
Di Lonardo, D. P., Boer, W. D., Klein Gunnewiek, P. J. A., Hannula, S. E., Van der Wal, A. (2017). Priming of soil organic matter: Chemical structure of added compounds is more important than the energy content.Soil Biology and Biochemistry , 108 , 41-54. https://doi.org/10.1016/j.soilbio.2017.01.017
Diamond, S., Andeer, P. F., Li, Z., Crits-Christoph, A., Burstein, D., Anantharaman, K., Lane, K. R., Thomas, B. C., Pan, C., Northern, T. R., & Banfield, J. F. (2019). Mediterranean grassland soil C-N compound turnover is dependent on rainfall and depth, and is mediated by genomically divergent microorganisms. Nature microbiology ,4 , 1356-1367. https://doi.org/10.1038/s41564-019-0449-y
Fayiah, M., Dong S. K., Khomera, S. W., Ur Rehman, S. A., Yang, M. Y., & Xiao, J. N. (2020). Status and challenges of Qinghai-Tibet Plateau’s grasslands: an analysis of causes, mitigation measures, and way forward.Sustainability , 12 , 1099. http://doi.org/10.3390/su12031099
Fontaine, S., Bardoux, G., Abbadie, L., & Mariotti, A. (2004). Carbon input to soil may decrease soil carbon content. Ecology Letters ,7 , 314-320.  https://doi.org/10.1111/j.1461-0248.2004.00579.x
Fontaine, S., Henault, C., Aamor, A., Bdioui, N., Bloor, J. M. G., Maire, V., Mary, B., Revaillot, S., & Maron, P. A. (2011). Fungi mediate long term sequestration of carbon and nitrogen in soil through their priming effect. Soil Biology and Biochemistry , 43 , 86-96. https://doi.org/10.1016/j.soilbio.2010.09.017
Fontaine, S., Mariottib, A., Abbadie, L. (2003). The priming effect of organic matter: a question of microbial competition? Soil Biology and Biochemistry , 35 , 837-843. http://doi.org/10.1016/S0038-0717(03)00123-8
Fornara, D. A., Banin, L., & Crwley, M. J. (2013). Multi-nutrient vs. nitrogen-only effects on carbon sequestration in grassland soils.Global Change Biology , 19 , 3848-3857. https://doi.org/10.1111/gcb.12323
Fornara, D.A., & Tilman, D. (2012). Soil carbon sequestration in prairie grasslands increased by chronic nitrogen addition.Ecology , 93 , 2030-2036.  https://doi.org/10.1890/12-0292.1
Galloway, J. N., Townsend, A. R., Erisman, J. W., Bekunda, M., Cai, Z. C., Freney, J. R., Martinelli, L. A., Seitzinger, S. P., & Sutton, M. A. (2008). Transformation of the nitrogen cycle: recent trends, questions, and potential solutions. Science , 320 , 889-892. http://doi.org/10.1126/science.1136674
Geyer, K. M., Kyker-Snowman, E., Grandy, A. S., Frey, S. D. (2016). Microbial carbon use efficiency: accounting for population, community, and ecosystem-scale controls over the fate of metabolized organic matter. Biogeochemistry , 127 , 173-188. http://doi.org/10.1007/s10533-016-0191-y
Hou, Y. L. (2018). Effect of fertilization on carbon components in soil aggregates and decomposition dynamic of soil organic carbon in alpine meadows on the Qinghai-Tibetan Plateau. Lanzhou: MSc Dissertation, Lanzhou University.
Isbell, F., Reich, P. B., Tilman, D., Hobbie, S. E., Polasky, S., & Binder, S. (2013). Nutrient enrichment, biodiversity loss, and consequent declines in ecosystem productivity. Proceedings of National Academy of Sciences , 110 , 11911-11916. http://doi.org/10.1073/pnas.1310880110. http://doi.org/10.1073/pnas.1310880110
Jackson, R. B., Lajtha, K., Crow, S. E., Hugelius, G., Kramer, M. G.,  Piñeiro, G. (2017). The ecology of soil carbon: pools, vulnerabilities, and biotic and abiotic controls. Annual Review of Ecology, Evolution, and Systematics , 48 , 419-445. https://doi.org/10.1146/annurev-ecolsys-112414- 054234
Kuzyakov, Y. (2010). Priming effects: interactions between living and dead organic matter. Soil Biology and Biochemistry , 42 , 1363-1371. http://doi.org/10.1016/j.soilbio.2010.04.003
Kuzyakov, Y., & Bol, R. (2006). Sources and mechanisms of priming effect induced in two grassland soils amended with slurry and sugar.Soil Biology and Biochemistry , 38 , 747-758. https://doi.org/10.1016/j.soilbio.2005.06.025
Kuzyakov, Y., Friedel, J.K., & Stahr, K. (2000). Review of mechanisms and quantification of priming effects. Soil Biology and Biochemistry , 32 , 1485-1498. https://doi.org/10.1016/S0038-0717(00)00084-5
Leff, J. W., Jones, S. E., Prober, S. M., Barberan, A., Borer. E. T., Firn, J. L., Harpole, W. S., Hobbie, S. E., Hofmockel, K. S., Knops, J. M. H., McCulley, R. L., Pierre, K. L., Risch, A. C., Seabloom, E. W., Schütz, M., Steenbock, C., Stevens, C. J., & Fierer, N. (2015). Consistent responses of soil microbial communities to elevated nutrient inputs in grasslands across the globe. Proceedings of National Academy of Sciences , 112 , 10967-10972. http://doi.org/10.1073/pnas.1508382112.
Li, H., Yang, S., Xu, Z. W., Yan, Q. Y., Li, X. B., van Nostrand, J. D., He, Z. L., Yao, F., Han, X. G., Zhou, J. Z., Deng, Y., & Jiang, Y. (2017). Responses of soil microbial functional genes to global changes are indirectly influenced by aboveground plant biomass variation.Soil Biology and Biochemistry , 104 , 18-29. http://doi.org/ 10.1016/j.soilbio.2016.10.009
Li, J. H., Hou, Y. L., Zhang, S. X., Li, W. J., Xu, D. H., Knops, J. M. H., & Shi, X. M. (2018a). Fertilization with nitrogen and/or phosphorus lowers soil organic carbon sequestration in alpine meadows. Land Degradation & Development , 29 , 1634-1641. http://doi.org/10.1002/ldr.2961
Li, J. H., Li, F., Chen, S., Li, W. J., Abbott, L. K., & Knops, J. M. H. (2018b). Nitrogen additions promote decomposition of soil organic carbon in a Tibetan alpine meadow. Soil Science Society of America Journal , 82 , 614-621. http://doi.org/10.2136/sssaj2017.12.0417
Li, J. H., Yang, Y. J., Li, B. W., Li, W. J., Wang, G., & Knops, J. M. H. (2014). Effects of nitrogen and phosphorus fertilization on soil carbon fractions in alpine meadows on the Qinghai-Tibetan plateau. PLoS One, 9(7), e103266. https://doi.org/10.1371/journal.pone.0103266
Lin, Y. X., Ye, G. P., Kuzyakov, Y., Liu, D. Y., Fan, J. B., & Ding, W. X. (2019). Long-term manure application increases soil organic matter and aggregation, and alters microbial community structure and keystone taxa. Soil Biology and Biochemistry , 134 , 187-196. http://doi.org/10.1016/j.soilbio.2019.03.030
Liu, X. J., Zhang, Y., Han, W. H., Tang, A. H., Shen, J. L., Cui, Z. L., Vitousek, P., Erisman, J. W., Goulding, K., Christie, P., Fangmeier, A., & Zhang, F. S. (2013). Enhanced nitrogen deposition over China. Nature 494(7438):459-462. https://doi.org/10.1038/nature11917
Liu, L. L., & Greaver, T. L. (2010). A global perspective on belowground carbon dynamics under nitrogen enrichment. Ecology Letters , 13 , 819-828. http://doi.org/10.1111/j.1461-0248.2010.01482.x
Liu, S., Zamanian, K., Schleuss, P., Zarebanadkouki, M., & Kuzyakov, Y. (2018). Degradation of Tibetan grasslands: consequences for carbon and nutrient cycles. Agriculture Ecosystem & Environment ,252 , 93-104. http://doi.org/10.1016/j.agee.2017.10.011
Luo, R. Y., Fan, J. L., Wang, W. J., Luo, J. F., Kuzyakov, Y., He, J. S., Chu, H. Y., & Ding, W. X. (2019). Nitrogen and phosphorus enrichment accelerates soil organic carbon loss in alpine grassland on the Qinghai-Tibetan Plateau. The Science of the Total Environment , 650 , 303-312. https://doi.org/10.1016/j.scitotenv.2018.09.038
Luo, R. Y., Kuzyakov, Y., Liu, D. Y., Fan, J. L., Luo, J. F., Lindsey, S., He, J. S., & Ding, W. X. (2020). Nutrient addition reduces carbon sequestration in a Tibetan grassland soil: Disentangling microbial and physical controls. Soil Biology and Biochemistry , 144 , 107764. https://doi.org/10.1016/j.soilbio.2020.107764
Mack, M. C., Schuur, E. A. G., Bret-Harte, M. S., shaver G. S., & Chapin III, F. S. (2004). Ecosystem carbon storage in arctic tundra reduced by long term nutrient fertilization. Nature , 431 , 440-443. https://doi.org/10.1038/nature02887
Nottingham, A. T., Griffiths, H., Chamberlain, P. M., Stott, A. W., Tanner, E. V. J. (2009). Soil priming by sugar and leaf-litter substrates: A link to microbial groups. Applied Soil Ecology ,42 , 83-90. https://doi.org/10.1016/j.apsoil.2009.03.003
Paterson, E., & Sim, A. (2013). Soil-specific response functions of organic matter mineralization to the availability of labile carbon.Global Change Biology , 19 , 1562-1571.  https://doi.org/10.1111/gcb.12140
Qiao, N., Schaefer, D., Blagodatskaya, E., Zou, X., Xu, X., Kuzyakov, Y. (2014). Labile carbon retention compensates for CO2released by priming in forest soils. Global Change Biology ,20, 1943-1954. http:// doi.org/10.1111/gcb.12458.
Ramirez, K. S., Craine, J. M., & Fierer, N. (2010). Nitrogen fertilization inhibits soil microbial respiration regardless of the form of nitrogen applied. Soil Biology and Biochemistry , 42 , 2336-2338. http://doi.org/ 10.1016/j.soilbio.2010.08.032
Ramirez, K. S., Craine, J. M., & Fierer, N. (2012). Consistent effects of nitrogen amendments on soil microbial communities and processes across biomes. Global Change Biology, 18, 1918-1927. https://doi.org/10.1111/j.1365-2486.2012.02639.x
Razanamalala, K., Fanomezana, R. A., Razafimbelo, T., Chevallier, T., Trap, J., Blanchart, E., & Bernard, L. (2018). The priming effect generated by stoichiometric decomposition and nutrient mining in cultivated tropical soils: Actors and drivers. Applied Soil Ecology , 126 , 21-33. https://doi.org/10.1016/j.apsoil.2018.02.008
Reid, J. P., Adair, E. C., Hobbie, S. E., Reich, P. B. (2012). Biodiversity, nitrogen deposition, and CO2 affect grassland soil carbon cycling but not storage. Ecosystems ,15 , 580-590. https://doi.org/10.1007/s10021-012-9532-4
Riggs, C. E., & Hobbie, S. E. (2016). Mechanisms driving the soil organic matter decomposition response to nitrogen enrichment in grassland soils. Soil Biology and Biochemistry , 99 , 54-65. http://doi.org/10.1016/j.soilbio.2016.04.023
Riggs, C. E., Hobbie, S. E., Bach, E. M., Hofmockel, K. S., & Kazanski, C. E. (2015). Nitrogen addition changes grassland soil organic matter decomposition. Biogeochemistry , 125 , 203-219. https://doi.org/10.1007/s10533‐015‐0123‐2
Sokol, N. W., Sanderman, J., & Bradford, M. A. (2019). Pathways of mineral-associated soil organic matter formation: integrating the role of plant carbon source, chemistry, and point of entry. Global Change Biology , 25 , 12-24. https://doi.org/10.1111/gcb.14482
Soudzilovskaia, N. A., Onipchenko, V. G., Cornelissen, J. H. C., & Aerts, R. (2007). Effects of fertilization and irrigation on ‘foliar afterlife’ in alpine tundra. Journal of Vegetation Science ,18 , 755-766. http://doi.org/10.1111/j.1654-1103.2007.tb02591.x.
Wang, H., Boutton, T. W., Xu, W. H., Hu, G. Q., Jiang, P., & Bai, E. (2015). Quality of fresh organic matter affects priming of soil organic matter and substrate utilization patterns of microbes. Scientific Reports , 5 , 10102 . http://doi.org/10.1038/srep10102
Wen, L., Dong, S. K., Li, Y. Y., Wang, X. X., Li, X. Y., Shi, J. J., & Dong, Q. M. (2013). The impact of land degradation on the C pools in alpine grasslands of the Qinghai-Tibet Plateau. Plant and Soil ,368 , 329-340. http://doi.org/10.1007/s11104-012-1500-4
Werth, M., & Kuzyakov, Y. (2010). 13C fractionation at the root-microorganisms-soil interface: a review and outlook for partitioning studies. Soil Biology and Biochemistry , 42 , 1372-1384. https://doi.org/10.1016/j.soilbio.2010.04.009
Wild, B., Schnecker, J., Alves, R. J. E., Barsukov, P., Bárta, J., Capek, P., Gentsch, N., Gittel, A., Guggenberger, G., Lashchinsky, N., Mikutta, R., Rusalimova, O., Santrucková, H., Shibistova, O., Urich, T., Watzka, M., Zrazhevskaya, G., & Richter, A. (2014). Input of easily available organic C and N stimulates microbial decomposition of soil organic matter in arctic permafrost soil. Soil Biology and Biochemistry , 75 , 143-151. http://doi.org/10.1016/j.soilbio.2014.04.014
Wu, L. W., Yang, Y. F., Wang, S. P., Yue, H. W., Lin, Q.Y., Hu, Y.G. , He, Z. L., Nostrand, J. D. V., Hale, L., Li, X. Z., Gilbert, J. A., & Zhou, J. Z. (2017). Alpine soil carbon is vulnerable to rapid microbial decomposition under climate cooling. The ISME Journal , 11 , 2102-2111. https://doi.org/10.1038/ismej.2017.75
Yang, Y. H., Fang, J. Y., Tang, Y. H., Ji, C. J., Zheng, C. Y., He, J. S., & Zhu, B. (2008). Storage, patterns and controls of soil organic carbon in the Tibetan grasslands. Global Change Biology ,14 , 1592-1599. https://doi.org/10.1111/j.1365-2486.2008.01591.x
Zeng, J., Liu, X. J., Song, L., Lin, X. G., Zhang, H. Y., Shen, C. C, & Chu, H. Y. (2016). Nitrogen fertilization directly affects soil bacterial diversity and indirectly affects bacterial community composition. Soil Biology and Biochemistry , 92 , 41-49. http://doi.org/10.1016/j.soilbio.2015.09.018
Zhang, T. A., Chen, Y. H., & Ruan H. H. (2018). Global negative effects of nitrogen deposition on soil microbes. The ISME Journal ,12 , 1817-1825. http://doi.org/10.1038/s41396-018-0096-y
Zhao, H., Sun, J., Xu, X. L., & Qin, X. J. (2017). Stoichiometry of soil microbial biomass carbon and microbial biomass nitrogen in China’s temperate and alpine grasslands. European Journal of Soil Biology , 83 , 1-8. https://doi.org/10.1016/j.ejsobi.2017.09.007
Zhu, Z. K., Ge, T. D., Luo, Y., Liu, S. L., Xu, X. L., Tong C. L, Shibistova, O., Guggenberger, G., & Wu, J. S. (2018). Microbial stoichiometric flexibility regulates rice straw mineralization and its priming effect in paddy soil. Soil Biology and Biochemistry ,121 , 67-76. https://doi.org/10.1016/j.soilbio.2018.03.003
Table 1 Correlations between priming effects (PEs) and stoichiometric properties of soil and microorganisms