References
Averill C, Turner BL, Finzi AC (2014)Mycorrhiza-mediated competition
between plants and decomposers drives soil carbon storage. Nature
505:543–545.
White, R., Murray, S., Rohweder, M., 2000. Pilot Analysis of Global
Ecosystems: Grassland Ecosystems.World Resources Institute, Washington
D. C,p.81.
Maestre, F.T., Salguero-Gomez, R., Quero, J.L., 2012. It is getting
hotter in here: determining and projecting the impacts of global
environmental change on drylands. Philos. Trans. R. Soc. B-Biol. Sci.
367 (1606), 3062–3075.
Kemp, D.R., Han, G., Hou, X., Michalk, D.L., Hou, F., Wu, J., et al.,
2013. Innovative grassland management systems for environmental and
livelihood benefits. Proc. Natl. Acad. Sci. Unit. States Am. 110 (21),
8369–8374.
Davidson, E.A., Nepstad, D.C., Klink, C., Trumbore, S., 1995. Pasture
soils as carbon sink. Nature 376, 472–473.
Scurlock, J.M.O., Hall, D.O., 1998. The global carbon sink: a grassland
perspective.Global Change Biology 4,
229–233.
Tan, Z., Liu, S., Johnston, C.A., Liu, J., Tieszen, L.L., 2006. Analysis
of ecosystem controls on soil carbon source–sink relationships in the
northwest Great Plains.Global Biogeochemical Cycles 20, GB4012,
doi:10.1029/2005GB002610.
Lugo, A.E., Brown, S., 1993. Management of tropical soils as sinks or
sources of
atmospheric carbon. Plant and Soil 19, 27–41.
Post, W.M., Kwon, K.C., 2000. Soil carbon sequestration and land-use
change:
processes and potential. Global Change Biology 6, 317–327.
Jones, M.B., Donnelly, A., 2004. Carbon sequestration in temperate
grassland
ecosystems and the influence of management, climate and elevated CO2.
New
Phytologist 164, 423–439.
Billings, S.A., 2006. Soil organic matter dynamics and land use change
at a grassland/forest ecotone. Soil Biology & Biochemistry 38,
2934–2943.
Elmore, A.J., Asner, G.P., 2006. Effects of grazing intensity on soil
carbon stocks
following deforestation of a Hawaiian dry tropical forest. Global Change
Biology
12, 1761–1772.
Liao, J.D., Boutton, T.W., Jastrow, J.D., 2006. Storage and dynamics of
carbon and
nitrogen in soil physical fractions following woody plant invasion of
grassland.
Soil Biology & Biochemistry 38, 3184–3196.
Harpole, W.S., Potts, D.L., Suding, K.N., 2007. Ecosystem responses to
water and
nitrogen amendment in a California grassland. Global Change Biol. 13
(11),
2341–2348.
Houghton, R.A., Hackler, J.L., Lawrence, K.T., 1999. The U.S. carbon
budget: contributions from land-use change. Science 285, 574–578.
Li, Y.H., 1994. Research on the grazing degradation model of the main
steppe rangelands in Inner Mongolia and some considerations for the
establishment of a computerized rangeland monitoring system. Acta
Phytoecologica Sinica 18, 68–79 (in Chinese with English abstract).
Dong, X.B., Zhang, X.S., 2005. The grassland in the Inner Mongolia is
overloaded and change of production pattern is highlighted. Resources
Science 27, 175–179 (in
Chinese, with English abstract).
Stampfli, A., Bloor, J.M.G., Fischer, M., Zeiter, M., 2018. High land
use intensity
exacerbates shifts in grassland vegetation composition after severe
experimental drought. Global Change Biol. 24 (5), 2021–2034. Xu, Z.,
Ren, H., Cai, J., Wang, R., Li, M., Wan, S., et al., 2014. Effects of
experimentallyenhanced precipitation and nitrogen on resistance,
recovery and resilience of a semiarid grassland after drought. Oecologia
176 (4), 1187–1197.
Mackie, K.A., Zeiter, M., Bloor, J.M., Stampfli, A., 2019. Plant
functional groups mediate drought resistance and recovery in a multisite
grassland experiment. J. Ecol. 107 (2), 937–949.
Xu, Z., Wan, S., Ren, H., Han, X., Li, M.H., Cheng, W., Jiang, Y., 2012.
Effects of waterand nitrogen addition on species turnover in temperate
grasslands in norther china PLoS ONE 7, e3976.
Morra, M.J., Bland, R.R., Freeborn, L.L., Shafii, B., 1991. Size
fractionation of soil organicmineral complexes using ultrasonic
dispersion. Soil Science 152, 294–303.
Nelson, D.W., Sommers, L.E., 1982. Total carbon, organic carbon, and
organic matter.
In: Page, A.L., Miller, R.H., Keeney, D.R. (Eds.), Methods of Soil
Analysis.
Gallaher, R.N., Weldon, C.O., Boswell, F.C., 1976. A semi-automated
procedure for
total nitrogen in plant and soil samples. Soil Science Society of
America Journal 40, 887–889.
Vance, E.D., Brookes, P.C., Jenkinson, D.S., 1987. An extraction method
for measuring soil microbial biomass-C. Soil Biology & Biochemistry 19,
703–707.
Bossio DA, Scow KM (1998) Impacts of carbon and flooding on soil
microbial communities: phospholipid fatty acid profiles and substrate
utilization patterns. Microb Ecol 35:265–278.
Zak, D.R., Holmes, W.E., White, D.C., Peacock, A.D., Tilman, D., 2003.
Plant diversity,soil microbial communities, and ecosystem function: are
there any links?
Ecology 84, 2042–2050.
Pinkart HC, Ringelberg DB, Piceno YM, Macnaughton SJ, White DC (2002)
Biochemical approaches to biomass measurements and community structure
analysis. In: Hurst CJ (Ed) Manual of environmental microbiology. ASM
Press, Washington, DC, pp 101–113.
Zhang N, Wan S, Guo J, Han G, Gutknecht J, Schmid B, Yu L, Liu W, Bi J,
Wang Z, Ma K (2015) Precipitation modifies the effects of warming and
nitrogen addition on soil microbial communities in northern Chinese
grasslands. Soil Biol Biochem 89:12–23.
DeForest JL, Zak DR, Pregitzer KS, Burton AJ (2004) Atmospheric nitrate
deposition, microbial community composition, and enzyme activity in
northern hardwood forests. Soil Sci Soc Am J 68:132–138.
Dong, X.B., Zhang, X.S., 2005. The grassland in the Inner Mongolia is
overloaded and change of production pattern is highlighted. Resources
Science 27, 175–179 (in
Chinese, with English abstract).
Xiao, X. M., Wang, Y.F., Chen, Z.Z., 1996. Dynamics of primary
productivity and soil
organic matter of typical steppe in the Xilin River basin of Inner
Mongolia and their response to climate change. Acta Botanica Sinica 38,
45–52 (in Chinese,with English abstract).
Bai, Y. F., Han, X.G., Wu, J.G., Chen, Z.Z., Li, L.H., 2004. Ecosystem
stability and
compensatory effects in the Inner Mongolia grassland. Nature 431,
181–184.
Hulbert, L. C., 1988. Causes of fire effects in tallgrass prairie.
Ecology 69, 46–58.
David, N. T., Schimel, D.S., Owensby, C.E., Ojima, D.S., 1991. Fire and
grazing in the tallgrass prairie: contingent effects on nitrogen
budgets. Ecology 72, 1374–1382.
Collins, S. L., Smith, M. D., 2006. Scale-dependent interaction of fire
and grazing on
community heterogeneity in tallgrass prairie. Ecology 87, 2058–2067.
MacNeil, M. D., Haferkamp, M. R., Vermeire, L. T., Muscha, J. M., 2008.
Prescribed fire and grazing effects on carbon dynamics in a northern
mixed-grass prairie. Agriculture, Ecosystems and Environment 127,
66–72.
Wu, H. B., Guo, Z. T., Peng, C. H., 2003. Land use induced changes of
organic carbon storage in soils of China. Global Change Biology 9,
305–315.
Post, W.M., Emanuel, W. R., Zinke, P. J., Stangenberger, A. G., 1982.
Soil carbon pools and world life zones. Nature 298, 156–159.
Burke, I. C., Lauenroth, W. K., Coffin, D. P., 1995. Soil organic matter
recovery in semiarid grasslands: implications for the conservation
reserve program. Ecological Applications 5, 793–801.
Ma, Q., Liu, X., Li, Y., Li, L., Yu, H., Qi, M., et al., 2020. Nitrogen
deposition magnifies the sensitivity of desert steppe plant communities
to large changes in precipitation. J. Ecol. 108 (2), 598–610.
DeAngelis, D. L., Mulholland, P. J., Palumbo, A. V., Stienman, A. D.,
Huston, A., Elwood, J. W., 1989. Nutrient dynamics and food web
stability. Annu. Rev. Ecol. Systemat. 20, 71–95.
Herbert, D. A., Fownes, J. H., Vitousek, P. M., 1999. Hurricane damage
to a Hawaiian
forest: nutrient supply rate affects resistance and resilience. Ecology
80 (3), 908–920. Xu, Z., Zhou, G., Shimizu, H., 2009. Are plant growth
and photosynthesis limited by predrought following rewatering in grass?
J. Exp. Bot. 60 (13), 3737–3749.
Schwalm, C. R., Anderegg, W. R. L., Michalak, A. M., Fisher, J. B.,
Biondi, F., Koch, G., et al., 2017. Global patterns of drought recovery.
Nature 548 (7666), 202–205. https://doi. org/10.1038/nature23021.
Mackie, K. A., Zeiter, M., Bloor, J. M., Stampfli, A., 2019. Plant
functional groups mediate drought resistance and recovery in a multisite
grassland experiment. J. Ecol. 107 (2), 937–949.
Chen, N., Zhang, Y., Zu, J., Zhu, J., Zhang, T., Huang, K., et al.,
2020. The compensation effects of post-drought regrowth on earlier
drought loss across the Tibetan plateau grasslands. Agric. For.
Meteorol. 281, 107822 .2019.107822.
Sankaran, M., 2019. Droughts and the ecological future of tropical
savanna vegetation. J. Ecol. 107 (4), 1531–1549.
Xu, Z., Zhou, G., 2007. Photosynthetic recovery of a perennial grass
Leymus chinensis after different periods of soil drought. Plant Prod.
Sci. 10 (3), 277–285. Sankaran, M., 2019. Droughts and the ecological
future of tropical savanna vegetation. J. Ecol. 107 (4), 1531–1549.
Xu, Z., Ren, H., Cai, J., Wang, R., Li, M., Wan, S., et al., 2014.
Effects of experimentallyenhanced precipitation and nitrogen on
resistance, recovery and resilience of a semiarid grassland after
drought. Oecologia 176 (4), 1187–1197.
Manzoni S, Schimel J P, Porporato A (2012) Responses of soil microbial
communities to water stress: results from a meta-analysis. Ecology
93:930–938.
Pennanen T, Fritze H, Vanhala P, Kiikkilä O, Neuvonen S, Bååth E (1998)
Structure of a microbial community in soil after prolonged addition of
low levels of simulated acid rain. Appl Environ Microb 64:2173–2180.
Ruzhen, Wang, Maxim, et al. Sensitivities to nitrogen and water addition
vary among microbial groups within soil aggregates in a semiarid
grassland[J]. Biology and Fertility of Soils, 2016.
Zhang, N., Liu, W., Yang, H., Yu, X., Gutknecht, J.L.M., Zhang, Z., Wan,
S., Ma, K.,
2013a. Soil microbial responses to warming and increased precipitation
and their implications for ecosystem C cycling. Oecologia 173,
1125e1142.
Dungait J A, Hopkins D W, Gregory A S, Whitmore A P (2012) Soil organic
matter turnover is governed by accessibility not recalcitrance. Glob
Chang Biol 18:1781–1796.
Nielsen U N, Ball B A (2015) Impacts of altered precipitation regimes on
soil communities and biogeochemistry in arid and semi-arid ecosystems.
Glob Chang Biol 21:1407–1421.
Griffiths B S, Ritz K, Ebblewhite N, Dobson G (1998) Soil microbial
community structure: effects of substrate loading rates. Soil Biol
Biochem 31:145–153.
Frey S D, Knorr M, Parrent J L, Simpson R T (2004) Chronic nitrogen
enrichment affects the structure and function of the soil microbial
community in temperate hardwood and pine forests. Forest Ecol Manag
196:159–171.
Strickland M S, Rousk J (2010) Considering fungal: bacterial dominance
in soils—methods, controls, and ecosystem implications. Soil Biol
Biochem 42:1385–1395.
Bai Y, Wu J, Clark C M, Naeem S, Pan Q, Huang J, Zhang L, Han X (2010)
Tradeoffs and thresholds in the effects of nitrogen addition on
biodiversity and ecosystem functioning: evidence from Inner Mongolia
grasslands. Glob Chang Biol 16:358–372.
Xu, Z., Wan, S., Zhu, G., Ren, H., Han, X., 2010. The inflfluence of
historical land use and water availability on grassland restoration.
Restoration Ecology 18, 217e225.
Hobbie, E. A., Jumpponen, A., Trappe, J., 2005. Foliar and fungal 15N:
14N ratios reflect development of mycorrhizae and nitrogen supply during
primary succession:
testing analytical models. Oecologia 146, 258e268.
Wei, C., Yu, Q., Bai, E., Lü, X., Li, Q., Xia, J., Kardol, P., Liang,
W., Wang, Z., Han, X., 2013.Nitrogen deposition weakens plantemicrobe
interactions in grassland ecosystems. Global Change Biology 19,
3688-3697.
Treseder, K. K., 2008. Nitrogen additions and microbial biomass: a
meta-analysis of
ecosystem studies. Ecology Letters 11, 1111-1120.
Gutknecht, J. L. M., Field, C. B., Balser, T. C., 2012. Microbial
communities and their
responses to simulated global change fluctuate greatly over multiple
years.Global Change Biology 18, 2256-2269.
Wei, C., Yu, Q., Bai, E., Lü, X., Li, Q., Xia, J., Kardol, P., Liang,
W., Wang, Z., Han, X., 2013.Nitrogen deposition weakens plantemicrobe
interactions in grassland ecosystems. Global Change Biology 19,
3688-3697.
Table 1 Characteristics of experimental plots (DS, dry-season; WS,
wet-season)