[1] Kang L,Han X G,Zhang Z B,et al.Grassland ecosystems in China:review of current knowledge and research advancement[J].Philosophical Transactions of the Royal Society of London,2007,362(1482):997-1008. [2] Schonbach P,Wan H W,Gierus M,et al.Grassland responses to grazing:effects of grazing intensity and management system in an Inner Mongolian steppe ecosystem[J].Plant and Soil,2011,340(1/2):103-115. [3] Deng L,Sweeney S,Shangguan Z.Long-term effects of natural enclosure:carbon stocks,sequestration rates and potential for grassland ecosystems in the Loess Plateau[J].Clean-Soil Air Water,2014,42(5):617-625. [4] Wang K B,Deng L,Ren Z P,et al.Grazing exclusion significantly improves grassland ecosystem C and N pools in a desert steppe of Northwest China[J].Catena,2016,137:441-448. [5] McNaughton S J.Compensatory plant-growth as a response to herbivory[J].Oikos,1983,40(3):329-336. [6] Ma W L,Shi P L,Li W H,et al.Changes in individual plant traits and biomass allocation in alpine meadow with elevation variation on the Qinghai-Tibetan Plateau[J].Science China-Life Sciences,2010,53(9):1142-1151. [7] Sun J,Wang X D,Cheng G W,et al.Effects of grazing regimes on plant traits and soil nutrients in an alpine steppe,Northern Tibetan Plateau[J].Plos One,2014,9(9):e108821. [8] Hilbert D W,Swift D M,Detling J K,et al.Relative growth-rats and the grazing optimization hypothesis[J].Oecologia,1981,51(1):14-18. [9] Lipowsky A,Schmid B,Roscher C.Selection for monoculture and mixture genotypes in a biodiversity experiment[J].Basic and Applied Ecology,2011,12(4):360-371. [10] Kiaer L P,Weisbach A N,Weiner J.Root and shoot competition:a meta-analysis[J].Journal of Ecology,2013,101(5):1298-1312. [11] Liu M,Liu G,Wu X,et al.Vegetation traits and soil properties in response to utilization patterns of grassland in Hulun Buir City,Inner Mongolia,China[J].Chinese Geographical Science,2014,24(4):471-478. [12] Deng L,Sweeney S,Shangguan Z P.Grassland responses to grazing disturbance:plant diversity changes with grazing intensity in a desert steppe[J].Grass and Forage Science,2014,69(3):524-533. [13] 王敏,苏永中,杨荣,等.黑河中游荒漠草地地上和地下生物量的分配格局[J].植物生态学报,2013,37(3):209-219. [14] Titlyanova A A,Romanova I P,Kosykh N P,et al.Pattern and process in above-ground and below-ground components of grassland ecosystems[J].Journal of Vegetation Science,1999,10(3):307-320. [15] Hong J T,Ma X X,Wang X D.Leaf meristems:an easily ignored component of the response to human disturbance in alpine grasslands[J].Ecology and Evolution,2016,6(8):2325-2332. [16] 杨丽丽,龚吉蕊,王忆慧,等.内蒙古温带草原不同放牧强度和围栏封育对凋落物分解的影响[J].植物生态学报,2016,40(8):748-759. [17] 乌云娜,雒文涛,霍光伟,等.微生境尺度上放牧退化草原群落特征与土壤有机质的空间分异性[J].中国沙漠,2012,32(4):972-978. [18] 王晓朦,乌云娜,宋彦涛,等.放牧对克氏针茅草原(Stipa krylovii)土壤物理、化学及微生物性状的影响[J].中国沙漠,2015,35(5):1193-1199. [19] McNaughton S J,Banyikwa F F,McNaughton M M.Promotion of the cycling of diet-enhancing nutrients by African grazers[J].Science,1997,278(5344):1798-1800. [20] Sun D S,Wesche K,Chen D D,et al.Grazing depresses soil carbon storage through changing plant biomass and composition in a Tibetan alpine meadow[J].Plant Soil & Environment,2011,57(6):271-278. [21] Shi X M,Li X G,Li C T,et al.Grazing exclusion decreases soil organic C storage at an alpine grassland of the Qinghai-Tibetan Plateau[J].Ecological Engineering,2013,57:183-187. [22] Whitford W G,Steinberger Y.Effects of seasonal grazing,drought,fire,and carbon enrichment on soil microarthropods in a desert grassland[J].Journal of Arid Environments,2012,83:10-24. [23] Ma W M,Ding K Y,Li Z W.Comparison of soil carbon and nitrogen stocks at grazing-excluded and yak grazed alpine meadow sites in Qinghai-Tibetan Plateau,China[J].Ecological Engineering,2016,87:203-211. [24] Wang D,Wu G L,Zhu Y J,et al.Grazing exclusion effects on above-and below-ground C and N pools of typical grassland on the Loess Plateau(China)[J].Catena,2014,123:113-120. [25] Deng L,Zhang Z N,Shangguan Z P.Long-term fencing effects on plant diversity and soil properties in China[J].Soil & Tillage Research,2014,137:7-15. [26] Yan L,Zhou G S,Zhang F.Effects of different grazing intensities on grassland production in China:a meta-analysis[J].Plos One,2013,8(12):e81466. [27] Klumpp K,Fontaine S,Attard E,et al.Grazing triggers soil carbon loss by altering plant roots and their control on soil microbial community[J].Journal of Ecology,2009,97(5):876-885. [28] Kuzyakov Y.Priming effects:interactions between living and dead organic matter[J].Soil Biology & Biochemistry,2010,42(9):1363-1371. [29] Jarvis S C,Hatch D J,Roberts D H.The effects of grassland management on nitrogen losses from grazed swards through ammonia volatilization-the relationship to excretal-N returns from cattle[J].Journal of Agricultural Science,1989,112:205-216. [30] Zhu G Y,Deng L,Zhang X B,et al.Effects of grazing exclusion on plant community and soil physicochemical properties in a desert steppe on the Loess Plateau,China[J].Ecological Engineering,2016,90:372-381. [31] Lempesi A,Kyriazopoulos A P,Orfanoudakis M,et al.Soil properties and plant community changes along a goat grazing intensity gradient in an open canopy oak forest[J].Notulae Botanicae Horti Agrobotanici Cluj-Napoca,2013,41(2):567-575. [32] Reeder J D,Schuman G E,Morgan J A,et al.Response of organic and inorganic carbon and nitrogen to long-term grazing of the shortgrass steppe[J].Environmental Management,2004,33(4):485-495. [33] Li W,Huang H Z,Zhang Z N,et al.Effects of grazing on the soil properties and C and N storage in relation to biomass allocation in an alpine meadow[J].Journal of Soil Science and Plant Nutrition,2011,11(4):27-39. [34] Stewart A M,Frank D A.Short sampling intervals reveal very rapid root turnover in a temperate grassland[J].Oecologia,2008,157(3):453-458. [35] Vermeire L T,Wester D B,Mitchell R B,et al.Fire and grazing effects on wind erosion,soil water content,and soil temperature[J].Journal of Environmental Quality,2005,34(5):1559-1565. [36] Frank D A,Gehring C A,Machut L,et al.Soil community composition and the regulation of grazed temperate grassland[J].Oecologia,2003,137(4):603-609. |