Grazing impact on forage quality and macronutrient content of rangelands in Qilian Mountains, NW China
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摘要
An important indicator of the rangeland health, associated with land degradation, is the ability of semi-natural rangelands to provide forage of sufficient quality for livestock production. In Qilian Mountains(Gansu Province, NW China) biomass production and forage quality are dependent on the seasonality of precipitation and temperature; most of the precipitation falls during summer season, when sheep, goats and yaks graze mountain rangelands. To sustain the rangelands and to improve the management strategies, the assessment of the forage quality should be implemented. The purpose of this research was to study the response of biomass, forage quality and macronutrient content different levels of grazing intensity in Qilian rangelands. We sampled aboveground biomass in the growing seasons in 2012 and 2013 within spring/autumn or summer grazing regimes in two altitudinal zones below and above 3000 m a.s.l.(montane-subalpine and subalpine-alpine respectively). In order to estimate forage quality, biomass was sampled in 1 m × 1 m plots, assigned to the center of 10 ×10 m sites, fromwhich we collected different indicator parameters of rangeland health. Mineral and fiber content of forage biomass was estimated under different levels of grazing intensity with regard to the growing period. It was found that an increase in grazing intensity led to a decrease in dry matter weight. No linearity was observed in the relationship between nutritive value and grazing intensity. The highest fiber content(59.20 %) was found in plots mostly disturbed by grazing. The highest protein(16.30 %) and the lowest fiber(51.30 %) contents were associated with slightly grazing intensity. Concentrations of the mineral elements, such as Zn, P, K and S varied significantly and showed maximum values under low grazing intensity.
An important indicator of the rangeland health, associated with land degradation, is the ability of semi-natural rangelands to provide forage of sufficient quality for livestock production. In Qilian Mountains(Gansu Province, NW China) biomass production and forage quality are dependent on the seasonality of precipitation and temperature; most of the precipitation falls during summer season, when sheep, goats and yaks graze mountain rangelands. To sustain the rangelands and to improve the management strategies, the assessment of the forage quality should be implemented. The purpose of this research was to study the response of biomass, forage quality and macronutrient content different levels of grazing intensity in Qilian rangelands. We sampled aboveground biomass in the growing seasons in 2012 and 2013 within spring/autumn or summer grazing regimes in two altitudinal zones below and above 3000 m a.s.l.(montane-subalpine and subalpine-alpine respectively). In order to estimate forage quality, biomass was sampled in 1 m × 1 m plots, assigned to the center of 10 ×10 m sites, fromwhich we collected different indicator parameters of rangeland health. Mineral and fiber content of forage biomass was estimated under different levels of grazing intensity with regard to the growing period. It was found that an increase in grazing intensity led to a decrease in dry matter weight. No linearity was observed in the relationship between nutritive value and grazing intensity. The highest fiber content(59.20 %) was found in plots mostly disturbed by grazing. The highest protein(16.30 %) and the lowest fiber(51.30 %) contents were associated with slightly grazing intensity. Concentrations of the mineral elements, such as Zn, P, K and S varied significantly and showed maximum values under low grazing intensity.
An important indicator of the rangeland health, associated with land degradation, is the ability of semi-natural rangelands to provide forage of sufficient quality for livestock production. In Qilian Mountains(Gansu Province, NW China) biomass production and forage quality are dependent on the seasonality of precipitation and temperature; most of the precipitation falls during summer season, when sheep, goats and yaks graze mountain rangelands. To sustain the rangelands and to improve the management strategies, the assessment of the forage quality should be implemented. The purpose of this research was to study the response of biomass, forage quality and macronutrient content different levels of grazing intensity in Qilian rangelands. We sampled aboveground biomass in the growing seasons in 2012 and 2013 within spring/autumn or summer grazing regimes in two altitudinal zones below and above 3000 m a.s.l.(montane-subalpine and subalpine-alpine respectively). In order to estimate forage quality, biomass was sampled in 1 m × 1 m plots, assigned to the center of 10 ×10 m sites, fromwhich we collected different indicator parameters of rangeland health. Mineral and fiber content of forage biomass was estimated under different levels of grazing intensity with regard to the growing period. It was found that an increase in grazing intensity led to a decrease in dry matter weight. No linearity was observed in the relationship between nutritive value and grazing intensity. The highest fiber content(59.20 %) was found in plots mostly disturbed by grazing. The highest protein(16.30 %) and the lowest fiber(51.30 %) contents were associated with slightly grazing intensity. Concentrations of the mineral elements, such as Zn, P, K and S varied significantly and showed maximum values under low grazing intensity.
引文
Andrighetto I,Cozzi G,Berzaghi P,et al.(1993)Avoidance of degradation of alpine pasture through grazing management:Investigations of change in vegetation nutrition characteristics as a consequence of sheep grazing at different periods of the growing season.Land Degradatio n&Development 4:37-43.https://doi.org/10.1002/ldr.3400040105
Baranova,A,Schickhoff,U,Wang,S,et al.(2016)Mountain pastures of Qilian Shan:plant communities,grazing impact and degradation status(Gansu province,NW China).Hacquetia 15(2):21-35.https://doi.org/10.1515/hacq-2016-0014
Chang X,Zhao W,Zhao A(2004)Species diversity of pasture community at different altitude levels in Qilian Mountains.Chinese Journal of Applied Ecology 15:1599-1603.
Deng S,Yang T,Zeng B,et al.(2013)Vegetation cover variation in the Qilian Mountains and its response to climate change in2000-2011.Journal of Mountain Science 10:1050-1062.https://doi.org/10.1007/s11629-013-2558-z
D?nnem I,Randby?,Ekn?s M(2011)Effect of grass silage growing stage and level of concentrate supplementation on goat milk quality.Animal Feed Science and Technology 163:118-129.https://doi.org/10.1016/j.anifeedsci.2010.10.013
Gamoun M(2014)Grazing intensity effects on the vegetation in desert rangelands of Southern Tunisia.Journal of Arid Land 6:324-333.https://doi.org/10.1007/s40333-013-0202-y
Giraudoux P(2015)Pgirmess:Data Analysis in Ecology.Miscellaneous functions for data analysis in ecology,with special emphasis on spatial data.https://cran.rproject.org/web/packages/pgirmess/index.html(accessed on18 December 2015)
Guo XS,Ding LM,Long RJ,et al.(2012)Changes of chemical composition to high altitude results in Kobresia littledalei growing in alpine meadows with high feeding values for herbivores.Animal Feed Science and Technology 173:186-193.https://doi.org/10.1016/j.anifeedsci.2012.01.011
Horrocks RD,Vallentine JF(1999)Harvested forages.San Diego:Academic Press,p426
Hu G,Liu H,Yin Y,Song Z(2015)The Role of Legumes in Plant Community Succession of Degraded Grasslands in Northern China.Land Degradation&Development 27:366-372.https://doi.org/10.1002/ldr.2382
Islam M,Razzaq A,Shamim G,et al.(2018)Impact of grazing on soil,vegetation and ewe production performances in a semi-arid rangeland.Journal of Mountain Science 15(4):685-694.https://doi.org/10.1007/s11629-017-4702-7
Knowles SO,Grace ND(2014)A recent assessment of the elemental composition of New Zealand pastures in relation to meeting the dietary requirements of grazing livestock.Journal of Animal Science 92:303-310.https://doi.org/10.2527/jas.2013-6847
Li Y,Squires VR(2009)Case Study 5:Hexi Corridor,Gansu.In:Squires VR,Lu Q,Wang T,Yang Y(Ed).Rangeland Degradation and Recovery in China's Pastoral Lands.Wallingford-Cambridge.pp 151-170.
Linn LG,Martin NP(1991)Forage Quality Tests and Interpretation.The Veterinary clinics of North America.Food animal practice 7:509-523.
Mc Eniry J,O’Kiely P(2013)Anaerobic methane production from five common grassland species at sequential stages of maturity.Bioresource Technology 127:143-150.https://doi.org/10.1016/j.biortech.2012.09.084
Miao F,Guo Z,Xue R,Wang X,Shen Y(2015)Effects of grazing and precipitation on herbage biomass,herbage nutritive value,and yak performance in an alpine meadow on the QinghaiTibetan Plateau.PLoS ONE.https://doi.org/10.1371/journal.pone.0127275
Miller DJ(2005)The Tibetan Steppe.In:Suttie JM,Reynolds SG,Batello C.(eds),Plant Producrion and Protection Series,Vol 34:Grasslands of the world.Rome,Italy:FAO.
Mountousis I,Papanikolaou K,Stanogias G,et al.(2008).Seasonal variation of chemical composition and dry matter digestibility of rangelands in NW Greece.Journal of Central European Agriculture 9(3):547-556.
National Research Council(NRC)(2001)Nutrient Requirements of dairy cattle.7th ed.Washington,DC,USA:National Academies Press,p 408
National Research Council(NRC)(2007)Nutrient Requirements of Small Ruminants:Sheep,Goats,Cervids,and New World Camelids.Washington,DC,USA:National Academies Press.p.384.
Nagy L,Grabherr G(2009)The biology of alpine habitats.Oxford,New York:Oxford University Press.The biology of habitats series.p 376.
Oba G,Vetaas OR,Stenseth NC(2001)Relationships between biomass and plant species richness in arid-zone grazing lands.Journal of Applied Ecology 38:836-845.
Ortmann S,Bradley BJ,Stolter C,et al.(2006)Estimating the quality and composition of wild animal diets-a critical survey of methods.In:Hohmann J,Robbins MM,Boesch C(eds.),Feeding ecology in Apes and other Primates.Ecological,Physical and Behavioral Aspects.Cambridge:Cambridge University Press.pp 395-418.
Pellant M,Shaver P,Pyke DA,et al.(2005)Interpreting indicators of rangeland health,version 4.Technical Reference1734-6.U.S.Department of the Interior,Bureau of Land Management,National Science and Technology Center,Denver,CO.https://jornada.nmsu.edu/files/bibliography/05-010.pdf(Accessed on 2 September 2017)
R Core Team(2015)R:A Language and Environment for Statistical Computing.Vienna,Austria:Foundation for Statistical Computing.https://www.R-project.org/(Accessed on 9 September 2015)
Ren H,Han G,Sch?nbach P,et al.(2016)Forage nutritional characteristics and yield dynamics in a grazed semiarid steppe ecosystem of Inner Mongolia,China.Ecological Indicators 60:460-469.https://doi.org/10.1016/j.ecolind.2015.07.027
Sasaki T,Ohkuro T,Jamsran U,Takeuchi K(2012)Changes in the herbage nutritive value and yield associated with threshold responses of vegetation to grazing in Mongolian rangelands.Grass and Forage Science 67:446-455.https://doi.org/10.1111/j.1365-2494.2012.00862.x
Sch?nbach P,Wan H,Gierus M,et al.(2011)Grassland responses to grazing:effects of grazing intensity and management system in an Inner Mongolian steppe ecosystem.Plant Soil 340:103-115.https://doi.org/10.1007/s11104-010-0366-6
Sch?nbach P,Wan H,Gierus M,et al.(2012)Effects of grazing and precipitation on herbage production,herbage nutritive value and performance of sheep in continental steppe.Grass and Forage Science 67:535-545.https://doi.org/10.1111/j.1365-2494.2012.00874.x
Sch?nbach P,Wan H,Schiborra A,et al.(2009)Short-term management and stocking rate effects of grazing sheep on herbage quality and productivity of Inner Mongolia steppe.Crop and Pasture Science 60:963-974.http://dx.doi.org/10.1071/CP09048
Siegel S,Castellan JN(1998)Nonparametric Statistics for the Behavioral Sciences.McGraw-Hill Inc.,New York.p.399.
Stolter C,Ball JP,Julkunen-Tiitto R,et al.(2005)Winter browsing of moose on two different willow species:food selection in relation to plant chemistry and plant response.Canadian Journal of Zoology 83:807-819.https://doi.org/10.1139/z05-077
Su YZ,Li YL,Cui JY,et al.(2005)Influences of continuous grazing and livestock exclusion on soil properties in a degraded sandy grassland,Inner Mongolia,northern China.CATENA 59:267-278.https://doi.org/10.1016/j.catena.2004.09.001
Suttie JM,Reynolds SG,Batello C(2005)Grasslands of the World.FAO,Plant production and protection series.http://www.fao.org/docrep/008/y8344e/y8344e00.htm(Accessed on 6 April 2018)
Suttle NF(2010)Mineral Nutrition of Livestock,4th:CABI.p 587.
UNESCO,Laboratoire de Cartographie thématique du CERCG(1977)Map of the World Distribution of Arid Regions.Paris:UNESCO,Laboratoire de Cartographie thématique du CERCG.
Van Soest PJ,Robertson JB(1980)Systems of analysis for evaluating fibrous feeds.In:Pigden,WJ,Balch CC,Graham M(eds.),Standartization of analytical methodology for feeds.Proc.Workshop,IDRC,Ottawa,ON,CA.pp 46-60.
Wang C,Wang S,Zhou H,et al.(2011)Influence of grassland degradation on forage availability by sheep in the Inner Mongolian steppes of China.Animal Science Journal 82(4):537-542.https://doi.org/10.1111/j.1740-0929.2011.00878.x
Wang CJ,Wang SP,Zhou H,et al.(2007)Effects of forage composition and growing season on methane emission from sheep in the Inner Mongolia steppe of China.Ecological Research22:41-48.https://doi.org/10.1007/s11284-006-0191-9
Wang G,Zhou G,Yang L,Li Z(2002)Distribution,species diversity and life-form spectra of plant communities along an altitudinal gradient in the northern slopes of Qilianshan Mountains,Gansu,China.Plant Ecology 165:169-181.
Wiener G,Han J,Long R(2003)The Yak.2nd ed.Bangkok,Thailand:Regional Office for Asia and the Pacific,Food and Agriculture Organization of the United Nations.http://www.fao.org/docrep/006/AD347E/ad347e00.htm(Accessed on 6 April 2018)
Wiesmeier M,Kreyling O,Steffens M,et al.(2012)Short-term degradation of semiarid grasslands-results from a controlledgrazing experiment in Northern China.Zeitschrift für Pflanzenern?hrung und Bodenkunde 175:434-442.https://doi.org/10.1002/jpln.201100327
Yan Y,Lu X(2015)Is grazing exclusion effective in restoring vegetation in degraded alpine grasslands in Tibet,China.Peer J 3:e1020.https://doi.org/10.7717/peerj.1020
Yang YH,Fang JY,Pan YD,et al.(2009)Aboveground biomass in Tibetan grasslands.Journal of Arid Environments 73:91-95.https://doi.org/10.1016/j.jaridenv.2008.09.027
Yuan H,Hou F(2015)Grazing intensity and soil depth effects on soil properties in alpine meadow pastures of Qilian Mountain in northwest China.Acta Agriculturae Scandinavica,Section B-Soil&Plant Science 65:222-232.https://doi.org/10.1080/09064710.2014.992940
Zhang Y,Chen X,Cheng Y,et al.(2015)Effects of stocking rates on functional group diversity and forage quality in rangeland of Qilian Mountain,China.Journal of Environmental Biology36:713-719.
Zhao CY,Peng SZ,Feng ZD(2011)Spatial modelling of the variability of the soil moisture regime at the landscape scale in the Southern Qilian Mountains,China.Hydrology&Earth System Sciences Discussions 6(5):6335-6358.https://doi.org/10.4172/2157-7625.1000102
Zhao H,Zhao X,Zhou R,et al.(2005)Desertification processes due to heavy grazing in sandy rangeland,Inner Mongolia.Journal of Arid Environments 62:309-319.https://doi.org/10.1016/j.jaridenv.2004.11.009
Zhou H,Tang Y,Zhao X,et al.(2006)Long-term grazing alters species composition and biomass of a shrub meadow on the Qinghai-Tibet Plateau.Pakistan Journal of Botany 38(4):1055-1069.
Baranova,A,Schickhoff,U,Wang,S,et al.(2016)Mountain pastures of Qilian Shan:plant communities,grazing impact and degradation status(Gansu province,NW China).Hacquetia 15(2):21-35.https://doi.org/10.1515/hacq-2016-0014
Chang X,Zhao W,Zhao A(2004)Species diversity of pasture community at different altitude levels in Qilian Mountains.Chinese Journal of Applied Ecology 15:1599-1603.
Deng S,Yang T,Zeng B,et al.(2013)Vegetation cover variation in the Qilian Mountains and its response to climate change in2000-2011.Journal of Mountain Science 10:1050-1062.https://doi.org/10.1007/s11629-013-2558-z
D?nnem I,Randby?,Ekn?s M(2011)Effect of grass silage growing stage and level of concentrate supplementation on goat milk quality.Animal Feed Science and Technology 163:118-129.https://doi.org/10.1016/j.anifeedsci.2010.10.013
Gamoun M(2014)Grazing intensity effects on the vegetation in desert rangelands of Southern Tunisia.Journal of Arid Land 6:324-333.https://doi.org/10.1007/s40333-013-0202-y
Giraudoux P(2015)Pgirmess:Data Analysis in Ecology.Miscellaneous functions for data analysis in ecology,with special emphasis on spatial data.https://cran.rproject.org/web/packages/pgirmess/index.html(accessed on18 December 2015)
Guo XS,Ding LM,Long RJ,et al.(2012)Changes of chemical composition to high altitude results in Kobresia littledalei growing in alpine meadows with high feeding values for herbivores.Animal Feed Science and Technology 173:186-193.https://doi.org/10.1016/j.anifeedsci.2012.01.011
Horrocks RD,Vallentine JF(1999)Harvested forages.San Diego:Academic Press,p426
Hu G,Liu H,Yin Y,Song Z(2015)The Role of Legumes in Plant Community Succession of Degraded Grasslands in Northern China.Land Degradation&Development 27:366-372.https://doi.org/10.1002/ldr.2382
Islam M,Razzaq A,Shamim G,et al.(2018)Impact of grazing on soil,vegetation and ewe production performances in a semi-arid rangeland.Journal of Mountain Science 15(4):685-694.https://doi.org/10.1007/s11629-017-4702-7
Knowles SO,Grace ND(2014)A recent assessment of the elemental composition of New Zealand pastures in relation to meeting the dietary requirements of grazing livestock.Journal of Animal Science 92:303-310.https://doi.org/10.2527/jas.2013-6847
Li Y,Squires VR(2009)Case Study 5:Hexi Corridor,Gansu.In:Squires VR,Lu Q,Wang T,Yang Y(Ed).Rangeland Degradation and Recovery in China's Pastoral Lands.Wallingford-Cambridge.pp 151-170.
Linn LG,Martin NP(1991)Forage Quality Tests and Interpretation.The Veterinary clinics of North America.Food animal practice 7:509-523.
Mc Eniry J,O’Kiely P(2013)Anaerobic methane production from five common grassland species at sequential stages of maturity.Bioresource Technology 127:143-150.https://doi.org/10.1016/j.biortech.2012.09.084
Miao F,Guo Z,Xue R,Wang X,Shen Y(2015)Effects of grazing and precipitation on herbage biomass,herbage nutritive value,and yak performance in an alpine meadow on the QinghaiTibetan Plateau.PLoS ONE.https://doi.org/10.1371/journal.pone.0127275
Miller DJ(2005)The Tibetan Steppe.In:Suttie JM,Reynolds SG,Batello C.(eds),Plant Producrion and Protection Series,Vol 34:Grasslands of the world.Rome,Italy:FAO.
Mountousis I,Papanikolaou K,Stanogias G,et al.(2008).Seasonal variation of chemical composition and dry matter digestibility of rangelands in NW Greece.Journal of Central European Agriculture 9(3):547-556.
National Research Council(NRC)(2001)Nutrient Requirements of dairy cattle.7th ed.Washington,DC,USA:National Academies Press,p 408
National Research Council(NRC)(2007)Nutrient Requirements of Small Ruminants:Sheep,Goats,Cervids,and New World Camelids.Washington,DC,USA:National Academies Press.p.384.
Nagy L,Grabherr G(2009)The biology of alpine habitats.Oxford,New York:Oxford University Press.The biology of habitats series.p 376.
Oba G,Vetaas OR,Stenseth NC(2001)Relationships between biomass and plant species richness in arid-zone grazing lands.Journal of Applied Ecology 38:836-845.
Ortmann S,Bradley BJ,Stolter C,et al.(2006)Estimating the quality and composition of wild animal diets-a critical survey of methods.In:Hohmann J,Robbins MM,Boesch C(eds.),Feeding ecology in Apes and other Primates.Ecological,Physical and Behavioral Aspects.Cambridge:Cambridge University Press.pp 395-418.
Pellant M,Shaver P,Pyke DA,et al.(2005)Interpreting indicators of rangeland health,version 4.Technical Reference1734-6.U.S.Department of the Interior,Bureau of Land Management,National Science and Technology Center,Denver,CO.https://jornada.nmsu.edu/files/bibliography/05-010.pdf(Accessed on 2 September 2017)
R Core Team(2015)R:A Language and Environment for Statistical Computing.Vienna,Austria:Foundation for Statistical Computing.https://www.R-project.org/(Accessed on 9 September 2015)
Ren H,Han G,Sch?nbach P,et al.(2016)Forage nutritional characteristics and yield dynamics in a grazed semiarid steppe ecosystem of Inner Mongolia,China.Ecological Indicators 60:460-469.https://doi.org/10.1016/j.ecolind.2015.07.027
Sasaki T,Ohkuro T,Jamsran U,Takeuchi K(2012)Changes in the herbage nutritive value and yield associated with threshold responses of vegetation to grazing in Mongolian rangelands.Grass and Forage Science 67:446-455.https://doi.org/10.1111/j.1365-2494.2012.00862.x
Sch?nbach P,Wan H,Gierus M,et al.(2011)Grassland responses to grazing:effects of grazing intensity and management system in an Inner Mongolian steppe ecosystem.Plant Soil 340:103-115.https://doi.org/10.1007/s11104-010-0366-6
Sch?nbach P,Wan H,Gierus M,et al.(2012)Effects of grazing and precipitation on herbage production,herbage nutritive value and performance of sheep in continental steppe.Grass and Forage Science 67:535-545.https://doi.org/10.1111/j.1365-2494.2012.00874.x
Sch?nbach P,Wan H,Schiborra A,et al.(2009)Short-term management and stocking rate effects of grazing sheep on herbage quality and productivity of Inner Mongolia steppe.Crop and Pasture Science 60:963-974.http://dx.doi.org/10.1071/CP09048
Siegel S,Castellan JN(1998)Nonparametric Statistics for the Behavioral Sciences.McGraw-Hill Inc.,New York.p.399.
Stolter C,Ball JP,Julkunen-Tiitto R,et al.(2005)Winter browsing of moose on two different willow species:food selection in relation to plant chemistry and plant response.Canadian Journal of Zoology 83:807-819.https://doi.org/10.1139/z05-077
Su YZ,Li YL,Cui JY,et al.(2005)Influences of continuous grazing and livestock exclusion on soil properties in a degraded sandy grassland,Inner Mongolia,northern China.CATENA 59:267-278.https://doi.org/10.1016/j.catena.2004.09.001
Suttie JM,Reynolds SG,Batello C(2005)Grasslands of the World.FAO,Plant production and protection series.http://www.fao.org/docrep/008/y8344e/y8344e00.htm(Accessed on 6 April 2018)
Suttle NF(2010)Mineral Nutrition of Livestock,4th:CABI.p 587.
UNESCO,Laboratoire de Cartographie thématique du CERCG(1977)Map of the World Distribution of Arid Regions.Paris:UNESCO,Laboratoire de Cartographie thématique du CERCG.
Van Soest PJ,Robertson JB(1980)Systems of analysis for evaluating fibrous feeds.In:Pigden,WJ,Balch CC,Graham M(eds.),Standartization of analytical methodology for feeds.Proc.Workshop,IDRC,Ottawa,ON,CA.pp 46-60.
Wang C,Wang S,Zhou H,et al.(2011)Influence of grassland degradation on forage availability by sheep in the Inner Mongolian steppes of China.Animal Science Journal 82(4):537-542.https://doi.org/10.1111/j.1740-0929.2011.00878.x
Wang CJ,Wang SP,Zhou H,et al.(2007)Effects of forage composition and growing season on methane emission from sheep in the Inner Mongolia steppe of China.Ecological Research22:41-48.https://doi.org/10.1007/s11284-006-0191-9
Wang G,Zhou G,Yang L,Li Z(2002)Distribution,species diversity and life-form spectra of plant communities along an altitudinal gradient in the northern slopes of Qilianshan Mountains,Gansu,China.Plant Ecology 165:169-181.
Wiener G,Han J,Long R(2003)The Yak.2nd ed.Bangkok,Thailand:Regional Office for Asia and the Pacific,Food and Agriculture Organization of the United Nations.http://www.fao.org/docrep/006/AD347E/ad347e00.htm(Accessed on 6 April 2018)
Wiesmeier M,Kreyling O,Steffens M,et al.(2012)Short-term degradation of semiarid grasslands-results from a controlledgrazing experiment in Northern China.Zeitschrift für Pflanzenern?hrung und Bodenkunde 175:434-442.https://doi.org/10.1002/jpln.201100327
Yan Y,Lu X(2015)Is grazing exclusion effective in restoring vegetation in degraded alpine grasslands in Tibet,China.Peer J 3:e1020.https://doi.org/10.7717/peerj.1020
Yang YH,Fang JY,Pan YD,et al.(2009)Aboveground biomass in Tibetan grasslands.Journal of Arid Environments 73:91-95.https://doi.org/10.1016/j.jaridenv.2008.09.027
Yuan H,Hou F(2015)Grazing intensity and soil depth effects on soil properties in alpine meadow pastures of Qilian Mountain in northwest China.Acta Agriculturae Scandinavica,Section B-Soil&Plant Science 65:222-232.https://doi.org/10.1080/09064710.2014.992940
Zhang Y,Chen X,Cheng Y,et al.(2015)Effects of stocking rates on functional group diversity and forage quality in rangeland of Qilian Mountain,China.Journal of Environmental Biology36:713-719.
Zhao CY,Peng SZ,Feng ZD(2011)Spatial modelling of the variability of the soil moisture regime at the landscape scale in the Southern Qilian Mountains,China.Hydrology&Earth System Sciences Discussions 6(5):6335-6358.https://doi.org/10.4172/2157-7625.1000102
Zhao H,Zhao X,Zhou R,et al.(2005)Desertification processes due to heavy grazing in sandy rangeland,Inner Mongolia.Journal of Arid Environments 62:309-319.https://doi.org/10.1016/j.jaridenv.2004.11.009
Zhou H,Tang Y,Zhao X,et al.(2006)Long-term grazing alters species composition and biomass of a shrub meadow on the Qinghai-Tibet Plateau.Pakistan Journal of Botany 38(4):1055-1069.