Carbon balance of yak ranch in alpine meadow

Abstract

Livestock husbandry is a primary anthropogenic source of global greenhouse gas (GHG) emissions. The Qinghai-Tibetan Plateau (QTP), an important geography for animal husbandry in China, and is therefore a significant contributor to the global GHG budget. Therefore, this study employs the life cycle assessment method to comprehensively assess the effect of yak grazing on GHG balance and enhance our understanding and monitoring of GHG budgeting in the alpine ecosystem. The results show that yak grazing alters the GHG balance of alpine meadow ecosystems from sink to source (Critical value = 1.3 yak/ha). Sequestration of CO₂ in soil organic matter is the most significant contributor to the GHG balance in both grazed and ungrazed grassland. In grazed grassland, enteric fermentation and livestock manure and its management (dung and urine patches, manure heaps, night pens, and dry stored manure combustion) are important contributors to the total GHG balance, where implementing mitigation practices that target reductions of enteric fermentation and improve manure management can help to alleviate these emissions. Due to the unique geographical and biophysical environment of the QTP, solar and wind energy are viable emission-free alternatives to dry manure consumption, and livestock enclosure has the potential to restore soil organic carbon stocks by increasing sequestration of atmospheric CO₂. In conclusion, our findings suggest that successful implementation of targeted emission reduction measures is conducive to the sustainable development of animal husbandry, while also maintaining a balance with ecosystem functions under the multifaceted ecological landscape of QTP.

Keywords

Greenhouse gas / global warming potential / life cycle assessment / yak grazing farm / Qinghai-Tibet Plateau

References

[1] He D,Wang X.Livestock greenhouse gas emission and mitigation potential in China.J Environ Manag2023;348:119494

[2] Wei C,Xu W,Qu Y.Temporal and spatial dynamics of carbon emissions in animal husbandry and their influencing factors: a case study of three provinces in Northeast China.J Clean Prod2025;508:145418

[3] Li L,Shi Y,Kaiser M.Global greenhouse gas emissions from agriculture: pathways to sustainable reductions.Glob Chang Biol2025;31:e70015 PMCID:PMC11683860

[4] He D,Gao Y.How does digitalization affect carbon emissions in animal husbandry? A new evidence from China.Resour Conserv Recy2025;214:108040

[5] Soussana J,Pilegaard K.Full accounting of the greenhouse gas (CO₂, N₂O, CH₄) budget of nine European grassland sites.Agr Ecosyst Environ2007;121:121-34

[6] Wan L,Su X.Global meta-analysis reveals different grazing management strategies change greenhouse gas emissions and global warming potential in grasslands.Geogr Sustain2025;6:100251

[7] Imer D,Eugster W.Temporal and spatial variations of soil CO₂, CH₄ and N₂O fluxes at three differently managed grasslands.Biogeosciences2013;10:5931-45

[8] You C,Tan X.Inner Mongolia grasslands act as a weak regional carbon sink: a new estimation based on upscaling eddy covariance observations.Agr Forest Meteorol2023;342:109719

[9] Dong S.Revitalizing the grassland on the Qinghai-Tibetan Plateau.Grassland Res2023;2:241-50

[10] Wang L,Zhang J,Ouyang Z.Spatiotemporal patterns and alleviating of grassland overgrazing under current and future conditions in Qinghai-Tibet Plateau.J Environ Manag2025;376:124456

[11] Li S,Wang W.Dietary habits of pastoralists on the Tibetan plateau are influenced by remoteness and economic status.Food Res Int2023;174:113627

[12] Wang T,Wei J.The Tibetan Plateau acts as a net greenhouse gas sink.Sci Bull2025;70:2147-56

[13] Li W,Lin Q.Identification of ecological security pattern in the Qinghai-Tibet Plateau.Ecol Indic2025;170:113057

[14] Dong S,Li S,Yang M.Restoration actions associated with payment for ecosystem services promote the economic returns of alpine grasslands in China.J Clean Prod2024;458:142439

[15] Chen H,Zhu Q.Carbon and nitrogen cycling on the Qinghai-Tibetan Plateau.Nat Rev Earth Environ2022;3:701-16

[16] Wang Y,Xue K.Grassland changes and adaptive management on the Qinghai-Tibetan Plateau.Nat Rev Earth Environ2022;3:668-83

[17] Xu X,Guo J.Inequality in agricultural greenhouse gas emissions intensity has risen in rural China from 1993 to 2020.Nat Food2024;5:916-28

[18] Mayer R.Long-term effects of grazing on subalpine and alpine grasslands in the Central Alps, Austria.Basic Appl Ecol2017;24:9-18

[19] Wilson KM,Brewer SC.Climate and demography drive 7000 years of dietary change in the Central Andes.Sci Rep2022;12:2026 PMCID:PMC8821598

[20] Bai Y,Li S.Instability of decoupling livestock greenhouse gas emissions from economic growth in livestock products in the Tibetan highland.J Environ Manag2021;287:112334

[21] Cai Y,Tian L,Lu X.The impact of excretal returns from yak and Tibetan sheep dung on nitrous oxide emissions in an alpine steppe on the Qinghai-Tibetan Plateau.Soil Biol Biochem2014;76:90-9

[22] Liu Y,Matthew C,Hou F.Key sources and seasonal dynamics of greenhouse gas fluxes from yak grazing systems on the Qinghai-Tibetan Plateau.Sci Rep2017;7:40857 PMCID:PMC5247759

[23] Sun Y,Hou FJ.Effects of grazing systems on herbage mass and liveweight gain of Tibetan sheep in Eastern Qinghai-Tibetan Plateau, China.Rangeland J2015;37:181-90

[24] Yang C,Hou F,Wang Z.Grazing activity increases decomposition of yak dung and litter in an alpine meadow on the Qinghai-Tibet plateau.Plant Soil2019;444:239-50

[25] ISO 14040:2006. Environmental management - Life cycle assessment - Principles and framework. Available from: https://www.iso.org/standard/37456.html#lifecycle [Last accessed on 25 Nov 2025]

[26] Ding X,Kreuzer M,Yang B.Methane emissions from yak (Bos grunniens) steers grazing or kept indoors and fed diets with varying forage:concentrate ratio during the cold season on the Qinghai-Tibetan Plateau.Anim Feed Sci Technol2010;162:91-8

[27] Eggleston H,Miwa K. 2006 IPCC guidelines for national greenhouse gas inventories. Available from: https://www.ipcc-nggip.iges.or.jp/public/2006gl/ [Last accessed on 25 Nov 2025]

[28] Schönbach P,Dickhöfer U.Grazing effects on the greenhouse gas balance of a temperate steppe ecosystem.Nutr Cycl Agroecosyst2012;93:357-71

[29] Xue B,Zhang Y.Feed intake dynamic of grazing livestock in nature grassland in Qinghai-Tibetan Plateau (In Chinese).Ecol Domest Anim2004;25:21-5Available from: https://kns.cnki.net/kcms2/article/abstract?v=LYi8dJWcB0US51TTv_C0U4AAqF2FuFOkoAXGRTl7404KJ1Qoy52Bdlh9WbwYV0z1p4flRkQcJ6l8iCRzTVKJ272OVCIy7ZXRiBkgy1Gkt07Mv5FB8Mpm73JKDQv6y5O9sSEcPvCqRKgX-H9g6QA0EDr-I0fkdDYXr5Q5MMUmnuoiSI673IL6IA==&uniplatform=NZKPT&language=CHS [Last accessed on 25 Nov 2025]

[30] Lin X,Ma X.Fluxes of CO₂, CH₄, and N₂O in an alpine meadow affected by yak excreta on the Qinghai-Tibetan plateau during summer grazing periods.Soil Biol Biochem2009;41:718-25

[31] Wang S.The influence of diffeent stocking rates and grazing periods on the amount of feces and its relationship to DM intake and digestibility of grazing sheep.Acta Zoonutrimenta Sin1997;9:47-54Available from: https://kns.cnki.net/kcms2/article/abstract?v=LYi8dJWcB0UPd7L8kJKrdcsbssXk5pZr-ZHMMYqw4yxP6J-ES5t3Bzolan81VvPQ33lADw3uLJ5D8ns2ZUhZnURSYBEOzbJzXP4zDWjI9ebDiKr4qN1wpwddgsXQCpgQoGzJvfcA_wINxul8XUCXmZmiBF01kSIxB7yJIUKOuvli-ls19ttOtg==&uniplatform=NZKPT&language=CHS [Last accessed on 27 Nov 2025]

[32] Yan L.Contributions of ruminants and their excreta to N₂O and CH₄ emissions.CJE2011;30:2604-12

[33] Artaxo P,Betts R. Changes in atmospheric constituents and in radiative forcing. 2007. Available from: https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg1-chapter2-1.pdf [Last accessed on 25 Nov 2025]

[34] Yelery A.The national development reform commission’s report at the 4th session of 12th national people’s congress: a review.Sage J2016;52:228-34

[35] Piñeiro G,Oesterheld M.Pathways of grazing effects on soil organic carbon and nitrogen.Rangeland Ecol Manag2010;63:109-19

[36] Cui X,Yan T,Hou F.Modulation of feed digestibility, nitrogen metabolism, energy utilisation and serum biochemical indices by dietary Ligularia virgaurea supplementation in Tibetan sheep.Animal2023;17:100910

[37] Reay MK,Powell S.The soil microbial community and plant biomass differentially contribute to the retention and recycling of urinary-N in grasslands.Soil Biol Biochem2023;180:109011

[38] Zhou X,Huang X,Hao Y.Effect of grazing intensities on the activity and community structure of methane-oxidizing bacteria of grassland soil in Inner Mongolia.Nutr Cycl Agroecosyst2008;80:145-52

[39] Ren S,Ji X.Grazing reverses climate-induced soil carbon gains on the Tibetan Plateau.Nat Commun2025;16:6978 PMCID:PMC12307948

[40] Kato T,Tang Y.Strong temperature dependence and no moss photosynthesis in winter CO₂ flux for a Kobresia meadow on the Qinghai-Tibetan plateau.Soil Biol Biochem2005;37:1966-9

[41] Cai Y,Ding W,Zhao H.Potential short-term effects of yak and Tibetan sheep dung on greenhouse gas emissions in two alpine grassland soils under laboratory conditions.Biol Fertil Soils2013;49:1215-26

[42] Wang X,Zhang Y,Chen P.Black carbon: a general review of its sources, analytical methods, and environmental effects in snow and ice in the Tibetan Plateau.Environ Sci Pollut Res Int2024;31:3413-24

[43] Cao G,Mo W,Li Y.Grazing intensity alters soil respiration in an alpine meadow on the Tibetan plateau.Soil Biol Biochem2004;36:237-43

[44] Nyamuryekung’e S.Transforming ranching: precision livestock management in the internet of things era.Rangelands2024;46:13-22

[45] Arango J,Costa C Jr. Scaling up Hacienda San Jose sustainable ranch model and securing private sector finance. Montpellier: CGIAR System Organization. 2024. Available from: https://www.sidalc.net/search/Record/dig-cgspace-10568-173196/Description [Last accessed on 25 Nov 2025]

[46] Gill M,Wilkinson JM.Mitigating climate change: the role of domestic livestock.Animal2010;4:323-33

[47] Dayoub M,Tarawneh R,Al-Barakeh F.Enhancing animal production through smart agriculture: possibilities, hurdles, resolutions, and advantages.Ruminants2024;4:22-46

[48] Zhang Y,Gao M.Digital twin perception and modeling method for feeding behavior of dairy cows.Comput Electron Agr2023;214:108181