适度放牧增加内蒙古典型草原甲烷氧化菌丰度和甲烷吸收
|
摘要
微生物氧化是大气甲烷唯一的生物汇.认识草原甲烷(CH_4)通量对不同利用方式的响应是制定低碳高效草原管理体系的基础.本研究通过测定内蒙古中部典型草原在放牧、割草和围封管理下生态系统的CH_4通量和土壤甲烷氧化菌丰度,旨在确定不同利用方式对内蒙古典型草原生态系统CH_4吸收的影响,验证甲烷氧化菌功能基因(pmoA)丰度调控CH_4通量.测定草原是连续5年实施4种不同利用处理的试验草原,4个处理为全植物生长季(5—9月)放牧(T_1)、春夏5月和7月放牧(T_2)、秋季割草(T_3)和围封禁牧(T_0).在测定植物生物量和土壤理化特征的基础上,采用静态箱置法测定草原植物生长季CH_4通量,采用分子技术测定草原表层土壤甲烷氧化菌pmoA功能基因的丰度.结果表明:放牧显著促进CH_4吸收,增加甲烷氧化菌丰度(即每克干土pmoA功能基因拷贝数),其在生长季的变化范围是6.9×10~4～3.9×10~5.T_1处理下植物生长季的CH_4平均吸收量为(68.21±3.01)μg·m~(-2)·h~(-1),显著高于T_2、T_3和T_0处理22.1%、37.5%和30.9%.草原CH_4吸收与甲烷氧化菌丰度呈极显著正相关,与土壤砂粒占比呈显著正相关,而与土壤粉粒占比、土壤水分含量、土壤铵态氮和硝态氮含量,以及植物地上生物量呈显著负相关.表明不同利用方式下内蒙古典型草原都是CH_4的汇,而适度放牧可增加草原土壤砂粒占比,降低土壤无机氮含量和植被生物量,提高土壤甲烷氧化菌丰度和CH_4吸收.本结果对制定低排放草原管理体系具有重要意义.
Microbial oxidation is the only biological sink of atmospheric methane(CH_4). It is essential to understand the variation of CH_4 fluxes among different grassland use types for developing low-emission management system. Here, we measured the CH_4 flux and the soil methane-oxidizing bacteria abundance in a typical steppe under grazing, mowing and fencing management in central Inner Mongolia, with the aims to determine the effects of these grassland use types on CH_4 flux, and to test the hypothesis that pmoA functional gene abundance regulates CH_4 fluxes. The measurements were conducted on the experimental grassland that had experienced four grassland use treatments over five years. The treatments were whole growing season grazing from May to September(T_1), spring and summer grazing(twice in May and July)(T_2), autumn mowing(T_3) and enclosure(T_0). We measured CH_4 flux using static chamber method, and quantified the abundance of pmoA functional genes using molecular techniques. Moreover, we measured plant biomass and soil physicochemical properties. The results showed that moderate grazing significantly enhanced CH_(4 )uptake rate and the methane-oxidizing bacteria abundance(i.e., the pmoA gene copy number per gram of dry soil). The pmoA gene copy number ranged from 6.9×10~4 to 3.9×10~5 per gram of dry soil in growing season. The CH_4 uptake rate was(68.21±3.01) μg·m~(-2)·h~(-1) under T_1, which was 22.1%, 37.5% and 30.9% higher than that under T_2, T_3 or T_0, respectively. The CH_4 uptake rate was positively correlated with abundance of CH_4 oxidizing bacteria and soil sand content, but negatively correlated with soil silt content, soil moisture, NH_4~+-N and NO_3~--N content, and plant biomass. These results suggested that the steppe ecosystem is a CH_4 sink under all land-use types in central Inner Mongolia, and that moderate grazing would enhance methane-oxidizing bacteria abundance and CH_(4 )uptake by improving soil sand content, reducing soil mineral nitrogen content and plant production in the typical steppe ecosystem. These results were of significance for the development of low-emission grassland management system.
Microbial oxidation is the only biological sink of atmospheric methane(CH_4). It is essential to understand the variation of CH_4 fluxes among different grassland use types for developing low-emission management system. Here, we measured the CH_4 flux and the soil methane-oxidizing bacteria abundance in a typical steppe under grazing, mowing and fencing management in central Inner Mongolia, with the aims to determine the effects of these grassland use types on CH_4 flux, and to test the hypothesis that pmoA functional gene abundance regulates CH_4 fluxes. The measurements were conducted on the experimental grassland that had experienced four grassland use treatments over five years. The treatments were whole growing season grazing from May to September(T_1), spring and summer grazing(twice in May and July)(T_2), autumn mowing(T_3) and enclosure(T_0). We measured CH_4 flux using static chamber method, and quantified the abundance of pmoA functional genes using molecular techniques. Moreover, we measured plant biomass and soil physicochemical properties. The results showed that moderate grazing significantly enhanced CH_(4 )uptake rate and the methane-oxidizing bacteria abundance(i.e., the pmoA gene copy number per gram of dry soil). The pmoA gene copy number ranged from 6.9×10~4 to 3.9×10~5 per gram of dry soil in growing season. The CH_4 uptake rate was(68.21±3.01) μg·m~(-2)·h~(-1) under T_1, which was 22.1%, 37.5% and 30.9% higher than that under T_2, T_3 or T_0, respectively. The CH_4 uptake rate was positively correlated with abundance of CH_4 oxidizing bacteria and soil sand content, but negatively correlated with soil silt content, soil moisture, NH_4~+-N and NO_3~--N content, and plant biomass. These results suggested that the steppe ecosystem is a CH_4 sink under all land-use types in central Inner Mongolia, and that moderate grazing would enhance methane-oxidizing bacteria abundance and CH_(4 )uptake by improving soil sand content, reducing soil mineral nitrogen content and plant production in the typical steppe ecosystem. These results were of significance for the development of low-emission grassland management system.
引文
[1] IPCC.Climate Change 2013:The Physical Science Basis.Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.Cambridge:Cambridge University Press,2014
[2] Lowe DC.Global change:A green source of surprise.Nature,2006,439:148-149
[3] Laure D,Verchot LV.A global inventory of the soil CH4 sink.Global Biogeochemical Cycles,2007,21:GB4013
[4] IPCC.Climate Change 2007:The Physical Science Basis.Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change.Cambridge:Cambridge University Press,2007
[5] Han D-X (韩冬雪),Wang N (王宁),Wang N-N (王楠楠),et al.Soil microbial functional diversity of different altitude Pinus koraiensis forests.Chinese Journal of Applied Ecology (应用生态学报),2015,26(12):3649-3656 (in Chinese)
[6] Wu Z-Y (吴则焰),Lin W-X (林文雄),Chen Z-F (陈志芳),et al.Characteristics of soil microbial community under different vegetation types in Wuyishan National Nature Reserve,East China.Chinese Journal of Applied Ecology (应用生态学报),2013,24(8):2301-2309 (in Chinese)
[7] Duxbury JM.The significance of agricultural sources of greenhouse gases.Fertilizer Research,1994,38:151-163
[8] Xu X,Inubushi K.Effects of N sources and methane concentrations on methane uptake potential of a typical coniferous forest and its adjacent orchard soil.Biology & Fertility of Soils,2004,40:215-221
[9] Wang Y,Xue M,Zheng X,et al.Effects of environmental factors on N2O emission from and CH4 uptake by the typical grasslands in the Inner Mongolia.Chemosphere,2005,58:205-215
[10] Jang I,Lee S,Hong JH,et al.Methane oxidation rates in forest soils and their controlling variables:A review and a case study in Korea.Ecological Research,2006,21:849-854
[11] Surinder S,Bolan NS,Bhandral R,et al.A review of emissions of methane,ammonia,and nitrous oxide from animal excreta deposition and farm effluent application in grazed pastures.New Zealand Journal of Agricultural Research,2004,47:513-544
[12] Zhong L,Zhou X,Wang Y,et al.Mixed grazing and clipping is beneficial to ecosystem recovery but may increase potential N2O emissions in a semi-arid grassland.Soil Biology & Biochemistry,2017,114:42-51
[13] Cao S-B (曹淑宝),Wang L-Q (王立群).Research progress on effects of grazing on microorganisms in grassland soil.Chinese Agricultural Science Bulletin (中国农学通报),2011,27(29):271-275 (in Chinese)
[14] Foster BL,Kindscher K,Houseman GR,et al.Effects of hay management and native species sowing on grassland community structure,biomass,and restoration.Ecological Applications,2009,19:1884-1896
[15] Ma T,Chen H,Wang Y,et al.Effects of enclosure time on the community composition of methanotrophs in the soils of the Inner Mongolia grasslands.Journal of Soils & Sediments,2016,16:1022-1031
[16] Tang S,Wang C,Wilkes A,et al.Contribution of gra-zing to soil atmosphere CH4 exchange during the growing season in a continental steppe.Atmospheric Environment,2013,67:170-176
[17] Liu J,Chen H,Yang X,et al.Annual methane uptake from different land uses in an agro-pastoral ecotone of northern China.Agricultural & Forest Meteorology,2017,236:67-77
[18] Wang X,Zhang Y,Huang D,et al.Methane uptake and emissions in a typical steppe grazing system during the grazing season.Atmospheric Environment,2015,105:14-21
[19] Cai Y,Yan Z,Bodelier PLE,et al.Conventional metha-notrophs are responsible for atmospheric methane oxidation in paddy soils.Nature Communications,2016,7:11728,doi:10.1038/ncomms11728
[20] Chen W,Wolf B,Zheng X,et al.Annual methane uptake by temperate semiarid steppes as regulated by stocking rates,aboveground plant biomass and topsoil air permeability.Global Change Biology,2011,17:2803-2816
[21] Zhu X,Luo C,Wang S,et al.Effects of warming,gra-zing/cutting and nitrogen fertilization on greenhouse gas fluxes during growing seasons in an alpine meadow on the Tibetan Plateau.Agricultural & Forest Meteorology,2015,214/215:506-514
[22] Ding W-X (丁维新),Cai Z-C (蔡祖聪).Effect of temperature on methane production and oxidation in soils.Chinese Journal of Applied Ecology (应用生态学报),2003,14(4):604-608 (in Chinese)
[23] Clegg CD.Impact of cattle grazing and inorganic fertiliser additions to managed grasslands on the microbial community composition of soils.Applied Soil Ecology,2006,31:73-82
[24] Bauer A,Cole CV,Black AL.Soil property comparisons in virgin grasslands between grazed and nongrazed mana-gement systems.Soil Science Society of America Journal,1987,51:176-182
[25] Desjardins T,Andreux F,Volkoff B,et al.Organic carbon and 13C contents in soils and soil size-fractions,and their changes due to deforestation and pasture installation in eastern Amazonia.Geoderma,1994,61:103-118
[26] Pratscher J,Dumont MG,Conrad R.Assimilation of acetate by the putative atmospheric methane oxidizers belonging to the USCα clade.Environmental Microbiology,2011,13:2692-701
[27] Wieczorek AS,Drake HL,Kolb S.Organic acids and ethanol inhibit the oxidation of methane by mire methanotrophs.FEMS Microbiology Ecology,2011,77:28-39
[28] Sullivan BW,Selmants PC,Hart SC.Does dissolved organic carbon regulate biological methane oxidation in semiarid soils?Global Change Biology,2013,19:2149,doi:10.1111/gcb.12201
[29] Wang ZP,Han XG.Diurnal variation in methane emissions in relation to plants and environmental variables in the Inner Mongolia marshes.Atmospheric Environment,2005,39:6295-6305
[30] Boeckx P,Ovan C,Villaralvo I.Methane oxidation in soils with different textures and land use.Nutrient Cycling in Agroecosystems,1997,49:91-95
[31] Saari A,Martikainen PJ,Ferm A,et al.Methane oxidation in soil profiles of Dutch and Finnish coniferous forests with different soil texture and atmospheric nitrogen deposition.Soil Biology & Biochemistry,1998,29:1625-1632
[32] Kou Y,Li J,Wang Y,et al.Scale-dependent key dri-vers controlling methane oxidation potential in Chinese grassland soils.Soil Biology & Biochemistry,2017,111:104-114
[33] Shi X-H (史小红),Fan C-R (樊才睿),Li C-Y (李畅游),et al.Soil hydrological characteristics of diffe-rent grazing system grassland in Hulun-Beier.Journal of Soil and Water Conservation (水土保持学报),2015,29(2):145-149 (in Chinese)
[34] Bodelier PL,Laanbroek HJ.Nitrogen as a regulatory factor of methane oxidation in soils and sediments.FEMS Microbiology Ecology,2004,47:265-277
[35] Reay DS,Nedwell DB.Methane oxidation in temperate soils:Effects of inorganic N.Soil Biology & Biochemistry,2004,36:2059-2065
[36] Wang Z P and Ineson P.Methane oxidation in a tempe-rate coniferous forest soil:Effects of inorganic N.Soil Biology & Biochemistry,2003,35:427-433
[37] Xu XK,Inubushi K.Effects of nitrogen sources and glucose on the consumption of ethylene and methane by temperate volcanic forest surface soils.Chinese Science Bulletin,2007,52:3281-3291
[38] Niu C,He Z,Ge Y,et al.Effect of plant species richness on methane fluxes and associated microbial processes in wetland microcosms.Ecological Engineering,2015,84:250-259
[2] Lowe DC.Global change:A green source of surprise.Nature,2006,439:148-149
[3] Laure D,Verchot LV.A global inventory of the soil CH4 sink.Global Biogeochemical Cycles,2007,21:GB4013
[4] IPCC.Climate Change 2007:The Physical Science Basis.Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change.Cambridge:Cambridge University Press,2007
[5] Han D-X (韩冬雪),Wang N (王宁),Wang N-N (王楠楠),et al.Soil microbial functional diversity of different altitude Pinus koraiensis forests.Chinese Journal of Applied Ecology (应用生态学报),2015,26(12):3649-3656 (in Chinese)
[6] Wu Z-Y (吴则焰),Lin W-X (林文雄),Chen Z-F (陈志芳),et al.Characteristics of soil microbial community under different vegetation types in Wuyishan National Nature Reserve,East China.Chinese Journal of Applied Ecology (应用生态学报),2013,24(8):2301-2309 (in Chinese)
[7] Duxbury JM.The significance of agricultural sources of greenhouse gases.Fertilizer Research,1994,38:151-163
[8] Xu X,Inubushi K.Effects of N sources and methane concentrations on methane uptake potential of a typical coniferous forest and its adjacent orchard soil.Biology & Fertility of Soils,2004,40:215-221
[9] Wang Y,Xue M,Zheng X,et al.Effects of environmental factors on N2O emission from and CH4 uptake by the typical grasslands in the Inner Mongolia.Chemosphere,2005,58:205-215
[10] Jang I,Lee S,Hong JH,et al.Methane oxidation rates in forest soils and their controlling variables:A review and a case study in Korea.Ecological Research,2006,21:849-854
[11] Surinder S,Bolan NS,Bhandral R,et al.A review of emissions of methane,ammonia,and nitrous oxide from animal excreta deposition and farm effluent application in grazed pastures.New Zealand Journal of Agricultural Research,2004,47:513-544
[12] Zhong L,Zhou X,Wang Y,et al.Mixed grazing and clipping is beneficial to ecosystem recovery but may increase potential N2O emissions in a semi-arid grassland.Soil Biology & Biochemistry,2017,114:42-51
[13] Cao S-B (曹淑宝),Wang L-Q (王立群).Research progress on effects of grazing on microorganisms in grassland soil.Chinese Agricultural Science Bulletin (中国农学通报),2011,27(29):271-275 (in Chinese)
[14] Foster BL,Kindscher K,Houseman GR,et al.Effects of hay management and native species sowing on grassland community structure,biomass,and restoration.Ecological Applications,2009,19:1884-1896
[15] Ma T,Chen H,Wang Y,et al.Effects of enclosure time on the community composition of methanotrophs in the soils of the Inner Mongolia grasslands.Journal of Soils & Sediments,2016,16:1022-1031
[16] Tang S,Wang C,Wilkes A,et al.Contribution of gra-zing to soil atmosphere CH4 exchange during the growing season in a continental steppe.Atmospheric Environment,2013,67:170-176
[17] Liu J,Chen H,Yang X,et al.Annual methane uptake from different land uses in an agro-pastoral ecotone of northern China.Agricultural & Forest Meteorology,2017,236:67-77
[18] Wang X,Zhang Y,Huang D,et al.Methane uptake and emissions in a typical steppe grazing system during the grazing season.Atmospheric Environment,2015,105:14-21
[19] Cai Y,Yan Z,Bodelier PLE,et al.Conventional metha-notrophs are responsible for atmospheric methane oxidation in paddy soils.Nature Communications,2016,7:11728,doi:10.1038/ncomms11728
[20] Chen W,Wolf B,Zheng X,et al.Annual methane uptake by temperate semiarid steppes as regulated by stocking rates,aboveground plant biomass and topsoil air permeability.Global Change Biology,2011,17:2803-2816
[21] Zhu X,Luo C,Wang S,et al.Effects of warming,gra-zing/cutting and nitrogen fertilization on greenhouse gas fluxes during growing seasons in an alpine meadow on the Tibetan Plateau.Agricultural & Forest Meteorology,2015,214/215:506-514
[22] Ding W-X (丁维新),Cai Z-C (蔡祖聪).Effect of temperature on methane production and oxidation in soils.Chinese Journal of Applied Ecology (应用生态学报),2003,14(4):604-608 (in Chinese)
[23] Clegg CD.Impact of cattle grazing and inorganic fertiliser additions to managed grasslands on the microbial community composition of soils.Applied Soil Ecology,2006,31:73-82
[24] Bauer A,Cole CV,Black AL.Soil property comparisons in virgin grasslands between grazed and nongrazed mana-gement systems.Soil Science Society of America Journal,1987,51:176-182
[25] Desjardins T,Andreux F,Volkoff B,et al.Organic carbon and 13C contents in soils and soil size-fractions,and their changes due to deforestation and pasture installation in eastern Amazonia.Geoderma,1994,61:103-118
[26] Pratscher J,Dumont MG,Conrad R.Assimilation of acetate by the putative atmospheric methane oxidizers belonging to the USCα clade.Environmental Microbiology,2011,13:2692-701
[27] Wieczorek AS,Drake HL,Kolb S.Organic acids and ethanol inhibit the oxidation of methane by mire methanotrophs.FEMS Microbiology Ecology,2011,77:28-39
[28] Sullivan BW,Selmants PC,Hart SC.Does dissolved organic carbon regulate biological methane oxidation in semiarid soils?Global Change Biology,2013,19:2149,doi:10.1111/gcb.12201
[29] Wang ZP,Han XG.Diurnal variation in methane emissions in relation to plants and environmental variables in the Inner Mongolia marshes.Atmospheric Environment,2005,39:6295-6305
[30] Boeckx P,Ovan C,Villaralvo I.Methane oxidation in soils with different textures and land use.Nutrient Cycling in Agroecosystems,1997,49:91-95
[31] Saari A,Martikainen PJ,Ferm A,et al.Methane oxidation in soil profiles of Dutch and Finnish coniferous forests with different soil texture and atmospheric nitrogen deposition.Soil Biology & Biochemistry,1998,29:1625-1632
[32] Kou Y,Li J,Wang Y,et al.Scale-dependent key dri-vers controlling methane oxidation potential in Chinese grassland soils.Soil Biology & Biochemistry,2017,111:104-114
[33] Shi X-H (史小红),Fan C-R (樊才睿),Li C-Y (李畅游),et al.Soil hydrological characteristics of diffe-rent grazing system grassland in Hulun-Beier.Journal of Soil and Water Conservation (水土保持学报),2015,29(2):145-149 (in Chinese)
[34] Bodelier PL,Laanbroek HJ.Nitrogen as a regulatory factor of methane oxidation in soils and sediments.FEMS Microbiology Ecology,2004,47:265-277
[35] Reay DS,Nedwell DB.Methane oxidation in temperate soils:Effects of inorganic N.Soil Biology & Biochemistry,2004,36:2059-2065
[36] Wang Z P and Ineson P.Methane oxidation in a tempe-rate coniferous forest soil:Effects of inorganic N.Soil Biology & Biochemistry,2003,35:427-433
[37] Xu XK,Inubushi K.Effects of nitrogen sources and glucose on the consumption of ethylene and methane by temperate volcanic forest surface soils.Chinese Science Bulletin,2007,52:3281-3291
[38] Niu C,He Z,Ge Y,et al.Effect of plant species richness on methane fluxes and associated microbial processes in wetland microcosms.Ecological Engineering,2015,84:250-259
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |