采伐对小兴安岭森林沼泽非生长季土壤温室气体排放的影响
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摘要
中高纬度地区非生长季温室气体排放对生态系统碳、氮循环具有重要影响,但采伐干扰如何影响森林沼泽非生长季土壤温室气体排放尚不明确.本研究采用静态箱-气相色谱法,观测小兴安岭4种森林沼泽(毛赤杨沼泽、白桦沼泽、落叶松苔草沼泽、落叶松藓类沼泽)不同采伐方式下(对照、择伐45%、皆伐,试验处理已10年)非生长季土壤CO_2、CH_4、和N_2O通量及其相关环境因子(温度、湿度及碳氮含量等),分析采伐干扰对温带森林沼泽非生长季土壤温室气体排放的影响规律及主控因子.结果表明:采伐干扰10年后,4种森林沼泽土壤CO_2、CH_4和N_2O非生长季平均通量分别在53.08～81.31 mg·m~(-2)·h~(-1)、0.09～3.07 mg·m~(-2)·h~(-1)和4.07～8.83μg·m~(-2)·h~(-1),其中,皆伐显著提高毛赤杨沼泽和落叶松藓类沼泽非生长季土壤CO_2、CH_4和N_2O排放量,择伐显著提高白桦沼泽、落叶松藓类沼泽及降低毛赤杨沼泽的CO_2排放量,且显著降低4种森林沼泽CH_4排放量及落叶松苔草沼泽的N_2O排放量;天然森林沼泽非生长季土壤CO_2排放受土壤温度、有机碳含量及C/N调控,CH_4受土壤温度、有机碳含量调控,N_2O受气温、土壤pH调控,采伐增加了CO_2排放与气温、土壤含水量及积雪深度的相关性,增加了CH_4排放与气温、土壤含水量、C/N的相关性,增加了N_2O排放与土壤全氮和C/N的相关性;温带天然森林沼泽非生长季土壤CO_2、CH_4和N_2O的年贡献率分别为33.2%～46.5%、6.3%～9.1%和61.5%～68.3%,皆伐提高了白桦沼泽和落叶松藓类沼泽CO_2年贡献率和除落叶松藓类沼泽外其他样地的N_2O年贡献率,择伐提高了落叶松苔草沼泽、落叶松藓类沼泽CO_2、CH_4和N_2O年贡献率,但降低了白桦沼泽3种气体年贡献率.温带天然森林沼泽非生长季土壤N_2O和CO_2的年贡献率相对较大,皆伐使两者年贡献率进一步提高,择伐却较大幅度提高了其CH_4的年贡献率.
Soil greenhouse gas emission during non-growing season plays an important role in ecosystem carbon and nitrogen cycling in mid and high latitude regions. However, the effects of harvest on greenhouse gas emission during non-growing remain unclear. We measured the fluxes of CO_2, CH_4 and N_2O and environmental factors(soil temperature, moisture, soil organic carbon and total nitrogen etc.) during non-growing season from four kinds of forested swamps(Alnus sibirica swamp, Betula platyphylla swamp, Larix gmelinii-Carex schmidti swamp, L. gmelinii-moss swamp) under different harvest disturbances for 10 years, including control(no cutting), 45% selective cutting, clear cutting, by using static chamber technique and gas chromatography in Xiaoxing'an Mountains, Northeast China. The aim of this study was to reveal the effects of harvest on greenhouse gas emission from temperate forested swamp during non-growing season and the main controlling factors. The results showed that the average fluxes of CO_2, CH_4 and N_2O from four kinds of swamps distributed in 53.08-81.31 mg·m~(-2)·h~(-1), 0.09-3.07 mg·m~(-2)·h~(-1) and 4.07-8.83 μg·m~(-2)·h~(-1), respectively. Clear cutting significantly increased the fluxes of CO_2, CH_4, and N_2O from A. sibirica swamp and L. gmelinii-moss swamp. Selective cutting significantly increased CO_2 fluxes from B. platyphylla swamp and L. gmelinii-moss swamp and decreased CO_2 flux from A. sibirica swamp. Selective cutting significantly decreased CH_4 fluxes from all the four forested swamps and N_2O flux from Larix gmelinii-Carex schmidti swamp. The CO_2 fluxes from natural forested swamps were strongly influenced by soil temperature, soil organic carbon and C/N. CH_4 fluxes were influenced by soil temperature, soil organic carbon. N_2O fluxes were affected by air temperature and soil pH. Harvesting increased the correlation between soil CO_2 flux and air temperature, soil moisture and snow depth, the correlation between soil CH_(4 )flux and air temperature, soil moisture and C/N, as well as the correlation between soil N_2O flux and soil total nitrogen and C/N. The annual cumulative contribution of CO_2, CH_4 and N_2O emission from natural forested swamp during non-growing season were 33.2%-46.5%, 6.3%-9.1% and 61.5%-68.3%, respectively. The clear cutting increased the annual cumulative contribution of CO_2 from B. platyphylla swamp and L. gmelinii-moss swamp and that of N_2O from other swamps except L. gmelinii-moss swamp. The selective cutting increased the annual cumulative contribution of CO_2, CH_4 and N_2O from L. gmelinii-C. schmidti swamp and L. gmelinii-moss swamp, but decreased that from B. platyphylla swamp. The annual cumulative contributions of N_2O and CO_2 during non-growing season were relatively high from temperate natural forested swamps, and clear cutting further increased their contribution, while the selective cutting just increased that of CH_4 during non-growing season.
Soil greenhouse gas emission during non-growing season plays an important role in ecosystem carbon and nitrogen cycling in mid and high latitude regions. However, the effects of harvest on greenhouse gas emission during non-growing remain unclear. We measured the fluxes of CO_2, CH_4 and N_2O and environmental factors(soil temperature, moisture, soil organic carbon and total nitrogen etc.) during non-growing season from four kinds of forested swamps(Alnus sibirica swamp, Betula platyphylla swamp, Larix gmelinii-Carex schmidti swamp, L. gmelinii-moss swamp) under different harvest disturbances for 10 years, including control(no cutting), 45% selective cutting, clear cutting, by using static chamber technique and gas chromatography in Xiaoxing'an Mountains, Northeast China. The aim of this study was to reveal the effects of harvest on greenhouse gas emission from temperate forested swamp during non-growing season and the main controlling factors. The results showed that the average fluxes of CO_2, CH_4 and N_2O from four kinds of swamps distributed in 53.08-81.31 mg·m~(-2)·h~(-1), 0.09-3.07 mg·m~(-2)·h~(-1) and 4.07-8.83 μg·m~(-2)·h~(-1), respectively. Clear cutting significantly increased the fluxes of CO_2, CH_4, and N_2O from A. sibirica swamp and L. gmelinii-moss swamp. Selective cutting significantly increased CO_2 fluxes from B. platyphylla swamp and L. gmelinii-moss swamp and decreased CO_2 flux from A. sibirica swamp. Selective cutting significantly decreased CH_4 fluxes from all the four forested swamps and N_2O flux from Larix gmelinii-Carex schmidti swamp. The CO_2 fluxes from natural forested swamps were strongly influenced by soil temperature, soil organic carbon and C/N. CH_4 fluxes were influenced by soil temperature, soil organic carbon. N_2O fluxes were affected by air temperature and soil pH. Harvesting increased the correlation between soil CO_2 flux and air temperature, soil moisture and snow depth, the correlation between soil CH_(4 )flux and air temperature, soil moisture and C/N, as well as the correlation between soil N_2O flux and soil total nitrogen and C/N. The annual cumulative contribution of CO_2, CH_4 and N_2O emission from natural forested swamp during non-growing season were 33.2%-46.5%, 6.3%-9.1% and 61.5%-68.3%, respectively. The clear cutting increased the annual cumulative contribution of CO_2 from B. platyphylla swamp and L. gmelinii-moss swamp and that of N_2O from other swamps except L. gmelinii-moss swamp. The selective cutting increased the annual cumulative contribution of CO_2, CH_4 and N_2O from L. gmelinii-C. schmidti swamp and L. gmelinii-moss swamp, but decreased that from B. platyphylla swamp. The annual cumulative contributions of N_2O and CO_2 during non-growing season were relatively high from temperate natural forested swamps, and clear cutting further increased their contribution, while the selective cutting just increased that of CH_4 during non-growing season.
引文
[1] IPCC.Climate Change 2014:Synthesis Report.Contribution of Working Groups I,II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.Geneva,Switzerland:IPCC,2014
[2] Stocker TF,Qin D,Plattner GK,et al.IPCC,2013: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,2013
[3] Schulze ED,Luyssaert S,Ciais P,et al.Importance of methane and nitrous oxide for Europe’s terrestrial greenhouse-gas balance.Nature Geoscience,2009,3:65
[4] Montzka SA,Dlugokencky EJ,Butler JH.Non-CO2 greenhouse gases and climate change.Nature,2011,476:43-50
[5] Whiting GJ,Chanton JP.Greenhouse carbon balance of wetlands:Methane emission versus carbon sequestration.Tellus B,2001,53:521-528
[6] Brix H,Sorrell BK,Lorenzen B.Are Phragmites-dominated wetlands a net source or net sink of greenhouse gases.Aquatic Botany,2001,69:313-324
[7] Bubier JL,Moore TR.An ecological perspective on methane emissions from northern wetlands.Trends in Ecology and Evolution,1994,9:460-464
[8] Regina K,Nen HN,Silvola J,et al.Fluxes of nitrous oxide from boreal peatlands as affected by peatland type,water table level and nitrification capacity.Biogeochemistry,1996,35:401-418
[9] Martikainen PJ,Nyk?nen H,Crill P,et al.Effect of a lowered water table on nitrous oxide fluxes from northern peatlands.Nature,1993,366:51-53
[10] Messina MG,Conner WH.Southern Forested Wetlands:Ecology and Management.Boca Raton:CRC Press Inc,1997
[11] Alongi DM,Trott LA,Pfitzner J.Deposition,mineralization,and storage of carbon and nitrogen in sediments of the far northern and northern Great Barrier Reef shelf.Continental Shelf Research,2007,27:2595-2622
[12] Keenan RJ,Kimmins JP.The ecological effects of clear-cutting.Environmental Review,1993,1:121-144
[13] Page KL,Dalal RC,Raison RJ.The impact of harvesting native forests on vegetation and soil C stocks,and soil CO2,N2O and CH4 fluxes.Australian Journal of Botany,2011,59:654-669
[14] Chimner RA,Cooper DJ.Influence of water table levels on CO2 emissions in a Colorado subalpine fen:An in situ microcosm study.Soil Biology and Biochemistry,2003,35:345-351
[15] Chen H,Mothapo NV,Wei S.Soil moisture and pH control relative contributions of fungi and bacteria to N2O production.Microbial Ecology,2015,69:180-191
[16] M?kiranta P,Laiho R,Penttil? T,et al.The impact of logging residue on soil GHG fluxes in a drained peatland forest.Soil Biology and Biochemistry,2012,48:1-9
[17] Ullah S,Frasier R,Pelletier L,et al.Greenhouse gas fluxes from boreal forest soils during the snow-free period in Quebec,Canada.Canadian Journal of Forest Research,2009,39:666-680
[18] Liu X (刘霞),Mu C-C (牟长城),Li W-S (李婉姝),et al.Emissions of CH4 and N2O from Alnus sibirica swamps and the response to human disturbance in the Xiaoxing'an Mountains.Acta Scientiae Circumstantiae (环境科学学报),2009,39 (12):2642-2650 (in Chinese)
[19] Mu C-C (牟长城),Wu Y-X (吴云霞),Li W-S (李婉姝),et al.Effects of forest cutting on greenhouse gas emissions from Larix gemlinii-Sphagnum swamps in Lesser Xing’an Mountains of Heilongjiang,China.Chinese Journal of Applied Ecology (应用生态学报),2010,21(2):287-293 (in Chinese)
[20] Sun X-X (孙晓新),Mu C-C (牟长城),Song C-C (宋长春),et al.Impact of harvesting on methane flux from forested marsh in Xiaoxing’an Mountains.Chinese Journal of Soil Science (土壤通报),2011,42(1):190-194 (in Chinese)
[21] Huttunen JT,Nen HN,Martikainen PJ,et al.Fluxes of nitrous oxide and methane from drained peatlands following forest clear-felling in southern Finland.Plant and Soil,2003,255:457-462
[22] Saari P,Saarnio S,Kukkonen JVK,et al.DOC and N2O dynamics in upland and peatland forest soils after clear-cutting and soil preparation.Biogeochemistry,2009,94:217-231
[23] Nieminen M.Changes in nitrogen cycling following the clearcutting of drained peatland forests in southern Finland.Boreal Environment Research 1998,3:9-21
[24] Alm J,Saarnio S,Nyk?nen H,et al.Winter CO2,CH4 and N2O fluxes on some natural and drained boreal peatlands.Biogeochemistry,1999,44:163-186
[25] Brooks PD,Grogan P,Templer PH,et al.Carbon and nitrogen cycling in snow-covered environments.Geography Compass,2011,5:682-699
[26] Hubbard RM,Ryan MG,Elder K,et al.Seasonal patterns in soil surface CO2 flux under snow cover in 50 and 300 year old subalpine forests.Biogeochemistry,2005,73:93-107
[27] Monson RK,Sparks JP,Rosenstiel TN,et al.Climatic influences on net ecosystem CO2 exchange during the transition from wintertime carbon source to springtime carbon sink in a high-elevation,subalpine forest.Oecologia,2005,146:130-147
[28] Jones HG,Pomeroy JW,Davies TD,et al.CO2 in Arctic snow cover:Landscape form,in-pack gas concentration gradients,and the implications for the estimation of gaseous fluxes.Hydrological Processes,1999,13:2977-2989
[29] Monson RK,Lipson DL,Burns SP,et al.Winter forest soil respiration controlled by climate and microbial community composition.Nature,2006,439:711-714
[30] Groffman PM,Hardy JP,Driscoll CT,et al.Snow depth,soil freezing,and fluxes of carbon dioxide,nitrous oxide and methane in a northern hardwood forest.Global Change Biology,2006,12:1748-1760
[31] Oechel WC,Vourlitis G,Hastings SJ.Cold season CO2 emission from Arctic soils.Global Biogeochemical Cycles,1997,11:163-172
[32] Mast MA,Wickland KP,Striegl RT,et al.Winter fluxes of CO2 and CH4 from subalpine soils in Rocky Mountain National Park,Colorado.Global Biogeochemical Cycles,1998,12:607-620
[33] Wickland KP,Striegl RG,Mast MA,et al.Carbon gas exchange at a southern Rocky Mountain wetland,1996-1998.Global Biogeochemical Cycles,2001,15:321-335
[34] Lafleur PM,Roulet NT,Admiral SW.Annual cycle of CO2 exchange at a bog peatland.Journal of Geophysical Research:Atmospheres,2001,106:3071-3081
[35] Wille C,Kutzbach L,Sachs T,et al.Methane emission from Siberian arctic polygonal tundra:Eddy covariance measurements and modeling.Global Change Biology,2008,14:1395-1408
[36] Dise NB.Winter fluxes of methane from Minnesota Peatlands.Biogeochemistry,1992,17:71-83
[37] Melloh RA,Crill PM.Winter methane dynamics in a temperate peatland.Global Biogeochemical Cycles,1996,10:247-254
[38] Panikov NS,Dedysh SN.Cold season CH4 and CO2 emission from boreal peat bogs (West Siberia):Winter fluxes and thaw activation dynamics.Global Biogeochemical Cycles,2000,14:1071-1080
[39] Regina K,Syvasalo E,Hannukkala A,et al.Fluxes of N2O from farmed peat soils in Finland.European Journal of Soil Science,2004,55:591-599
[40] Laine J,Silvola J,Tolonen K,et al.Effect of water-level drawdown on global climatic warming:Northern Peatlands.Ambio,1996,25:179-184
[41] Zhang Y (张悦),Mu C-C (牟长城),Liu H (刘辉),et al.Effects of light-felling on soil greenhouse gas emission in Korean pine forests in non-growing season in Maoer Mountains,China.Chinese Journal of Applied Ecology (应用生态学报),2010,21(2):287-293 (in Chinese)
[42] Monson RK,Burns SP,Williams MW,et al.The contribution of beneath-snow soil respiration to total ecosystem respiration in a high-elevation,subalpine forest.Global Biogeochemical Cycles,2006,20:GB3030
[43] Ewel KC,Jr.Cropper WP,Gholz HL.Soil CO2 evolution in Florida slash pine plantationsI:Changes through time.Canadian Journal of Forest Research,1987,17:330-333
[44] Yang Y-S (杨玉盛),Chen G-S (陈光水),Wang X-G (王小国).Effect of clear-cutting on soil respiration of Chinese fir plantation.Acta Peologica Sinica (土壤学报),2005,42(4):548-590 (in Chinese)
[45] Sun H-L (孙海龙),Zhang Y-D (张彦东).Effects of harvest disturbance on soil CH4 flux in a secondary hardwood forest in Northeast China.Chinese Journal of Applied Ecology (应用生态学报),2013,24(10):2737-2745 (in Chinese)
[46] Ding W,Cai Z,Tsuruta H,et al.Effect of standing water depth on methane emissions from freshwater marshes in northeast China.Atmospheric Environment,2002,36:5149-5157
[47] Takakai F,Desyatkin AR,Lopez CML,et al.Influence of forest disturbance on CO2,CH4 and N2O fluxes from larch forest soil in the permafrost taiga region of eastern Siberia.Soil Science and Plant Nutrition,2008,54:938-949
[48] Steinkamp R,Butterbach-Bahl K,Papen H.Methane oxidation by soils of an N limited and N fertilized spruce forest in the Black Forest,Germany.Soil Biology and Biochemistry,2001,33:145-153
[49] K?hk?nen MA,Wittmann C,Ilvesniemi H,et al.Mineralization of detritus and oxidation of methane in acid boreal coniferous forest soils:Seasonal and vertical distribution and effects of clear-cut.Soil Biology and Biochemistry,2002,34:1191-1200
[50] Teepe R,Brumme R,Beese F.Nitrous oxide emissions from frozen soils under agricultural,fallow and forest land.Soil Biology and Biochemistry,2000,32:1807-1810
[51] Hu Y,Chang X,Lin X,et al.Effects of warming and grazing on N2O fluxes in an alpine meadow ecosystem on the Tibetan plateau.Soil Biology and Biochemistry,2010,42:944-952
[52] Morkved PT,D?rsch P,Henriksen TM,et al.N2O emissions and product ratios of nitrification and denitrification as affected by freezing and thawing.Soil Biology and Biochemistry,2006,38:3411-3420
[53] Teepe R,Brumme R,Beese F.Nitrous oxide emissions from soil during freezing and thawing periods.Soil Biology and Biochemistry,2001,33:1269-1275
[54] Merbold L,Steinlin C,Hagedorn F.Winter greenhouse gas fluxes (CO2,CH4,N2O) from a subalpine grassland.Biogeosciences,2013,10:3185-3203
[55] Liptzin D,Williams MW,Helmig D,et al.Process-level controls on CO2 fluxes from a seasonally snow-covered subalpine meadow soil,Niwot Ridge,Colorado.Biogeochemistry,2009,95:151-166
[56] Miao Y,Song C,Wang X,et al.Greenhouse gas emissions from different wetlands during the snow-covered season in Northeast China.Atmospheric Environment,2012,62:328-335
[57] Bj?rkman MP,Morgner E,Cooper EJ,et al.Winter carbon dioxide effluxes from Arctic ecosystems:An overview and comparison of methodologies.Global Biogeochemical Cycles,2010,24:GB3010
[58] Shi W,Yan M,Zhang J,et al.Soil CO2 emissions from five different types of land use on the semiarid Loess Plateau of China,with emphasis on the contribution of winter soil respiration.Atmospheric Environment,2014,88:74-82
[59] Weslien P,Kasimir Klemedtsson ?,B?rjesson G,et al.Strong pH influence on N2O and CH4 fluxes from forested organic soils.European Journal of Soil Science,2009,60:311-320
[60] Furon AC,Wagner-Riddle C,Smith CR,et al.Wavelet analysis of wintertime and spring thaw CO2 and N2O fluxes from agricultural fields.Agricultural and Forest Meteorology,2008,148:1305-1317
[61] Klemedtsson L,Von Arnold K,Weslien P,et al.Soil C N ratio as a scalar parameter to predict nitrous oxide emissions.Global Change Biology,2005,11:1142-1147
[2] Stocker TF,Qin D,Plattner GK,et al.IPCC,2013: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,2013
[3] Schulze ED,Luyssaert S,Ciais P,et al.Importance of methane and nitrous oxide for Europe’s terrestrial greenhouse-gas balance.Nature Geoscience,2009,3:65
[4] Montzka SA,Dlugokencky EJ,Butler JH.Non-CO2 greenhouse gases and climate change.Nature,2011,476:43-50
[5] Whiting GJ,Chanton JP.Greenhouse carbon balance of wetlands:Methane emission versus carbon sequestration.Tellus B,2001,53:521-528
[6] Brix H,Sorrell BK,Lorenzen B.Are Phragmites-dominated wetlands a net source or net sink of greenhouse gases.Aquatic Botany,2001,69:313-324
[7] Bubier JL,Moore TR.An ecological perspective on methane emissions from northern wetlands.Trends in Ecology and Evolution,1994,9:460-464
[8] Regina K,Nen HN,Silvola J,et al.Fluxes of nitrous oxide from boreal peatlands as affected by peatland type,water table level and nitrification capacity.Biogeochemistry,1996,35:401-418
[9] Martikainen PJ,Nyk?nen H,Crill P,et al.Effect of a lowered water table on nitrous oxide fluxes from northern peatlands.Nature,1993,366:51-53
[10] Messina MG,Conner WH.Southern Forested Wetlands:Ecology and Management.Boca Raton:CRC Press Inc,1997
[11] Alongi DM,Trott LA,Pfitzner J.Deposition,mineralization,and storage of carbon and nitrogen in sediments of the far northern and northern Great Barrier Reef shelf.Continental Shelf Research,2007,27:2595-2622
[12] Keenan RJ,Kimmins JP.The ecological effects of clear-cutting.Environmental Review,1993,1:121-144
[13] Page KL,Dalal RC,Raison RJ.The impact of harvesting native forests on vegetation and soil C stocks,and soil CO2,N2O and CH4 fluxes.Australian Journal of Botany,2011,59:654-669
[14] Chimner RA,Cooper DJ.Influence of water table levels on CO2 emissions in a Colorado subalpine fen:An in situ microcosm study.Soil Biology and Biochemistry,2003,35:345-351
[15] Chen H,Mothapo NV,Wei S.Soil moisture and pH control relative contributions of fungi and bacteria to N2O production.Microbial Ecology,2015,69:180-191
[16] M?kiranta P,Laiho R,Penttil? T,et al.The impact of logging residue on soil GHG fluxes in a drained peatland forest.Soil Biology and Biochemistry,2012,48:1-9
[17] Ullah S,Frasier R,Pelletier L,et al.Greenhouse gas fluxes from boreal forest soils during the snow-free period in Quebec,Canada.Canadian Journal of Forest Research,2009,39:666-680
[18] Liu X (刘霞),Mu C-C (牟长城),Li W-S (李婉姝),et al.Emissions of CH4 and N2O from Alnus sibirica swamps and the response to human disturbance in the Xiaoxing'an Mountains.Acta Scientiae Circumstantiae (环境科学学报),2009,39 (12):2642-2650 (in Chinese)
[19] Mu C-C (牟长城),Wu Y-X (吴云霞),Li W-S (李婉姝),et al.Effects of forest cutting on greenhouse gas emissions from Larix gemlinii-Sphagnum swamps in Lesser Xing’an Mountains of Heilongjiang,China.Chinese Journal of Applied Ecology (应用生态学报),2010,21(2):287-293 (in Chinese)
[20] Sun X-X (孙晓新),Mu C-C (牟长城),Song C-C (宋长春),et al.Impact of harvesting on methane flux from forested marsh in Xiaoxing’an Mountains.Chinese Journal of Soil Science (土壤通报),2011,42(1):190-194 (in Chinese)
[21] Huttunen JT,Nen HN,Martikainen PJ,et al.Fluxes of nitrous oxide and methane from drained peatlands following forest clear-felling in southern Finland.Plant and Soil,2003,255:457-462
[22] Saari P,Saarnio S,Kukkonen JVK,et al.DOC and N2O dynamics in upland and peatland forest soils after clear-cutting and soil preparation.Biogeochemistry,2009,94:217-231
[23] Nieminen M.Changes in nitrogen cycling following the clearcutting of drained peatland forests in southern Finland.Boreal Environment Research 1998,3:9-21
[24] Alm J,Saarnio S,Nyk?nen H,et al.Winter CO2,CH4 and N2O fluxes on some natural and drained boreal peatlands.Biogeochemistry,1999,44:163-186
[25] Brooks PD,Grogan P,Templer PH,et al.Carbon and nitrogen cycling in snow-covered environments.Geography Compass,2011,5:682-699
[26] Hubbard RM,Ryan MG,Elder K,et al.Seasonal patterns in soil surface CO2 flux under snow cover in 50 and 300 year old subalpine forests.Biogeochemistry,2005,73:93-107
[27] Monson RK,Sparks JP,Rosenstiel TN,et al.Climatic influences on net ecosystem CO2 exchange during the transition from wintertime carbon source to springtime carbon sink in a high-elevation,subalpine forest.Oecologia,2005,146:130-147
[28] Jones HG,Pomeroy JW,Davies TD,et al.CO2 in Arctic snow cover:Landscape form,in-pack gas concentration gradients,and the implications for the estimation of gaseous fluxes.Hydrological Processes,1999,13:2977-2989
[29] Monson RK,Lipson DL,Burns SP,et al.Winter forest soil respiration controlled by climate and microbial community composition.Nature,2006,439:711-714
[30] Groffman PM,Hardy JP,Driscoll CT,et al.Snow depth,soil freezing,and fluxes of carbon dioxide,nitrous oxide and methane in a northern hardwood forest.Global Change Biology,2006,12:1748-1760
[31] Oechel WC,Vourlitis G,Hastings SJ.Cold season CO2 emission from Arctic soils.Global Biogeochemical Cycles,1997,11:163-172
[32] Mast MA,Wickland KP,Striegl RT,et al.Winter fluxes of CO2 and CH4 from subalpine soils in Rocky Mountain National Park,Colorado.Global Biogeochemical Cycles,1998,12:607-620
[33] Wickland KP,Striegl RG,Mast MA,et al.Carbon gas exchange at a southern Rocky Mountain wetland,1996-1998.Global Biogeochemical Cycles,2001,15:321-335
[34] Lafleur PM,Roulet NT,Admiral SW.Annual cycle of CO2 exchange at a bog peatland.Journal of Geophysical Research:Atmospheres,2001,106:3071-3081
[35] Wille C,Kutzbach L,Sachs T,et al.Methane emission from Siberian arctic polygonal tundra:Eddy covariance measurements and modeling.Global Change Biology,2008,14:1395-1408
[36] Dise NB.Winter fluxes of methane from Minnesota Peatlands.Biogeochemistry,1992,17:71-83
[37] Melloh RA,Crill PM.Winter methane dynamics in a temperate peatland.Global Biogeochemical Cycles,1996,10:247-254
[38] Panikov NS,Dedysh SN.Cold season CH4 and CO2 emission from boreal peat bogs (West Siberia):Winter fluxes and thaw activation dynamics.Global Biogeochemical Cycles,2000,14:1071-1080
[39] Regina K,Syvasalo E,Hannukkala A,et al.Fluxes of N2O from farmed peat soils in Finland.European Journal of Soil Science,2004,55:591-599
[40] Laine J,Silvola J,Tolonen K,et al.Effect of water-level drawdown on global climatic warming:Northern Peatlands.Ambio,1996,25:179-184
[41] Zhang Y (张悦),Mu C-C (牟长城),Liu H (刘辉),et al.Effects of light-felling on soil greenhouse gas emission in Korean pine forests in non-growing season in Maoer Mountains,China.Chinese Journal of Applied Ecology (应用生态学报),2010,21(2):287-293 (in Chinese)
[42] Monson RK,Burns SP,Williams MW,et al.The contribution of beneath-snow soil respiration to total ecosystem respiration in a high-elevation,subalpine forest.Global Biogeochemical Cycles,2006,20:GB3030
[43] Ewel KC,Jr.Cropper WP,Gholz HL.Soil CO2 evolution in Florida slash pine plantationsI:Changes through time.Canadian Journal of Forest Research,1987,17:330-333
[44] Yang Y-S (杨玉盛),Chen G-S (陈光水),Wang X-G (王小国).Effect of clear-cutting on soil respiration of Chinese fir plantation.Acta Peologica Sinica (土壤学报),2005,42(4):548-590 (in Chinese)
[45] Sun H-L (孙海龙),Zhang Y-D (张彦东).Effects of harvest disturbance on soil CH4 flux in a secondary hardwood forest in Northeast China.Chinese Journal of Applied Ecology (应用生态学报),2013,24(10):2737-2745 (in Chinese)
[46] Ding W,Cai Z,Tsuruta H,et al.Effect of standing water depth on methane emissions from freshwater marshes in northeast China.Atmospheric Environment,2002,36:5149-5157
[47] Takakai F,Desyatkin AR,Lopez CML,et al.Influence of forest disturbance on CO2,CH4 and N2O fluxes from larch forest soil in the permafrost taiga region of eastern Siberia.Soil Science and Plant Nutrition,2008,54:938-949
[48] Steinkamp R,Butterbach-Bahl K,Papen H.Methane oxidation by soils of an N limited and N fertilized spruce forest in the Black Forest,Germany.Soil Biology and Biochemistry,2001,33:145-153
[49] K?hk?nen MA,Wittmann C,Ilvesniemi H,et al.Mineralization of detritus and oxidation of methane in acid boreal coniferous forest soils:Seasonal and vertical distribution and effects of clear-cut.Soil Biology and Biochemistry,2002,34:1191-1200
[50] Teepe R,Brumme R,Beese F.Nitrous oxide emissions from frozen soils under agricultural,fallow and forest land.Soil Biology and Biochemistry,2000,32:1807-1810
[51] Hu Y,Chang X,Lin X,et al.Effects of warming and grazing on N2O fluxes in an alpine meadow ecosystem on the Tibetan plateau.Soil Biology and Biochemistry,2010,42:944-952
[52] Morkved PT,D?rsch P,Henriksen TM,et al.N2O emissions and product ratios of nitrification and denitrification as affected by freezing and thawing.Soil Biology and Biochemistry,2006,38:3411-3420
[53] Teepe R,Brumme R,Beese F.Nitrous oxide emissions from soil during freezing and thawing periods.Soil Biology and Biochemistry,2001,33:1269-1275
[54] Merbold L,Steinlin C,Hagedorn F.Winter greenhouse gas fluxes (CO2,CH4,N2O) from a subalpine grassland.Biogeosciences,2013,10:3185-3203
[55] Liptzin D,Williams MW,Helmig D,et al.Process-level controls on CO2 fluxes from a seasonally snow-covered subalpine meadow soil,Niwot Ridge,Colorado.Biogeochemistry,2009,95:151-166
[56] Miao Y,Song C,Wang X,et al.Greenhouse gas emissions from different wetlands during the snow-covered season in Northeast China.Atmospheric Environment,2012,62:328-335
[57] Bj?rkman MP,Morgner E,Cooper EJ,et al.Winter carbon dioxide effluxes from Arctic ecosystems:An overview and comparison of methodologies.Global Biogeochemical Cycles,2010,24:GB3010
[58] Shi W,Yan M,Zhang J,et al.Soil CO2 emissions from five different types of land use on the semiarid Loess Plateau of China,with emphasis on the contribution of winter soil respiration.Atmospheric Environment,2014,88:74-82
[59] Weslien P,Kasimir Klemedtsson ?,B?rjesson G,et al.Strong pH influence on N2O and CH4 fluxes from forested organic soils.European Journal of Soil Science,2009,60:311-320
[60] Furon AC,Wagner-Riddle C,Smith CR,et al.Wavelet analysis of wintertime and spring thaw CO2 and N2O fluxes from agricultural fields.Agricultural and Forest Meteorology,2008,148:1305-1317
[61] Klemedtsson L,Von Arnold K,Weslien P,et al.Soil C N ratio as a scalar parameter to predict nitrous oxide emissions.Global Change Biology,2005,11:1142-1147