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1.
魏达  旭日  王迎红  姚檀栋 《草地学报》2011,19(3):412-419
青藏高原广泛分布着以高寒草甸和高寒草原为主的陆地生态系统。由于高寒草地生态系统异质性较大,对高寒草地主要温室气体通量的估算具有较大的不确定性。为研究高寒草原温室气体通量规律及其驱动因子,并为动态碳-氮耦合模式在高寒生态系统的参数化与检验提供数据支持,于2008年7-9月,使用静态箱-气相色谱法在位于青藏高原腹地的纳木错高寒草原开展了主要温室气体通量(CO2,CH4,N2O)及环境因子的同步观测。结果表明:纳木错高寒草原生态系统CH4,N2O通量和CO2排放分别为:-0.047 mg·m-2·h-1,0.49μg·m-2·h-1和208.2 mg·m-2·h-1;在季节尺度上,土壤温度与CO2排放呈显著正相关,与N2O和CH4通量线性关系不显著;土壤含水量与CH4和N2O通量呈正相关关系,但与CO2通量无显著相关。在日变化尺度上,土壤湿度稳定,土壤温度变化与N2O和CO2通量成正相关,对CH4通量影响不显著。  相似文献   

2.
为探讨草地温室气体通量对不同刈割强度的响应情况、优化草地利用方式及强度,本研究通过在晋西北赖草(Leymus secalinus)草地构建不同强度的刈割试验,采用静态箱/气相色谱法定量研究了不刈割、轻度刈割、中度刈割和重度刈割对3种温室气体(CO2,CH4和N2O)通量的影响及温室气体通量与主要环境因子的关系。2017年和2018年生长季及非生长季观测结果表明,不同刈割强度下的草地均表现为CO2和N2O的源、CH4的汇;刈割于2018年生长季显著影响CH4和N2O通量(P<0.05);3种温室气体通量与土壤温度呈显著指数相关(P<0.05),CO2通量与土壤体积含水量、N2O通量呈显著线性相关(P<0.05)。本研究为采用合理的草地刈割强度提供一定的参考和理论依据。  相似文献   

3.
推动低碳发展建设研究,探讨实现碳达峰路径,并在此基础上实现碳中和目标,已成为当下我国应对气候变化和加强生态文明建设的首要任务。本研究以山东省烟台市某规模化猪场为研究对象,通过测算该猪场生猪生长过程和粪便贮存过程CH4和N2O排放量、粪便农田利用过程N2O排放量,以及能源消耗CO2排放量,对生猪养殖过程中各排放源的碳排放特性进行分析。结果表明:该猪场生猪肠道发酵CH4排放CO2当量仅占生猪生长过程温室气体排放总量的6.4%,而生猪呼出CO2排放占比高达93.6%;粪便贮存过程N2O排放CO2当量仅占粪便贮存过程温室气体排放总量的15.2%,占粪便贮存过程CH4排放CO2当量的17.9%;农田利用过程N2O直接排放量为间接排放量的10倍;耗煤、耗电、耗油CO2排放量分别占能源消耗CO2排...  相似文献   

4.
黄土高原雨养农业区不同种植模式土壤温室气体排放特征   总被引:1,自引:0,他引:1  
研究陇中黄土高原旱作农田,设置了苜蓿-苜蓿(L-L)、苜蓿-休闲(L-F)、苜蓿-小麦(L-W)、苜蓿-玉米(L-C)、苜蓿-马铃薯(L-P)和苜蓿-谷子(L-M)6个处理,采用静态箱-气相色谱法和碳通量测量系统LI-8100对苜蓿后茬轮作不同作物土壤温室气体排放动态及其影响因素进行了测定与分析。研究结果表明,农田土壤表现为CO2源、N2O源和CH4吸收汇,且呈现夏秋高,春冬低的季节性变化特征。L-L处理的CO2累积排放量最高,L-W处理较之降低了42.43%;L-C处理的N2O累积排放量最高,L-P处理最低;CH4吸收量以L-M处理最高,较L-F和L-L分别增加了62.71%和31.87%,综合增温潜势表现为L-L>L-M>L-C>L-P>L-F>L-W。相关分析结果表明,CO2、CH4、N2O排放量与脲酶、过氧化氢酶活性及土壤温度呈极显著相关(P<0.01),与土壤水分在不同土层有显著相关性;逐步回归分析发现,土壤温度、过氧化氢酶是CO2和CH4排放的主导因素,土壤温度极显著影响气体排放,N2O排放主要受到环境因子的影响。综合来看,与长期苜蓿连作相比,黄土高原地区苜蓿种植一定年限之后轮作粮食作物能减少土壤温室气体排放量,减弱农田温室气体的增温效应,其中以小麦效果最佳。  相似文献   

5.
田间盆栽试验研究了不同降水格局下填闲种植对冬小麦农田夏闲期土壤温室气体排放的影响。试验采用控制降水格局(自然降水和减半降水)和填闲作物(黑麦草单播、长武怀豆单播、黑麦草和怀豆混播、裸地对照)双因素处理设计, 利用静态箱-气相色谱法对土壤CO2、N2O和CH4排放通量进行观测。结果表明:1)各处理土壤是CO2、N2O的排放源, 是CH4的弱吸收汇。2)降水格局和填闲种植对土壤温室气体排放均具有显著影响。与自然降水相比, 减半降水的土壤CO2日均排放通量降低了33%, N2O日均排放通量降低了17.9%, 但对CH4通量影响不大。3)与裸地对照相比, 单播黑麦草、长武怀豆和二者混播日均CO2排放通量提高了140.8%、135.6%和137.7%, 不同填闲处理间差异不显著。而日均N2O排放通量分别降低了8.0%、21.8%和27.4%, 其中单播长武怀豆和混播处理与单播黑麦草处理差异显著。单播长武怀豆处理土壤日均CH4吸收通量较裸地对照、单播黑麦草和混播处理分别降低了65.8%、63.7%和68.9%。4)与自然降水相比, 减半降水农田综合增温潜势平均下降了26.1%, 温室气体排放强度平均提高了47.2%。而与裸地对照相比, 单播黑麦草、单播长武怀豆和二者混播处理综合增温潜势平均分别提高了67.9%、65.5%和67.8%, 且各填闲作物处理间差异不显著。与单播黑麦草和混播处理相比, 在冬小麦夏闲期单播长武怀豆具有更高的地上生物量和更低的温室气体排放强度, 在自然降水条件下能够兼顾经济效益与生态效益, 适宜在本地区加以推广种植。  相似文献   

6.
高寒灌丛土壤温室气体释放对添加不同形态氮素的响应   总被引:4,自引:0,他引:4  
为探索不同形态氮素输入对青藏高原高寒灌丛土壤CO2、N2O和CH4排放的影响,采集青藏高原东部金露梅高寒灌丛土壤,设置1个对照(CK)和3个添加不同形态氮素的处理(NH4Cl,NH4NO3,KNO3),在实验室恒温15℃下进行培养,分析了土壤CO2、N2O和CH4的释放量以及土壤NH4+,NO3-和可溶性有机碳(DOC)含量。结果表明:1)所有氮素处理抑制了高寒灌丛土壤CO2的排放,土壤CO2排放量与DOC浓度呈显著正相关关系;2)所有氮素处理显著增加了土壤N2O的排放,而且以添加NO3--N增加的N2O最为显著;3)高寒灌丛土壤N2O的产生过程以反硝化作用为主;4)添加不同形态氮素对高寒灌丛土壤CH4吸收没有显著影响。5)不同形态氮素施入后,高寒灌丛土壤温室气体全球增温潜能(GWP)顺序:KNO3>NH4NO3>NH4Cl>CK。  相似文献   

7.
黄河口滨岸潮滩湿地CO2、CH4和N2O通量特征初步研究   总被引:3,自引:1,他引:2  
2009年8月,运用静态暗箱-气相色谱法对夏季黄河口滨岸潮滩湿地CO2、CH4和N2O通量的日变化特征进行了原位观测。结果表明,夏季低潮滩沉积物-大气界面的CO2、CH4和N2O通量均具有明显日变化特征,日通量范围分别为-18.755~43.731,-0.070~0.224和-0.002~0.008 mg/(m2·h),均值为11.630,0.079和0.005 mg/(m2·h),全天表现为三者的排放“源”;中潮滩沉积物-大气界面CO2、CH4和N2O通量的日变化范围分别为-30.780~25.734,-0.111~0.100和-0.004~0.006 mg/(m2·h),均值为4.570,0.011和0.002 mg/(m2·h),全天亦表现为三者的排放“源”;中潮滩-大气界面CO2、CH4和N2O通量的日变化范围分别为46.253~102.637,-0.211~0.048和-0.008~0.008 mg/(m2·h),均值为76.656,-0.038和-0.002 mg/(m2·h),全天表现为CO2的“源”、CH4和N2O的“汇”。 本研究还发现,中潮滩的CO2通量与气温呈显著正相关(P<0.05)关系,低潮滩沉积物的CH4通量与气温、地表温度和5 cm地温呈极显著正相关(P<0.01)关系,而中潮滩的N2O通量与气温、地表温度和不同深度地温(5,10,20 cm)呈显著(P<0.05)或极显著(P<0.01)负相关关系;沉积物基质和翅碱蓬群落是影响CO2、CH4和N2O通量特征的重要因素,而水分、盐分对于三者通量特征的影响也不容忽视。  相似文献   

8.
DNDC模型评估苜蓿绿肥对水稻产量和温室气体排放的影响   总被引:4,自引:0,他引:4  
DNDC(denitrifiction-decompostion)模型是以生物地球化学进程为基础模拟碳氮循环的模型,被广泛用来预测稻田温室气体的排放,但利用DNDC模型研究苜蓿绿肥对稻田生态系统的相关研究尚未见报道。因此,本研究结合两种绿肥在上海地区的使用,模拟了4个不同处理:对照(未施氮肥和绿肥)、氮肥(200 kg/hm2)、紫花苜蓿绿肥(3000 kg DM/hm2)+氮肥和蚕豆绿肥(3000 kg DM/hm2)+氮肥,研究苜蓿绿肥对水稻产量和稻田温室气体排放的影响,同时,对DNDC模型进行本地化修正,建立适宜我国长江中下游地区绿肥-水稻轮作生态系统的DNDC模型,结果表明,与对照相比,苜蓿、蚕豆和氮肥处理下的水稻产量分别提高了41.85%,29.81%和25.36%;蚕豆绿肥处理下的CH4排放量高于苜蓿绿肥处理,温室气体的排放强度在苜蓿绿肥处理下未显著提高。通过对DNDC模型多个参数的调整和模拟,DNDC模型对水稻产量和CH4排放的模拟值与实测值十分接近,其中,水稻产量实测值和模拟值的决定系数R2为0.89,相对平均误差RMD为-0.8%。大气温度、大气CO2浓度、土壤有机碳和土壤粘粒对稻田CH4和N2O排放十分敏感,其中,大气温度、CO2浓度和土壤有机碳与CH4和N2O的排放强度呈显著的正相关关系,而土壤粘粒与CH4排放呈显著的负相关关系,本研究结果说明本地化改进的DNDC模型能够准确模拟紫花苜蓿绿肥对水稻产量和稻田温室气体排放的作用效果。  相似文献   

9.
赵静雯  吴慧光 《中国畜牧兽医》2015,42(11):3105-3110
随着人们生活水平的不断提高,中国奶牛养殖数量和规模的不断扩大,奶牛正常的生理活动产生的大量气体(CO2和CH4)对土壤、空气和水造成了日益严重的污染。大气中CO2和CH4等微量气体浓度的增加所导致的温室效应已越来越受到各国的重视。奶牛胃肠道发酵所产生的CH4是牧场温室气体排放的主要来源之一,控制奶牛CH4排放能有效减缓温室气体的排放。因此,在畜牧业生产中,有必要有效降低反刍动物产生的CH4。奶牛生产中CH4的排放涉及饲料营养、瘤胃发酵调控、遗传选择和牧场管理等方面,现针对如何降低奶牛生产中CH4产生的研究情况做简要综述。  相似文献   

10.
采用室内培养试验监测紫云英翻压后土壤还原物质和温室气体的动态变化,旨在为紫云英还田造成水稻僵苗及带来的环境效应提供理论依据。结果表明,翻压紫云英显著增加土壤还原性物质总量、活性还原性物质含量、Fe2+和Mn2+含量,显著降低土壤氧化还原电位(Eh)。与对照(CK)相比,翻压紫云英15000(M1)、30000(M2)、45000 kg·hm-2(M3)处理土壤还原性物质总量平均值分别增加0.34、0.80、1.16 cmol·kg-1,土壤活性还原性物质含量平均值分别增加0.14、0.35、0.52 cmol·kg-1,Fe2+含量平均值分别增加87.91、182.91、280.61 mg·kg-1,Mn2+含量平均值分别增加10.12、12.77、15.73 mg·kg-1,Eh平均值分别降低32.88、47.98、57.26 mV。还原性物质均在培养近15 d时达到高峰,M3处理Fe2+含量最高超过400 mg·kg-1,已达到水稻幼苗中毒浓度。翻压紫云英显著增加CO2、CH4排放,降低N2O排放,增加了全球增温潜势(GWP)。与CK相比,M1、M2、M3的CO2排放速率平均值分别增加7.67、12.48、20.54 mg·kg-1·d-1,CO2累计排放量分别增加171.63、293.42、498.45 mg·kg-1,CH4排放速率平均值分别增加0.04、0.09、0.21 mg·kg-1·d-1,CH4累计排放量分别增加0.36、0.69、1.77 mg·kg-1,N2O排放速率平均值分别降低0.46、0.64、0.72 μg·kg-1·d-1,N2O累计排放量分别降低10.00、13.02、14.36 μg·kg-1,M1、M2、M3的GWP平均值分别是CK的1.59、2.04、2.91倍。CO2、N2O排放主要集中在培养前期,CH4排放主要集中在培养后期。还原性物质含量与CO2、CH4的排放呈显著正相关,与N2O排放呈显著负相关。综上,翻压紫云英增加还原性物质含量,促使CO2、CH4排放,抑制N2O排放,增加GWP。实践中翻压紫云英可增加水稻产量,探索适宜紫云英翻压量确保单位水稻产量下的GWP不增加实现增产和环境效应的双赢具有重要实践意义,但这需要通过盆栽和大田试验验证。  相似文献   

11.
青藏高原高寒草地占我国天然草地的40%,研究其温室气体源汇强度及驱动因子具有重要意义。采用静态箱-气相色谱法,在西藏纳木错地区开展高寒草原、高寒草甸和沼泽化草甸的生态系统呼吸、CH4和N2O通量观测,生长季内的观测表明:高寒草原和高寒草甸生态系统呼吸分别为(283.7±14.4) mg·m-2·h-1和(275.7±20.6) mg·m-2·h-1,低于有机质丰富的沼泽化草甸,为(591.6±53.2) mg·m-2·h-1。高寒草原和高寒草甸均是CH4的汇,其生长季均值分别为(-84.9±7.6) μg·m-2·h-1和(-39.2±4.6) μg·m-2·h-1;而沼泽化草甸是CH4的源其均值为(149.2±34.2) μg·m-2·h-1。高寒草原、高寒草甸和沼泽化草甸均为N2O的源,生长季排放量分别为(7.3±2.8),(3.0±1.1)和(2.2±4.3) μg·m-2·h-1。土壤水分总体控制着高寒草地CH4通量的时空变化,在土壤水分含量约大于30%的沼泽化草甸表现为CH4的排放源,而在土壤水分含量低于30%的高寒草原和草甸表现为CH4的汇;生长季水分含量越高,对CH4的吸收越弱。  相似文献   

12.
A new methodology based on (1) national data concerning livestock and rearing practices and (2) a mass-flow approach was developed to quantify ammonia (NH3), methane (CH4) and nitrous oxide (N2O) emissions resulting from manure management in France. A literature review was performed to determine emission factors for each animal type and each management stage. A Microsoft Access® database containing these emission factors, the census data and manure compositions was then developed, allowing the calculation of gaseous emissions by the mass-flow approach. From this database, a national gas emissions inventory resulting from manure management was drawn up for the year 2003. Total NH3 emissions were estimated at 382 kt N, mainly arising from cattle (72%). Greenhouse gas emissions were estimated at 14.0 Tg CO2-eq. for N2O and 10.2 Tg CO2-eq. for CH4. Most of the N2O emissions occurred after the deposition of manure on soil during cattle grazing, while the CH4 was mainly produced during the period where cattle manure remained in livestock buildings and in outside storage facilities. Moreover, an evaluation of the uncertainty was performed considering the standard deviation obtained for the emission factors.  相似文献   

13.
Animal welfare and environmental protection are increasingly important. Housing systems must be found that offer animal welfare while minimizing the overall emissions of ammonia and greenhouse gases. The straw flow system is an animal friendly housing system for fattening pigs, which can be operated economically on commercial farms. Emissions from conventional slurry based pig houses have been intensively studied, but more research is needed into straw based systems. In this study, we quantified emissions of ammonia and greenhouse gases from a straw flow system with or without daily removal of slurry to an outside store. The effect of applying a solid cover during outside storage was also examined.

Emissions of NH3, N2O, CH4, and volatile organic C (VOC) from a commercial straw flow system for fattening pigs in Upper Austria were measured between June 2003 and March 2004. Emissions of CH4 during housing were 1.24 and 0.54 kg CH4 per pig place per year without and with daily manure removal, respectively. The corresponding N2O emissions amounted to 39.9 and 24.5 g N2O per pig place per year, and NH3 emissions to 2.10 and 1.90 kg NH3 per pig place per year without and with daily manure removal. Emissions of CH4, N2O and NH3, and of total greenhouse gases, from the straw flow system were lower than literature reference values for forced ventilated fully slatted floor systems. Daily removal of the manure to an outside store reduced emissions from the pig house.

Emissions during storage of pig slurry derived from a straw flow system were quantified between June 2004 and June 2005. Slurry was stored in pilot scale stores with or without a solid cover and emissions quantified by a large open dynamic chamber. The solid cover reduced NH3 and greenhouse gas emissions by 30 and 50%, respectively. During cold climatic conditions stored pig manure emitted less NH3 and greenhouse gases than when stored under warm climatic conditions. We recommend the use of separate emission factors for slurry storage in the colder and warmer periods in the national emission inventory, and the use of covers on pig slurry stores.

Overall, it is concluded that the straw flow system may combine recommendations of animal welfare and environmental protection.  相似文献   


14.
泛北极地区和青藏高原是陆地生态系统重要的有机碳、氮库。在气候变暖驱动下,高纬度或高海拔冻土融化加速,冻土活动层冻融格局改变,土壤有机质分解增加,成为全球重要的温室气体排放源,其对气候变化的“正反馈”效应受到越来越多关注。本文重点综述了近年泛北极和青藏高原冻土区土壤CO2,CH4和N2O三种主要温室气体通量对冻土退化及冻融作用的响应特征和影响机制,探讨了高寒地区生态系统净温室效应与气候变暖的相互关系,并简要提出了目前冻土区土壤碳排放和氮转化关键过程研究中需要加强的方面,旨在为继续深入开展气候变化背景下冻土碳氮循环研究提供参考。  相似文献   

15.
Ruminant livestock systems contribute to global warming through the emission of nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2). This paper discusses a general framework for a whole-farm approach to develop cost-effective GHG mitigation strategies. A dairy farm is a complex system with different interacting components. Generally, whole-farm approaches distinguish at least an animal component and a soil–crop component. Whole-farm models should be able to give an accurate representation of the internal cycling of materials and its constituents as well as the exchange between the farming system and its environment. The paper gives an overview of current whole-farm models that are able to simulate GHG emissions for dairy farms. These models are DairySim, FarmGHG, SIMSDAIRY and FarmSim. All models are able to calculate CH4 and N2O emissions, but differences appear in the ability to calculate CO2 emissions, economics and other parameters. The effects of selected mitigation strategies are demonstrated with some of the models. It is concluded that a whole-farm approach is a powerful tool for the development of cost-effective GHG mitigation options as it reveals relevant interactions between farm components. Model calculations underlined the relationship between farm gate N surplus and GHG emissions, and thus the possibility to use N surpluses as an indicator for GHG emissions.  相似文献   

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