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1.
华东地区稻麦轮作农田生态系统N2O5排放的模拟研究 总被引：3，自引：0，他引：3
利用ＤＮＤＣ（ＤｅＮｉｔｒｉｆｉｃａｔｉｏｎ ａｎｄ ＤｅＣｏｍｐｏｓｉｔｉｏｎ）模式,对华东地区典型稻麦轮作农田生态系统的Ｎ２Ｏ排放特征进行了模拟研究。结果表明：该模式能模拟出轮作周期中Ｎ２Ｏ的主要排放峰值和排放趋势,但与实测值相比,模拟结果普遍有些偏小。相对而言,该模式对旱地阶段的模拟结果比较理想,尤其是对春季小麦返青至成熟期的模拟最好。因此,我们就该阶段影响Ｎ２Ｏ排放的主要因子进行了敏感性研 相似文献
2.
内蒙古草原温室气体排放日变化规律研究 总被引：11，自引：0，他引：11
采用静态值－气相色谱法研究内蒙古草原温室气体N2O、CO2、CH4与大气交换的日变化规律。CO2日排放变化形式基本相同，和大气交换的总结果是向大气排放，影响草原N2O排放日变化形式的关键是土壤含水量和表层土壤理化特性，日温变化主要影响其日变化强度；影响草原CH4日变化形式的关键因子是土壤水分和供氧状况，而温度和植物的生长状况则影响吸收强度，利用内蒙古草原温室气候排放相对固定的日变化形式，可以对相同生产季内每周1次的观测结果进行矫正。 相似文献
3.
种植不同作物对农田N2O和CH4排放的影响及其驱动因子 总被引：3，自引：0，他引：3
以种植玉米(Zea mays)、大豆(Glycine max)和水稻(Oryza sativa)的农田生态系统为研究对象,于2003年6~10月系统观测了N2O和CH4的排放、土壤温度和湿度以及相关的生物学因子。玉米和水稻分别施化肥氮300 kg.hm-2,大豆未施氮肥。研究结果表明,作物类型对农田N2O和CH4排放具有显著的影响。土壤-玉米系统、土壤-大豆系统和土壤-水稻系统的N2O季节性平均排放通量分别为620.5±57.6、338.0±7.5和238.8±13.6μg.m-2.h-1(N2O)。种植作物促进了农田生态系统的N2O排放,玉米地土壤和裸地土壤的N2O平均排放通量分别为364.2±11.7和163.7±10.5μg.m-2.h-1(N2O)。土壤-玉米系统、土壤-水稻系统、玉米地土壤和裸地土壤N2O排放受土壤温度的影响,与土壤湿度无显著统计相关,但受土壤温度和水分的综合影响。土壤-大豆系统N2O排放随作物绿叶干重的增加而指数增加,与土壤温度和水分条件无统计相关,由大豆作物自身氮代谢所产生的N2O-N季节总量约为6.2 kg.hm-2(N)。土壤-水稻系统CH4平均排放通量为1.7±0.1 mg.m-2.h-1(CH4),烤田抑制了稻田CH4的排放。烤田前影响稻田CH4排放的主要因素是水稻生物量,烤田后的浅水灌溉及湿润灌溉阶段的CH4排放与土壤温度和水稻生物量无关。本研究未观测到旱作农田有吸收CH4的现象。 相似文献
4.
太湖地区冬小麦田与蔬菜地N2O排放对比观测研究 总被引：10，自引：0，他引：10
2003年11月8日至2004年6月5日对太湖地区相邻的蔬菜地和稻麦轮作生态系统的冬小麦田,在当季不施肥情况下的N2O排放进行了田间同步对比观测,分析了N2O排放时间变化以及土壤湿度、土壤温度、土壤速效氮含量和农业管理措施对N2O排放的影响。研究结果表明,小麦播种前的耕翻(表层大约7cm土壤旋耕)处理不会明显改变稻麦轮作农田整个旱地阶段的N2O排放总量,但却使小麦生长季初期的N2O排放明显减弱69%(p<0.01,p为相关概率),使小麦生长季后期的N2O排放明显偏高2.6倍(p<0.05),而对其余时间段的N2O排放作用不明显。与长期实行稻麦轮作的旱地阶段农田相比,由稻田改种蔬菜20多年的蔬菜地,其整个观测期的N2O排放总量比免耕处理小麦田同期的排放高85%(p<0.05),比耕翻处理小麦田同期的排放高99%(p<0.01)。蔬菜地N2O排放偏高的原因是土壤速效氮,特别是铵态氮含量明显偏高(p<0.01)。 相似文献
5.
影响农田氧化亚氮排放过程的土壤因素 总被引：23，自引：1，他引：22
土壤理化特性是影响农田氧化亚氮(N2O)产生和排放的重要因素.作者主要讨论了土壤微生物、土壤质地、土壤中化学物质、土壤温度和土壤pH值等对农田N2O的影响.继续深入研究这些因素对农田N2O排放的综合影响和机理以及与其排放量之间的数量关系应是未来的研究重点.为准确估计区域乃至全球范围的农田N2O排放总量,对农田N2O排放模型中关键土壤参数的确定尤为重要. 相似文献
6.
华东稻麦轮作农田CH4、N2O和NO排放特征 总被引：2，自引：0，他引：2
利用同步自动观测系统对华东稻麦轮作农田的CH4、N2O和NO排放进行了长期连续观测,分析了这3种气体排放的季节特征及决定因素,结果表明,华东稻麦轮作农田的CH4、N2O和NO排放具有完全不同的季节变化形式。CH4的排放发生在水稻生长期,其他阶段排放不明显,土壤水分状况是决定整个轮作周期内CH4排放变化的主要因素。N2O排放具有"冬季无,水田少,旱地多"的季节变化特点,尤其以旱地阶段的排放为主,土壤水分状况和温度共同决定着N2O排放的季节变化形式。NO排放具有"冬季无,水田很少,春季旱地多于秋季旱地"的季节分布特点,轮作周期内97.3%±0.6%的NO排放都发生在除冬季以外的旱地阶段,NO排放的季节变化形式由土壤水分状况和温度共同决定。大多数情况下稻田CH4和N2O排放呈互为消长的关系,但在烤田期间,二者却有时甚至同时出现高排放。在N2O日平均排放通量小于5 mg.m-2.h-1时,稻麦轮作农田的N2O和NO排放呈明显的互为消长关系,但大于5 mg.m-2.h-1时,N2O排放很强,同时NO排放也很强。 相似文献
7.
模式内部变率是模拟结果不确定性的重要来源,然而它对于1.5℃和2℃升温阈值出现时间不确定性的影响尚不清楚。因此,基于耦合模式比较计划第五阶段(CMIP5)的多模式数据研究了模式内部变率对1.5℃和2℃升温阈值出现时间不确定性的影响以及对未来排放情景的敏感性。结果表明,模式内部变率对升温阈值出现时间模拟的影响与外强迫的影响相当,单个模式内部不同成员达到全球平均1.5℃或2℃增温的年份相差2~12年;其影响具有明显的空间差异,影响极大值出现在欧亚大陆以北洋面、白令海峡周围区域、北美东北部及其与格陵兰岛之间的海域、南半球高纬地区等;低排放情景下模式内部变率的影响大于高排放情景。 相似文献
8.
本文建立了一个区域尺度稻田生态系统CH4排放的初步模式，该模式能从理论上反映稻田CH4产生、传输与排放的机理，并提供了一种估计不同区域气候和土壤条件下稻田生态系统CH4排放总量的有效方法。模式主要包括三个部分:水稻的生长、土壤有机物的分解和CH4的产生、传输及排放过程。模式分别模拟了早稻和晚稻CH4的排放，模拟结果与实测比较接近，CH4的季平均排放量，模拟值与实测值的偏差在10% 左右。模式的敏感性实验表明，温度是稻田CH4排放规律的主要控制因子。 相似文献
9.
1992年大气甲烷增长速率异常
下降的模拟研究 总被引：4，自引：0，他引：4
应用初步建立的全球二维大气化学模式,模拟了甲烷、一氧化碳和OH自由基自工业革命以来的长期变化,对1992年大气中甲烷增长速率突然下降这一异常现象的可能原因如平流层O3下降,皮纳图博火山引起对流层温度下降、甲烷排放源减少等逐一进行了定量研究。研究还发现一氧化碳排放源的减少是另一重要影响因子,并进行了验证。结果表明,1992年甲烷增长速率急剧下降的主要原因来自甲烷和一氧化碳排放源的减少。 相似文献
10.
半干旱草原温室气体排放/吸收与环境因子的关系研究 总被引：13，自引：3，他引：10
静态箱一气相色谱法对内蒙古半干旱草原连续两年的实验观测研究结果表明,内蒙古草原是大气CO2和N2O的排放源,而是CH4的汇.在植物生长不同季节,草原生态系统排放/吸收温室气体CO2,CH4和N2O的日变化形式各有不同,其中在植物生长旺季日变化形式最具特征.3种温室气体的季节排放/吸收高峰主要出现在土壤湿度较大的春融和降雨较为集中时期.所有草原植物生长季节CO2净排放日变化形式均为白天出现排放低值,夜间出现排放高值.较高的温度有利于CO2排放,地上生物量决定着光合吸收CO2量值的高低.影响半干旱草原吸收CH4和排放N2O日变化形式的关键是土壤含水量和供氧状况,日温变化则主要影响日变化强度.吸收CH4和排放N2O的季节变化与土壤湿度季节变化分别呈线性反、正相关,相关系数均在0.4～0.6之间.自由放牧使CO2、N2O和CH4交换速率日较差降低,同时使N2O和CH4年度排放/吸收量减少和CO2年度排放量增加. 相似文献
11.
l.Intr0ductionWiththedevelopmentofeconomy,theenvironmentalproblemsarebec0mingincreasinglyserious.Am0ngthem,theenhancementofgreenh0useeffectsandglobalwarm-ingaretwoimPOrtantonesthathavear0usedwideattention.Nitrousoxide(N,O)isanim-POrtantgreenhousegasandplayingagreatroleinthesetwoprocesses.SincetheIndustrialRevolution,theatmosphericN2Oconcentrationhasincreasedbyaboutl5%(IPCC,l995).Inthelast4Oyears,itincreasedrapidlyatarateof0.2%ro.3%yr-'(IPCC,l99O).Ifitin-creasesatthisrate,theatmospheri… 相似文献
12.
DNDC, a rainfall-driven and process-oriented model of soil carbon and nitrogen biogeochemistry, is applied to simulate the nitrous oxide emissions from agricultural ecosystem in Southeast China. We simulated the soil N2O emission during a whole rice-wheat rotation cycle (from Nov. 1, 1996 to Oct. 31, 1997) under three different conditions, which are A) no fertilizer, B) both chemical fertilizer and manure and, C) chemical fertilizer only. The processes of N2O emission were discussed in detail by comparing the model outputs with the results from field measurement. The comparison shows that the model is good at simulating most of the N2O emission pulses and trends. Although the simulated N2O emission fluxes are generally less than the measured ones, the model outputs during the dryland period, especially during the wheat reviving and maturing stages in spring, are much better than those during the paddy field period. Some sensitive experiments were made by simulating the N2O emissions in spring, when there is a smallest gap between the simulated fluxes and the measured ones. Meanwhile, the effects of some important regulating factors, such as the rainfall, N deposition by rainfall, temperature, tillage, nitrogen fertilizer and manure application on N2O emission during this period were analyzed. From the analysis, we draw a conclusion that soil moisture and fertilization are the most important regulating factors while the N2O emission is sensitive to some other factors, such as temperature, manure, tillage and the wet deposition of atmospheric nitrate. 相似文献
13.
对甲烷湿地排放模型CH4MODwetland进行灵敏度分析表明,环境驱动因素——温度和地表水深是影响甲烷排放通量的主要因素,地表水深对季节性积水沼泽甲烷排放通量的灵敏度大于常年积水沼泽。模型对植物和土壤输入参数的灵敏度响应依次为Wmax(地上生物量最大值)FR(地下净初级生产力占植物总净初级生产力的比例)fV(植被类型系数)TAmax(植物从生长初期到最大地上生物量所需有效积温)ρ(容量),OM(土壤有积质含量)SAND(土壤砂粒含量)。以经验水位模型驱动CH4MODwetland,模拟三江平原毛果苔草和小叶章沼泽(1950年代～2000年代),以及若尔盖高原木里苔草和乌拉苔草沼泽(1960年代～2000年代)多年甲烷排放通量的变化。结果表明,年代际甲烷排放通量的变化主要受降水量的影响,但气候变暖使得降水量基本相同的年代甲烷排放通量增加:三江平原毛果苔草沼泽和小叶章沼泽(1980年代～2000年代比1950年代～1970年代模拟的甲烷排放通量分别增加了9.5%和8.3%;若尔盖高原乌拉苔草沼泽和木里苔草沼泽(1990年代～2000年代比1960年代～1970年代)分别增加了6.0%和5.5%。该结论能够为评估未来气候变化对中国湿地甲烷排放的影响提供依据。 相似文献
14.
Mitigation options for methane, nitrous oxide and nitric oxide emissions from agricultural ecosystems 总被引：9，自引：0，他引：9
Zheng Xunhu Wang Mingxing Wang Yuesi Shen Renxing Li Jing J. Heyer M. Koegge H. Papen 《大气科学进展》2000,17(1):83-92
1.IntroductionNitrousoxide(N,O)andmethane(CH.)arethemostimportantgreenhousegassesintheatmospherewithitscontributiontoglobalwarmingjustlowerthanCO2.Theirconcentrationsinatmospherehavebeennotedtoincreasecurrentlyattherateof0.25%yr--'andl.02%yr',respectively(IPCC,1995).Atpresent,theincreaseofNZOandCH4intheatmospherehasbeenestimatedtoaccountfor20--25%oftheglobalwarming(FAO&IAEA,1992;Bailes&Bridges,1992).NOdoesnotabsorbradiationdirectlyintheatmosphere,buttheincreasingconcentrationofNOmay… 相似文献
15.
In order to numerically simulate daily nitrous oxide(N2O) emission from a rice-winter wheat rotation cropping system,a process-based site model was developed(referred to as IAP-N-GAS) to track the movement and transformation of several forms of nitrogen in the agro-ecosystem,which is affected by climate,soil,crop growth and management practices.The simulation of daily N2O fluxes,along with key daily environmental variables,was validated with three-year observations conducted in East China.The validation dem... 相似文献
16.
农田生态系统温室气体排放研究进展 总被引：39，自引：0，他引：39
自1985年起,中国科学院大气物理研究所利用自行设计制造的自动观测仪器系统,历时十六年先后对我国四大类主要水稻产区的甲烷排放规律及其与土壤、气象条件和农业管理措施的关系进行了系统野外观测实验,并对稻田甲烷产生、转化和输送机理进行了理论研究,探讨了控制稻田甲烷排放的实用措施,建立了估算和预测稻田甲烷排放的数值模型.在甲烷排放的时空变化规律和转化率研究方面有一系列新的发现,在稻田甲烷产生率、排放率及其与环境条件的关系方面取得一系列新的成果,以充分证据改变了国际上关于全球和中国稻田甲烷排放总量的估算.在对稻田甲 相似文献
17.
Methane and Nitrous Oxide Emissions from Three Paddy Rice Based Cultivation Systems in Southwest China 总被引：4，自引：0，他引：4
To understand methane (CH4) and nitrous oxide (N2O) emissions from permanently flooded rice paddy fields and to develop mitigation options, a field experiment was conducted in situ for two years (from late 2002 to early 2005) in three rice-based cultivation systems, which are a permanently flooded rice field cultivated with a single time and followed by a non-rice season (PF), a rice-wheat rotation system (RW) and a rice-rapeseed rotation system (RR) in a hilly area in Southwest China. The results showed that the total CH4 emissions from PF were 646.3±52.1 and 215.0±45.4 kg CH4 hm-2 during the rice-growing period and non-rice period, respectively. Both values were much lower than many previous reports from similar regions in Southwest China. The CH4 emissions in the rice-growing season were more intensive in PF, as compared to RW and RR. Only 33% of the total annual CH4 emission in PF occurred in the non-rice season, though the duration of this season is two times longer than the rice season. The annual mean N2O flux in PF was 4.5±0.6 kg N2O hm-2 yr-1. The N2O emission in the rice-growing season was also more intensive than in the non-rice season, with only 16% of the total annual emission occurring in the non-rice season. The amounts of N2O emission in PF were ignorable compared to the CH4 emission in terms of the global warming potential (GWP). Changing PF to RW or RR not only eliminated CH4 emissions in the non-rice season, but also substantially reduced the CH4 emission during the following rice-growing period (ca. 58%, P<0.05). However, this change in cultivation system substantially increased N2O emissions, especially in the non-rice season, by a factor of 3.7 to 4.5. On the 100-year horizon, the integrated GWP of total annual CH4 and N2O emissions satisfies PF>>RR≈RW. The GWP of PF is higher than that of RW and RR by a factor of 2.6 and 2.7, respectively. Of the total GWP of CH4 and N2O emissions, CH4 emission contributed to 93%, 65% and 59% in PF, RW and RR, respectively. These results suggest that changing PF to RW and RR can substantially reduce not only CH4 emission but also the total GWP of the CH4 and N2O emissions. 相似文献
18.
小麦秸秆还田量对晋南地区裸地土壤—大气间甲烷、二氧化碳、氧化亚氮和一氧化氮交换的影响 总被引：11，自引：0，他引：11
采用静态暗箱采样—气相色谱/化学发光分析相结合的方法,对晋南地区盐碱地不同小麦秸秆还田量裸地土壤夏、秋季(2008年6～10月)的甲烷(CH4)、二氧化碳(CO2)、氧化亚氮(N2O)和一氧化氮(NO)交换通量进行了原位观测。结果表明:观测期内,秸秆全还田(FS)、秸秆一半还田(HS)和秸秆不还田(NS)处理土壤—大气间CH4、CO2、N2O和NO平均交换通量分别为-0.8±2.7、-1.4±2.3、-6.5±1.8μg(C).m-2.h-1(CH4),267.1±23.1、212.0±17.8、188.5±13.6mg(C).m-2.h-1(CO2),20.7±3.0、16.3±2.3、14.7±1.7μg(N).m-2.h-1(N2O),3.9±0.5、3.4±0.5、3.0±0.4μg(N).m-2.h-1(NO)。交换通量表现出明显的季节变化趋势,灌溉、降雨和温度变化是影响该趋势的主要因素。相对于NS处理,FS和HS处理降低了累积CH4吸收量(66%和59%),增加了累积CO2(42%和12%)、N2O(41%和9%)和NO(30%和13%)排放量,因此,秸秆还田促进了农田土壤总的温室气体排放。计算得到FS和HS处理小麦秸秆的CO2、N2O、NO排放系数分别为73.4%±1.6%和43.3%±1.0%(CO2)、0.37%±0.01%和0.17%±0.00%(N2O)、0.06%±0.00%和0.05%±0.00%(NO),FS处理的排放系数显著高于HS处理,且均低于同一实验地种植玉米、施肥农田的小麦秸秆排放系数(N2O和NO排放系数分别为2.32%和0.42%)。可见,在采用排放因子方法估算还田秸秆CO2、N2O和NO排放量时,应考虑秸秆还田量、农作物种植和施肥因素的影响。 相似文献
19.
F. Slemr G. Baumbach P. Blank U. Corsmeier F. Fiedler R. Friedrich M. Habram N. Kalthoff D. Klemp J. Kühlwein K. Mannschreck M. Möllmann-Coers K. Nester H.-J. Panitz P. Rabl J. Slemr U. Vogt B. Wickert 《Journal of Atmospheric Chemistry》2002,42(1):207-233
Emission inventories of NOx, CO, and individual volatile organic compounds (VOC), highly resolved in space and time, belong to the most important input parameters for chemistry and transport models (CTM) used for ozone prediction. Because of the decisive influence of the input quality on the outcome of CTM simulations, the quality of emission inventories has to be assessed. This paper presents an experimental evaluation of the highly resolved emission inventories for the city of Augsburg. The emissions of the city, determined in March and October 1998 using mass balance and tracer techniques, and derived from the measured receptor concentration ratios, were compared with emissions modeled from an emission inventory. The modeled CO emissions were in agreement with the measured ones within the combined experimental and model uncertainties. More detailed CO emission model simulations suggest that the tendency of calculated CO emissions being smaller than the measured ones may be due to higher traffic activity in Augsburg. Modeled NOx emissions were in agreement with the measured ones within the combined experimental and model uncertainties. Large deviations between modeled and measured values have been found for some individual NMHC compounds. The measured NMHC emission fingerprints were dominated by mobile sources. Substantial model predicted NMHC emissions from the solvent use could not be detected by measurements suggesting that they may not be correctly represented by the emission model. 相似文献