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1.
No studies have examined the effect of experimental warming on the microbial biomass and community composition of soil in agricultural ecosystem on the Qinghai-Tibet Plateau. Thus it is unclear whether the influences of experimental warming on microbial communities in soil are related to warming magnitude in croplands on this Plateau. This study performed warming experiment (control, low- and high-level) in a highland barley system of the Lhasa River in May 2014 to examine the correlation between the response of microbial communities in soil to warming and warming magnitude. Topsoil samples (0-10 and 10-20 cm) were collected on September 14, 2014. Experimental warming at both low and high levels significantly increased soil temperature by 1.02 ℃ and 1.59 ℃, respectively at the depth of 15 cm. Phospho lipid fatty acid (PLFA) method was used to determine the microbial community in soil. The low-level experimental warming did not significantly affect the soil’s total PLFA, fungi, bacteria, arbuscular mycorrhizal fungi (AMF), actinomycetes, gram-positive bacteria (G+), gram-negative bacteria (G-), protozoa, the ratio of fungi to bacteria (F/B ratio), and ratio of G+ to G- (G+/G- ratio) at the 0-10 and 10-20 cm depth. The low-level experimental warming also did not significantly alter the composition of microbial community in soil at the 0-10 and 10-20 cm depth. The high-level experimental warming significantly increased total PLFA by 74.4%, fungi by 78.0%, bacteria by 74.0%, AMF by 66.9%, actinomycetes by 81.4%, G+ by 67.0% and G- by 74.4% at the 0-10 cm depth rather than at 10-20 cm depth. The high-level experimental warming significantly altered microbial community composition in soil at the 0-10 cm depth rather than at 10-20 cm depth. Our findings suggest that the response of microbial communities in soil to warming varied with warming magnitudes in the highland barley system of the Lhasa River. 相似文献
2.
开垦对荒漠土壤微生物群落结构特征的影响 总被引：3，自引：3，他引：0
以古尔班通古特沙漠南缘典型流域（玛纳斯河、吉木萨尔河、三工河、四工河、水磨河）的绿洲农田与毗邻荒漠土壤为研究对象,采用磷脂脂肪酸（PLFA）方法分析不同开垦年限的土壤微生物生物量、群落结构、多样性变化特征。结果表明：荒漠开垦后,土壤微生物总PLFA含量、真菌PLFA、细菌PLFA、革兰氏阳性菌（G+）和革兰氏阴性菌（G-）PLFA含量均显著增加。荒漠开垦5 a内,细菌PLFA与G-PLFA增长更强烈,使得真菌PLFA/细菌PLFA比值降低了48%,G+PLFA/G-PLFA比值（革兰氏阳性菌与革兰氏阴性菌的PLFA比值）降低了67%。但随着开垦年限的延长,这两个比值没有显著变化,表明与开垦年限相比,荒漠的开垦行为对土壤微生物群落结构有着更加强烈的影响。随着开垦年限的增加,土壤微生物群落多样性总体呈上升趋势。虽然荒漠在开垦50 a后多样性指数略有下降,但仍远高于荒漠土壤。土壤微生物总PLFA含量和大部分菌群PLFA含量与土壤电导率显著负相关,与全氮和有机碳显著正相关。荒漠在开垦过程中灌溉增加了土壤水分且降低了土壤盐分,全氮和有机碳含量增加,这些改变是土壤微生物群落变化的主要原因。荒漠开垦有助于提高土壤微生物PLFA含量、改善土壤微生物的群落结构、丰富土壤微生物群落多样性,有利于土壤质量的提高。 相似文献
3.
In order to investigate the general tendency of soil microbial community responses to fertilizers, a meta-analysis approach was used to synthesise observations on the effects of inorganic and organic fertilizer addition (N: nitrogen; P: phosphorus; NP: nitrogen and phosphorus; PK: phosphorus and potassium; NPK: nitrogen, phosphorus and potassium; OF: organic fertilizer; OF+NPK: organic fertilizer plus NPK) on soil microbial communities. Among the various studies, PK, NPK, OF and OF+NPK addition increased total phospholipid fatty acid (PLFA) by 52.0%, 19.5%, 334.3% and 58.3%, respectively; while NP, OF and OF+NPK addition increased fungi by 5.6%, 21.0% and 8.2%, respectively. NP, NPK and OF addition increased bacteria by 6.4%, 9.8% and 13.3%, respectively; while NP and NPK addition increased actinomycetes by 7.0% and 14.8%, respectively. Addition of ammonium nitrate rather than urea decreased gram-negative bacteria (G -). N addition increased total PLFA、bacteria and actinomycetes in croplands, but decreased fungi and bacteria in forests, and the F/B ratio in grasslands. NPK addition increased total PLFA in forests but not in croplands. The N addition rate was positively correlated with the effects of N addition on gram-positive bacteria (G +) and G -. Therefore, different fertilizers appear to have different effects on the soil microbial community. Organic fertilizers can have a greater positive effect on the soil microbial community than inorganic fertilizers. The effects of fertilizers on the soil microbial community varied with ecosystem types. The effect of N addition on the soil microbial community was related to both the forms of nitrogen that were added and the nitrogen addition rate. 相似文献
4.
The priming effect is well acknowledged in soil systems but the effect of nitrogen (N) fertilization remains elusive. To explore how N modifies the priming effect in soil organic matter (SOM), one in situ experiment with 13C labeled glucose addition (0.4 mg C g-1 soil, 3.4 atom % 13C) was conducted on soil plots fertilized with three gradients of urea (0, 4 and 16 g N m-2 yr-1). After glucose addition, the soil CO2 concentration and phospholipid fatty acid (PLFA) were measured on day 3, 7, 21 and 35. The study found that N fertilization decreased soil CO2, PLFA and the fungi to bacteria ratio. Glucose triggered the strongest positive priming in soil at 0 g N m-2 yr-2, meanwhile N fertilization decreased SOM-derived CO2. Soil at 4 g N m-2 yr-2 released the largest amount of glucose-derived carbon (C), likely due to favorable nutrient stoichiometry between C and N. Stable microbial community biomass and composition during early sampling suggests “apparent priming” in this grassland. This study concludes that N fertilization inhibited soil priming in semi-arid grassland, and shifted microbial utilization of C substrate from SOM to added labile C. Diverse microbial functions might be playing a crucial role in soil priming and requires attention in future N fertilization studies. 相似文献
5.
生物模块沙障是一种新型沙袋沙障,同时具备防风固沙、局部土壤改良和植被建植功能.区别于其他沙袋沙障,生物模块沙障外包装为黄麻纤维,内部除填充风沙土外,还添加了玉米芯和羊粪.为了解生物模块沙障的局部土壤改良功能,从土壤微生物角度出发,测定和研究了生物模块沙障内部及周围土壤空间内细菌、真菌、放线菌数量分布情况.结果表明:生物模块沙障内部土壤细菌、真菌、放线菌数量及三者总数量分别达到了2.41×107 cfu·g-1、4.51×107 cfu·g-1、1.19×107 cfu·g-1及8.11×107 cfu·g-1,而对照仅分别为1.56×106 cfu·g-1、3.01×106 cfu·g-1、1.26×106 cfu·g-1及5.83×106 cfu·g-1;生物模块沙障内部3种微生物及三者总数量均高于其覆盖的下方土层,下方各土层3种微生物数量均显著高于未设置沙障区;在生物模块沙障迎风侧50 cm至背风侧50 cm区域,3种微生物总数量大小顺序为沙障放置处 > 沙障背风侧20 cm处 > 沙障迎风侧20 cm处 > 沙障背风侧50 cm处 > 沙障迎风侧50 cm处,在此防护区内土壤细菌、真菌及放线菌数量平均值分别是流动沙丘的19.56、24.47、8.39倍.生物模块沙障设置5年后,其内部3种微生物数量显著高于周围土壤,说明生物模块沙障对周围土壤微生物的影响依然存在潜力. 相似文献
6.
Inter-annual variability in total precipitation can lead to significant changes in carbon flux. In this study, we used the eddy covariance (EC) technique to measure the net CO2 ecosystem exchange (NEE) of an alpine meadow in the northern Tibetan Plateau. In 2005 the meadow had precipitation of 489.9 mm and in 2006 precipitation of 241.1 mm, which, respectively, represent normal and dry years as compared to the mean annual precipitation of 476 mm. The EC measured NEE was 87.70 g C m-2 yr-1 in 2006 and -2.35 g C m-2 yr-1 in 2005. Therefore, the grassland was carbon neutral to the atmosphere in the normal year, while it was a carbon source in the dry year, indicating this ecosystem will become a CO2 source if climate warming results in more drought conditions. The drought conditions in the dry year limited gross ecosystem CO2 exchange (GEE), leaf area index (LAI) and the duration of ecosystem carbon uptake. During the peak of growing season the maximum daily rate of NEE and Pmax and α were approximately 30%-50% of those of the normal year. GEE and NEE were strongly related to photosynthetically active radiation (PAR) on half-hourly scale, but this relationship was confounded by air temperature (Ta), soil water content (SWC) and vapor pressure deficit (VPD). The absolute values of NEE declined with higher Ta, higher VPD and lower SWC conditions. Beyond the appropriate range of PAR, high solar radiation exacerbated soil water conditions and thus reduced daytime NEE. Optimal Ta and VPD for maximum daytime NEE were 12.7℃ and 0.42 KPa respectively, and the absolute values of NEE increased with SWC. Variation in LAI explained around 77% of the change in GEE and NEE. Variations in Re were mainly controlled by soil temperature (Ts), whereas soil water content regulated the responses of Re to Ts. 相似文献
7.
利用静态暗箱-气相色谱法在植物生长旺季测算了内蒙古锡林河流域羊草草原的土壤微生物呼吸、土壤呼吸和生态系统呼吸。地温和水分是植物生长旺季呼吸最重要的影响因素。地温在水分条件适宜的情况下可以解释CO2通量的部分变化(R2 = 0.376~0.655)。土壤水分含量也可以解释土壤呼吸和生态系统呼吸的部分变化(R2 = 0.314~0.583),但基本不能解释土壤微生物呼吸的变化(R2 = 0.063)。即使在较高温度下,较低的土壤水分含量(≤ 5%) 也会显著的抑制CO2排放。长期干旱后降雨使CO2通量在高温下迅速增大。基于5 cm地温和0~10 cm土壤水分含量的双变量模型可以解释CO2通量约70%的变化。观测期间,土壤呼吸占生态系统呼吸的比例介于47.3%~72.4%之间,平均为59.4%;根呼吸占土壤呼吸的比例介于11.7%~51.7%之间,平均为20.5%。由于植物体去除引起的土壤水分含量上升可能使我们对土壤呼吸占生态系统呼吸比例的估计略微偏高,根呼吸占土壤呼吸的比例略微偏低。 相似文献
8.
大兴安岭多年冻土区森林土壤温室气体通量 总被引：1，自引：0，他引：1
多年冻土温室气体排放对全球气候变化有重要影响。采用静态暗箱—气相色谱法,于2016—2017年生长季（5—9月）,对大兴安岭多年冻土区兴安落叶松林、樟子松林和白桦林土壤二氧化碳（CO2）、甲烷（CH4）和氧化亚氮（N2O）通量进行野外原位观测,对比分析温室气体通量的动态变化特征及其关键影响因子。结果表明：3种林型土壤CO2通量范围为65.88~883.59 mg·m-2·h-1;CH4通量范围为-93.29~-2.82 μg·m-2·h-1;N2O通量范围为-5.31~45.22 μg·m-2·h-1。整个生长季兴安落叶松林、樟子松林和白桦林土壤均表现为CO2、N2O的排放源、CH4的吸收汇,土壤CO2和CH4通量在不同林型和年际间差异显著。3种林型土壤CO2通量与5 cm、10 cm和15 cm土壤温度呈极显著正相关（P < 0.01）;CH4通量受土壤含水量和10 cm、15 cm土壤温度的影响较大（P < 0.05）;兴安落叶松林和樟子松林土壤N2O通量与气温呈显著正相关（P < 0.05）,而白桦林土壤N2O则与15 cm土壤温度呈显著负相关（P < 0.05）。基于100 a时间尺度计算温室气体全球综合增温潜势,3种林型土壤温室气体的排放对气候变暖具有正反馈作用。 相似文献
9.
利用涡度相关技术对青海湖高寒湿地生态系统不同时间尺度CO2通量和水汽通量间的耦合关系进行了研究。结果显示：不同天气条件下青海湖高寒湿地生态系统30 min净CO2交换量（NEE）与水汽通量间均显示了极显著负相关关系（P<0.0001）;30 min总生态系统生产力（GEP）与水汽通量呈极显著线性正相关关系（P<0.0001）;阴天水汽通量参与生态系统净CO2交换和生态系统总碳吸收的比例最高。月均30 min NEE与水汽通量呈极显著线性负相关（R2=0.71,P<0.0001）。从植物返青期、生长期至枯草期,月均30 min的GEP与水汽通量不仅呈极显著线性正相关（P<0.0001）,且在生长期和枯黄期阶段表现出极显著一元二次多项式关系（P<0.0001）。在日尺度上,NEE日总量与日蒸散量呈极显著一元二次多项式负相关关系（R2=0.58,P<0.0001）;GEP日总量与日蒸散量呈极显著指数正相关（R2=0.42,P<0.0001）。在月尺度上,NEE月总量与月蒸散量呈极显著线性负相关（R2=0.60,P<0.0001）,两者还表现为极显著一元二次多项式负相关关系（R2=0.63,P<0.0001）。GEP月总量与月蒸散量呈极显著线性正相关（R2=0.51,P<0.0001）,且表现出极显著指数正相关关系（R2=0.64,P<0.0001）。 相似文献
10.
大气氮沉降可能会影响陆地生态系统的碳通量。本文主要目的是探讨在氮素缺乏的草地生态系统中,氮素添加是否会增加CO2通量。本研究于2008和2009生长季进行,采用静态箱-气相色谱法研究CO2通量对氮沉降增加的响应。结果表明,2年的氮素添加并没有显著影响土壤NH4+含量,NO3-含量只是在2009年生长季后期有所增加。高氮处理增加了CO2通量,而低氮处理在2008年抑制了CO2通量,2009年后期增加了CO2通量。而且氮素添加显著增加了地上生物量和根系的生物量。CO2通量与土壤水分、土壤温度的关系并没有因为氮素的添加而改变,但是氮素添加增加了CO2通量对土壤水分和土壤温度的敏感性。这些结果表明,在未来大气氮沉降增加的背景下,呼伦贝尔草甸草原CO2通量有可能会增加。 相似文献
11.
白令海是北冰洋太平洋扇区的边缘海,是亚北极生态系统向北极生态系统过渡的典型区域,白令海CO_2源汇的研究可为高纬度边缘海相关的研究提供重要的参考。在全球持续变暖的背景下,白令海正在发生着一些气候和环境的变化,这些变化对CO_2源汇以及控制CO_2源汇的生物地球化学过程产生重要影响。对目前白令海CO_2源汇特征及其控制因素相关研究进行了归纳总结,预测了白令海CO_2源汇的未来变化趋势并提出了展望。以往的研究都认为白令海是一个大气CO_2的汇区,但是碳汇研究结果差异较大,最近的研究结果表明白令陆架区的碳汇约–6.81 Tg C·a~(–1)(1 Tg=10~(12)g),整个白令海的碳汇约–34 Tg C·a~(–1)。在未来白令海气候和环境变化继续加剧的条件下,使得白令海碳汇增强或减弱的因素将同时存在,因此,未来白令海的碳汇是增强还是减弱尚无定论。 相似文献
12.
凋落物矿化分解是维持生态系统养分循环的关键过程,也是陆地生态系统C向大气释放的主要动力,因此影响和控制生态系统凋落物矿化分解的主要因素一直备受关注。土地沙漠化是科尔沁沙地最严重的环境问题,并且导致土壤粗质化和贫瘠化,凋落物输入和矿化分解对于改善该地区土壤质地和养分状况至关重要。通过室内培养的方法,对科尔沁沙质草地27种主要植物叶凋落物矿化分解及其与凋落物C含量、N含量、木质素含量、C/N、木质素/N、极易分解有机物含量(LOMⅠ)、中易分解有机物含量(LOMⅡ)及难分解有机物含量(RP)等指标关系进行研究。结果表明:科尔沁沙地27种植物叶凋落物质量存在较大差异(P<0.001),相应的27种植物叶凋落物培养样品矿化有机碳总量和干物质损失量存在显著差异(P<0.001),分别在9.0 mg C·g-1干土至12.7 mg C·g-1干土和14.7%至40.4%之间变化。添加凋落物后培养样品的CO2释放总量显著大于对照(不添加凋落物),说明土壤中添加凋落物后,培养样品的有机碳矿化速率明显增大。27种植物叶凋落物矿化有机碳总量以及损失干物质总量与凋落物的N含量、C/N、木质素/N、LOMⅠ、LOMⅡ和RP等指标存在显著的相关性,叶凋落物的矿化分解主要受LOMⅠ和木质素/N的影响。 相似文献
13.
大气CO2浓度升高和施氮对棉田土壤理化性质及微生物区系的影响 总被引：2，自引：0，他引：2
针对耕地非农转化过程中产生的一系列社会问题,采用参与性农户调查方法,对西部欠发达地区西宁市郊区5个样本村190户农户进行了随机入户调查。根据城市开发进程、到市区距离和种植类型等条件,将调查样本村分为近郊城区化农村、近郊农村和远郊农村,就农户对耕地非农转换的基本认知及耕地非农转换的经济、社会和环境价值感知进行分析。结果表明:耕地征用后农户能理性感知和判别耕地非农转换价值,并普遍认为失去耕地后生活费用增加、生活保障降低、收入来源和就业机会少;感知主要受耕地数量、区位条件、耕地开发阶段等因素的影响;处于不同区位条件的农户对耕地非农转换的价值感知存在差异性,城区化农户已逐渐适应城市生活,近郊农户的非农转换经济和社会感知压力最大,远郊农民也感知经济和生活保障压力,但更希望能通过打工增加收入。 相似文献
14.
YE Shu GUO Chuying HAN Jiayin ZHANG Leiming DAI Guanhua WEN Xuefa YU Guirui 《资源与生态学报(英文版)》2019,10(2):127-136
Fluctuations in soil greenhouse gas (GHG) are an important part of the terrestrial ecosystem carbon-nitrogen cycle, but uncertainties remain about the dynamic change and budget assessment of soil GHG flux. Using high frequency and consecutive soil GHG fluxes measured with an automatic dynamic chamber system, we tested the applicability of the current Forest-DNDC model in simulating soil CH4, CO2 and N2O fluxes in a temperate broad-leaved Korean pine forest at Changbai Mountain. The results showed that the Forest-DNDC model reproduced general patterns of environmental variables, however, simulated seasonal variation in soil temperature, snow melt processes and soil moisture partly deviated from measured variables, especially during the non-growing season. The modeled CH4 flux was close to the field measurement and co-varied mainly with soil temperature and snowpack. The modeled soil CO2 flux had the same seasonal trend to that of the observation along with variation in temperature, however, simulated CO2 flux in the growing season was underestimated. The modeled N2O flux attained a peak in summer due to the influence of temperature, which was apparently different from the observed peak of N2O flux in the freeze-thaw period. Meanwhile, both modeled CO2 flux and N2O flux were dampened by rainfall events. Apart from consistent estimation of annual soil CH4 flux, the annual accumulation of CO2 and N2O was underestimated. It is still necessary to further optimize model parameters and processes using long-term high-frequency observation data, especially transference of heat and water in soil and GHG producing mechanism. Continues work will improve modeling, ecosystem carbon-nitrogen budget assessment and estimation of soil GHGs flux from the site to the region. 相似文献
15.
喀斯特生态系统服务价值评价 ——以贵州花江示范区为例 总被引：2，自引：0，他引：2
采用频度法对喀斯特生态系统服务类型及指标进行分析,结合中国南方喀斯特环境特征、生态功能区位等因素,构建了石漠化生态系统服务价值评估指标体系;并以贵州花江示范区为例,基于实测和调查数据,采用物质量和价值量相结合的方法对其2010年生态系统服务价值进行评估。结果表明：示范区生态系统服务价值为19 604.71万元。其中,固碳制氧价值11 181.25万元、土壤肥力价值3 051.56万元、产品供给价值为2 850.40万元、涵养水源价值2 521.13万元、土壤保持价值为0.37万元。示范区生态系统服务价值以间接价值为主,占85.5%,直接价值仅占14.5%;生态功能价值主要依靠灌丛、经济林、耕地和疏林生态系统提供,裸岩荒坡尽管是研究区的优势景观,但提供服务价值较低。 相似文献
16.
固沙植被区土壤质地与土壤微生物数量的关系 总被引：1，自引：1，他引：0
土壤微生物是荒漠生态系统的重要组分,参与成土过程与生物地球化学循环,其数量反映土壤质量,是判别退化生态系统恢复程度的重要指标。选取沙坡头固沙植被区土壤中的真菌、细菌、放线菌数量进行研究,分析了其时空分布、恢复特征及影响因子。结果表明：土壤微生物数量随固沙年限增加而增加,随土层深度增加而减少,夏秋季显著大于冬春季。三大类群微生物数量恢复曲线均呈现S型,在固沙植被建立18~24 a后恢复速率达到峰值,24~36 a后数量能够达到天然植被区的31.6%~83.7%。土壤微生物数量恢复过程主要受土壤细物质含量的影响,土壤pH是限制因子。土壤微生物对土壤状况与覆被变化敏感,能较早且敏感地指示生态系统功能的变化。 相似文献
17.
生物结皮显著影响土壤微生物数量和群落组成。干扰是自然界常见现象,可引起生物结皮盖度及组分发生改变,进而导致生物结皮土壤微生物群落结构的变化。以发育8年的生物结皮为研究对象,采用平板培养法,研究了干扰下生物结皮层和其下0~2 cm土壤微生物数量的动态变化。结果表明：（1）干扰第2天不同菌种均有响应。生物结皮层土壤细菌、真菌和放线菌数量波动范围分别为91.2×105~303.5×105 cfu·g-1,0~487.2×103 cfu·g-1和23.0×105~376.1×105 cfu·g-1;下层0~2 cm波动范围分别为65.6×105~792.3×105 cfu·g-1,8.0×103~506.3×103 cfu·g-1和17.3×105~801.3×105 cfu·g-1。（2）生物结皮层和下层0~2 cm土壤细菌数量分别在干扰后第10天和第7天恢复稳定,真菌数量在第16天和第8天趋于平稳,放线菌数量在第8天和第4天恢复稳定。生物结皮层较0~2 cm土壤微生物数量恢复稳定滞后。（3）重新稳定后生物结皮层和下层0~2 cm细菌数量较干扰前分别下降了81.8%和79.6%.生物结皮层真菌数量显著增加,是干扰前的7.43倍;下层0~2 cm真菌数量下降了70.1%。生物结皮层和下层0~2 cm放线菌数量较干扰前分别降低46.5%和72.6%。（4）干扰显著改变土壤微生物群落结构,受影响程度细菌 > 放线菌 > 真菌变为放线菌 > 细菌 > 真菌。干扰可显著影响土壤微生物数量,但是随着时间延长微生物数量又会达到一个新的稳态,在研究微生物对干扰响应时,采样时间是研究结果的一个重要影响因素。 相似文献
18.
交通是旅游过程中能源消耗和碳排放的主要环节,认识旅游交通能源效率变化及其影响因素对推动旅游低碳化发展具有重要意义。基于中国旅游交通及相关数据,在测算不同类型旅游交通工具能源消耗系数的基础上,遵循"自上而下"原则构建新的研究方法,分析考察1994-2013年旅游交通的能源消耗、碳排放、能源效率及其影响因素。结果显示,1)中国旅游交通能源消耗由178.21PJ增长至565.82PJ,年均增长率为6.27%,相应的CO_2排放由14.96×10~6 t增长至47.94×10~6 t,主要由旅游出游人次数快速增长和旅游出行距离增加引起;2)中国旅游交通能源服务效率由3.22×10~6人次PJ~(-1)提高至5.99×10~6人次PJ~(-1),能源生态效率由26.07 kg人次~(-1)提升至14.01 kg人次~(-1);3)单位交通能耗降低、规模效应、政策推动等成为能源效率提高的主导推动因素,但旅游出行方式变化、享受型交通工具的发展等阻碍了能源效率的提升。基于分析结果,提出了中国旅游交通降低能源消耗、提高能源效率的建议措施。 相似文献
19.
干旱区盐碱土无机CO2通量是一个崭新、独特的科学现象,打破了土壤CO2通量完全来自于有机源的假设;然而,盐碱土无机CO2通量在土壤CO2通量和全球碳循环中的重要性还缺乏分离和量化的依据,因而存在很大的不确定性。通过采用高压灭菌的方法,将盐土和碱土的土壤无机CO2通量从土壤CO2通量中分离。结果表明：高压灭菌方法并不改变土壤的理化性质,并通过土壤有机CO2通量与温度的关系验证了分离方法的有效性,从而为盐碱土无机CO2通量的分离、量化和评估提供了一个可靠有效的方法。盐碱土的土壤无机CO2通量是土壤CO2通量的重要组分,土壤无机CO2通量的分离对精确解析干旱区盐碱土生态系统的碳循环是必要的;对盐碱土土壤无机CO2通量的研究,将促进对干旱区盐碱土土壤CO2通量和全球碳循环的理解。 相似文献
20.
CO2 emissions to the atmosphere were studied in a fertilized sandy agricultural soil with and without a catch crop sown into the main crop. The catch crop was grown primarily with the purpose to decrease N-leaching but this study also wanted to find out if the catch crop could have an effect in a climate change perspective. Plots with catch crop showed decreased CO2 emissions from the soil. Since previous results have shown that catch crops effectively decrease N-leaching we recommend growing catch crops as an effective measure for helping both the climate and the eutrophication issue. Seasonal variations in CO2 emissions were pronounced with maximum emissions from the fertilized agricultural soil in June and from an adjacent unmanaged grassland in August. From the plot with catch crop emissions decreased in July and August but somewhat increased later in the autumn. Fertilized agricultural soil showed a within-soil CO2 sink after harvest, i.e. within-soil CO2 uptake. Availability of NH4+ or NO3- in the soil seems to influence the within-soil CO2 sink, with NH4+ enforcing the sink while the same amount of NO3- instead increased CO2 emissions. 相似文献