Air Pollution and Lichen Physiology. Physiological Responses of Different Lichens in a Transplant Experiment Following an SO2-Gradient

Four lichen species, Parmelia sulcata Taylor, Hypogymnia physodes (L.) Nyl., Cetraria islandica (L.)Ach., and Bryoria fuscescens (Gyelnik) Brodo andHawksworth were exposed during autumn and winter at differentsites of the Erzgebirge (Ore Mountains), the Fichtelgebirge andcontrol sites. All lichens tested became visibly damaged withtime. Thallus bleaching started from the edges and went on tothe centre of the thallus. Sites of facilitated gas exchangelike the soralia of P. sulcata and the pseudocyphelles ofC. islandica became preferentially bleached. The sulfateconcentration increased with exposure time reaching 200% ofunpolluted controls. In contrast to coniferous trees (e.g. Picea abies), further exposure lead to a reduction in the S-concentration in the lichens, as sulfate and otherintracellular metabolites were leached from the thalli due tomembrane damage. The changes in the K-concentration proved tobe an excellent measure for membrane leakiness; it wascorrelated with time of exposure and with SO₂ concentrations at the different sites. Photosynthetic capacityand respiration were also strongly affected. Depending on theSO₂-dose, the Bryoria species were unable tophotosynthesize as early as 4–8 weeks after exposure, whereasCetraria and Hypogymnia showed clear reduction intheir ability to photoreduce CO₂ within 8–10 weeks ofexposure in the field. Parmelia sulcata was found to bethe most tolerant species. After 3–4 months, photosynthesis wasreduced by only 30%. The bioindicative value of theseobservations is discussed.     

Environmental Limitations to O3 Uptake - Some Key Results from Young Trees Growing at Elevated Co2 Concentrations

Elevated carbon dioxide concentrations and limited water supply have been shown to reduce the impact of ozone pollution on the growth and physiology of Quercus petraea in a long-term factorial experiment. These responses can be explained by observed reductions in stomatal conductance, and thus potential ozone exposure of 28% and 40% for CO₂ and drought treatments respectively. However, parameterisation of a stomatal conductance model for Quercus robur and Fagus sylvatica grown under ambient and elevated CO₂ concentrations in a separate experiment has demonstrated that elevated CO₂ also reduces the responsiveness of stomata to both saturation deficit (LAVPD) and soil moisture deficit (ψ) in beech, and to a lesser extent, in oak. Season-long model simulations of ozone fluxes suggest that LAVPD and ψ conductance parameters derived at ambient CO₂ concentrations will lead to these fluxes being underestimated by 24% and 2% for beech and oak respectively at 615 ppm CO₂.     

Na2S2O3对植物修复Hg污染土壤的影响

为研究添加化学调控剂对植物修复Hg污染土壤的影响,寻找经济有效的Hg污染土壤的植物修复手段。采用盆栽试验,研究添加Na2S2O3后对金盏菊(Kalendae)和芥菜(Mustum)修复Hg污染土壤的影响。Na2S2O3的加入促进了植物对各形态Hg的吸收,植物修复后土壤中各形态Hg的含量表现为残留态>过氧化氢态>酸溶态>碱溶态>水溶态。高浓度的Na2S2O3对植物生长产生一定的抑制作用,同时也会抑制土壤Hg向植物体内迁移。Na2S2O3浓度为1mg/kg时,植物对Hg的吸收量最大,金盏菊和芥菜中Hg的含量分别达到0.089 9,0.083 8mg/kg。Na2S2O3对金盏菊吸收Hg的促进作用比芥菜明显。Hg在植物根部的富集作用比茎叶部分强,芥菜的根部对Hg的富集能力比金盏菊根部强。添加Na2S2O3后能明显提高金盏菊和芥菜修复Hg污染土壤的效果,且在浓度为1mg/kg时,金盏菊和芥菜对污染土壤修复效果最好。     

Effects of phosphorus addition on N2O and NO emissions from soils of an Acacia mangium plantation

Abstract

An incubation experiment was conducted to examine the effects of the phosphorus (P) application on nitrous oxide (N₂O) and nitric oxide (NO) emissions from soils of an Acacia mangium plantation in Indonesia. The soils were incubated with and without the addition of P (Ca[H₂PO₄]₂; 2 mg P g soil)^?1) after adjusting the water-filled pore space (WFPS) to 75% or 100%. The P addition increased N₂O emissions under both WFPS conditions and NO emissions at 75% WFPS. Some possible mechanisms are considered. First, the P addition stimulated nitrogen (N) cycling, and N used for nitrification and/or denitrification also increased. Second, the P addition could have relieved the P shortage for nitrifying and/or denitrifying bacteria, producing N₂O and NO. Our results suggest that the application of P fertilizer has the potential to stimulate N₂O and NO emissions from Acacia mangium plantations, at least when soils are under relatively wet conditions.     

Fe2O3-TiO2/UV/O3+PSAF协同处理猪场废水效果及其除碳脱氮机制

为实现低碳高氨氮猪场废水深度除碳脱氮,该研究提出了Fe2O3-TiO2/UV/O3+PSAF组合处理工艺技术。应用响应面法确立了组合工艺的最优工况条件,采用三维荧光和紫外-可见吸收光谱分析了有机物的荧光和分子结构变化特征,并结合碳、氮形态变化探明了其协同处理特性及除碳脱氮机制。结果表明,Fe2O3-TiO2投加量为1.06 g/L、O3流量为3.02 g/h、曝气时间为90.75 min、聚硅酸铝铁（PSAF）用量为833.29 mg/L,COD及NH3-N去除效果最好,试验值与预测值偏差0.75％和0.56%,拟合性良好;组合工艺对猪场废水中的溶解性微生物代谢产物和类腐殖质处理效果显著,溶解性有机碳和总溶解性氮去除率分别达77.7%和82.6%,协同因子分别为1.11和1.50。其中,Fe2O3-TiO2/UV/O3对类腐殖质削减效果显著,O3和•OH协同氧化类腐殖质、NH3-N为小分子物质、NO3--N和N2（N2转化率达39.71%）,提高了富氧官能团的数量,促进了氮素的转化和矿化,利于PSAF对小分子物质和NO3--N等污染物的去除,组合工艺协同互补作用明显。研究结果为深度处理低碳高氨氮有机废水提供一种新思路。     

Effects of nitrogen fertilization and irrigation on N2O emissions from a sandy soil in Germany

The aim of this study was to investigate the effect of supplemental irrigation on the amount of N₂O emissions on a sandy soil in north-east Germany. N₂O flux measurements were carried out over two vegetation periods from the emergence of plants to harvest. The level of N₂O emissions was low, which is typical for sandy soils in north-east Germany. In both periods, irrigation had no increasing effect on N₂O emissions. Relevant factors were the soil temperature and the soil water-filled pore space (WFPS), which were mainly influenced by weather conditions. This may indicate that nitrification was the main source of N₂O emissions. In conclusion, this study has confirmed that sandy soils under weather conditions of north-east Germany generally have a very low potential for N₂O emissions.     

Negative effects of rare earth oxide nanoparticles of La2O3, Nd2O3, and Gd2O3 on the ammonia-oxidizing microorganisms

Journal of Soils and Sediments - Nanoparticles released into soil environment potentially impact microorganisms, which furtherly disturb terrestrial biogeochemical cycles. However, how rare earth...     

Influence of nitrapyrin on the evolution of N2O from an organic medium with and without plants

Abstract

Nitrapyrin in the presence of a plant decreased N₂O evolution after a five to six day period of incubation. These findings show that the inhibiting effect of nitrapyrin on the denitrification process is indirect. Evidence is also presented that suggest N₂O evolution is greater in the presence of a plant and thus cropped soils, than from bare soils.     

大气CO2和O3升高对菜地土壤酶活性和微生物量的影响

利用OTC平台和青菜盆栽实验,探索[CO2]、[O3]或[CO2+O3]升高条件下,土壤理化性质、微生物量和土壤酶活性的变化,以期获得未来大气CO2或/和O3升高对土壤微生态系统的风险性。结果表明,[CO2]升高不同程度地提高了土壤的可溶性有机碳（DOC）、可溶性有机氮（DON）、总磷（TP）、总碳（TC）、铵态氮（AN）、硝态氮（NN）含量和含水量（SWC）,进而不同程度地提高了土壤微生物量碳（MBC）、微生物量氮（MBN）含量以及土壤蛋白酶（PRA）、蔗糖酶（SA）、脲酶（UA）、多酚氧化酶（POA）、酸性磷酸酶（APA）和中性磷酸酶（NPA）活性。相反,[O3]升高不同程度降低了土壤DOC、TP、TK、TC、TN、AN、NN、SWC、MBC和MBN含量,提高了MBC/MBN比值,在不同程度上降低了土壤PRA、SA、UA、POA、APA和NPA酶活性。而[CO2+O3]在一定程度上消减了[O3]对土壤微生物量和酶活性的抑制作用,也降低了[CO2]升高对土壤微生物量和酶活性的刺激效应。因此,土壤微生物量和土壤酶活性的变化可用于评价未来大气CO2或/和O3升高对菜地土壤微生态环境的影响。     

pH 升高对红壤硝化过程产生 N2O 的影响

对红壤添加NaOH培养获得不同pH系列的土壤.通过室内培养试验.研究了3种pH条件下土壤的N_2O排放和无机N的变化情况.结果表明:硝化活性随土壤pH升高而增强:pH升高增加了土壤N_2O的释放;纯化学过程对N_2O散发的贡献随pH的升高而降低;Nitrapyrin在pH 4.8和pH 6.0时表现山硝化抑制作用,在pH 8.5时抑制效果不明显,且提高了培养期间pH8.5土壤N_2O的释放量.     

Effect of cattle slurry application techniques on N2O and NH3 emissions from a loamy soil

We determined N₂O fluxes from an unfertilized control (CON), from a treatment with mineral N‐fertilizer (MIN), from cattle slurry with banded surface application and subsequent incorporation (INC), and from slurry injection (INJ) to silage maize (Zea mays, L.) on a Haplic Luvisol in southwest Germany. In both years, amount of available N (total N fertilized + N_min content before N application) was 210 kg N ha^?1. In the slurry treatment of the 1^st year, 140 kg N ha^?1 were either injected or incorporated, whereas 30 kg N ha^?1 were surface applied to avoid destruction of the maize plants. In the 2^nd year, all fertilizers were applied with one single application. We calculated greenhouse gas emissions (GHG) on field level including direct N₂O emissions (calculated from the measured flux rates), indirect N₂O emissions (NH₃ and ${\mathrm{NO}}_3^{-}$ induced N₂O emission), net CH₄ fluxes, fuel consumption and pre‐chain emissions from mineral fertilizer. NH₃ losses were measured in the 2^nd year using the Dräger‐Tube Method and estimated for both years. NH₃ emission was highest in the treatment without incorporation. It generally contributed less than 5% of the greenhouse gas (GHG) emission from silage maize cultivation. The mean area‐related N₂O emission, determined with the closed chamber method was 2.8, 4.7, 4.4 and 13.8 kg N₂O‐N ha^?1 y^?1 for CON, MIN, INC, and INJ, respectively. Yield‐related N₂O emission showed the same trend. Across all treatments, direct N₂O emission was the major contributor to GHG with an average of 79%. Trail hose application with immediate incorporation was found to be the optimum management practice for livestock farmers in our study region.     

不同施肥量对设施菜地N2O排放通量的影响

为明确北京地区设施菜地的N2O排放特征,寻求既能减少N2O排放又使蔬菜增产或保持原有产量的切实有效措施,该研究采用静态箱/气相色谱法对北京地区设施菜地的黄瓜进行了全生长季N2O排放通量的观测,并分析了不同施肥量对N2O排放量、蔬菜产量和经济效益的影响。结果如下：土壤N2O排放通量的季节变化有明显的时间变异性,试验初期受基肥的影响,N2O排放量较大,随着时间的推移,土壤N2O排放量有所减少并保持稳定;试验后期由于追肥,出现一次排放高峰,且持续时间较长。各处理土壤N2O排放总量的次序是：T4（常规施肥量+鸡粪）＞T3（3/4常规施肥量+鸡粪）＞T1（1/4常规施肥量+鸡粪）＞T2（1/2常规施肥量+鸡粪）＞Tn（鸡粪）＞T0（无肥处理）,各处理之间N2O排放量差异达到极显著水平。综合考虑施肥量、N2O排放量和黄瓜产量,研究认为T3（3/4常规施肥量+鸡粪）的施肥量比较合理,可以为合理施肥、降低农民生产成本以及估算中国农田温室气体排放量和编制温室气体排放清单提供 依据。     

Effects of option mitigating ammonia volatilization on CH4 and N2O emissions from a paddy field fertilized with anaerobically digested cattle slurry

A lysimeter experiment was carried out to evaluate the effects of the NH₃ volatilization mitigation by adding anaerobically digested cattle slurry (ADCS) alone, with wood vinegar (WV) or with a higher level of floodwater (HFW), on emissions of CH₄ and N₂O from a paddy soil planted with fodder rice. We have carried out the following treatments: (1) chemical fertilizer, (2) ADCS, (3) ADCS + WV, and (4) ADCS + HFW; the height of floodwater was 10 cm in the latter treatment, and it was 3 to 4 cm in the other treatments just before fertilizer applications. Nitrogen fertilizer rate added to soil in each treatment was 30 g NH₄⁺–N m⁻² (split in one basal and two top-dressing additions). Ammonia volatilization in the ADCS treatment was 2.7 g NH₃–N m⁻² throughout the growing season, and it was significantly reduced by 79% and 55% in the ADCS + WV and ADCS + HFW treatments, respectively. The total amount of CH₄ emitted in the ADCS treatment in the growing season was not significantly enhanced by the mitigation of NH₃ volatilization either by adding wood vinegar or by increasing the height of the floodwater. Negligible N₂O emissions were observed in all treatments during the growing period.     

Effects of aggregate size,soil compaction,and bovine urine on N2O emissions from a pasture soil

The dominant N₂O emission source in New Zealand, calculated using the Intergovernmental Panel on Climate Change methodology, is agricultural soils. The largest source of N₂O emissions in New Zealand occurs as a result of excreta deposition onto pasture during grazing. There is a dearth of studies examining the effect of soil compaction and soil aggregate size on N₂O emissions from urine patches in grazed pastures. In this study, we repacked soil cores with four different soil aggregate sizes (<1.0–5.6 mm diameter), applied bovine urine, and then subjected the soil cores to four levels of soil compaction. Fluxes of N₂O were monitored for 37 days after which soil cores were allowed to dry out prior to a rewetting event. There was an interaction between aggregate size and soil compaction with the cumulative loss of N₂O over the first 37 days ranging from 0.3% to 9.6% of the urine-N applied. The highest N₂O emissions occurred from the smallest and most compacted aggregates. Even under the highest levels of compaction the N₂O loss from the large aggregates (4.0–5.6 mm diameter) was <1% of the urine-N applied. Reasons for the observed differences in the N₂O flux from the different-sized aggregates included varying gas diffusivities and higher rates of denitrification in the smallest aggregates, as evidenced by the disappearance of nitrate.     

炭输入及生化调控对设施菜田土壤N_2O排放的影响

本研究以河北永清蔬菜基地设施菜田土壤为研究对象,控制温度(25±1)℃和土壤含水量(70%WFPS),采用静态培养方法,通过监测培养期间土壤N_2O排放通量、无机氮含量及土壤中酶活性的变化情况,研究炭输入及生化调控对设施菜田N_2O排放及氮素转化的影响。结果表明,土壤添加尿素后,N_2O排放峰值达到644.11μg N·kg~(-1)·d~(-1),添加双氰胺(DCD)和石灰氮(CaCN_2)的土壤N_2O排放峰值分别为101.47μg N·kg~(-1)·d~(-1)和36.74μg N·kg~(-1)·d~(-1),对于N_2O减排效果好,且能有效抑制亚硝态氮的产生;施用控释尿素、添加黑炭或有机肥能减少N_2O排放,而添加石灰氮闷棚显著增加了N_2O排放。控释尿素、秸秆、黑炭、DCD和CaCN_2均对铵态氮向硝态氮的转化有一定抑制作用,施加石灰氮或有机肥有助于减少硝态氮向亚硝态氮的转化。相关分析表明,土壤中硝态氮和亚硝态氮含量增加,有助于反硝化过程的进行,增加了N_2O排放的风险。     

钾肥对苜蓿植株吸收氮磷钾的影响

通过田间试验探讨钾肥对苜蓿植株吸收氮、磷、钾的影响。结果表明,在播种当年,施钾肥降低了苜蓿植株中N和P2O5的百分含量,增加了K2O的百分含量。苜蓿植株中N、P2O5和K2O的积累量均可用曲线方程Y=eb0 b1/X来表达,拟合良好。高钾处理降低了苜蓿干草中N和P2O5的积累量,施钾均增加了K2O的积累量,但K2O的积累量不随施钾量的增加而持续增加。施钾对N的吸收速率影响不明显,但有利于提高K2O的吸收速率;施相对低水平钾可提高磷的吸收速率,高水平钾则降低了磷的吸收速率。     

金属催化剂Pd/Al_3O_2对胶原蛋白肽粉脱腥除臭处理

为去除林蛙胶原蛋白肽(LWT)作为精细化工原料在储存和加工中产生的不良气味,使用金属催化剂Pd/Al3O2进行脱硫处理,利用响应面法优化金属催化剂对LWT的脱腥除臭处理工艺,并采用电子扫描电镜和能谱仪对处理后样品进行分析比较。结果表明,金属催化剂Pd/Al3O2对LWT脱腥除臭处理的最佳条件为:金属催化剂添加量7.30%、p H值6、时间0.55h、温度43.75℃,此条件下的综合指标高达82.38;金属催化剂Pd/Al3O2处理后,LWT的结构无明显变化,其活性未受到影响,且所含元素种类无变化,但硫元素的Wt%和At%明显减少。本研究可为肽粉脱腥除臭提供技术参考。     

黑麦草鲜草翻压还田对双季稻CH4与N2O排放的影响

为了研究黑麦草鲜草翻压还田对稻田温室气体排放的影响,该文利用静态箱-盆栽装置观测了尿素、黑麦草鲜草翻压还田、半量尿素与半量黑麦草鲜草混施和对照4个处理稻田CH4和N2O排放.结果表明:黑麦草鲜草翻压还田、半量尿素与半量黑麦草鲜草混施的CH4排放通量分别比对照增加了371％和210％,比尿素增加了152％和66％:尿素的CH4排放比对照高87％,差异均达到显著水平(P＜0.05).黑麦草鲜草翻压还田的CH4排放在3个时期(早稻移栽前,早稻生长期和晚稻生长期)分布均匀,约60％的CH4排放于早稻移栽前和早稻生长期.尿素的N2O排放分别为黑麦草鲜草翻压还田、半量尿素与半量黑麦草鲜草混施和对照的18倍、6.6倍和25倍.CH4和N2O的全球增温潜势(GWP)依次为黑麦草鲜草翻压还田＞半量尿素与半量黑麦草鲜草混施＞尿素＞对照,差异均显著(P＜0.05).黑麦草鲜草翻压还田虽然增加了稻田CH4排放,但减少了N2O排放,抑制了 尿素对N2O的排放.     

水肥减量对设施芹菜地N2O排放的影响

为明确减量灌溉和施肥对设施菜地N₂O排放的影响,提出有效的N2O减排措施,本研究采用静态箱法,对北京郊区设施芹菜在灌溉和有机肥（沼渣）减量处理下的N₂O排放进行全生长季监测,分析灌溉和有机肥减量对土壤充水孔隙度（WFPS）、NO₃--N和NH₄+-N含量及土壤N2O排放的影响。试验为2个灌溉量和3个有机肥施用量的裂区双因素设计,具体为：常规灌溉量（H处理）下的常规施肥(HN)、减量1/3施肥(HN₃)和不施肥 (HN0),以及减量20%灌溉（L处理）下的常规施肥(LN)、减量1/3施肥(LN3)和不施肥 (LN0)共6个处理。结果表明,L处理在保证芹菜产量的前提下,对土壤充水孔隙度及无机氮含量无显著影响,但N₂O排放总量较H处理减少32.23%,达极显著水平（P＜0.01）。与常规施肥处理相比,减量1/3施肥和不施肥处理的土壤NO₃--N含量分别降低43.96%和76.42%,均达极显著水平（P＜0.01）,不同施肥量处理间土壤NH₄+-N含量无显著差异;芹菜产量随施氮量增加而增加,但减量1/3施肥和常规施肥处理对芹菜产量影响无显著差异,芹菜全生长季的土壤累积N₂O排放总量显著减少62.04%（P＜0.01）。本试验条件下,减量20%灌溉（L处理）和减量1/3施肥（N3处理）均能保证芹菜产量,显著降低芹菜地N2O排放通量,减少生产成本投入。