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1.
Ecosystem CO2 and N2 O exchanges between soils and the atmosphere play an important role in climate warming and global carbon and nitrogen cycling; however, it is still not clear whether the fluxes of these two greenhouse gases are correlated at the ecosystem scale. We collected 143 pairs of ecosystem CO2 and N2 O exchanges between soils and the atmosphere measured simultaneously in eight ecosystems around the world and developed relationships between soil CO2 and N2 O fluxes. Significant linear regressions of soil CO2 and N2 O fluxes were found for all eight ecosystems; the highest slope occurred in rice paddies and the lowest in temperate grasslands. We also found the dominant role of growing season on the relationship of annual CO2 and N2 O fluxes. No significant relationship between soil CO2 and N2 O fluxes was found across all eight ecosystem types. The estimated annual global N2 O emission based on our findings is 13.31 Tg N yr−1 with a range of 8.19–18.43 Tg N yr−1 for 1980–2000, of which cropland contributes nearly 30%. Our findings demonstrated that stoichiometric relationships may work on ecological functions at the ecosystem level. The relationship of soil N2 O and CO2 fluxes developed here could be helpful in biogeochemical modeling and large-scale estimations of soil CO2 and N2 O fluxes. 相似文献
2.
畜禽废弃物堆肥处理过程中产生的二氧化碳(CO2)、氧化亚氮(N2O)、甲烷(CH4)和氨气(NH3)等是重要的温室气体和大气污染物。但目前有关该过程气体排放的研究多基于室内小型模拟的反应器式堆肥,在工厂化堆肥条件下的原位气体排放监测较少。为探究工厂化堆肥产生气体对区域环境的影响,本研究对沈阳某堆肥厂畜禽废弃物堆体的气体排放进行了19 d的监测,并量化了排放氨气的自然丰度15N(δ15N)特征。结果表明: 堆置周期内,CO2、CH4、N2O和NH3的平均排放速率分别为86.8 g CO2-C·d-1·m-2、9.8 g CH4-C·d-1·m-2、3.7 mg N2O-N·d-1·m-2和736.6 mg NH3-N·d-1·m-2。温室气体日增温潜势(GWP)的贡献大小为CH4>CO2>NH3(间接)>N2O,其中CH4贡献了65%。堆肥排放NH3的δ15N在-21.8‰~-7.2‰,平均-11.6‰±1.2‰。本研究结果可为区域畜禽废弃物堆肥过程中温室气体排放的核算及大气氨溯源提供数据支持。 相似文献
3.
JANET E. BERTRAM TIM J. CLOUGH ROBERT R. SHERLOCK LEO M. CONDRON MAUREEN O'CALLAGHAN† NAOMI S. WELLS JESSICA L. RAY 《Global Change Biology》2009,15(8):2067-2077
Atmospheric concentrations of the greenhouse gas nitrous oxide (N2 O) have continued to rise since the advent of the industrial era, largely because of the increase in agricultural land use. The urine deposited by grazing ruminant animals is a major global source of agricultural N2 O. With the first commitment period for reducing greenhouse gas emissions under the Kyoto Protocol now underway, mitigation options for ruminant urine N2 O emissions are urgently needed. Recent studies showed that increasing the urinary concentration of the minor urine constituent hippuric acid resulted in reduced emissions of N2 O from a sandy soil treated with synthetic bovine urine, due to a reduction in denitrification. A similar effect was seen when benzoic acid, a product of hippuric acid hydrolysis, was used. This current laboratory experiment aimed to investigate these effects using real cow urine for the first time. Increased concentrations of hippuric acid or benzoic acid in the urine led to reduction of N2 O emissions by 65% (from 17% to <6% N applied), with no difference between the two acid treatments. Ammonia volatilization did not increase significantly with increased hippuric acid or benzoic acid concentrations in the urine applied. Therefore, there was a net reduction in gaseous N loss from the soil with higher urinary concentrations of both hippuric acid and benzoic acid. The results show that elevating hippuric acid in the urine had a marked negative effect on both nitrification and denitrification rates and on subsequent N2 O fluxes. This study indicates the potential for developing a novel mitigation strategy based on manipulation of urine composition through ruminant diet. 相似文献
4.
Mixed cultures of the cellulolytic fungus Trichoderma harzianum with the anaerobic diazotroph Clostridium butyricum were shown to co-operatively degrade cellulose and utilize the degradation products for N2 fixation. Cellulose degradation and N2 fixation were stimulated by small (0.1 mg/ml) additions of (NH4 )2 SO4 . The (NH42 SO4 stimulates cellulolysis thereby increasing the supply of cellulose degradation products to the diazotroph. In aerobic environments the anaerobe depends on the respiration of the aerobe to create anaerobic microsites. The N source increased O2 uptake by the fungus increasing the number of sites suitable for the development of the anaerobe. Stimulation in the growth of T. harzianum by (NH42 SO4 resulted in increased growth and N2 fixation by Cl. butyricum. 相似文献
5.
6.
Lesley A. Robertson Tage Dalsgaard Niels-Peter Revsbech J.Gijs Kuenen 《FEMS microbiology ecology》1995,18(2):113-120
Abstract: Because of a revival in the controversy surrounding 'aerobic denitrification', especially in relation to Thiosphaera pantotropha , activity in aerobic batch cultures was evaluated using gas chromatography and mass spectrometry after the addition of 15 N-labelled NH4 + and NO2 − . Aerobic denitrifying activity in T. pantotropha was present, but only at about 10% of the originally-reported levels. The activity of ' Pseudomonas denitrificans ' was similar to previously-reported values. Alcaligenes faecalis showed significant aerobic denitrifying activity, producing almost equivalent amounts of N2 and N2 O. An unidentified pseudomonad, isolate G4, presumably requires anoxia for enzyme activity as it did not denitrify aerobically, even though it has a constitutive denitrifying pathway. 相似文献
7.
Effects of phenolic acids on ammonia oxidation by terrestrial autotrophic nitrifying microorganisms 总被引:2,自引:0,他引:2
Abstract It has been hypothesized that vegetation in certain ecosystems inhibits nitrification in soil by producing phenolic compounds that inhibit oxidation of ammonia by nitrifying microorganisms. This hypothesis is based largely on a report that very low concentrations (10−6 M–10−8 M) of several phenolic acids (notably ferulic acid) completely inhibited NO2 − production in an aqueous suspension of soil treated with (NH4 )2 SO4 and a nutrient solution suitable for growth of Nitrosomonas and other autotrophic nitrifying microorganisms. To evaluate this hypothesis, we determined the effects of three ohenolic acids (ferulic acid, caffeic acid, and p -coumaric on nitrite production by representatives of three genera of terrestrial autotrophic nitrifying microorganisms ( Nitrosospira, Nitrosomonas , or Nitrosolubos ) grown on a defined medium containing NH4 + . We found that nitrite production by the Nitrososspira was not inhibited by ferulic acid, caffeic acid, or p -coumaric acid at concentrations of 10−6 or 10−5 M and was only slightly inhibited when these acids were at a concentration of 10−4 M. We also found that ferulic acid did not markedly inhibit nitrite production by the three genera of nitrifying microorganisms studied, even when its concentration was as high as 10−3 M. These observations invalidate the hypothesis tested because the phenolic acids studied did not significantly retard ammonia oxidation by autotrophic microorganisms even when their concentration in cultures of these microorganisms greatly exceeded their concentrations in soils. 相似文献
8.
Leif Skøt 《Physiologia plantarum》1983,59(4):581-584
The quantitative relationship between C2 H2 reduction, H2 evolution and 15 N2 fixation was investigated in excised root nodules from pea plants ( Pisum sativum L. cv. Bodil) grown under controlled conditions. The C2 H2 /N2 conversion factor varied from 3.31 to 5.12 between the 32nd and the 67th day after planting. After correction for H2 evolution in air, the factor (C2 H2 -H2 )/N2 decreased to values near the theoretical value 3, or in one case to a value significantly ( P < 0.05) below 3. The proportion of the total electron flow through nitrogenase, which is not wasted in H2 production but used for N2 reduction, is often stated as the relative efficiency (1-H2 /C2 H2 ). This factor varied significantly ( P < 0.05) during the growth period. The actual allocation of electrons to H2 and N2 , expressed as the H2 /N2 ratio, was independent of plant age, however. This discrepancy and the observation that the (C2 H2 -H2 )/N2 conversion factor tended to be lower than 3, suggests that the C2 H2 reduction assay underestimates the total electron flow through nitrogenase. 相似文献
9.
Methane-dependent nitrate production by a microbial consortium enriched from a cultivated humisol 总被引:2,自引:0,他引:2
Abstract A consortium was enriched from a humisol incubated with 3.6 kPa CH4 and NH4 + . This consortium oxidized NH4 + to NO2 − and NO3 − (NO3 − /NO2 − ratio about 20) with smaller amounts of N2 O. This oxidation stopped in the stationary phase after depletion of CH4 . CH3 OH or CO2 did not support oxidation. Growth and resting cell experiments suggested that nitrification was associated with methanotrophic activity and that chemoautotrophic nitrifiers were absent. 相似文献
10.
Physiological effects of long-term exposure to low and moderate concentrations of atmospheric NH3 on poplar leaves 总被引:2,自引:0,他引:2
L. W. A. VAN HOVE O. VAN KOOTEN E. H. ADEMA W. J. VREDENBERG G. A. PIETERS 《Plant, cell & environment》1989,12(9):899-908
Abstract. Poplar shoots ( Populus euramericana L.) obtained from cuttings were exposed for 6 or 8 weeks to NH3 concentrations of 50 and 100 μgm−3 or filtered air in fumigation chambers. After this exposure the rates of NH3 uptake, transpiration, CO2 assimilation and respiration of leaves were measured using a leaf chamber. During the long-term exposure also modulated chlorophyll fluorescence measurements were carried out to obtain information about the photosynthetic performance of individual leaves. Both fluorescence and leaf chamber measurements showed a higher photosynthetic activity of leaves exposed to 100 μg NH3 m−3 . These leaves showed also a larger leaf conductance and a larger uptake rate of NH3 than leaves exposed to 50 μg m−3 NH3 or filtered air. The long-term NH3 exposure did not induce an internal resistance against NH3 transport in the leaf, nor did it affect the leaf cuticle. So, not only at a short time exposure, but also at a long-term exposure NH3 uptake into leaves can be calculated from data on the boundary layer and stomatal resistance for H2 O and ambient NH3 -concentration. Furthermore, the NH3 exposure had no effect on the relation between CO2 -assimilation and stomatal conductance, indicating that NH3 in concentrations up to 100 μg m−3 has no direct effect on stomatal behaviour; for example, by affecting the guard or contiguous cells of the stomata. 相似文献
11.
Denitrification in river sediments: relationship between process rate and properties of water and sediment 总被引:6,自引:0,他引:6
1. A survey was made of denitrification and nitrous oxide (N2 O) production in river sediments at fifty sites in north‐east England during one season in order to investigate the relationship between rates and environmental factors likely to influence these processes. The sites were chosen to represent a wide range of physical and chemical conditions. Denitrification rate and N2 O production were measured within 5 h of sampling using the slurry acetylene blockage technique.
2. Denitrification rate ranged from less than 0.005–260 nmol N g–1 DW h–1 , tending to increase in a downstream direction. N2 O production ranged from negative values (net consumption) to 13 nmol N2 O‐N g–1 DW h–1 and accounted for 0–115% of the N gases produced.
3. Denitrification rate and N2 O concentration in the sediment were correlated positively with nitrate concentration in the water column, water content of the sediment and percentage of fine (< 100 μm) particles in the sediment.
4. The variation in denitrification rate was satisfactorily explained (64% total variance) by a model employing measurements of water nitrate and water content of sediments. No simple or multiple relationship was found for N2 O production. 相似文献
2. Denitrification rate ranged from less than 0.005–260 nmol N g
3. Denitrification rate and N
4. The variation in denitrification rate was satisfactorily explained (64% total variance) by a model employing measurements of water nitrate and water content of sediments. No simple or multiple relationship was found for N
12.
Symbiotic N2 fixation in a high Alpine grassland: effects of four growing seasons of elevated CO2 总被引:1,自引:0,他引:1
J. A. Arnone Iii 《Functional ecology》1999,13(3):383-387
1. Increasing carbon dioxide concentration (E: 680 μl CO2 litre–1 vs ambient, A: 355 μl CO2 litre–1 ) around late-successional Alpine sedge communities of the Swiss Central Alps (2450 m) for four growing seasons (1992–1995) had no detectable effect on symbiotic N2 fixation in Trifolium alpinum —the sole N2 -fixing plant species in these communities (74 ± 30 mg N m–2 year–1 , A and E plots pooled).
2. This result is based on data collected in the fourth growing season showing that elevated CO2 had no effect on Trifolium above-ground biomass (4·4 ± 1·7 g m–2 , A and E plots pooled, n = 24) or N content per unit land area (124 ± 51 mg N m–2 , A and E pooled), or on the percentage of N Trifolium derived from the atmosphere through symbiotic N2 fixation (%Ndfa: 61·0 ± 4·1 across A and E plots) estimated using the 15 N dilution method.
3. Thus, it appears that N inputs to this ecosystem via symbiotic N2 fixation will not be dramatically affected in the foreseeable future even as atmospheric CO2 continues to rise. 相似文献
2. This result is based on data collected in the fourth growing season showing that elevated CO
3. Thus, it appears that N inputs to this ecosystem via symbiotic N
13.
Anthropogenic nitrogen (N) enrichment of ecosystems, mainly from fuel combustion and fertilizer application, alters biogeochemical cycling of ecosystems in a way that leads to altered flux of biogenic greenhouse gases (GHGs). Our meta-analysis of 313 observations across 109 studies evaluated the effect of N addition on the flux of three major GHGs: CO2 , CH4 and N2 O. The objective was to quantitatively synthesize data from agricultural and non-agricultural terrestrial ecosystems across the globe and examine whether factors, such as ecosystem type, N addition level and chemical form of N addition influence the direction and magnitude of GHG fluxes. Results indicate that N addition increased ecosystem carbon content of forests by 6%, marginally increased soil organic carbon of agricultural systems by 2%, but had no significant effect on net ecosystem CO2 exchange for non-forest natural ecosystems. Across all ecosystems, N addition increased CH4 emission by 97%, reduced CH4 uptake by 38% and increased N2 O emission by 216%. The net effect of N on the global GHG budget is calculated and this topic is reviewed. Most often N addition is considered to increase forest C sequestration without consideration of N stimulation of GHG production in other ecosystems. However, our study indicated that although N addition increased the global terrestrial C sink, the CO2 reduction could be largely offset (53–76%) by N stimulation of global CH4 and N2 O emission from multiple ecosystems. 相似文献
14.
Community structure and population dynamics of ammonia oxidizers in composting processes of ammonia-rich livestock waste 总被引:2,自引:0,他引:2
Takeshi Yamada Shinya Araki Wakako Ikeda-Ohtsubo Keiko Okamura Akira Hiraishi Hideyo Ueda Yasuichi Ueda Keisuke Miyauchi Ginro Endo 《Systematic and applied microbiology》2013
This study investigated the relationship between the population dynamics of ammonia-oxidizing bacteria (AOB) and archaea (AOA), and changes in the concentrations of nitrogenous compounds during ammonia-rich livestock waste-composting processes. The data showed that ammonia in beef and dairy cow livestock waste-composting piles was slowly oxidized to nitrite and nitrate after approximately 21–35 days under thermophilic or moderately thermophilic and mesophilic conditions. Real-time quantitative PCR (qPCR) assays showed a relative abundance of betaproteobacterial AOB during ammonia oxidation but did not detect AOA in any composting stage. Furthermore, real-time qPCR and terminal-restriction fragment length polymorphism (T-RFLP) analyses for the AOB in two composting processes (beef and dairy cow livestock waste) out of the three studied found that thermophilic or moderately thermophilic uncultured betaproteobacterial AOB from the “compost AOB cluster” contributed to ammonia oxidation during hot composting stages. Non-metric multidimensional scaling analyses of the data from T-RFLP showed that only a few analogous species predominated during composting of beef, dairy cow and pig livestock wastes, and thus, the AOB community structures in the three composting piles operating under different conditions were similar. AOB-targeted clone library analyses revealed that uncultured members of the “compost AOB cluster”, which could be clearly distinguished from the authentic species of the genus Nitrosomonas, were the major constituents of the AOB populations. These results suggested that a limited and unique species of AOB played a role in ammonia oxidation during the composting of ammonia-rich livestock waste. 相似文献
15.
Sulfide-induced dissimilatory nitrate reduction to ammonia in anaerobic freshwater sediments 总被引:12,自引:0,他引:12
Abstract: Different reduced sulfur compounds (H2 S, FeS, S2 O3 2− ) were tested as electron donors for dissimilatory nitrate reduction in nitrate-amended sediment slurries. Only in the free sulfide-enriched slurries was nitrate appreciably reduced to ammonia ( ), with concomitant oxidation of sulfide to S0 ( ). The initial concentration of free sulfide appears as a factor determining the type of nitrate reduction. At extremely low concentrations of free S2− (metal sulfides) nitrate was reduced via denitrification whereas at higher S2− concentrations, dissimilatory nitrate reduction to ammonia (DNRA) and incomplete denitrification to gaseous nitrogen oxides took place. Sulfide inhibition of NO- and N2 O- reductases is proposed as being responsible for the driving part of the electron flow from S2− to NH4 + . 相似文献
16.
Vittoria Di Martino Rigano Vincenza Vona Catello Di Martino Carmelo Rigano 《Physiologia plantarum》1986,68(1):34-38
Cyanidium caldarium (Tilden) Geitler, a non-vacuolate unicellular alga, resuspended in medium flushed with air enriched with 5% CO2 , assimilated NH4 + at high rates both in the light and in the dark. The assimilation of NO3 − , by contrast, was inhibited by 63% in the dark. In cell suspensions flushed with CO2 -free air, NH4 + assimilation decreased with time both in the light and in the dark and ceased almost completely after 90 min. The addition of CO2 completely restored the capacity of the alga to assimilate NH4 + . NO3 − assimilation, by contrast, was 33% higher in the absence of CO2 and was linear with time. It is suggested that NO3 − and NH4 + metabolism in C. caldarium are differently controlled in response to the light and carbon conditions of the cell. 相似文献
17.
Annemieke F. Pronk Charles Affourtit Cyril Mashingaidze Adriaan H. Stouthamer Henk W. van Verseveld Fred C. Boogerd 《FEMS microbiology letters》1995,129(2-3):149-155
Abstract The in situ method for determination of reduction levels of cytochromes b and c pools during steady-state growth (Pronk et al., Anal. Biochem. 214, 149–155, 1993) was applied to chemostat cultures of the wild-type, a cytochrome aa3 single mutant and a cytochrome aa3 /d double mutant of Azorhizobium caulinodans . For growth with NH4 + as the N source, the results indicate that (i) the aa3 mutant strains growing at a dissolved O2 tension of 0.5% possess an active alternative cytochrome c oxidase, which is hardly present during fully aerobic growth, and assuming that (i) also pertains to the wild-type, (ii) the wild-type uses cytochrome aa3 under fully aerobic conditions. For growth with N2 as the N source, it was found that the aa3 mutant strains growing at dissolved O2 tensions ranging from 0.5 to 3.0% also contain an active alternative cytochrome c oxidase. 相似文献
18.
Ying Zhang Anas Ghadouani Ellie E. Prepas Bernadette Pinel-Alloul Sharon Reedyk Patricia A. Chambers Richard D. Robarts Ginette Méthot Assia Raik & Meike Holst 《Freshwater Biology》2001,46(8):1105-1119
1. The impact of whole-lake lime (slaked lime, Ca(OH)2 , and/or calcite, CaCO3 ) addition on plankton communities was evaluated in eutrophic hardwater lakes on the North American Boreal Plain.
2. Two lakes received a single treatment of lime (Ca(OH)2 at 74 or 107 mg L–1 ), two lakes received multiple treatments with Ca(OH)2 and/or CaCO3 (5–78 mg L–1 ), and four lakes were untreated and served as reference systems.
3. Over the long-term (> 1 year), phytoplankton biomass was reduced in multiple-dose lakes, but not in single-dose lakes. Cyanobacteria typically dominated the algal community in the years before, during and after lime treatment in both single- and multiple-dose lakes.
4. In the single-dose lakes, randomized intervention analysis showed no significant change in the biomass of zooplankton after lime addition. 相似文献
2. Two lakes received a single treatment of lime (Ca(OH)
3. Over the long-term (> 1 year), phytoplankton biomass was reduced in multiple-dose lakes, but not in single-dose lakes. Cyanobacteria typically dominated the algal community in the years before, during and after lime treatment in both single- and multiple-dose lakes.
4. In the single-dose lakes, randomized intervention analysis showed no significant change in the biomass of zooplankton after lime addition. 相似文献
19.
Snow depth, soil freezing, and fluxes of carbon dioxide, nitrous oxide and methane in a northern hardwood forest 总被引:14,自引:0,他引:14
PETER M. GROFFMAN JANET P. HARDY† CHARLES T. DRISCOLL‡ TIMOTHY J. FAHEY§ 《Global Change Biology》2006,12(9):1748-1760
Soil–atmosphere fluxes of trace gases (especially nitrous oxide (N2 O)) can be significant during winter and at snowmelt. We investigated the effects of decreases in snow cover on soil freezing and trace gas fluxes at the Hubbard Brook Experimental Forest, a northern hardwood forest in New Hampshire, USA. We manipulated snow depth by shoveling to induce soil freezing, and measured fluxes of N2 O, methane (CH4 ) and carbon dioxide (CO2 ) in field chambers monthly (bi-weekly at snowmelt) in stands dominated by sugar maple or yellow birch. The snow manipulation and measurements were carried out in two winters (1997/1998 and 1998/1999) and measurements continued through 2000. Fluxes of CO2 and CH4 showed a strong seasonal pattern, with low rates in winter, but N2 O fluxes did not show strong seasonal variation. The snow manipulation induced soil freezing, increased N2 O flux and decreased CH4 uptake in both treatment years, especially during winter. Annual N2 O fluxes in sugar maple treatment plots were 207 and 99 mg N m−2 yr−1 in 1998 and 1999 vs. 105 and 42 in reference plots. Tree species had no effect on N2 O or CO2 fluxes, but CH4 uptake was higher in plots dominated by yellow birch than in plots dominated by sugar maple. Our results suggest that winter fluxes of N2 O are important and that winter climate change that decreases snow cover will increase soil:atmosphere N2 O fluxes from northern hardwood forests. 相似文献
20.
Metabolism of nitric oxide and nitrous oxide during nitrification and denitrification in soil at different incubation conditions 总被引:1,自引:0,他引:1
Abstract NO production and consumption rates as well as N2 O accumulation rates were measured in a loamy cambisol which was incubated under different conditions (i.e. soil moisture content, addition of nitrogen fertilizer and/or glucose, aerobic or anaerobic gas phase). Inhibition of nitrification with acetylene allowed us to distinguish between nitrification and denitrification as sources of NO and N2 O. Under aerobic conditions untreated soil showed very low release of NO and N2 O but high consumption of NO. Fertilization with NH4 + or urea stimulated both NO and N2 O production by nitrification. Addition of glucose at high soil moisture contents led to increased N2 and N2 O production by denitrification, but not to increased NO production rates. Anaerobic conditions, however, stimulated both NO and N2 O production by denitrification. The production of NO and N2 O was further stimulated at low moisture contents and after addition of glucose or NO3 − . Anaerobic consumption of NO by denitrification followed Michaelis-Menten kinetics and was stimulated by addition of glucose and NO3 − . Aerobic consumption of NO followed first-order kinetics up to mixing ratios of at least 14 ppmv NO, was inhibited by autoclaving but not by acetylene, and decreased with increasing soil moisture content. The high NO-consumption activity and the effects of soil moisture on the apparent rates of anaerobic and aerobic production and consumption of NO suggest that diffusional constraints have an important influence on the release of NO, and may be a reason for the different behaviour of NO release vs N2 O release. 相似文献