Responses of soil N 2 O emissions and their abiotic and biotic drivers to altered rainfall regimes and co‐occurring wet N deposition in a semi‐arid grassland

2021 ◽  
Author(s):  
Yujie Shi ◽  
Junfeng Wang ◽  
Yunna Ao ◽  
Jiayu Han ◽  
Zhihan Guo ◽  
...  
Keyword(s):  
N Deposition ◽  
Soil N ◽  
Semi Arid ◽  
Rainfall Regimes

Plant and Soil N Response of Southern Californian Semi-arid Shrublands After 1 Year of Experimental N Deposition

Ecosystems ◽  
2007 ◽  
Vol 10 (2) ◽  
pp. 263-279 ◽  
Author(s):  
George L. Vourlitis ◽  
Sarah Pasquini ◽  
Gypsi Zorba
Keyword(s):  
N Deposition ◽  
Soil N ◽  
Arid Shrublands ◽  
Semi Arid

Rainfall-associated chronic N deposition induces higher soil N2O emissions than acute N inputs in a semi-arid grassland

2021 ◽  
Vol 304-305 ◽  
pp. 108434
Author(s):  
Yujie Shi ◽  
Junfeng Wang ◽  
Ya'nan Li ◽  
Jinwei Zhang ◽  
Yunna Ao ◽  
...  
Keyword(s):  
N Deposition ◽  
N2o Emissions ◽  
Semi Arid

scholarly journals Effects of nitrogen and phosphorus additions on nitrous oxide emission in a nitrogen-rich and two nitrogen-limited tropical forests

2016 ◽  
Vol 13 (11) ◽  
pp. 3503-3517 ◽  
Author(s):  
Mianhai Zheng ◽  
Tao Zhang ◽  
Lei Liu ◽  
Weixing Zhu ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Tropical Forests ◽  
N2o Emission ◽  
N Deposition ◽  
Soil N ◽  
N Addition ◽  
Old Growth ◽  
Old Growth Forest ◽  
P Addition ◽  
Stimulation Of

Abstract. Nitrogen (N) deposition is generally considered to increase soil nitrous oxide (N2O) emission in N-rich forests. In many tropical forests, however, elevated N deposition has caused soil N enrichment and further phosphorus (P) deficiency, and the interaction of N and P to control soil N2O emission remains poorly understood, particularly in forests with different soil N status. In this study, we examined the effects of N and P additions on soil N2O emission in an N-rich old-growth forest and two N-limited younger forests (a mixed and a pine forest) in southern China to test the following hypotheses: (1) soil N2O emission is the highest in old-growth forest due to the N-rich soil; (2) N addition increases N2O emission more in the old-growth forest than in the two younger forests; (3) P addition decreases N2O emission more in the old-growth forest than in the two younger forests; and (4) P addition alleviates the stimulation of N2O emission by N addition. The following four treatments were established in each forest: Control, N addition (150 kg N ha−1 yr−1), P addition (150 kg P ha−1 yr−1), and NP addition (150 kg N ha−1 yr−1 plus 150 kg P ha−1 yr−1). From February 2007 to October 2009, monthly quantification of soil N2O emission was performed using static chamber and gas chromatography techniques. Mean N2O emission was shown to be significantly higher in the old-growth forest (13.9 ± 0.7 µg N2O-N m−2 h−1) than in the mixed (9.9 ± 0.4 µg N2O-N m−2 h−1) or pine (10.8 ± 0.5 µg N2O-N m−2 h−1) forests, with no significant difference between the latter two. N addition significantly increased N2O emission in the old-growth forest but not in the two younger forests. However, both P and NP addition had no significant effect on N2O emission in all three forests, suggesting that P addition alleviated the stimulation of N2O emission by N addition in the old-growth forest. Although P fertilization may alleviate the stimulated effects of atmospheric N deposition on N2O emission in N-rich forests, this effect may only occur under high N deposition and/or long-term P addition, and we suggest future investigations to definitively assess this management strategy and the importance of P in regulating N cycles from regional to global scales.

scholarly journals The simulated N deposition accelerates net N mineralization and nitrification in a tropical forest soil

2019 ◽  
Vol 16 (21) ◽  
pp. 4277-4291
Author(s):  
Yanxia Nie ◽  
Xiaoge Han ◽  
Jie Chen ◽  
Mengcen Wang ◽  
Weijun Shen
Keyword(s):  
N Deposition ◽  
Functional Genes ◽  
Net N Mineralization ◽  
Soil N ◽  
Wet Season ◽  
Inorganic N ◽  
N Transformations ◽  
N Transformation ◽  
Soil N Transformation ◽  
N Additions

Abstract. Elevated nitrogen (N) deposition affects soil N transformations in the N-rich soil of tropical forests. However, the change in soil functional microorganisms responsible for soil N cycling remains largely unknown. Here, we investigated the variation in soil inorganic N content, net N mineralization (Rm), net nitrification (Rn), inorganic N leaching (Rl), N2O efflux and N-related functional gene abundance in a tropical forest soil over a 2-year period with four levels of N addition. The responses of soil net N transformations (in situ Rm and Rn) and Rl to N additions were negligible during the first year of N inputs. The Rm, Rn, and Rl increased with the medium nitrogen (MN) and high nitrogen (HN) treatments relative to the control treatments in the second year of N additions. Furthermore, the Rm, Rn, and Rl were higher in the wet season than in the dry season. The Rm and Rn were mainly associated with the N addition-induced lower C:N ratio in the dry season but with higher microbial biomass in the wet season. Throughout the study period, high N additions increased the annual N2O emissions by 78 %. Overall, N additions significantly facilitated Rm, Rn, Rl and N2O emission. In addition, the MN and HN treatments increased the ammonia-oxidizing archaea (AOA) abundance by 17.3 % and 7.5 %, respectively. Meanwhile, the HN addition significantly increased the abundance of nirK denitrifiers but significantly decreased the abundance of ammonia-oxidizing bacteria (AOB) and nosZ-containing N2O reducers. To some extent, the variation in functional gene abundance was related to the corresponding N-transformation processes. Partial least squares path modelling (PLS-PM) indicated that inorganic N contents had significantly negative direct effects on the abundances of N-related functional genes in the wet season, implying that chronic N deposition would have a negative effect on the N-cycling-related microbes and the function of N transformation. Our results provide evidence that elevated N deposition may impose consistent stimulatory effects on soil N-transformation rates but differentiated impacts on related microbial functional genes. Long-term experimentation or observations are needed to decipher the interrelations between the rate of soil N-transformation processes and the abundance or expression of related functional genes.

Environmental properties and microbial abundance explain soil nitrous oxide flux variation synergistically under the addition of nitrogen and water in temperate semi-arid steppe

2020 ◽  
Author(s):  
Zhang Jiaqi ◽  
Liu Yinghui
Keyword(s):  
Nitrous Oxide ◽  
Soil Ph ◽  
Northern China ◽  
Annual Rainfall ◽  
Ammonia Oxidizing Bacteria ◽  
Soil N ◽  
Flux Change ◽  
Environmental Properties ◽  
Arid Steppe ◽  
Semi Arid

<p>  With the increasing of nitrogen(N) deposition and changing of precipitation patterns worldwide, large amounts of N are loaded in terrestrial ecosystem, resulting in soil nutrient imbalance and soil nitrous oxide(N<sub>2</sub>O) flux change. Nitrification and denitrification in soil are two major sources of N<sub>2</sub>O emission mediated by microorganisms. However, It is still unclear how the soil N<sub>2</sub>O flux and the abundance of nitrifiers and denitrifiers might change under the addition of N and water(W) in temperate semi-arid steppe. In this study, we established a one-year-long field experiment investigating how soil N<sub>2</sub>O flux, the abundance of nitrifiers and denitrifiers, and environmental properties, including soil pH, soil moisture, soil dissolved organic carbon content(DOC) and soil available N content responsed when N(NH<sub>4</sub>NO<sub>3</sub> was applied at a rate of 4 g N·m<sup>-2</sup>·yr<sup>-1</sup>, which is equivalent to one time the annual nitrogen deposition) and/or W(water was applied at a rate of 112.5 mm·yr<sup>-1</sup>, which is equivalent to 30% of the annual rainfall) were added to temperate semi-arid steppe in northern China with the natural condition without any treatment as control. Quantitative PCR was used to analyze the abundance of ammonia oxidizers(ammonia-oxidizing bacteria and archaea amoA) and denitrifiers(nirS/nirK and nosZ). Our experimental results demonstrated that soil N<sub>2</sub>O emission decreased when W was added and W and N were added in temperate semi-arid steppe in northern China. The abundance of nirS and nosZ genes increased when W and N were added. Compared with AOA/AOBamoA and nirK genes, the abundance of nirS and nosZ genes is more sensitive to the addition of N and W. Soil N<sub>2</sub>O flux was negatively correlated with the abundance of nirS-denitrifier. The nirS gene abundance, soil pH and DOC were the main controls on soil N<sub>2</sub>O flux and totally explained 78.2% of the variation of soil N<sub>2</sub>O flux. The results of this study provide a theoretical basis for N cycle mechanism mediated by microorganisms and have practical significance for the prediction of N<sub>2</sub>O flux change in temperate semi-arid steppe under the background of global change.</p>

The influence of mistletoes on nitrogen cycling in a semi-arid savanna, south-west Zimbabwe

2013 ◽  
Vol 29 (2) ◽  
pp. 147-159 ◽  
Author(s):  
Hilton G. T. Ndagurwa ◽  
John S. Dube ◽  
Donald Mlambo
Keyword(s):  
Soil Nutrient ◽  
Nutrient Concentrations ◽  
Ecosystem Structure ◽  
Soil N ◽  
Mineral N ◽  
N Transformations ◽  
South West ◽  
Tree Canopies ◽  
Ecosystem Structure And Functioning ◽  
Semi Arid

Abstract:This study investigated the effects of mistletoe infection on N cycling in a semi–arid savanna, south-west Zimbabwe. We established five plots (10 × 10 m) which each included three large canopy-dominantAcacia karrootrees infected by one of three mistletoes (Erianthemum ngamicum,Plicosepalus kalachariensisandViscum verrucosum) and non-infectedA. karrootrees. In each plot, we measured litterfall, litter quality (N, phenolics, tannins and lignin), soil nutrient concentrations and N transformations beneath tree canopies. Soil N, P and Ca were greatest beneath trees infected byP.kalachariensisthan beneath non-infected trees. Litterfall and litter N returns were 1.5, 2 and 1.4 times more beneathA. karrootrees infected byE.ngamicum,P.kalachariensisandV. verrucosum, respectively. Mineral N increased with mistletoe infection but did not exceed 20%. Soil N transformations were greater beneath trees infected byE.ngamicum(> 40%), and lower beneath trees infected byP.kalachariensis(<50%) andV.verrucosum(<48%) than beneath non-infectedA. karrootrees. Soil N transformations were negatively correlated with condensed tannins, lignin and lignin : N. We conclude that the improved N concentration can increase resource heterogeneity, which may alter the ecosystem structure and functioning in the semi-arid savanna.

scholarly journals Accumulation of nitrogen and organic matter during primary succession of <i>Leymus arenarius</i> dunes on the volcanic island Surtsey, Iceland

2014 ◽  
Vol 11 (20) ◽  
pp. 5763-5771 ◽  
Author(s):  
G. Stefansdottir ◽  
A. L. Aradottir ◽  
B. D. Sigurdsson
Keyword(s):  
Organic Matter ◽  
Primary Succession ◽  
Plant Biomass ◽  
Unit Area ◽  
Nutrient Retention ◽  
N Deposition ◽  
Soil N ◽  
Volcanic Island ◽  
Root Shoot Ratio ◽  
Leymus Arenarius

Abstract. Initial soil development and enhanced nutrient retention are often important underlying environmental factors during primary succession. We quantified the accumulation rates of nitrogen (N) and soil organic matter (SOM) in a 37-year-long chronosequence of Leymus arenarius dunes on the pristine volcanic island Surtsey in order to illuminate the spatiotemporal patterns in their build-up. The Leymus dune area, volume and height grew exponentially over time. Aboveground plant biomass, cover or number of shoots per unit area did not change significantly with time, but root biomass accumulated with time, giving a root / shoot ratio of 19. The dunes accumulated on average 6.6 kg N ha−1 year−1, which was 3.5 times more than is received annually by atmospheric deposition. The extensive root system of Leymus seems to effectively retain and accumulate a large part of the annual N deposition, not only deposition directly on the dunes but also from the adjacent unvegetated areas. SOM per unit area increased exponentially with dune age, but the accumulation of roots, aboveground biomass and SOM was more strongly linked to soil N than time: a 1 g m−2 increase in soil N led on average to a 6 kg C m−2 increase in biomass and SOM. The Leymus dunes, where most of the N has been accumulated, will therefore probably act as hot spots for further primary succession of flora and fauna on the tephra sands of Surtsey.

scholarly journals Accumulation of nitrogen and organic matter during primary succession of <i>Leymus arenarius</i> dunes on the volcanic island Surtsey, Iceland

2014 ◽  
Vol 11 (5) ◽  
pp. 6591-6613 ◽  
Author(s):  
G. Stefansdottir ◽  
A. L. Aradottir ◽  
B. D. Sigurdsson
Keyword(s):  
Organic Matter ◽  
Primary Succession ◽  
Plant Biomass ◽  
Unit Area ◽  
N Deposition ◽  
Soil N ◽  
Volcanic Island ◽  
Root Shoot Ratio ◽  
Leymus Arenarius ◽  
Natural Laboratory

Abstract. The volcanic island of Surtsey has been a natural laboratory where the primary succession of flora and fauna has been monitored, since it emerged from the N-Atlantic Ocean in 1963. We quantified the accumulation rates of nitrogen (N) and soil organic matter (SOM) in a 37 year long chronosequence of Leymus arenarius dunes in order to illuminate the spatiotemporal patterns in their build-up in primary succession. The Leymus dune area, volume and height grew exponentially over time. Aboveground plant biomass, cover or number of shoots per unit area did not change significantly with time, but root biomass accumulated with time, giving a root-shoot ratio of 19. The dunes accumulated on average 6.6 kg N ha−1 year−1, which was 3.5 times more than is received annually by atmospheric deposition. The extensive root system of Leymus seems to effectively retain and accumulate large part of the annual N deposition, not only deposition directly on the dunes but also from the adjacent unvegetated areas. SOM per unit area increased exponentially with dune age, but the accumulation of roots, aboveground biomass and SOM was more strongly linked to soil N than time: 1 g m−2 increase in soil N led on the average to 6 kg C m−2 increase in biomass and SOM. The Leymus dunes, where most of the N has been accumulated, will therefore probably act as hot-spots for further primary succession of flora and fauna on the tephra sands of Surtsey.

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