scholarly journals Increased microbial sequestration of soil organic carbon under nitrogen deposition over China’s terrestrial ecosystems

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Shu Liao ◽  
Siyi Tan ◽  
Yan Peng ◽  
Dingyi Wang ◽  
Xiangyin Ni ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Terrestrial Ecosystems ◽  
N Deposition ◽  
N Addition ◽  
Soil Organic C ◽  
Organic C ◽  
Soil Microbial ◽  
Biomass Turnover ◽  
Microbial Residues ◽  
Stimulation Of

Abstract Background China’s terrestrial ecosystems have been receiving increasing amounts of reactive nitrogen (N) over recent decades. External N inputs profoundly change microbially mediated soil carbon (C) dynamics, but how elevated N affects the soil organic C that is derived from microbial residues is not fully understood. Here, we evaluated the changes in soil microbial necromass C under N addition at 11 forest, grassland, and cropland sites over China’s terrestrial ecosystems through a meta-analysis based on available data from published articles. Results Microbial necromass C accounted for an average of 49.5% of the total soil organic C across the studied sites, with higher values observed in croplands (53.0%) and lower values in forests (38.6%). Microbial necromass C was significantly increased by 9.5% after N addition, regardless of N forms, with greater stimulation observed for fungal (+ 11.2%) than bacterial (+ 4.5%) necromass C. This increase in microbial necromass C under elevated N was greater under longer experimental periods but showed little variation among different N application rates. The stimulation of soil microbial necromass C under elevated N was proportional to the change in soil organic C. Conclusions The stimulation of microbial residues after biomass turnover is an important pathway for the observed increase in soil organic C under N deposition across China’s terrestrial ecosystems.

scholarly journals Topography modulates effects of nitrogen deposition on microbial resource limitation in a nitrogen-saturated subtropical forest

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hao Chen ◽  
Junjie Tang ◽  
Xibin Sun ◽  
Kayan Ma ◽  
Huaihai Chen ◽  
...  
Keyword(s):  
Resource Limitation ◽  
N Deposition ◽  
Subtropical Forest ◽  
N Saturation ◽  
N Addition ◽  
Microbial Decomposition ◽  
Organic C ◽  
Soil Microbial ◽  
N Limitation ◽  
P Limitation

Abstract Background Nitrogen (N) saturation theory proposes that an ecosystem might switch from N limitation to carbon (C), phosphorus (P), or other nutrient limitations if it receives continuous N input. Yet, after N limitation is removed, which nutrient is the most limited and whether topography modulates such change is rarely tested at a microbial level. Here, we conducted a two-year N addition experiment under two different topography positions (i.e. a slope and a valley) in a N-saturated subtropical forest. Soil enzyme activity was measured, and ecoenzymatic stoichiometry indexes were calculated as indicators of microbial resource limitation. Results In the valley, two-year N addition changed the activity of all studied enzymes to various degrees. As a result, microbial C limitation was aggravated in the valley, and consequently microbial decomposition of soil labile organic C increased, but microbial P limitation was alleviated due to the stoichiometry balance. On the slope, however, N addition did not significantly change the activity of the studied enzymes, and did not alter the status of microbial resource limitation. Conclusions These results indicate that C is a more limited element for microbial growth than P after removing N limitation, but we also highlight that topography can regulate the effect of N deposition on soil microbial resource limitation in subtropical forests. These findings provide useful supplements to the N saturation theory.

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 Phosphorus Reduces Negative Effects of Nitrogen Addition on Soil Microbial Communities and Functions

2020 ◽  
Vol 8 (11) ◽  
pp. 1828 ◽  
Author(s):  
Zongwei Xia ◽  
Jingyi Yang ◽  
Changpeng Sang ◽  
Xu Wang ◽  
Lifei Sun ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Bacterial Diversity ◽  
Soil Microbial Communities ◽  
N Deposition ◽  
N Fixation ◽  
N Addition ◽  
Soil Bacterial Diversity ◽  
Soil Microbial ◽  
Soil Bacterial ◽  
P Addition

Increased soil nitrogen (N) from atmospheric N deposition could change microbial communities and functions. However, the underlying mechanisms and whether soil phosphorus (P) status are responsible for these changes still have not been well explained. Here, we investigated the effects of N and P additions on soil bacterial and fungal communities and predicted their functional compositions in a temperate forest. We found that N addition significantly decreased soil bacterial diversity in the organic (O) horizon, but tended to increase bacterial diversity in the mineral (A) horizon soil. P addition alone did not significantly change soil bacterial diversity but mitigated the negative effect of N addition on bacterial diversity in the O horizon. Neither N addition nor P addition significantly influenced soil fungal diversity. Changes in soil microbial community composition under N and P additions were mainly due to the shifts in soil pH and NO3− contents. N addition can affect bacterial functional potentials, such as ureolysis, N fixation, respiration, decomposition of organic matter processes, and fungal guilds, such as pathogen, saprotroph, and mycorrhizal fungi, by which more C probably was lost in O horizon soil under increased N deposition. However, P addition can alleviate or switch the effects of increased N deposition on the microbial functional potentials in O horizon soil and may even be a benefit for more C sequestration in A horizon soil. Our results highlight the different responses of microorganisms to N and P additions between O and A horizons and provides an important insight for predicting the changes in forest C storage status under increasing N deposition in the future.

Impacts of nitrogen deposition on terrestrial plant diversity: a meta-analysis in China

2019 ◽  
Vol 12 (6) ◽  
pp. 1025-1033 ◽  
Author(s):  
Wen-Juan Han ◽  
Jia-Yu Cao ◽  
Jin-Liang Liu ◽  
Jia Jiang ◽  
Jian Ni
Keyword(s):  
Species Richness ◽  
Plant Diversity ◽  
Meta Analysis ◽  
N Deposition ◽  
Shannon Index ◽  
N Addition ◽  
Terrestrial Plant ◽  
Multiple Dimensions ◽  
Negative Effect ◽  
Experiment Duration

AbstractAimsWith the global atmospheric nitrogen (N) deposition increasing, the effect of N deposition on terrestrial plant diversity has been widely studied. Some studies have reviewed the effects of N deposition on plant species diversity; however, all studies addressed the effects of N deposition on plant community focused on species richness in specific ecosystem. There is a need for a systematic meta-analysis covering multiple dimensions of plant diversity in multiple climate zones and ecosystems types. Our goal was to quantify changes in species richness, evenness and uncertainty in plant communities in response to N addition across different environmental and experimental contexts.MethodsWe performed a meta-analysis of 623 experimental records published in English and Chinese journals to evaluate the response of terrestrial plant diversity to the experimental N addition in China. Three metrics were used to quantify the change in plant diversity: species richness (SR), evenness (Pielou index) uncertainty (Shannon index).Important FindingsResults showed that (i) N addition negatively affected SR in temperate, Plateau zones and subtropical zone, but had no significant effect on Shannon index in subtropical zones; (ii) N addition decreased SR, Shannon index and Pielou index in grassland, and the negative effect of N addition on SR was stronger in forest than in grassland; (iii) N addition negatively affected plant diversity (SR, Shannon index and Pielou index) in the long term, whereas it did not affect plant diversity in the short term. Furthermore, the increase in N addition levels strengthened the negative effect of N deposition on plant diversity with long experiment duration; and (iv) the negative effect of ammonium nitrate (NH4NO3) addition on SR was stronger than that of urea (CO(NH2)2) addition, but the negative effect of NH4NO3 addition on Pielou index was weaker than that of CO(NH2)2 addition. Our results indicated that the effects of N addition on plant diversity varied depending on climate zones, ecosystem types, N addition levels, N type and experiment duration. This underlines the importance of integrating multiple dimensions of plant diversity and multiple factors into assessments of plant diversity to global environmental change.

Soil microbial respiration responses of nitrogen addition: Evidence from a long-time semi-arid grassland soil incubation

2020 ◽  
Author(s):  
Zhaomin Wang ◽  
Zhongmiao Liu ◽  
Binhui Guo ◽  
Zhengchao Qi ◽  
Decao Niu ◽  
...  
Keyword(s):  
Microbial Respiration ◽  
Global Climate ◽  
Nitrogen Concentration ◽  
Terrestrial Ecosystems ◽  
Carbon Pools ◽  
N Addition ◽  
North West ◽  
Soil Microbial ◽  
Soil Microbial Respiration ◽  
Semi Arid

<p>Nitrogen is essential for the synthesis of key cellular compounds such as proteins and nucleic acids in all organisms, and it is one of the limiting elements in most terrestrial ecosystems. During past decades, terrestrial ecosystems nutrients availability have altered with nitrogen deposition increases rapidly so that under the soil microbial metabolism activities terrestrial ecosystem biogeochemical cycles are strongly affected. Therefore, maintaining the stability of soil carbon pools, especially microbial carbon pools has great importance for studying global carbon cycle and global climate change processes. Depending on whether soil microbial has already adapted to the environment nitrogen concentration, there exists different results, such as promotion, inhibition, and no impact. To date, how nitrogen will affect soil microbial respiration still has controversy. To determine the effects, we performed a 59 weeks incubation with the soil which has already treated with Urea for 9 years. The soil has been treated with four N addition levels in a semi-arid grassland where located in North-west part of China. We measured CO<sub>2</sub> effluxion under different treatments within the same temperature. Our results showed that during the first 8 weeks, soil microbial had strong responses about N addition and N9.2 showed greatest influence with soil microbial respiration. With the time passing, in the time of 9-59 weeks, N0 had highest soil microbial respiration rate while N2.3 was the lowest, this illustrated N2.3 had highest N use efficient (NUE), in order to meet soil microbial stoichiometry, microbial growth became strong C-limitation under the N2.3 treatment. What’s more, comparing with other studies which we shared same study area, we also found that the time of nitrogen application also had strong effect on soil microbial respiration. These results highlight the importance of microbial respiration and may also help us to have a better understand about how N deposition controls terrestrial C flows.</p>

Management of sugarcane harvest residues: consequences for soil carbon and nitrogen

Soil Research ◽  
2007 ◽  
Vol 45 (1) ◽  
pp. 13 ◽  
Author(s):  
Fiona A. Robertson ◽  
Peter J. Thorburn
Keyword(s):  
Microbial Biomass ◽  
Soil Fertility ◽  
Microbial Activity ◽  
Soil N ◽  
Soil Organic C ◽  
Total N ◽  
Organic C ◽  
Soil Microbial ◽  
C And N

The Australian sugar industry is moving away from the practice of burning the crop before harvest to a system of green cane trash blanketing (GCTB). Since the residues that would have been lost in the fire are returned to the soil, nutrients and organic matter may be accumulating under trash blanketing. There is a need to know if this is the case, to better manage fertiliser inputs and maintain soil fertility. The objective of this work was to determine whether conversion from a burning to a GCTB trash management system is likely to affect soil fertility in terms of C and N. Indicators of short- and long-term soil C and N cycling were measured in 5 field experiments in contrasting climatic conditions. The effects of GCTB varied among experiments. Experiments that had been running for 1–2 years (Harwood) showed no significant trash management effects. In experiments that had been running for 3–6 years (Mackay and Tully), soil organic C and total N were up to 21% greater under trash blanketing than under burning, to 0.10 or 0.25 m depth (most of this effect being in the top 50 mm). Soil microbial activity (CO2 production) and soil microbial biomass also increased under GCTB, presumably as a consequence of the improved C availability. Most of the trash C was respired by the microbial biomass and lost from the system as CO2. The stimulation of microbial activity in these relatively short-term GCTB systems was not accompanied by increased net mineralisation of soil N, probably because of the greatly increased net immobilisation of N. It was calculated that, with standard fertiliser applications, the entire trash blanket could be decomposed without compromising the supply of N to the crop. Calculations of possible long-term effects of converting from a burnt to a GCTB production system suggested that, at the sites studied, soil organic C could increase by 8–15%, total soil N could increase by 9–24%, and inorganic soil N could increase by 37 kg/ha.year, and that it would take 20–30 years for the soils to approach this new equilibrium. The results suggest that fertiliser N application should not be reduced in the first 6 years after adoption of GCTB, but small reductions may be possible in the longer term (>15 years).

scholarly journals Frequency and intensity of nitrogen addition alter soil inorganic sulfur fractions, but the effects vary with mowing management in a temperate steppe

2019 ◽  
Vol 16 (14) ◽  
pp. 2891-2904
Author(s):  
Tianpeng Li ◽  
Heyong Liu ◽  
Ruzhen Wang ◽  
Xiao-Tao Lü ◽  
Junjie Yang ◽  
...  
Keyword(s):  
Soil Ph ◽  
Terrestrial Ecosystems ◽  
N Deposition ◽  
Temperate Grassland ◽  
N Availability ◽  
N Addition ◽  
Organic S ◽  
S Uptake ◽  
N Input ◽  
Soil Inorganic

Abstract. Sulfur (S) availability plays a vital role in driving functions of terrestrial ecosystems, which can be largely affected by soil inorganic S fractions and pool size. Enhanced nitrogen (N) input can significantly affect soil S availability, but it still remains largely unknown if the N effect varies with frequency of N addition and mowing management in grasslands. To investigate changes in the soil S pool and inorganic S fractions (soluble S, adsorbed S, available S, and insoluble S), we conducted a field experiment with different frequencies (two times per year vs. monthly additions per year) and intensities (i.e., 0, 1, 2, 3, 5, 10, 15, 20, and 50 g N m−2 yr−1) of NH4NO3 addition and mowing (unmown vs. mown) over 6 years in a temperate grassland of northern China. Generally, N addition frequency, N intensity, and mowing significantly interacted with each other to affect most of the inorganic S fractions. Specifically, a significant increase in soluble S was only found at high N frequency with the increasing intensity of N addition. Increasing N addition intensity enhanced adsorbed S and available S concentrations at low N frequency in unmown plots; however, both fractions were significantly increased with N intensity at both N frequencies in mown plots. The high frequency of N addition increased the concentrations of adsorbed S and available S in comparison to the low frequency of N addition only in mown plots. Changes in soil S fractions were mainly related to soil pH, N availability, soil organic carbon (SOC), and plant S uptake. Our results suggested that N input could temporarily replenish soil-available S by promoting dissolution of soil-insoluble S with decreasing soil pH and mineralization of organic S due to increasing plant S uptake. However, the significant decrease in organic S and total S concentrations with N addition intensity in mown plots indicated that N addition together with biomass removal would eventually cause soil S depletion in this temperate grassland in the long term. Our results further indicated that using large and infrequent N additions to simulate N deposition can overestimate the main effects of N deposition and mowing management on soil S availability in semiarid grasslands.

scholarly journals Nitrogen Additions Retard Nutrient Release from Two Contrasting Foliar Litters in a Subtropical Forest, Southwest China

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 377 ◽  
Author(s):  
Liyan Zhuang ◽  
Qun Liu ◽  
Ziyi Liang ◽  
Chengming You ◽  
Bo Tan ◽  
...  
Keyword(s):  
Litter Decomposition ◽  
Critical Role ◽  
C:N Ratio ◽  
Terrestrial Ecosystems ◽  
N Deposition ◽  
Decay Rates ◽  
N Addition ◽  
K Value ◽  
P Release ◽  
N Additions

Litter decomposition plays a critical role in regulating biogeochemical cycles in terrestrial ecosystems and is profoundly impacted by increasing atmospheric nitrogen (N) deposition. Here, a N manipulation experiment was conducted to explore the effects of N additions (0 kg N ha−1 yr−1, 20 kg N ha−1 yr−1 and 40 kg N ha−1 yr−1) on decay rates and nutrients release of two contrasting species, the evergreen and nutrient-poor Michelia wilsonii and the deciduous and nutrient-rich Camptotheca acuminata, using a litterbag approach at the western edge of the Sichuan Basin of China. The decay rate and the mineralization of N and phosphorus (P) was faster in nutrient-rich C. acuminata litter than in nutrient-poor M. wilsonii litter, regardless of N regimes. N additions tended to decrease the decay constant (k value) in M. wilsonii litter, but had no effect on C. acuminata litter. N additions had no significant effects on carbon (C) release of both litter types. N additions showed negative effects on N and P release of M. wilsonii litter, particularly in the late decomposition stage. Moreover, for C. acuminata litter, N additions did not affect N release, but retarded P release in the late stage. N additions did not affect the C:N ratio in both litter types. However, N additions—especially high-N addition treatments—tended to reduce C:P and N:P ratios in both species. The effect of N addition on N and P remaining was stronger in M. wilsonii litter than in C. acuminata litter. The results of this study indicate that N additions retarded the nutrients release of two foliar litters. Thus, rising N deposition might favor the retention of N and P via litter decomposition in this specific area experiencing significant N deposition.

scholarly journals Soil Microbial Community Composition and Diversity Remained Unchanged in a Semiarid Grassland in Northwestern China After 7 Years of Nitrogen Addition

2021 ◽  
Author(s):  
Qian Guo ◽  
Zhongming Wen ◽  
Hossein Ghanizadeh ◽  
Cheng Zheng ◽  
Yongming Fan ◽  
...  
Keyword(s):  
Microbial Community ◽  
Soil Properties ◽  
Community Composition ◽  
Microbial Community Composition ◽  
N Deposition ◽  
Leaf Nitrogen Content ◽  
N Addition ◽  
Weighted Mean ◽  
Soil Microbial ◽  
Community Weighted Mean

Abstract Aims Nitrogen (N) deposition is a global environmental problem that can alter community compositions and functions, and consequently, the ecosystem services. In this study, we assessed the responses of aboveground vegetation, surface soil properties and microbial communities to N addition, and explored the drivers of microbial community in a semiarid steppe ecosystem in northwest of China. Methods Thirty-six 6×10-m2 plots composed of six N addition levels and six replicates were distributed in six columns and six rows. Nine vegetation characteristics and seven soil properties were measured and calculated. Soil microbial characteristics were analyzed by 16S rRNA high-throughput sequencing. Results N addition positively affected aboveground vegetation traits such as the community weighted-mean of leaf nitrogen content (LNCWM). High N inputs significantly altered the microbial community assembly process from random to deterministic. The microbial community diversity and composition, however, were not sensitive to N addition. A piecewise structural equation model (SEM) further showed that the microbial community composition was affected by both aboveground vegetation and soil properties. The composition of bacterial communities was mainly regulated by the composition of plant communities and soil total N. In contrast, the composition of fungal communities was driven by soil pH and the community weighted-mean of specific leaf area (SLACWM). Microbial diversity and composition remained unchanged because their drivers were not affected by N addition. The results of this research improved our understanding of the response of grassland ecosystems to N deposition, and provided a theoretical basis for grassland utilization and management under N deposition.

Sign in / Sign up

Export Citation Format

Share Document