scholarly journals Increased phosphorus availability mitigates the inhibition of nitrogen deposition on CH<sub>4</sub> uptake in an old-growth tropical forest, southern China

2011 ◽  
Vol 8 (9) ◽  
pp. 2805-2813 ◽  
Author(s):  
T. Zhang ◽  
W. Zhu ◽  
J. Mo ◽  
L. Liu ◽  
S. Dong
Keyword(s):  
Tropical Forest ◽  
Uptake Rate ◽  
Southern China ◽  
N Deposition ◽  
P Availability ◽  
N Addition ◽  
Old Growth ◽  
P Limitation ◽  
Ch4 Uptake ◽  
P Addition

Abstract. It is well established that tropical forest ecosystems are often limited by phosphorus (P) availability, and elevated atmospheric nitrogen (N) deposition may further enhance such P limitation. However, it is uncertain whether P availability would affect soil fluxes of greenhouse gases, such as methane (CH4) uptake, and how P interacts with N deposition. We examine the effects of N and P additions on soil CH4 uptake in an N saturated old-growth tropical forest in southern China to test the following hypotheses: (1) P addition would increase CH4 uptake; (2) N addition would decrease CH4 uptake; and (3) P addition would mitigate the inhibitive effect of N addition on soil CH4 uptake. Four treatments were conducted at the following levels from February 2007 to October 2009: 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). Static chamber and gas chromatography techniques were used to quantify soil CH4 uptake every month throughout the study period. Average CH4 uptake rate was 31.2 ± 1.1 μg CH4-C m−2 h−1 in the control plots. The mean CH4 uptake rate in the N-addition plots was 23.6 ± 0.9 μg CH4-C m−2 h−1, significantly lower than that in the controls. P-addition however, significantly increased CH4 uptake by 24% (38.8 ± 1.3 μg CH4-C m−2 h−1), whereas NP-addition (33.6 ± 1.0 μg CH4-C m−2 h−1) was not statistically different from the control. Our results suggest that increased P availability may enhance soil mathanotrophic activity and root growth, resulting in potentially mitigating the inhibitive effect of N deposition on CH4 uptake in tropical forests.

scholarly journals Responses of CH<sub>4</sub> uptake to the experimental N and P additions in an old-growth tropical forest, Southern China

2011 ◽  
Vol 8 (3) ◽  
pp. 4953-4983 ◽  
Author(s):  
T. Zhang ◽  
W. Zhu ◽  
J. Mo ◽  
L. Liu ◽  
S. Dong
Keyword(s):  
Greenhouse Gases ◽  
Tropical Forest ◽  
Uptake Rate ◽  
Southern China ◽  
N Deposition ◽  
P Availability ◽  
N Addition ◽  
Old Growth ◽  
Ch4 Uptake ◽  
P Addition

Abstract. It is well established that tropical forest ecosystems are often limited by phosphorus (P) availability, and elevated atmospheric nitrogen (N) deposition may further enhance such P limitation. However, it is uncertain whether P availability would affect soil fluxes of greenhouse gases, such as methane (CH4) uptake, and how P interacts with N deposition. We examine the effects of N and P additions on soil CH4 uptake in an N saturated old-growth tropical forest in Southern China to test the following hypotheses: (1) P addition would increase CH4 uptake; (2) N addition would decrease CH4 uptake; and (3) P addition would mitigate the inhibitive effect of N addition on soil CH4 uptake. Four treatments were conducted at the following levels from February 2007 to October 2009: control, N-addition (15 g N m−2 yr−1), P-addition (15 g P m−2 yr−1), and NP-addition (15 g N m−2 yr−1 plus 15 g P m−2 yr−1). Static chamber and gas chromatography techniques were used to quantify soil CH4 uptake every month throughout the study period. Average CH4 uptake rate was 31.2 ± 1.1 μg CH4-C m−2 h−1 in the control plots. The mean CH4 uptake rate in the N-addition plots was 23.6 ± 0.9 μg CH4-C m−2 h−1, significantly lower than that in the controls. P-addition however, significantly increased CH4 uptake by 24 % (38.8 ± 1.3 μg CH4-C m−2 h−1), whereas NP-addition (33.6 ± 1.0 μg CH4-C m−2 h−1) was not statistically different from the control. Our results suggest that increased P availability may enhance soil mathanotrophic activity and potentially mitigate the inhibitive effect of N deposition on CH4 uptake in tropical forests. Phosphorus and nitrogen treatments also significantly changed the fluxes of greenhouse gases N2O and CO2, altering the net global warming potential (GWP) of this tropical forest located in a high-N deposition zone of Southern China.

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 Nitrogen input <sup>15</sup>N-signatures are reflected in plant <sup>15</sup>N natural abundances of sub-tropical forests in China

2016 ◽  
Author(s):  
Geshere Abdisa Gurmesa ◽  
Xiankai Lu ◽  
Per Gundersen ◽  
Yunting Fang ◽  
Qinggong Mao ◽  
...  
Keyword(s):  
Tropical Forests ◽  
Southern China ◽  
Nitrogen Addition ◽  
N Deposition ◽  
Pine Forest ◽  
N Cycling ◽  
N Addition ◽  
Higher Plant ◽  
Old Growth ◽  
Old Growth Forest

Abstract. Natural abundance of 15N (δ15N) in plants and soils can provide integrated information on ecosystem nitrogen (N) cycling, but it has not been well tested in warm and humid sub-tropical forests. In this study, we examined the measurement of δ15N for its ability to assess changes in N cycling due to increased N deposition in an old-growth broadleaved forest and a secondary pine forest in a high N deposition area in southern China. We measured δ15N of inorganic N in input and output fluxes under ambient N deposition, and N concentration (N %) and δ15N of major ecosystem compartments under ambient and after decadal N addition at 50 kg N ha−1 yr−1. Our results showed that the N deposition was δ15N-depleted (−12 ‰) mainly due to high input of depleted NH4&amp;plus;-N. Plant leafs in both forest were also δ15N-depleted (−4 to −6 ‰). The old-growth forest had higher plant and soil N %, and was more 15N-enriched in most ecosystem compartments relative to the pine forest. Nitrogen addition did not significantly affect N % in both forests, indicating that the ecosystem pools are already N-rich. Soil δ15N was not changed significantly by the N addition in both forests. However, the N addition significantly increased the δ15N of plants toward the 15N signature of the added N (~ 0 ‰), indicating incorporation of added N into plants. Thus, plant δ15N was sensitive to ecosystem N input manipulation although N % was unchanged in these N-rich sub-tropical forests. We interpret the depleted δ15N values of plants as an imprint from the high and δ15N-depleted N deposition. The signal from the input (deposition or N addition) may override the enrichment effects of fractionation during the steps of N cycling that are observed in most warm and humid forests. Thus, interpretation of ecosystem δ15N values from high N deposition regions need to include data on the deposition δ15N signal.

scholarly journals Indications of nitrogen-limited methane uptake in tropical forest soils

2013 ◽  
Vol 10 (8) ◽  
pp. 5367-5379 ◽  
Author(s):  
E. Veldkamp ◽  
B. Koehler ◽  
M. D. Corre
Keyword(s):  
Tropical Forest ◽  
Forest Soils ◽  
Forest Ecosystems ◽  
Mineral Soil ◽  
N Deposition ◽  
Montane Forest ◽  
N Addition ◽  
Lowland Forest ◽  
Ch4 Production ◽  
Ch4 Uptake

Abstract. It is estimated that tropical forest soils contribute 6.2 Tg yr−1 (28%) to global methane (CH4) uptake, which is large enough to alter CH4 accumulation in the atmosphere if significant changes would occur to this sink. Elevated deposition of inorganic nitrogen (N) to temperate forest ecosystems has been shown to reduce CH4 uptake in forest soils, but almost no information exists from tropical forest soils even though projections show that N deposition will increase substantially in tropical regions. Here we report the results from two long-term, ecosystem-scale experiments in which we assessed the impact of chronic N addition on soil CH4 fluxes from two old-growth forests in Panama: (1) a lowland, moist (2.7 m yr−1 rainfall) forest on clayey Cambisol and Nitisol soils with controls and N-addition plots for 9–12 yr, and (2) a montane, wet (5.5 m yr−1 rainfall) forest on a sandy loam Andosol soil with controls and N-addition plots for 1–4 yr. We measured soil CH4 fluxes for 4 yr (2006–2009) in four replicate plots (40 m × 40 m each) per treatment using vented static chambers (four chambers per plot). CH4 fluxes from the lowland control plots and the montane control plots did not differ from their respective N-addition plots. In the lowland forest, chronic N addition did not lead to inhibition of CH4 uptake; instead, a negative correlation of CH4 fluxes with nitrate (NO3–) concentrations in the mineral soil suggests that increased NO3– levels in N-addition plots had stimulated CH4 consumption and/or reduced CH4 production. In the montane forest, chronic N addition also showed negative correlation of CH4 fluxes with ammonium concentrations in the organic layer, which suggests that CH4 consumption was N limited. We propose the following reasons why such N-stimulated CH4 consumption did not lead to statistically significant CH4 uptake: (1) for the lowland forest, this was caused by limitation of CH4 diffusion from the atmosphere into the clayey soils, particularly during the wet season, as indicated by the strong positive correlations between CH4 fluxes and water-filled pore space (WFPS); (2) for the montane forest, this was caused by the high WFPS in the mineral soil throughout the year, which may not only limit CH4 diffusion from the atmosphere into the soil but also favour CH4 production; and (3) both forest soils showed large spatial and temporal variations of CH4 fluxes. We conclude that in these extremely different tropical forest ecosystems there were indications of N limitation on CH4 uptake. Based on these findings, it is unlikely that elevated N deposition on tropical forest soils will lead to a rapid reduction of CH4 uptake.

scholarly journals Nitrogen addition mediates the response of foliar stoichiometry to phosphorus addition: a meta-analysis

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Chengming You ◽  
Changhui Peng ◽  
Zhenfeng Xu ◽  
Yang Liu ◽  
Li Zhang ◽  
...  
Keyword(s):  
Low Dose ◽  
Meta Analysis ◽  
N Deposition ◽  
Ecosystem Structure ◽  
P Availability ◽  
N Addition ◽  
Short Term ◽  
Positive Effects ◽  
Foliar N ◽  
P Addition

Abstract Background Changes in foliar nitrogen (N) and phosphorus (P) stoichiometry play important roles in predicting the effects of global change on ecosystem structure and function. However, there is substantial debate on the effects of P addition on foliar N and P stoichiometry, particularly under different levels of N addition. Thus, we conducted a global meta-analysis to investigate how N addition alters the effects of P addition on foliar N and P stoichiometry across different rates and durations of P addition and plant growth types based on more than 1150 observations. Results We found that P addition without N addition increased foliar N concentrations, whereas P addition with N addition had no effect. The positive effects of P addition on foliar P concentrations were greater without N addition than with N addition. Additionally, the effects of P addition on foliar N, P and N:P ratios varied with the rate and duration of P addition. In particular, short-term or low-dose P addition with and without N addition increased foliar N concentration, and the positive effects of short-term or low-dose P addition on foliar P concentrations were greater without N addition than with N addition. The responses of foliar N and P stoichiometry of evergreen plants to P addition were greater without N addition than with N addition. Moreover, regardless of N addition, soil P availability was more effective than P resorption efficiency in predicting the changes in foliar N and P stoichiometry in response to P addition. Conclusions Our results highlight that increasing N deposition might alter the response of foliar N and P stoichiometry to P addition and demonstrate the important effect of the experimental environment on the results. These results advance our understanding of the response of plant nutrient use efficiency to P addition with increasing N deposition.

scholarly journals Photosynthesis, Ecological Stoichiometry, and Non-Structural Carbohydrate Response to Simulated Nitrogen Deposition and Phosphorus Addition in Chinese Fir Forests

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1068
Author(s):  
Meihua Liu ◽  
Yaoxiong Wang ◽  
Quan Li ◽  
Wenfa Xiao ◽  
Xinzhang Song
Keyword(s):  
Plant Growth ◽  
Soluble Sugar ◽  
N Deposition ◽  
Chinese Fir ◽  
N Addition ◽  
C:N:P Stoichiometry ◽  
P Deficiency ◽  
P Limitation ◽  
Structural Carbohydrate ◽  
P Addition

Phosphorus (P) deficiency in soil affects plant growth and primary production. Accelerated nitrogen (N) deposition can cause ecological carbon:nitrogen:phosphorus (C:N:P) stoichiometry imbalance and increase the degree of relative P deficiency in the soil. However, it remains unclear how N deposition affects P uptake and C:N:P stoichiometry in coniferous timber forests, and whether P addition diminishes the effect of N-induced P limitation on plant growth. From January 2017 to April 2018, we investigated the effects of nine different N and P addition treatments on 10-year old trees of Chinese fir, Cunninghamia lanceolata (Lamb.) Hook. Our results demonstrated that N and P additions at a high concentration could improve the photosynthetic capacity in Chinese fir by increasing the chlorophyll content and stimulating the photosynthesis activity. The C:N:P stoichiometry varied with the season under different N and P addition treatments, indicating that N addition at a moderate concentration could diminish the effect of the P limitation on the growth of Chinese fir. The soluble sugar content in the leaves displayed more stable seasonal variations, compared with those of starch. However, the non-structural carbohydrate (NSC) content in the leaves did not vary with the season under both P and N addition treatment. The data suggested that N and P combination treatment at moderate concentrations promoted carbon assimilation by accelerating the photosynthetic rate. Thus, our results provide new insights into the adaptation mechanisms of coniferous timber forest ecosystems to the effects of N deposition under P deficiency and can help to estimate the ecological effects of environmental changes linked to human management practices.

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

2016 ◽  
Author(s):  
M. H. Zheng ◽  
T. Zhang ◽  
L. Liu ◽  
W. X. Zhu ◽  
W. 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 N O 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 (13.86 ± 0.71 μg N2O-N m–2 h–1) than in the mixed (9.86 ± 0.38 μg N2O-N m–2 h–1) or pine (10.83 ± 0.52 μg N) 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 N O emission in N-rich forests, 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 Indications of nitrogen-limited methane uptake in tropical forest soils

2013 ◽  
Vol 10 (3) ◽  
pp. 6007-6037 ◽  
Author(s):  
E. Veldkamp ◽  
B. Koehler ◽  
M. D. Corre
Keyword(s):  
Tropical Forest ◽  
Forest Soils ◽  
Forest Ecosystems ◽  
Mineral Soil ◽  
N Deposition ◽  
Montane Forest ◽  
N Addition ◽  
Lowland Forest ◽  
Ch4 Production ◽  
Ch4 Uptake

Abstract. Tropical forest soils contribute 6.2 Tg yr−1 (28%) to global methane (CH4) uptake, which is large enough to alter CH4 accumulation in the atmosphere if significant changes would occur to this sink. Elevated deposition of inorganic nitrogen (N) to temperate forest ecosystems has been shown to reduce CH4 uptake in forest soils, but almost no information exists from tropical forest soils even though projections show that N deposition will increase substantially in tropical regions. Here we report the results from long-term, ecosystem-scale experiments in which we assessed the impact of chronic N addition on soil CH4 fluxes from two old-growth forests in Panama: (1) a lowland, moist (2.7 m yr−1 rainfall) forest on clayey Cambisol and Nitisol soils with controls and N-addition plots for 9–12 yr, and (2) a montane, wet (5.5 m yr−1 rainfall) forest on a sandy loam Andosol soil with controls and N-addition plots for 1–4 yr. We measured soil CH4 fluxes for 4 yr (2006–2009) in 4 replicate plots (40 m × 40 m each) per treatment using vented static chambers (4 chambers per plot). CH4 fluxes from the lowland control plots and the montane control plots did not differ from their respective N-addition plots. In the lowland forest, chronic N addition did not lead to inhibition of CH4 uptake; instead, a negative correlation of CH4 fluxes with nitrate (NO3−) concentrations in the mineral soil suggests that increased NO3− levels in N-addition plots had stimulated CH4 consumption and/or reduced CH4 production. In the montane forest, chronic N addition also showed negative correlation of CH4 fluxes with ammonium concentrations in the organic layer, which suggests that CH4 consumption was N limited. We propose the following reasons why such N-stimulated CH4 consumption did not lead to statistically significant CH4 uptake: (1) for the lowland forest, this was caused by limitation of CH4 diffusion from the atmosphere into the clayey soils, particularly during the wet season, as indicated by the strong positive correlations between CH4 fluxes and water-filled pore space (WFPS); (2) for the montane forest, this was caused by the high WFPS in the mineral soil throughout the year, which may not only limit CH4 diffusion from the atmosphere into the soil but also favour CH4 production; and (3) both forest soils showed large spatial and temporal variations of CH4 fluxes. We conclude that in these extremely different tropical forest ecosystems there were indications of N limitation on CH4 uptake. Based on these findings, it is unlikely that elevated N deposition on tropical forests will lead to widespread inhibition of CH4 uptake.

Carbon storage in phosphorus limited grasslands may decline in response to elevated nitrogen deposition: a long term field manipulation and modelling study 

2021 ◽  
Author(s):  
Christopher Taylor ◽  
Victoria Janes-Bassett ◽  
Gareth Phoenix ◽  
Ben Keane ◽  
Iain Hartley ◽  
...  
Keyword(s):  
N Deposition ◽  
Calcareous Grassland ◽  
Organic P ◽  
N Addition ◽  
Soil C ◽  
P Limitation ◽  
P Cycling ◽  
Nutrient Manipulation ◽  
N And P Cycling

&lt;p&gt;In ecosystems where nitrogen (N) limits plant productivity, N deposition can stimulate plant growth, and consequently, promote carbon (C) sequestration by increasing input of detrital C and other forms of plant C to the soil. However, other forms of nutrient limitation such as phosphorus (P) limitation and N-P co-limitation are widespread and may increase in prevalence with N deposition. Our understanding of how terrestrial ecosystem C, N and P cycling may be affected by N deposition when N is not the sole limiting resource is fairly limited. In this work, we investigate the consequences of enhanced N addition on C, N and P cycling in grasslands that exhibit contrasting forms of nutrient limitation.&lt;/p&gt;&lt;p&gt;We do so by collecting data from a long-term nutrient manipulation experiment on two N-P co-limited grasslands; an acidic grassland of stronger N-limitation and a calcareous grassland of stronger P limitation, and integrating this into a mechanistic C, N and P cycling model (N14CP). To simulate the experimental grasslands and explore the role of P access mechanisms in determining ecosystem state, we allowed P access to vary, and compared the outputs to plant-soil C, N and P data. Combinations of organic P access and inorganic P availability most closely representing data were used to simulate the grasslands and quantify their temporal response to nutrient manipulation.&lt;/p&gt;&lt;p&gt;The modelled grasslands showed contrasting responses to simulated N deposition. In the acidic grassland, N addition greatly increased C stocks by stimulating biomass productivity, but the same N treatments reduced the organic C pool in the calcareous grassland. Nitrogen deposition exacerbated P limitation in the calcareous grassland by reducing the size of the bioavailable P pool to plants, reducing biomass input to the soil C pool. Plant acquisition of organic P played an important role in determining the nutrient conditions of the grasslands, as both simulated grasslands increased organic P uptake to meet enhanced P demand driven by N deposition. Greater access to organic P in the acidic grassland prevented a shift to P limitation under elevated levels of N deposition, but organic P access was too low in the calcareous grassland to prevent worsening P limitation.&lt;/p&gt;&lt;p&gt;We conclude that grasslands of differing limiting nutrients may respond to N deposition in contrasting ways, and stress that as N deposition shifts ecosystems toward P limitation, a globally important carbon sink risks degradation.&lt;/p&gt;

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.

Sign in / Sign up

Export Citation Format

Share Document