Effect of soil warming and N availability on the fate of recent carbon in subarctic grassland

2020 ◽  
Author(s):  
Kathiravan Meeran ◽  
Niel Verbrigghe ◽  
Lucia Fuchslueger ◽  
Johannes Ingrisch ◽  
Sara Vicca ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Respiration ◽  
Nitrogen Addition ◽  
Interactive Effects ◽  
N Availability ◽  
Soil Warming ◽  
Soil System ◽  
Soil C ◽  
Microbial C ◽  
The Individual

<p>Climate warming has been suggested to impact high latitude grasslands severely, causing considerable carbon (C) losses from soil. Warming can also stimulate nitrogen (N) turnover, but it is largely unclear whether and how altered N availability impacts soil C dynamics. Even less is known about the individual and interactive effects of warming and N availability on the fate of recently photosynthesized C in soil.  We hypothesized that warming would increase belowground C allocation, while enhanced N availability would decrease it, and that their interactive effects would be additive.</p><p>We studied a subarctic grassland located at a natural geothermal soil warming gradient close to Hveragerði, Iceland, which was established by an earthquake in 2008. We chose 14 plots along the gradient with soil warming temperatures ranging from 0 to 10°C above ambient, and fertilized a subset of plots with 50kg ha<sup>-1</sup> y<sup>-1</sup> of NH<sub>4</sub>NO<sub>3</sub> twice a year prior to the study. We performed <sup>13</sup>CO<sub>2</sub> canopy pulse labeling for an hour and tracked the <sup>13</sup>C pulse through the plant-microbe-soil system and into soil respiration for ten days after labeling.</p><p>Our preliminary results show that at higher temperatures microbial activity increased, causing higher C turnover and a higher respiration of recently assimilated C from the soil. Warming significantly decreased microbial biomass, however, the recent C allocated from roots to microbes increased. This indicates a higher microbial C-limitation and a tighter root-microbe coupling under warming. Nitrogen addition increased the allocation of recent C to roots, microbial biomass, and soil respiration. The effects of N addition and warming were additive with no interaction. Our results indicate that the microbes in warmed soil may not be N limited, but could be C limited and depend more on the supply of recent C from plants. We conclude that in a future climate with warmer soils, more C may be allocated belowground, however, its residence time may decrease.</p>

scholarly journals Effects of long-term warming and enhanced nitrogen and sulfur deposition on microbial communities in a boreal peatland

2019 ◽  
Author(s):  
Magalí Martí ◽  
Alexander Eiler ◽  
Moritz Buck ◽  
Stefan Bertilsson ◽  
Waleed Abu Al-Soud ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Synergistic Effects ◽  
Vascular Plant ◽  
Nitrogen Addition ◽  
Interactive Effects ◽  
Gene Repertoire ◽  
Ecosystem Responses ◽  
Shotgun Metagenomics ◽  
The Individual

AbstractWith ongoing environmental change, it is important to understand ecosystem responses to multiple perturbations over long time scales at in situ conditions. Here, we investigated the individual and combined effects of 18 years of warming and enhanced nitrogen and sulfate deposition on peat microbial communities in a nutrient-poor boreal mire. The three perturbations individually affected prokaryotic community composition, where nitrogen addition had the most pronounced effect, and its combination with the other perturbations led to additive effects. The functional potential of the community, characterized by shotgun metagenomics, was strongly affected by the interactive effects in the combined treatments. The responses in composition were also partly reflected in the functional gene repertoire and in altered carbon turnover, i.e. an increase of methane production rates as a result of nitrogen addition and a decrease with warming. Long-term nitrogen addition and warming-induced changes caused a shift from Sphagnum-dominated plant communities to vascular plant dominance, which likely transact with many of the observed microbial responses. We conclude that simultaneous perturbations do not always lead to synergistic effects, but can also counteract and even neutralize one another, and thus must be studied in combination when attempting to predict future characteristics and services of peatland ecosystems.

Pore size effect on soil carbon dynamics during decomposition of switchgrass

2020 ◽  
Author(s):  
Kyungmin Kim ◽  
Andrey Guber ◽  
Alexandra Kravchenko
Keyword(s):  
Microbial Biomass ◽  
Pore Size ◽  
Microbial Activity ◽  
Priming Effect ◽  
Pore Space ◽  
Phenol Oxidase ◽  
Physical Factors ◽  
Soil System ◽  
Soil C ◽  
C Cycle

<p>Soil pore size distribution (PSD) regulates oxygen diffusion and transport of water/mineralized nutrients. Microbial activity, which drives the carbon (C) cycle in the soil system, can react to these physical factors regulated by PSD. In this study, we investigated the contribution of PSD to C-related microbial activity during the switchgrass decomposition. We used two types of soils, which have controlled PSD (dominant pore size of < 10um and > 30 um). 13C labeled switchgrass leaf and root were incorporated into different PSD of soils and incubated for 21 days under 50% water-filled pore space. During the incubation, microbial activity was assessed with several indicators. i) Fate and transport of mineralized switchgrass, ii) Priming effect, iii) Spatial distribution of b-glucosidase and phenol oxidase, and iv) Microbial biomass. Our preliminary results showed that CO2 emission from switchgrass leaf was greater in the soil dominated by < 10 um pores. Higher b -glucosidase activity and mineralized C from switchgrass leaf supported greater C-related activity in such soil. However, interestingly, we observed a greater priming effect in the soil dominated by > 30 um pores. Due to the less mineralization and transport of switchgrass-derived C in such pores, enzymes targeting more complex substrate could be more active in such soil stimulating mineralization of native soil C. Our full results of phenol oxidase, microbial biomass, and more detailed analysis on 13C and C dynamics will help understanding how PSD can affect biochemical reactions in plant decomposition system.</p>

scholarly journals Introduction of Dalbergia odorifera enhances nitrogen absorption on Eucalyptus through stimulating microbially mediated soil nitrogen-cycling

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xianyu Yao ◽  
Qianchun Zhang ◽  
Haiju Zhou ◽  
Zhi Nong ◽  
Shaoming Ye ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Ph ◽  
N Cycling ◽  
N Availability ◽  
Soil N ◽  
Total N ◽  
Available N ◽  
Soil C ◽  
Hot Season ◽  
Dalbergia Odorifera

Abstract Background There is substantial evidence that Eucalyptus for nitrogen (N) absorption and increasing the growth benefit from the introduction of N-fixing species, but the underlying mechanisms for microbially mediated soil N cycling remains unclear. Methods We investigated the changes of soil pH, soil water content (SWC), soil organic carbon (SOC), total N (TN), inorganic N (NH4+-N and NO3−-N), microbial biomass and three N-degrading enzyme activities as well as the biomass and N productivity of Eucalyptus between a pure Eucalyptus urophylla × grandis plantation (PP) and a mixed Dalbergia odorifera and Eucalyptus plantation (MP) in Guangxi Zhuang Autonomous Region, China. Results Compared with the PP site, soil pH, SWC, SOC and TN in both seasons were significantly higher at the MP site, which in turn enhanced microbial biomass and the activities of soil N-degrading enzymes. The stimulated microbial activity at the MP site likely accelerate soil N mineralization, providing more available N (NH4+-N in both seasons and NO3−-N in the wet-hot season) for Eucalyptus absorption. Overall, the N productivity of Eucalyptus at the MP site was increased by 19.7% and 21.9%, promoting the biomass increases of 15.1% and 19.2% in the dry-cold season and wet-hot season, respectively. Conclusion Our results reveal the importance of microbially mediated soil N cycling in the N absorption on Eucalyptus. Introduction of D. odorifera enhances Eucalyptus biomass and N productivity, improve soil N availability and increased soil C and N concentration, which hence can be considered to be an effective sustainable management option of Eucalyptus plantations.

scholarly journals Nonnegligible role of warming-induced soil drying in regulating warming effect on soil respiration

2018 ◽  
Author(s):  
Enzai Du
Keyword(s):  
Soil Respiration ◽  
Annual Variation ◽  
Precipitation Anomaly ◽  
Soil Drying ◽  
Phase Pattern ◽  
Soil Warming ◽  
Soil C ◽  
C Dynamics

AbstractBased on results of a 26-year soil warming experiment (soil temperature being elevated by 5 °C) in a Harvard hardwood forest, Melillo et al. demonstrated a four-phase pattern of long-term warming effect on soil respiration, while the mechanisms were not fully elucidated because they neglected the indirect effect due to warming-induced soil drying. By showing a significant correlation between precipitation anomaly and inter-annual variation of warming effect on soil respiration, we suggest a nonnegligible role of warming-induced soil drying in regulating the long-term warming effect on soil respiration. Our analysis recommends further efforts to consider both the direct and indirect (i.e., warming-induced soil drying) warming effects to gain more in-depth understanding of the long-term soil C dynamics.

scholarly journals Biological and biochemical quality of pastoral soils: spatial and temporal variability

1996 ◽  
pp. 211-218 ◽  
Author(s):  
A. Ghani ◽  
U. Sarathchandra ◽  
K.W. Perrott ◽  
D.A. Wardle ◽  
P. Singleton ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Ph ◽  
Dairy Farms ◽  
Seasonal Effect ◽  
Climatic Data ◽  
Soil C ◽  
Olsen P ◽  
Significant Difference ◽  
C And N ◽  
Microbial C

This paper reports results of the first year of soil biochemical and microbiological monitoring programme carried out to establish "normal" ranges of values for these soil attributes. Study was conducted on 24 farm sites on yellow-brown loam soils around the Waikato area. Twelve dairy farms and a similar number of sheep-beef farms were selected on the basis of high productivity. Soil samples (0-75 mm depth) were collected at 3- monthly intervals and the following measurements were carried out: soil microbial- C, N, S and P, CO2 evolution, substrate-induced respiration, anaerobic mineralisable N, dehydrogenase activity, fluorescein diacetate (FDA) hydrolysis, amounts of soluble-C and N, extractable NO3 and NH4, soil pH, Olsen P, KH2PO4 extractable SO4-S and organic S, and hydraulic conductivity. Climatic data, records of fertiliser and other additives and productivity were also collected to interpret the variations in these properties. Variables measured from the Horotiu and Tirau silt loam soils showed considerable similarity, however, Otorohanga soils had significantly higher amounts of total and extractable soil C and N. As expected, being a higher input system, soil nutrient status (P, SO4, NO3 and NH4) on dairy farms was generally higher than the sheep-beef farms. The most significant difference was for the Olsen P values, which were about 60-70% higher under dairying. Soil pH on dairy farms was significantly higher than sheep- beef farms. However, total C and N values were significantly higher under sheep-beef than dairy farms. Similarly, the amounts of mineralisable N in all seasons were much higher for the sheep-beef than dairy farms. Apart from total microbial S, none of the other microbial biomass measurements showed any significant effect of season or difference among the soil types. This lack of seasonal effect on microbial biomass can be attributed to the unusual mild seasonal variation during the study. For the various microbial biomass measurements, sheep-beef farms generally had significantly higher values than dairy farms. Microbial C, N, SO4 and total S values were significantly higher for sheep-beef than dairying. The ratios between soil C, N to microbial C, N and microbial C:N showed no consistent pattern between the farm types. Keywords: C and N, enzyme activity, microbial biomass, seasonal variations, soil fertility

Corrigendum to: Early growing season immobilisation affects post-tillering wheat nitrogen uptake from crop stubble and 15N fertiliser in a sandy soil

Soil Research ◽  
2021 ◽  
Vol 59 (3) ◽  
pp. 318
Author(s):  
Pilar Muschietti Piana ◽  
Therese Marie McBeath ◽  
Ann Marie McNeill ◽  
Pablo Ariel Cipriotti ◽  
Vadakattu Gupta
Keyword(s):  
Microbial Biomass ◽  
Sandy Soil ◽  
N Uptake ◽  
Early Growth ◽  
Wheat Crop ◽  
Growth Stages ◽  
N Availability ◽  
Soil System ◽  
N Supply ◽  
Energy Limitation

In semiarid sandy soil environments there is a dual challenge of carbon and nitrogen (N) limitation that needs to be managed to ensure timely supply of N to crops. Management of N inputs to soil using combinations of legume stubble addition and fertiliser N in cereal systems is essential to meet crop demand and maintain N in soil organic matter. The aim of this study was to assess soil mineral and biological N pools that influence N supply and N uptake of wheat at early growth stages. The recovery of 15N-labelled fertiliser by wheat was evaluated using a factorial combination of either wheat, lupin or no stubble incorporated with or without 15N fertiliser in a sandy soil system. Soil and plant samples were collected at sowing, tillering, first node and booting to monitor changes in N pools and 15N uptake by the wheat. Crop stubble incorporation one week before sowing increased biological N pools in the surface soil (0–10 cm). Early N immobilisation (sowing–tillering) in all the treatments without 15N fertiliser may have limited N availability for wheat uptake in the subsequent period (tillering–first node), when fertiliser N appeared critical to maximise N supply for plant requirements. Up to 38% of the 15N fertiliser applied at sowing was incorporated into the soil microbial biomass pool, so that fertiliser N was critical to relieve short-term inherent N limitations for both plant and microbial growth, and to supply the longer-term biological pools (microbial biomass) to support subsequent mineralisation potential. Reducing the energy limitation to the microbial pool through inputs of carbon from stubble was also critical to ensure fertiliser N supplied sufficient N to satisfy plant demand later in the growing period. These results have implications for management decisions on semiarid sandy soil systems that aim to synchronise N from inputs of legume stubbles and fertiliser with crop N demand during early growth stages of wheat.

scholarly journals Effects of Soil Warming and Nitrogen Addition on Soil Respiration in a New Zealand Tussock Grassland

PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e91204 ◽  
Author(s):  
Scott L. Graham ◽  
John E. Hunt ◽  
Peter Millard ◽  
Tony McSeveny ◽  
Jason M. Tylianakis ◽  
...  
Keyword(s):  
New Zealand ◽  
Soil Respiration ◽  
Nitrogen Addition ◽  
Soil Warming ◽  
Tussock Grassland

ALLOCATION AND MICROBIAL UTILIZATION OF C IN TWO SOILS CROPPED TO BARLEY

1988 ◽  
Vol 68 (3) ◽  
pp. 495-505 ◽  
Author(s):  
G. D. DINWOODIE ◽  
N. G. JUMA
Keyword(s):  
Microbial Biomass ◽  
Black Soil ◽  
Water Soluble ◽  
Microbial Biomass C ◽  
Organic C ◽  
Soil C ◽  
Microbial Utilization ◽  
Below Ground ◽  
Microbial C ◽  
Soluble C

This study was undertaken to compare some aspects of carbon cycling in a Gray Luvisol at Breton and a Black soil at Ellerslie, Alberta cropped to barley. Comparisons of the above and below-ground allocation of carbon, distribution of carbon in soil, and microbial use of carbon were made between sites. Shoot C, root C, microbial biomass C, soil organic C, water soluble organic C, and polysaccharide C were measured on four dates between 31 July and 20 Oct. 1986. The total quantity of carbon in the soil-plant system at Ellerslie (17.2 kg C m−2) was greater than at Breton (6.6 kg C m−2). On average shoot C at Ellerslie (247 g C m−2) was greater than at Breton (147 g m−2). The quantity of root C (avg. 21 g C m−2) was the same at both sites resulting in higher shoot C:root C ratios at Ellerslie than Breton. Microbial biomass (expressed as g C m−2 or g C g−1 root C) was one to two times lower at Breton than at Ellerslie but respiration (g CO2-C g−1 microbial biomass C) during a 10-d laboratory incubation was two to four times greater. Microbial biomass C, soluble C and polysaccharide C expressed as mg C g−1 of soil were less at Breton than Ellerslie. However when these data were compared on a relative basis in terms of soil C (g C g−1 soil C), microbial biomass C and soluble C were higher at Breton than Ellerslie. Polysaccharide C was the same at both sites. Although the microbial biomass was smaller at Breton than at Ellerslie, more carbon was lost from the system by microbial respiration and a greater proportion of the carbon in the soil was in microbial and soluble C pools. Soil characteristics, and cropping history affected the amount of carbon stabilized in soil. Key words: Chernozemic, Luvisolic, microbial C, soluble C, polysaccharide C, soil organic matter, barley

scholarly journals Alteration of soil carbon and nitrogen pools and enzyme activities as affected by increased soil coarseness

2017 ◽  
Vol 14 (8) ◽  
pp. 2155-2166 ◽  
Author(s):  
Ruzhen Wang ◽  
Linyou Lü ◽  
Courtney A. Creamer ◽  
Feike A. Dijkstra ◽  
Heyong Liu ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Enzyme Activities ◽  
Organic C ◽  
Soil C ◽  
N Limitation ◽  
Soil C And N ◽  
C And N ◽  
Microbial C ◽  
Sandy Grasslands ◽  
Acid Phosphomonoesterase

Abstract. Soil coarseness decreases ecosystem productivity, ecosystem carbon (C) and nitrogen (N) stocks, and soil nutrient contents in sandy grasslands subjected to desertification. To gain insight into changes in soil C and N pools, microbial biomass, and enzyme activities in response to soil coarseness, a field experiment was conducted by mixing native soil with river sand in different mass proportions: 0, 10, 30, 50, and 70 % sand addition. Four years after establishing plots and 2 years after transplanting, soil organic C and total N concentrations decreased with increased soil coarseness down to 32.2 and 53.7 % of concentrations in control plots, respectively. Soil microbial biomass C (MBC) and N (MBN) declined with soil coarseness down to 44.1 and 51.9 %, respectively, while microbial biomass phosphorus (MBP) increased by as much as 73.9 %. Soil coarseness significantly decreased the enzyme activities of β-glucosidase, N-acetyl-glucosaminidase, and acid phosphomonoesterase by 20.2–57.5 %, 24.5–53.0 %, and 22.2–88.7 %, used for C, N and P cycling, respectively. However, observed values of soil organic C, dissolved organic C, total dissolved N, available P, MBC, MBN, and MBP were often significantly higher than would be predicted from dilution effects caused by the sand addition. Soil coarseness enhanced microbial C and N limitation relative to P, as indicated by the ratios of β-glucosidase and N-acetyl-glucosaminidase to acid phosphomonoesterase (and MBC : MBP and MBN : MBP ratios). Enhanced microbial recycling of P might alleviate plant P limitation in nutrient-poor grassland ecosystems that are affected by soil coarseness. Soil coarseness is a critical parameter affecting soil C and N storage and increases in soil coarseness can enhance microbial C and N limitation relative to P, potentially posing a threat to plant productivity in sandy grasslands suffering from desertification.

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