scholarly journals Effects of seabird nitrogen input on biomass and carbon accumulation after 50 years of primary succession on a young volcanic island, Surtsey

2014 ◽  
Vol 11 (5) ◽  
pp. 6269-6302 ◽  
Author(s):  
N. I. W. Leblans ◽  
B. D. Sigurdsson ◽  
P. Roefs ◽  
R. Thuys ◽  
B. Magnússon ◽  
...  
Keyword(s):  
Primary Succession ◽  
Soil Depth ◽  
Carbon Accumulation ◽  
Volcanic Island ◽  
N Accumulation ◽  
Total N ◽  
N Retention ◽  
C Storage ◽  
C Stocks ◽  
N Input

Abstract. What happens during primary succession after the first colonizers have occupied a pristine surface largely depends on how they ameliorate living conditions for other species. For vascular plants the onset of soil development and associated increase in nutrient (mainly nitrogen, N) and water availability is especially important. Here, we report the relation between N accumulation and biomass- and ecosystem carbon (C) stocks in a 50 year old volcanic island, Surtsey, in Iceland, where N stocks are still exceptionally low. However, 27 year old seagull colony on the island provided nutrient-enriched areas, which enabled us to assess the relationship between N stock and biomass- and ecosystem C stocks across a much larger range in N stock. Further, we compared areas on shallow and deep tephra sands as we expected that deep-rooted systems would be more efficient in retaining N. The sparsely vegetated area outside the colony was more efficient in N retention than we expected and had accumulated 0.7 kg N ha−1 yr−1, which was ca. 60% of the estimated N input rate from wet deposition. The seagulls have added, on average, 47 kg N ha−1 yr−1, which induced a shift from belowground to aboveground in ecosystem N and C stocks and doubled the ecosystem "N use efficiency", determined as the ratio of biomass and C storage per unit N input. Soil depth did not significantly affect total N stocks, which suggests a high N retention potential. Both total ecosystem biomass and C stocks were strongly correlated with N stock inside the colony, which indicated the important role of N during the first steps of primary succession. Inside the colony, the ecosystem biomass C stocks (17–27 kg C ha−1) had reached normal values for grasslands, while the soil organic carbon stocks (SOC; 4–10 kg C ha−1) were only a fraction of normal grassland values. Thus, it will take a long time until the SOC stock reaches equilibrium with the current primary production; during which conditions for new colonists may change.

scholarly journals Effects of seabird nitrogen input on biomass and carbon accumulation after 50 years of primary succession on a young volcanic island, Surtsey

2014 ◽  
Vol 11 (22) ◽  
pp. 6237-6250 ◽  
Author(s):  
N. I. W. Leblans ◽  
B. D. Sigurdsson ◽  
P. Roefs ◽  
R. Thuys ◽  
B. Magnússon ◽  
...  
Keyword(s):  
Primary Succession ◽  
Soil Depth ◽  
Carbon Accumulation ◽  
Volcanic Island ◽  
N Accumulation ◽  
Total N ◽  
C Storage ◽  
C Stocks ◽  
N Input ◽  
The Relationship

Abstract. What happens during primary succession after the first colonizers have occupied a pristine surface largely depends on how they ameliorate living conditions for other species. For vascular plants the onset of soil development and associated increase in nutrient (mainly nitrogen; N) and water availability is especially important. Here, we report the relationship between N accumulation and biomass and ecosystem carbon (C) stocks in a 50-year-old volcanic island, Surtsey, Iceland, where N stocks are still exceptionally low. However, a 28-year-old seagull colony on the island provided nutrient-enriched areas, which enabled us to assess the relationship between N stock and biomass and ecosystem C stocks across a much larger range in N stock. Further, we compared areas on shallow and deep tephra sands as we expected that deep-rooted systems would be more efficient in retaining N. The sparsely vegetated area outside the colony had accumulated 0.7 kg N ha−1 yr−1, which was ca. 50–60% of the estimated N input rate from wet deposition. This approximates values for systems under low N input and bare dune habitats. The seagulls have added, on average, 47 kg N ha−1 yr−1, which induced a shift from belowground to aboveground in ecosystem N and C stocks and doubled the ecosystem N-use efficiency, determined as the ratio of biomass and C storage per unit N input. Soil depth did not significantly affect total N stocks, which suggests a high N retention potential. Both total ecosystem biomass and C stocks were strongly correlated with N stock inside the colony, which indicated the important role of N during the first steps of primary succession. Inside the colony, the ecosystem biomass C stocks (17–27 ton C ha−1) had reached normal values for grasslands, while the soil organic carbon (SOC) stocks (4–10 ton C ha−1 were only a fraction of normal grassland values. Thus, it will take a long time until the SOC stock reaches equilibrium with the current primary production, during which conditions for new colonists may change.

Improving Dryland Cropping System Nitrogen Balance with No-Tillage and Nitrogen Fertilization

2018 ◽  
Author(s):  
Upendra Sainju ◽  
Rajan Ghimire ◽  
Gautam Pradhan
Keyword(s):  
Environmental Sustainability ◽  
Cropping System ◽  
N Fertilization ◽  
N Fixation ◽  
No Tillage ◽  
Soil N ◽  
Total N ◽  
N Retention ◽  
N Removal ◽  
N Input

Studies on N balance due to N inputs and outputs and soil N retention to measure cropping system performance and environmental sustainability are limited due to the complexity of measurements of some parameters. We measured N balance based on N inputs and outputs and soil N retention under dryland agroecosystem affected by cropping system and N fertilization from 2007 to 2011 in the northern Great Plains, USA. Cropping systems were conventional tillage barley (Hordeum vulgaris L.)-fallow (CTB-F), no-tillage barley-fallow (NTB-F), no-tillage barley-pea (Pisum sativum L.) (NTB-P), and no-tillage continuous barley (NTCB). Nitrogen rates to barley were 0, 40, 80, and 120 kg N ha-1. Total N input due to N fertilization, pea N fixation, soil N mineralization, atmospheric N deposition, nonsymbiotic N fixation, and crop seed N and total N output due to grain N removal, denitrification, volatilization, N leaching, gaseous N (NOx) emissions, surface runoff, and plant senescence were 28 to 37% greater with NTB-P and NTCB than CTB-F and NTB-F. Total N input and output also increased with increased N rate. Nitrogen sequestration rate at 0 to 10 cm averaged 22 kg N ha-1 yr-1 for all treatments. Nitrogen deficit ranged from 5 to 16 kg N ha-1 yr-1, with greater deficits for CTB-F and NTB-P and higher N rates. Because of increased grain N removal and reduced N loss to the environment and N fertilizer requirement, NTB-P with 40 kg N ha-1 can enhance agronomic performance and environmental sustainability while reducing N inputs compared to other management practices.

scholarly journals Effects of different N sources on riverine DIN export and retention in a subtropical high-standing island, Taiwan

2016 ◽  
Vol 13 (6) ◽  
pp. 1787-1800 ◽  
Author(s):  
Jr-Chuan Huang ◽  
Tsung-Yu Lee ◽  
Teng-Chiu Lin ◽  
Thomas Hein ◽  
Li-Chin Lee ◽  
...  
Keyword(s):  
Agricultural Land ◽  
Eastern Coast ◽  
N Availability ◽  
N Saturation ◽  
Agricultural Lands ◽  
Retention Capacity ◽  
Total N ◽  
N Retention ◽  
Nitrogen Inputs ◽  
N Input

Abstract. Increases in nitrogen (N) availability and mobility resulting from anthropogenic activities have substantially altered the N cycle, both locally and globally. Taiwan characterized by the subtropical montane landscape with abundant rainfall, downwind of the most rapidly industrializing eastern coast of China, can be a demonstration site for extremely high N input and riverine DIN (dissolved inorganic N) export. We used 49 watersheds with similar climatic and landscape settings but classified into low, moderate, and highly disturbed categories based on population density to illustrate their differences in nitrogen inputs (through atmospheric N deposition, synthetic fertilizers, and human emission) and DIN export ratios. Our results showed that the island-wide average riverine DIN export is ∼ 3800 kg N km−2 yr−1, approximately 18 times the global average. The average riverine DIN export ratios are 0.30–0.51, which are much higher than the averages of 0.20–0.25 of large rivers around the world, indicating excessive N input relative to ecosystem demand or retention capacity. The low disturbed watersheds have a high N retention capacity and DIN export ratios of 0.06–0.18 in spite of the high N input (∼ 4900 kg N km−2 yr−1). The high retention capacity is likely due to effective uptake by secondary forests in the watersheds. The moderately disturbed watersheds show a linear increase in DIN export with increases in total N inputs and mean DIN export ratios of 0.20 to 0.31. The main difference in land use between low and moderately disturbed watersheds is the greater proportion of agricultural land cover in the moderately disturbed watersheds. Thus, their greater DIN export could be attributed to N fertilizers used in the agricultural lands. The greater export ratios also imply that agricultural lands have a lower proportional N retention capacity and that reforestation could be an effective land management practice to reduce riverine DIN export. The export ratios of the highly disturbed watersheds are very high, 0.42–0.53, suggesting that much of the N input is transported downstream directly, and urges the need to increase the proportion of households connected to a sewage system and improve the effectiveness of wastewater treatment systems. The increases in the riverine DIN export ratio along the gradient of human disturbance also suggest a gradient in N saturation in subtropical Taiwan. Our results help to improve our understanding of factors controlling riverine DIN export and provide empirical evidence that calls for sound N emission/pollution control measures.

scholarly journals Optimal soil carbon sampling designs to achieve cost-effectiveness: a case study in blue carbon ecosystems

2018 ◽  
Vol 14 (9) ◽  
pp. 20180416 ◽  
Author(s):  
Mary A. Young ◽  
Peter I. Macreadie ◽  
Clare Duncan ◽  
Paul E. Carnell ◽  
Emily Nicholson ◽  
...  
Keyword(s):  
Soil Depth ◽  
Linear Equations ◽  
Cost Effective ◽  
Blue Carbon ◽  
Climate Mitigation ◽  
Sampling Effort ◽  
Natural Ecosystems ◽  
Soil C ◽  
C Storage ◽  
C Stocks

Researchers are increasingly studying carbon (C) storage by natural ecosystems for climate mitigation, including coastal ‘blue carbon’ ecosystems. Unfortunately, little guidance on how to achieve robust, cost-effective estimates of blue C stocks to inform inventories exists. We use existing data (492 cores) to develop recommendations on the sampling effort required to achieve robust estimates of blue C. Using a broad-scale, spatially explicit dataset from Victoria, Australia, we applied multiple spatial methods to provide guidelines for reducing variability in estimates of soil C stocks over large areas. With a separate dataset collected across Australia, we evaluated how many samples are needed to capture variability within soil cores and the best methods for extrapolating C to 1 m soil depth. We found that 40 core samples are optimal for capturing C variance across 1000's of kilometres but higher density sampling is required across finer scales (100–200 km). Accounting for environmental variation can further decrease required sampling. The within core analyses showed that nine samples within a core capture the majority of the variability and log-linear equations can accurately extrapolate C. These recommendations can help develop standardized methods for sampling programmes to quantify soil C stocks at national scales.

Carbon Accumulation and Partitioning Above and Belowground under Coppiced and Replanted Eucalypt Plantations

2021 ◽  
Author(s):  
Rodinei F Pegoraro ◽  
Ivo R Silva ◽  
Ivan F Souza ◽  
Roberto F Novais ◽  
Nairam F Barros ◽  
...  
Keyword(s):  
Genetic Material ◽  
Carbon Accumulation ◽  
Sink Strength ◽  
Large Contribution ◽  
Forest Residues ◽  
Coarse Roots ◽  
Soil C ◽  
C Storage ◽  
Eucalypt Plantations ◽  
C Stocks

Abstract The extent to which the C sink strength of eucalypt plantations can be affected by coppicing or replanting remains unclear. To address this issue, we evaluated variations in C stocks under coppiced or replanted eucalypt stands formed by clones or seedlings. For each field assessment (0 [T0], 2.5, 3.5, 4.5, 5.5 and 7.0 years [at harvest]), tree biomass, litterfall, and soil C stocks (0–120 cm depth) were determined. At harvest, debarked stemwood productivity was similar under coppice or replanting, about 50.0 Mg C ha–1. Generally, coppiced stands favored subsoil C storage (40–100 cm), whereas replanted stands favored soil C accrual in topsoil (0–20 cm), depending on the genetic material. Relative to T0, soil C increased about 2.14, 1.91, and 1.84 Mg C ha–1 yr–1 under coppice, replanting with seedlings and clones, respectively. Coarse root biomass under these stands were about 17.3, 13.4, and 9.5 Mg C ha–1, respectively, equivalent to 50% of total harvest residues. Hence, inputs from coarse roots could represent a large contribution to soil C over multiple rotations under coppiced or replanted stands. Otherwise, short-term C losses can be high where stumps and coarse roots are harvested, especially following successive coppice cycles. Study Implications: Our findings have important implications for forest managers growing eucalypt plantations aiming to maximize C accumulation. Both coppiced and replanted stands can fix up to 50 Mg C ha−1 only in debarked stemwood over 7 years, with a comparatively higher C storage in coarse roots under coppice. Despite the increasing demand for forest residues in bioenergy production, harvesting stumps and coarse roots should be avoided, especially upon replanting eucalypt stands after successive coppice cycles.

scholarly journals Quantification of nitrogen balance components in a commercial broiler barn 

2013 ◽  
Vol 58 (No. 12) ◽  
pp. 566-577 ◽  
Author(s):  
K. von Bobrutzki ◽  
S. Ammon ◽  
W. Berg ◽  
M. Fiedler
Keyword(s):  
Mass Balance ◽  
Management Practices ◽  
N Accumulation ◽  
Total N ◽  
N Input ◽  
Commercial Broiler ◽  
Use Efficiency ◽  
The Difference ◽  
Inputs And Outputs

Characterizing the respective nitrogen (N) use efficiency requires understanding the N flow of inputs and outputs from a commercial broiler barn. In this study, an N mass balance was performed for one entire growing cycle. The objectives were to quantify, sample, and analyze all N components entering and leaving the barn. The N from feed, chickens, and bedding material was considered as inputs, the outputs included the N accretion in mature broilers, the total N emissions (N<sub>TNE</sub>), the N accumulation in litter, and the N of mortality. Of particular relevance was the determination of an appropriate method to mirror the heterogenic texture of the litter. Litter samples were collected weekly according to a defined procedure. The major N input was feed N, accounting for 99% of the total N input. After the 36-day growing cycle, the N outputs were portioned as follows: 59% (1741.3 kg N) in mature broilers, 37% (1121.3 kg N) accumulated in litter, and 4% in NTNE (114.3 kg N). The N accumulations in broiler tissue and litter agree well with other studies. The measured emissions were consistently lower compared to other references, due to the fact that these references were mainly based on studies where broilers were raised on built-up litter. In contrast to in situ quantified N emissions in this study, other published values were assumed to be the difference of N between inputs and outputs. This study illustrates that extensive sampling of litter is a prerequisite for calculating litter masses. The accurate specification of the litter texture proved to be crucial within the mass balance approach. With this information, the feasible improvements within management practices can be identified.

Carbon accumulation in Colorado ponderosa pine stands

2004 ◽  
Vol 34 (6) ◽  
pp. 1283-1295 ◽  
Author(s):  
Jeffrey A Hicke ◽  
Rosemary L Sherriff ◽  
Thomas T Veblen ◽  
Gregory P Asner
Keyword(s):  
Ponderosa Pine ◽  
Carbon Budget ◽  
Accumulation Rate ◽  
Carbon Accumulation ◽  
Slope Aspect ◽  
Soil Conditions ◽  
Accumulation Rates ◽  
C Storage ◽  
C Stocks ◽  
The Us

Woody encroachment and thickening have occurred throughout the western United States and have been proposed as important processes in the US carbon (C) budget despite large uncertainty in the magnitude of these effects. In this study we investigated ponderosa pine encroachment near Boulder, Colorado. We reconstructed a time series of forest structure to estimate changes in C storage by the trees. Advantages of this technique include the ability to estimate changes in C stocks over time with a single series of measurements (i.e., no historical measurements), and the ability to calculate accumulation rate changes through time. Substantial variation occurred in the C amounts and accumulation rates among the three plots resulting from differences in slope, aspect, and soil conditions. Accumulation rates increased exponentially as trees increased in size and additional trees established within the plots, and were highly variable among plots (0.09–0.7 Mg C·ha–1·year–1 during 1980–2001). These rates were less than those used in studies of the US carbon budget, and only by assuming no mortality for the densest stand could we generate a projected rate in 2050 that was similar. Thus, time since the initiation of encroachment and rate of encroachment are variables that should be considered for accurately computing the continental C budget.

scholarly journals Effects of different N sources on riverine DIN export and retention in subtropical high-standing island, Taiwan

2015 ◽  
Vol 12 (19) ◽  
pp. 16397-16430
Author(s):  
J.-C. Huang ◽  
T.-Y. Lee ◽  
T.-C. Lin ◽  
T. Hein ◽  
L.-C. Lee ◽  
...  
Keyword(s):  
N Saturation ◽  
Agricultural Lands ◽  
Retention Capacity ◽  
Total N ◽  
Input Quantity ◽  
N Retention ◽  
Export Ratio ◽  
Nitrogen Inputs ◽  
N Input ◽  
Synthetic Fertilizers

Abstract. Increases in nitrogen (N) availability and mobility resulting from anthropogenic activities has substantially altered N cycle both locally and globally. Taiwan characterized by the subtropical montane landscape with abundant rainfall, downwind to the most rapidly industrializing east coast of China can be a demonstration site for extreme high N input and riverine DIN (dissolved inorganic N) export. We used 49 watersheds classified into low-, moderate-, and highly-disturbed categories based on population density to illustrate their differences in nitrogen inputs through atmospheric N deposition, synthetic fertilizers and human emission and DIN export ratios. Our results showed that the island-wide average riverine DIN export is ~ 3800 kg N km−2 yr−1, approximately 18-fold higher than the global average mostly due to the large input of synthetic fertilizers. The average riverine DIN export ratio is 0.30–0.51, which is much higher than the average of 0.20–0.25 of large rivers around the world indicating excessive N input relative to ecosystem demand or retention capacity. The low-disturbed watersheds, despite of high N input, only export 0.06–0.18 of the input so were well buffered to changes in input quantity suggesting high efficiency of nitrogen usage or high N retention capacity of the less disturbed watersheds. The high retention capacity probably is due to the effective uptake by secondary forests in the watersheds. The moderate-disturbed watersheds show a linear increase of output with increases in total N inputs and a mean DIN export ratio of 0.20 to 0.31. The main difference in land use between low and moderately disturbed watershed is the relative proportions of agricultural land and forests, not the built-up lands. Thus, their greater DIN export quantity could be attributed to N fertilizers used in the agricultural lands. The greater export ratios also imply that agricultural lands have lower proportional N retention capacity and that reforestation could be an effective land management practice to reduce riverine DIN export. The export ratio of the highly-disturbed watersheds is 0.42–0.53, which is very high and suggests that much of the N input is transported downstream and the need of improvement in wastewater treatment capacity or sewerage systems. The increases in riverine DIN export ratio along with the gradient of human disturbance indicates a gradient in N saturation in subtropical Taiwan. Our results help to understand factors controlling riverine DIN export and provide a sound basis for N emissions/pollution control.

scholarly journals Characterization of Soil Carbon Stocks in the City of Johannesburg

Land ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 83
Author(s):  
Kelebohile Rose Seboko ◽  
Elmarie Kotze ◽  
Johan van Tol ◽  
George van Zijl
Keyword(s):  
Bulk Density ◽  
Soil Depth ◽  
Soil Productivity ◽  
Rapid Urbanization ◽  
Organic C ◽  
C Stocks ◽  
Shallow Soils ◽  
Deep Soils ◽  
Soc Stocks ◽  
Soil Groups

Soil organic carbon (SOC) is a crucial indicator of soil health and soil productivity. The long-term implications of rapid urbanization on sustainability have, in recent years, raised concern. This study aimed to characterize the SOC stocks in the Johannesburg Granite Dome, a highly urbanized and contaminated area. Six soil hydropedological groups; (recharge (deep), recharge (shallow), responsive (shallow), responsive (saturated), interflow (A/B), and interflow (soil/bedrock)) were identified to determine the vertical distribution of the SOC stocks and assess the variation among the soil groups. The carbon (C) content, bulk density, and soil depth were determined for all soil groups, and thereafter the SOC stocks were calculated. Organic C stocks in the A horizon ranged, on average, from 33.55 ± 21.73 t C ha−1 for recharge (deep) soils to 17.11 ± 7.62 t C ha−1 for responsive (shallow) soils. Higher C contents in some soils did not necessarily indicate higher SOC stocks due to the combined influence of soil depth and bulk density. Additionally, the total SOC stocks ranged from 92.82 ± 39.2 t C ha−1 for recharge (deep) soils to 22.81 ± 16.84 t C ha−1 for responsive (shallow) soils. Future studies should determine the SOC stocks in urban areas, taking diverse land-uses and the presence of iron (Fe) oxides into consideration. This is crucial for understanding urban ecosystem functions.

scholarly journals Microbial Utilisation of Aboveground Litter-Derived Organic Carbon Within a Sandy Dystric Cambisol Profile

2021 ◽  
Vol 1 ◽  
Author(s):  
Sebastian Preusser ◽  
Patrick Liebmann ◽  
Andres Stucke ◽  
Johannes Wirsching ◽  
Karolin Müller ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Depth ◽  
Sampling Period ◽  
Beech Forest ◽  
Stable Isotope Labelling ◽  
C Stocks ◽  
Microbial Groups ◽  
Aboveground Litter ◽  
Over Time

Litter-derived dissolved organic carbon (DOC) is considered to be a major source of stabilised C in soil. Here we investigated the microbial utilisation of litter-derived DOC within an entire soil profile using a stable isotope labelling experiment in a temperate beech forest. The natural litter layer of a Dystric Cambisol was replaced by 13C enriched litter within three areas of each 6.57 m−2 for 22 months and then replaced again by natural litter (switching-off the 13C input). Samples were taken continuously from 0 to 180 cm depths directly after the replacement of the labelled litter, and 6 and 18 months thereafter. We followed the pulse of 13C derived from aboveground litter into soil microorganisms through depth and over time by analysing 13C incorporation into microbial biomass and phospholipid fatty acids. Throughout the sampling period, most of the litter-derived microbial C was found in the top cm of the profile and only minor quantities were translocated to deeper soil. The microbial 13C stocks below 30 cm soil depth at the different samplings accounted constantly for only 6–12% of the respective microbial 13C stocks of the entire profile. The peak in proportional enrichment of 13C in subsoil microorganisms moved from upper (≤ 80 cm soil depth) to lower subsoil (80–160 cm soil depth) within a period of 6 months after switch-off, and nearly disappeared in microbial biomass after 18 months (&lt; 1%), indicating little long-term utilisation of litter-derived C by subsoil microorganisms. Among the different microbial groups, a higher maximum proportion of litter-derived C was found in fungi (up to 6%) than in bacteria (2%), indicating greater fungal than bacterial dependency on litter-derived C in subsoil. However, in contrast to topsoil, fungi in subsoil had only a temporarily restricted increase in litter C incorporation, while in the Gram-positive bacteria, the C incorporation in subsoil raised moderately over time increasingly contributing to the group-specific C stock of the entire profile (up to 9%). Overall, this study demonstrated that microorganisms in topsoil of a Dystric Cambisol process most of the recently deposited aboveground litter C, while microbial litter-derived C assimilation in subsoil is low.

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