Mass loss and nitrogen dynamics of decaying litter of grasslands: the apparent low nitrogen immobilization potential of root detritus

1992 ◽  
Vol 70 (2) ◽  
pp. 384-391 ◽  
Author(s):  
T. R. Seastedt ◽  
W. J. Parton ◽  
D. S. Ojima
Keyword(s):  
Mass Loss ◽  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
C:N Ratio ◽  
Nitrogen Dynamics ◽  
Nitrogen Immobilization ◽  
Litter Bag ◽  
Root Litter ◽  
Low Nitrogen

Litter-bag studies and simulation modeling were used to examine the relationship between mass loss and nitrogen content of decaying prairie foliage and root litter. In contrast with forest studies, grassland roots were low in lignin and nitrogen, decayed more rapidly than foliage, and demonstrated very low nitrogen immobilization potentials. Our findings agree with reports indicating that buried substrates with high C:N ratios do not immobilize substantial amounts of nitrogen and that nitrogen-limited environments induce steeper slopes in the mass loss – nitrogen concentration relationship. However, results suggesting rapid nitrogen mineralization contradict our own studies demonstrating reduced inorganic nitrogen availability in soils of frequently burned prairie. Simulation of observed patterns using the CENTURY grassland model indicated that these results could not occur without creating soil organic matter with unrealistically high C:N ratios. Litter-bag studies of buried substrates therefore may provide an incomplete perspective on the mass loss and nitrogen dynamics of buried litter in grassland and agroecosystem soils. Key words: Andropogon gerardii, C:N ratio, decomposition, immobilization, mineralization, nitrogen.

scholarly journals Soil Nitrogen Dynamics in a Managed Temperate Grassland Under Changed Climatic Conditions

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 931
Author(s):  
Mona Giraud ◽  
Jannis Groh ◽  
Horst H. Gerke ◽  
Nicolas Brüggemann ◽  
Harry Vereecken ◽  
...  
Keyword(s):  
Nitrogen Uptake ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Nitrogen Dynamics ◽  
Climatic Conditions ◽  
Undisturbed Soil ◽  
Nitrogen Emissions ◽  
Growing Period ◽  
Grassland Type ◽  
Wide Range

Grasslands are one of the most common biomes in the world with a wide range of ecosystem services. Nevertheless, quantitative data on the change in nitrogen dynamics in extensively managed temperate grasslands caused by a shift from energy- to water-limited climatic conditions have not yet been reported. In this study, we experimentally studied this shift by translocating undisturbed soil monoliths from an energy-limited site (Rollesbroich) to a water-limited site (Selhausen). The soil monoliths were contained in weighable lysimeters and monitored for their water and nitrogen balance in the period between 2012 and 2018. At the water-limited site (Selhausen), annual plant nitrogen uptake decreased due to water stress compared to the energy-limited site (Rollesbroich), while nitrogen uptake was higher at the beginning of the growing period. Possibly because of this lower plant uptake, the lysimeters at the water-limited site showed an increased inorganic nitrogen concentration in the soil solution, indicating a higher net mineralization rate. The N2O gas emissions and nitrogen leaching remained low at both sites. Our findings suggest that in the short term, fertilizer should consequently be applied early in the growing period to increase nitrogen uptake and decrease nitrogen losses. Moreover, a shift from energy-limited to water-limited conditions will have a limited effect on gaseous nitrogen emissions and nitrate concentrations in the groundwater in the grassland type of this study because higher nitrogen concentrations are (over-) compensated by lower leaching rates.

Nitrogen cycling in a Venezuelan tropical seasonally flooded forest: soil nitrogen mineralization and nitrification

1994 ◽  
Vol 10 (3) ◽  
pp. 399-416 ◽  
Author(s):  
Barrios E. ◽  
Herrera R.
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Ammonium Nitrogen ◽  
Wet Season ◽  
Flooded Forest ◽  
Nitrogen Concentrations ◽  
Minimum Stress ◽  
Seasonally Flooded

ABSTRACTSeasonally flooded forests represent a transition between terrestrial and aquatic ecosystems. The Mapire river, a tributary of the Orinoco river, floods its surrounding forests during the wet season (May–December). The soils are very acid and the total nitrogen concentration (0.1%) is only half that found in nearby soils flooded by Orinoco waters. Ammonium-nitrogen predominates in the soil during the flooded period while nitrate-nitrogen concentrations are higher in the dry period. Wide fluctuations in the inorganic nitrogen fractions did not considerably affect the annual course of soil nitrogen.The predominance of mineralization versus nitrification (56 and 5 μgsoil month−1respectively) and possibly the synchronization of nitrogen availability with plant demand could be considered as nitrogen conserving mechanisms.In synchrony with the hydrologic cycle, the seasonally flooded forest studied shows a nitrogencycle where inputs and accumulation are maximized when the system is under minimum stress (dry season). During flooding, the system enters a period of dormancy making minimal use of nutrient and energy to avoid or tolerate anaerobiosis.

Internal nitrogen dynamics in stormwater pond sediments are influenced by pond age and inorganic nitrogen availability

2021 ◽  
Vol 156 (2) ◽  
pp. 255-278
Author(s):  
Steven P. Hohman ◽  
Ashley R. Smyth ◽  
Eban Z. Bean ◽  
Alexander J. Reisinger
Keyword(s):  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
Nitrogen Dynamics ◽  
Stormwater Pond ◽  
Pond Sediments

Influence of Light Regime and Leaf Nitrogen Concentration on 77k Fluorescence in Leaves of Four Tropical Grasses: No Evidence for Photoinhibition

1988 ◽  
Vol 15 (5) ◽  
pp. 669 ◽  
Author(s):  
MM Ludlow ◽  
SP Samarakoon ◽  
JR Wilson
Keyword(s):  
Nitrogen Content ◽  
Nitrogen Availability ◽  
Nitrogen Concentration ◽  
Chlorophyll Concentration ◽  
Leaf Nitrogen ◽  
Nitrogen Supply ◽  
Poor Growth ◽  
Full Sunlight ◽  
Nitrogen Treatments ◽  
Low Nitrogen

This work was undertaken to determine if the stimulation of growth associated with shading of some tropical C4 grasses growing on soils with low to moderate nitrogen availability is partly due to overcoming photoinhibition (i. e. damage caused by excessive light). Four grasses (green panic, carpet grass, buffalo grass and kikuyu) were grown in full sunlight and at 37% of full sunlight, and given a low or high nitrogen supply. Despite differences of up to twofold in leaf nitrogen and chlorophyll concentration between high and low nitrogen treatments in all four grasses, photoinhibition measured by reduction in chlorophyll fluorescence was less than 3% in leaves of low nitrogen content that developed in full sunlight. Therefore, photoinhibition is not a contributor to the poor growth of nitrogen-limited grasses in full sunlight. A second objective was to determine if low nitrogen content predisposed shade-grown leaves to photoinhibition when they were subsequently exposed to full sunlight. Green panic plants that had been given either high or low nitrogen supply and grown in 37% of full sunlight were transferred to full sunlight and the extent of photoinhibition was followed over 8 days. The amount of photoinhibition that occurred was small (<6%) compared with plants grown at either nitrogen level in full sunlight. Therefore, shade and low nitrogen content separately or in combination did not cause any appreciable photoinhibition in green panic.

Temporal scale and the accumulation of peat in a Sphagnum bog

1996 ◽  
Vol 74 (3) ◽  
pp. 366-377 ◽  
Author(s):  
Lisa R. Belyea ◽  
Barry G. Warner
Keyword(s):  
Mass Loss ◽  
Decay Rate ◽  
Nitrogen Concentration ◽  
Rate Coefficients ◽  
Short Term ◽  
Concentration Data ◽  
Peat Accumulation ◽  
Litter Bag ◽  
Sphagnum Bog

We examined short-term (decadal) and long-term (millenial) processes of peat accumulation, and the links between them, in a Sphagnum bog in continental Canada. A previously published model of bog growth was fitted to age profiles of the oxic acrotelm (surface, < 60 cm thick) and the underlying, anoxic catotelm (210 cm thick). Approximately 5300 years of accumulation were represented in a radiocarbon-dated core that extended to the base of the deepest part of the peat deposit. The model estimated that the overall rate at which material entered long-term storage in the catotelm was 60–66 g∙m−2∙a−1. Although the decay rate coefficient was near zero, the bog stopped accumulating peat within the past 1500 years, resulting from either a decrease in the rate of transfer of material from the acrotelm or an increase in the rate of decay of material at the top of the catotelm. The model of bog growth estimated recent inputs to the acrotelm (90–930 g∙m−2∙a−1) that were twofold higher than published field measurements of aboveground productivity, and decay rate coefficients (0.005–0.040 a−1) that were 10-fold lower than published litter-bag measurements of mass loss. The pattern of mass loss over time, approximated from nitrogen concentration data, deviated from the pattern predicted by exponential models of decay. Calculations of the balance between additions to and losses from the acrotelm suggest that the amount of material transferred to the underlying catotelm differs among microhabitats. Such spatial variability in short-term processes is incompatible with long-term processes determining the position of the acrotelm–catotelm boundary. We discuss the applicability of the model to continental peatlands and suggest ways to improve modelling of short-term autogenic processes. Keywords: peatland, peat accumulation, organic matter, decomposition, age profiles, mathematical models.

scholarly journals Small Roots of Parashorea chinensis Wang Hsie Decompose Slower than Twigs

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 301
Author(s):  
Gbadamassi G. O. Dossa ◽  
Yan-Qiang Jin ◽  
Xiao-Tao Lü ◽  
Jian-Wei Tang ◽  
Rhett D. Harrison
Keyword(s):  
Mass Loss ◽  
Nutrient Dynamics ◽  
Nitrogen Concentration ◽  
Nitrogen Transfer ◽  
Litter Bag ◽  
Carbon And Nitrogen ◽  
Ground Biomass ◽  
Study Results ◽  
Small Roots ◽  
Below Ground

Plants produce above- and below-ground biomass. However, our understanding of both production and decomposition of below-ground biomass is poor, largely because of the difficulties of accessing roots. Below-ground organic matter decomposition studies are scant and especially rare in the tropics. In this study, we used a litter bag experiment to quantify the mass loss and nutrient dynamics of decomposing twigs and small roots from an arbuscular mycorrhizal fungal associated tree, Parashorea chinensis Wang Hsie, in a tropical rain forest in Southwest China. Overall, twig litter decomposed 1.9 times faster than small roots (decay rate (k) twig = 0.255, root = 0.134). The difference in decomposition rates can be explained by a difference in phosphorus (P) concentration, availability, and use by decomposers or carbon quality. Twigs and small roots showed an increase in nitrogen concentration, with final concentrations still higher than initial levels. This suggests nitrogen transfer from the surrounding environment into decomposing twigs and small roots. Both carbon and nitrogen dynamics were significantly predicted by mass loss and showed a negative and positive relationship, respectively. Our study results imply that small roots carbon and nitrogen increase the resident time in the soil. Therefore, a better understanding of the carbon cycle requires a better understanding of the mechanisms governing below-ground biomass decomposition.

scholarly journals Nitrogen Immobilization in Plant Growth Substrates: Clean Chip Residual, Pine Bark, and Peatmoss

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Cheryl R. Boyer ◽  
H. Allen Torbert ◽  
Charles H. Gilliam ◽  
Glenn B. Fain ◽  
Thomas V. Gallagher ◽  
...  
Keyword(s):  
Nitrogen Availability ◽  
Microbial Respiration ◽  
Inorganic Nitrogen ◽  
Wood Fiber ◽  
Nitrogen Immobilization ◽  
Pine Bark ◽  
Available Nitrogen ◽  
Nursery Production ◽  
Total Inorganic Nitrogen ◽  
Nitrogen Rates

Rising costs of potting substrates have caused horticultural growers to search for alternative, lower-cost materials. Objectives of this study were to determine the extent of nitrogen immobilization and microbial respiration in a high wood-fiber content substrate, clean chip residual. Microbial activity and nitrogen availability of two screen sizes (0.95 cm and 0.48 cm) of clean chip residual were compared to control treatments of pine bark and peatmoss in a 60-day incubation experiment. Four rates (0, 1, 2, or 3 mg) of supplemental nitrogen were assessed. Peatmoss displayed little microbial respiration over the course of the study, regardless of nitrogen rate; followed by pine bark, 0.95 cm clean chip residual, and 0.48 cm clean chip residual. Respiration increased with increasing nitrogen. Total inorganic nitrogen (plant available nitrogen) was greatest with peatmoss; inorganic nitrogen in other treatments were similar at the 0, 1, and 2 mg supplemental nitrogen rates, while an increase occurred with the highest rate (3 mg). Clean chip residual and pine bark were similar in available nitrogen compared to peatmoss. This study suggests that nitrogen immobilization in substrates composed of clean chip residual is similar to pine bark and can be treated with similar fertilizer amendments during nursery production.

Acute seasonal drought does not permanently alter mass loss and nitrogen dynamics during decomposition of red maple (Acer rubrum L.) litter

2002 ◽  
Vol 9 (1) ◽  
pp. 117-123 ◽  
Author(s):  
E. G. O'Neill ◽  
D. W. Johnson ◽  
J. Ledford ◽  
D. E. Todd
Keyword(s):  
Mass Loss ◽  
Acer Rubrum ◽  
Nitrogen Dynamics ◽  
Red Maple ◽  
Seasonal Drought

Factors Influencing the Calibration of near Infrared Reflectometry Applied to the Assessment of Total Nitrogen in Potato. II. Operator, Moisture and Maturity Class

1995 ◽  
Vol 3 (3) ◽  
pp. 167-174 ◽  
Author(s):  
Mark W. Young ◽  
Donald K.L. MacKerron ◽  
Howard V. Davies
Keyword(s):  
Field Experiment ◽  
Spectral Data ◽  
Total Nitrogen ◽  
Near Infrared ◽  
Nitrogen Concentration ◽  
Moisture Contents ◽  
Factors Influencing ◽  
Maturity Class ◽  
The One ◽  
Low Nitrogen

Oven dried samples of leaf stem and tuber material taken from a nitrogen field experiment were analysed by Dumas combustion when fresh and by near infrared (NIR) then, and in the next two years, by a number of operators who made estimates of nitrogen concentration, [N]NIR, with differing degrees of error. The errors differed between years in the case of the one operator who made estimates in two years. Leaf, stem and tuber material of high and low nitrogen concentration were treated to produce samples at various moisture contents. These samples were scanned by NIR and the spectral data were examined. Higher moisture was found to decrease the reflectance at all the wavelengths used and would, therefore, introduce error into [N]NIR estimates. The NIR calibration used was found to be applicable to cultivars in a range of maturity classes. Several recommendations are made that will help to minimise the error introduced into [N]NIR estimates from various sources.

Leaf Mass Loss Estimated by the Litter Bag Technique

2020 ◽  
pp. 43-51
Author(s):  
Felix Bärlocher
Keyword(s):  
Mass Loss ◽  
Litter Bag ◽  
Leaf Mass
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