scholarly journals Nitrogen and phosphorus translocation of forest floor mosses as affected by a pulse of these nutrients

2020 ◽  
Vol 13 (5) ◽  
pp. 633-640
Author(s):  
Xin Liu ◽  
Zhe Wang ◽  
Xiaoming Li ◽  
Weikai Bao
Keyword(s):  
Forest Floor ◽  
N:P Ratio ◽  
Pulse Treatment ◽  
Nutrient Inputs ◽  
Nitrogen And Phosphorus ◽  
In Situ Experiment ◽  
Nutrient Pool ◽  
Nutrient Pulse ◽  
P Concentration ◽  
Concentration Changes

Abstract Aims Mosses are dominant in many ecosystems where nutrients from deposition are one of the main nutrient sources. However, it is difficult to evaluate mosses’ role in nutrient cycling without knowledge of how mosses use deposited nutrient inputs. To fill this gap, the present study aims to investigate: (i) how nitrogen (N) and phosphorus (P) concentrations of new-grown segments change along a gradient of N or P amount in a pulse treatment? (ii) how do a pulse of major nutrient (N or P) affect N or P translocation rate along a moss shoot? and (iii) to what extent do N or P translocation rates link to nutrient status of the new-grown segments of mosses? Methods We measured N and P concentrations of segments with different ages in two dominant forest floor mosses, Actinothuidium hookeri and Hylocomium splendens, on 8 days and 1 year after N and P pulse treatment with an in situ experiment in a subalpine fir forest in eastern Tibetan Plateau. Important Findings Both mosses were efficient in taking up nutrients from a pulse of either N or P. Nitrogen and P concentrations of new-grown segments were affected by nutrient pulse treatments. These N and P concentration changes were attributed to the initial N and P concentration of the young segments harvested 8 days after nutrient pulse treatments, suggesting that the captured nutrients were reallocated to the new-grown segments via translocation, which was largely controlled by a source–sink relationship. While no significant relationship was found between N translocation rate and N:P ratio of the new-grown segments, P translocation rate explained 21%–23% of the variance of N:P ratio of the new-grown segments, implying importance of P transport in supporting the new-grown sections. These results suggest that nutrient (N, P) translocation is a key process for mosses to utilize intermittent nutrient supply, and thus make mosses an important nutrient pool of the ecosystem.

scholarly journals A Sensitivity Analysis of the SPACSYS Model

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 624
Author(s):  
Yan Shan ◽  
Mingbin Huang ◽  
Paul Harris ◽  
Lianhai Wu
Keyword(s):  
Sensitivity Analysis ◽  
Wheat Yield ◽  
Climatic Conditions ◽  
Water Dynamics ◽  
Ecological Modelling ◽  
Soil Conditions ◽  
Model Parameters ◽  
Nutrient Inputs ◽  
Nutrient Pool ◽  
Wheat Field

A sensitivity analysis is critical for determining the relative importance of model parameters to their influence on the simulated outputs from a process-based model. In this study, a sensitivity analysis for the SPACSYS model, first published in Ecological Modelling (Wu, et al., 2007), was conducted with respect to changes in 61 input parameters and their influence on 27 output variables. Parameter sensitivity was conducted in a ‘one at a time’ manner and objectively assessed through a single statistical diagnostic (normalized root mean square deviation) which ranked parameters according to their influence of each output variable in turn. A winter wheat field experiment provided the case study data. Two sets of weather elements to represent different climatic conditions and four different soil types were specified, where results indicated little influence on these specifications for the identification of the most sensitive parameters. Soil conditions and management were found to affect the ranking of parameter sensitivities more strongly than weather conditions for the selected outputs. Parameters related to drainage were strongly influential for simulations of soil water dynamics, yield and biomass of wheat, runoff, and leaching from soil during individual and consecutive growing years. Wheat yield and biomass simulations were sensitive to the ‘ammonium immobilised fraction’ parameter that related to soil mineralization and immobilisation. Simulations of CO2 release from the soil and soil nutrient pool changes were most sensitive to external nutrient inputs and the process of denitrification, mineralization, and decomposition. This study provides important evidence of which SPACSYS parameters require the most care in their specification. Moving forward, this evidence can help direct efficient sampling and lab analyses for increased accuracy of such parameters. Results provide a useful reference for model users on which parameters are most influential for different simulation goals, which in turn provides better informed decision making for farmers and government policy alike.

Litter decomposition and nutrient release in a tropical rainforest, Southern Bakundu Forest Reserve, Cameroon

1995 ◽  
Vol 11 (3) ◽  
pp. 333-350 ◽  
Author(s):  
Nicholas C. Songwe ◽  
D. U. U. Okali ◽  
F. E. Fasehun
Keyword(s):  
Forest Floor ◽  
Tropical Rainforest ◽  
Great Influence ◽  
Wood Decay ◽  
Nutrient Release ◽  
Dry Weight ◽  
Nitrogen And Phosphorus ◽  
Forest Reserve ◽  
Ceiba Pentandra ◽  
Terminalia Superba

ABSTRACTDecomposition of litter on the forest floor and of leaves of five species, Celtis zenkeri, Cola lepidota, Desbordesia glaucescens, Ceiba pentandra and Terminalia superba in nylon mesh bags, as well as wood decay were studied in the tropical rainforest at Southern Bakundu Forest Reserve, Cameroon.The rate of loss of dry matter was fastest in Celtis zenkeri which was significantly different from the other species, while potassium was the most rapidly released element from all species with more than 50% being released in the first two months of the experiment. Nitrogen and phosphorus showed initial increases in bagged leaf litter independent of dry weight losses and while nitrogen was later released phosphorus continued to increase reaching 2–3 times the initial concentration. Decomposition constant (k) of litter on the forest floor was found to be 2.23 whereas the mean decomposition constants of the different species were as follows: Celtis zenkeri 4.18, Cola lepidota 2.18, Desbordesia glaucescens 1.60 and Ceiba pentandra 2.16 for the two experiments.Termites were found to have a very great influence on the decay of the wood of Terminalia superba with decay due to micro-organisms being negligible.

scholarly journals Stream Restoration for Legacy Sediments at Gramies Run, Maryland: Early Lessons from Implementation, Water Quality Monitoring, and Soil Health

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2164
Author(s):  
Katie Mattern ◽  
Alyssa Lutgen ◽  
Nathan Sienkiewicz ◽  
Grant Jiang ◽  
Jinjun Kan ◽  
...  
Keyword(s):  
Water Quality ◽  
Riparian Vegetation ◽  
Stream Restoration ◽  
Soil Health ◽  
Water Quality Monitoring ◽  
Quality Monitoring ◽  
Nutrient Inputs ◽  
Nitrogen And Phosphorus ◽  
Partial Removal ◽  
Riparian Trees

While stream restorations are increasingly being adopted to mitigate sediment and nutrient inputs and to meet water quality regulatory targets, less information is available on the drivers behind the design, implementation, effectiveness, and cost of restorations. We address these issues for a $4.2 million stream restoration for legacy sediments implemented for a rural Piedmont stream in Maryland, USA. A total of 1668 m of stream was restored in three phases, which included the partial removal of legacy sediments, the grading of streambanks, floodplain creation, channel reshaping with meanders and pool-riffle forms, the raising of the stream bed, and the planting of riparian vegetation. The sediment, nitrogen, and phosphorus concentrations and fluxes were monitored before- and during the restoration phases. The sites selected for restoration had legacy sediments vulnerable to erosion and were on state-owned land. The restoration design was based on the need to maintain mature riparian trees and preserve existing sensitive wetland habitats. Water quality monitoring indicated that the sediment and nutrient fluxes increased during the restoration phase and were attributed to disturbance associated with construction activities and increased runoff. We also recommend that soil health needs to be included as an integral component to enhance the effectiveness and resilience of stream restorations.

scholarly journals Flower litters of alpine plants affect soil nitrogen and phosphorus rapidly in the eastern Tibetan Plateau

2016 ◽  
Author(s):  
Jinniu Wang ◽  
Bo Xu ◽  
Yan Wu ◽  
Jing Gao ◽  
Fusun Shi
Keyword(s):  
Tibetan Plateau ◽  
Field Experiments ◽  
Underlying Mechanism ◽  
Pot Experiment ◽  
Eastern Tibetan Plateau ◽  
Nitrogen And Phosphorus ◽  
Nutrient Pool ◽  
Litter Addition ◽  
Litter Bag ◽  
Soil Nutrition

Abstract. Litters of reproductive organs have been rarely studied, despite their role in allocating nutrients for offspring reproduction. This study determines the mechanism through which flower litters efficiently increase the available soil nutrient pool. Field experiments were conducted to collect plant litters and calculate biomass production in an alpine meadow of the eastern Tibetan Plateau. Carbon, nitrogen, phosphorus, lignin, cellulose, and their relevant ratios of litters were analyzed to identify their decomposition features. A pot experiment was performed to determine the effects of litter addition on soil nutrition pool by comparison between the treated and control samples. Litter-bag method was used to verify decomposition rates. The flower litters of phanerophyte plants were comparable with non-flower litters. Biomass partitioning of other herbaceous species accounted for 10%–40% of the aboveground biomass. Flower litter possessed significantly higher N and P levels but less C/N, N/P, lignin/N, and lignin and cellulose concentrations than leaf litter. Flower litter fed soil nutrition pool more efficiently because of their faster decomposition rate and higher nutrient contents. Litter-bag experiment confirmed that the flower litters of Rhododendron przewalskii and Meconopsis integrifolia decomposes approximately three times faster than mixed litters within 50 days. Moreover, the findings of the pot experiment indicated that flower litter addition significantly increased the available nutrient pool. Flower litter influenced nutrition cycling in alpine ecosystems, as evident by its non-ignorable production and significantly faster decomposition. The underlying mechanism can enrich nutrients, which return to the soil, and non-structural carbohydrates, which feed and enhance the transitions of soil microorganisms.

Materials Accounting as a Policy Tool for Nutrient Management in the Danube Basin

1999 ◽  
Vol 40 (10) ◽  
pp. 43-49 ◽  
Author(s):  
Ch. Lampert ◽  
P. H. Brunner
Keyword(s):  
Nutrient Management ◽  
Early Recognition ◽  
Essential Elements ◽  
Limited Resources ◽  
Time Interval ◽  
Nutrient Inputs ◽  
Scenario Development ◽  
Nitrogen And Phosphorus ◽  
Danube Basin ◽  
Efficient Measures

Nutrient management has to consider both: Nutrients as essential elements for the biosphere with limited resources and nutrients as potential environmental pollutants (eutrophication, groundwater-deterioration). Materials Accounting techniques enable to describe and quantify the metabolism of Nitrogen and Phosphorus in large river Basins, such as the Danube Basin. By knowing the sources and pathways of nutrients it is possible (i) to identify the key causes of pollution problems and (ii) to point out inefficient use of the limited resource “nutrients”. Additionally, it is possible to design efficient measures based on nutrient balances. Materials Accounting observes the changes of stocks within a time interval. Therefore, it allows the early recognition of the accumulation and depletion of harmful substances (e.g. Nitrate in the groundwater) or of limited resources (e.g. P in topsoils) in the environment. In combination with scenario development Materials Accounting has a high predictive power. There is a substantial difference in designing the most efficient measures for reducing nutrient inputs or to optimise the use of limited resources in the entire Danube Basin and in individual countries.

Nitrogen and phosphorus cycling following prescribed burning in natural and managed Aleppo pine forests

1999 ◽  
Vol 29 (8) ◽  
pp. 1237-1247 ◽  
Author(s):  
D Gillon ◽  
C Houssard ◽  
J C Valette ◽  
E Rigolot
Keyword(s):  
Forest Floor ◽  
Prescribed Burning ◽  
Pinus Halepensis ◽  
Fire Severity ◽  
Nutrient Balance ◽  
Pine Needles ◽  
Aleppo Pine ◽  
Slight Reduction ◽  
Nitrogen And Phosphorus ◽  
Natural Stand

Two prescribed burnings (downhill and uphill fires) were conducted in two stands of Aleppo pine (Pinus halepensis Mill.): a natural stand and a managed stand that was subject to thinning, pruning, and shrub removal. The concentrations of nitrogen (N) and phosphorus (P) in the pine needles and regrowth of the main shrub species, Quercus coccifera L., and the quantities of N and P in the needle fall and in the forest floor were measured during the 6 months following the fires. The concentrations of N and P in the pine needles and leaves of Q. coccifera increased compared with the unburned control after both fires in the natural stand, where there was only a slight reduction in fuel during prescribed burnings and where there was an abundant fall of scorched needles. In contrast, the chemical composition of the foliage was unchanged after the fires in the managed stand, where there was a greater reduction in fuel, and where only small quantities of scorched needles fell. This study showed that first opening prescribed burnings (natural stand) were less severe in terms of nutrient balance than maintenance prescribed burnings (managed stand) and that the forest floor reduction was a good indicator of fire severity.

scholarly journals Temporal variability of nitrogen and phosphorus concentrations in a German catchment: water sampling implication

2014 ◽  
Vol 18 (8) ◽  
pp. 811-818
Author(s):  
Cristiano A. Pott ◽  
Sidnei O. Jadoski ◽  
Britta Schmalz ◽  
Georg Hörmann ◽  
Nicola Fohrer
Keyword(s):  
Temporal Variability ◽  
Major Part ◽  
Ammonium Nitrogen ◽  
Quality Parameters ◽  
Particulate Phosphorus ◽  
Water Sampling ◽  
Nitrogen And Phosphorus ◽  
Daily Monitoring ◽  
P Concentration ◽  
Daily Time

Daily time series were used to verify the temporal variability and to characterize the nitrogen (N) and phosphorus (P) pollution in a 462 km² catchment of the Stör river, a typical rural lowland catchment in Germany. Also, this study aimed to identify the best sampling frequency of pollution by N and P. Total phosphorus (TP), soluble orthophosphate-phosphorus (PO4-P), particulate-phosphorus (PP), total nitrogen (TN), nitrate-nitrogen (NO3-N) ammonium-nitrogen (NH4-N) and total suspended sediment (TSS) were analysed. Daily monitoring from August 8, 2009 until August 10, 2011 was conducted with an automatic water sampler at the outlet of the catchment. The results show a seasonal variability of water quality parameters with more N and P concentration in winter. PP represents the major part of P and it is highly dependent on TSS. NO3-N constitutes the major part of N. Autocorrelation analysis was successfully applied to characterize the N and P pollution in the Upper River Stör. The water sampling for N and P monitoring must be different, N can be sampled biweekly or monthly, while P must be sampled with more frequency, weekly or biweekly.

Nitrogen and phosphorus nutrition and nutrient cycling by evergreen and deciduous understory shrubs in an Alaskan black spruce forest

1983 ◽  
Vol 13 (5) ◽  
pp. 773-781 ◽  
Author(s):  
F. Stuart Chapin III
Keyword(s):  
Nutrient Cycling ◽  
Aboveground Biomass ◽  
Black Spruce ◽  
Leaf Biomass ◽  
Nitrogen And Phosphorus ◽  
Plant Parts ◽  
P Concentration ◽  
Aboveground Production ◽  
Understory Shrubs ◽  
Leaf N

Seasonal patterns of biomass, nitrogen (N), and phosphorus (P) were determined for major plant parts of the deciduous shrub Vacciniumuliginosum L. and the evergreen shrub Ledumgroenlandicum Oeder. in a black spruce (Piceamariana (Mill.) B.S.P.) forest in interior Alaska. New growth comprised 52 ± 7% of aboveground biomass in Vaccinium compared with the evergreen Ledum for which a maximum of 38 ± 3% of aboveground biomass was new growth. In Vaccinium the spring decline in leaf N and P concentration was due to dilution by increasing leaf biomass, whereas the autumn decline in N and P concentration was due to retranslocation, at which time 68–72% of leaf N and P was retranslocated from leaves. In contrast, the entire decline in N and P concentration of new growth in Ledum was due to dilution by increasing leaf biomass. Uptake contributed 60–68% of the maximum N and P requirement for aboveground growth of Vaccinium, with the remainder coming from stored reserves. Ledum supported 71–79% of its aboveground nutrient requirement by direct uptake from soil and may have been less dependent upon stored nutrient reserves. Vaccinium and Ledum together comprised only 0.8–2.8% of the standing crop of aboveground vascular biomass and N and P pools at Washington Creek but contributed 16% of vascular aboveground production and 19–24% of the N and P cycled annually by vascular plants. The importance of understory shrubs is due to their small support structure and rapid turnover of biomass and nutrients (34–43% of aboveground pools annually) relative to that of the trees (2–5% annually). Understory shrubs at Washington Creek and in other evergreen forests are much more important in nutrient cycling than their small biomass would suggest.

Nutrients in Australian tropical rivers: changes with agricultural development and implications for receiving environments

2005 ◽  
Vol 56 (3) ◽  
pp. 279 ◽  
Author(s):  
Jon E. Brodie ◽  
Alan W. Mitchell
Keyword(s):  
Agricultural Development ◽  
Nutrient Dynamics ◽  
Inorganic Nitrogen ◽  
Nutrient Concentrations ◽  
Tropical Rivers ◽  
Nutrient Inputs ◽  
Material Transport ◽  
Nitrogen And Phosphorus ◽  
North East ◽  
The North

In tropical Australia, intensive studies of river suspended sediment (SS) and nutrient dynamics have been restricted to streams on the north-east coast between the Fitzroy and Normanby Rivers (Queensland), Magela Creek/East Alligator River (Northern Territory) and the Ord River (Western Australia). Historical conditions in these rivers were probably characterised by low–moderate SS concentrations and low concentrations of dissolved inorganic nitrogen and phosphorus in flow events. Introduction of agriculture has transformed SS and nutrient dynamics. Grazing has led to soil erosion and increased SS and particulate nutrient concentrations and fluxes in event flows. Fertilised cropping has increased nutrient inputs to catchments, where it forms a substantial proportion of the catchment area. Consequently, both particulate and dissolved inorganic nutrient concentrations and fluxes have increased. Australian tropical rivers have episodic flows, with most material transport occurring during large flow events. The restricted period of these highly energetic flows means little trapping of materials in waterways occurs. Loads are transported efficiently downstream and processes such as denitrification and in-channel sedimentation may be of limited importance. Owing to excessive nutrient inputs associated with agriculture, a number of northern freshwater, estuarine and coastal ecosystems are now eutrophic. Continued development, especially fertilised cropping, without adequate management of nutrient losses is likely to exacerbate these problems.

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