scholarly journals Modeling of Nitrogen Dynamics in an Austrian Alpine Forest Ecosystem on Calcareous Soils: A Scenario-Based Risk Assessment under Changing Environmental Conditions

2007 ◽  
Vol 7 ◽  
pp. 159-165 ◽  
Author(s):  
Friedl Herman ◽  
Stefan Smidt ◽  
Klaus Butterbach-Bahl ◽  
Michael Englisch ◽  
Ernst Gebetsroither ◽  
...  
Keyword(s):  
Nitrogen Cycling ◽  
Nitrate Leaching ◽  
Forest Ecosystem ◽  
Calcareous Soils ◽  
Forest Productivity ◽  
Balance Model ◽  
Emission Rates ◽  
Nitrogen Input ◽  
Alpine Forest ◽  
The Individual

We modeled the behavior of an Austrian alpine forest ecosystem on calcareous soils under changing climate and atmospheric nitrogen deposition scenarios. The change of nitrate leaching, emission rates of nitrogen compounds, and forest productivity were calculated using four process-oriented models for the periods 1998–2002 and 2048–2052. Each model reflects with high detail a segment of the ecosystem: PnET-N-DNDC (photosynthesis-evapotranspiration-nitrification-denitrification-decomposition; shortterm nitrogen cycling), BROOK90 (water balance for small and homogenous forest watersheds), HYDRUS (water flux in complex and heterogenous soils), and PICUS v1.3 (forest productivity). The nitrogen balance model (NBM) combines the individual results into a comprehensive picture and extends the specific values beyond the limits of the individual models. The evaluation of the findings was outlined with TRACE, a model enabling a long-term prognosis of nitrogen cycling in annual time steps.Temperature increase and nitrogen input are influenced by various components and processes of the forest ecosystem. An increase of the temperature of 2.5°C led to an enhancement of the N2O emission rates and affected the mineralization and the nitrification rates with the consequence of increased nitrate leaching into the subsoil. Enhanced nitrogen input also showed notable effects on nitrate leaching.

Estimating local CH4 emissions in the Upper Silesian Coal Basin using inverse modelling

2021 ◽  
Author(s):  
Sebastian Wolff ◽  
Friedemann Reum ◽  
Christoph Kiemle ◽  
Gerhard Ehret ◽  
Mathieu Quatrevalet ◽  
...  
Keyword(s):  
Remote Sensing ◽  
A Priori ◽  
Point Sources ◽  
Airborne Lidar ◽  
Inverse Modelling ◽  
Emission Rates ◽  
Coal Basin ◽  
Upper Silesian Coal Basin ◽  
The Individual ◽  
Modelling Approach

<p>Methane (CH<sub>4</sub>) is the second most important anthropogenic greenhouse gas (GHG) with respect to radiative forcing. Since pre-industrial times, the globally averaged CH<sub>4</sub> concentration in the atmosphere has risen by a factor of 2.5. A large fraction of global anthropogenic CH<sub>4</sub> emissions originates from localized point sources, e.g. coal mine ventilation shafts. International treaties foresee GHG emission reductions, entailing independent monitoring and verification support capacities. Considering the spatially widespread distribution of point sources, remote sensing approaches are favourable, in order to enable rapid survey of larger areas. In this respect, active remote sensing by airborne lidar is promising, such as provided by the integrated-path differential-absorption lidar CHARM-F operated by DLR. Installed onboard the German research aircraft HALO, CHARM-F serves as a demonstrator for future satellite missions, e.g. MERLIN. CHARM-F simultaneously measures weighted vertical column mixing ratios of CO<sub>2</sub> and CH<sub>4</sub> below the aircraft. In spring 2018, during the CoMet field campaign, measurements were taken in the Upper Silesian Coal Basin (USCB) in Poland. The USCB is considered to be a European hotspot of CH<sub>4</sub> emissions, covering an area of approximately 50 km × 50 km. Due to the high number of coal mines and density of ventilation shafts in the USCB, individual CH<sub>4</sub> exhaust plumes can overlap. This makes simple approaches to determine the emission rates of single shafts, i.e. the cross-sectional flux method, difficult. Therefore, we use an inverse modelling approach to obtain an estimate of the individual emission rates. Specifically, we employ the Weather Research and Forecast Model (WRF) coupled to the CarbonTracker Data Assimilation Shell (CTDAS), an Ensemble Kalman Filter. CTDAS-WRF propagates an ensemble realization of the a priori CH<sub>4</sub> emissions forward in space and time, samples the simulated CH<sub>4</sub> concentrations along the measurement’s flight path, and scales the a priori emission rates to optimally fit the measured values, while remaining tied to the prior. Hereby, we obtain a regularized a posteriori best emission estimate for the individual ventilation shafts. Here, we report on the results of this inverse modelling approach, including individual and aggregated emission estimates, their uncertainties, and to which extent the data are able to constrain individual emitters independently.</p>

Changes in soil nitrogen cycling in a northern temperate forest ecosystem during succession

2014 ◽  
Vol 121 (3) ◽  
pp. 471-488 ◽  
Author(s):  
L. E. Nave ◽  
J. P. Sparks ◽  
J. Le Moine ◽  
B. S. Hardiman ◽  
K. J. Nadelhoffer ◽  
...  
Keyword(s):  
Nitrogen Cycling ◽  
Soil Nitrogen ◽  
Forest Ecosystem ◽  
Temperate Forest ◽  
Soil Nitrogen Cycling ◽  
Temperate Forest Ecosystem

Nitrogen cycling in acid forest soils subject to increased atmospheric nitrogen input

1993 ◽  
Vol 57 (1-4) ◽  
pp. 29-44 ◽  
Author(s):  
A. Tietema ◽  
L. Riemer ◽  
J.M. Verstraten ◽  
M.P. van der Maas ◽  
A.J. van Wijk ◽  
...  
Keyword(s):  
Nitrogen Cycling ◽  
Forest Soils ◽  
Atmospheric Nitrogen ◽  
Nitrogen Input ◽  
Acid Forest Soils

Nitrogen cycling on the livestock farm

1986 ◽  
Vol 1986 ◽  
pp. 45-45 ◽  
Author(s):  
R J Unwin
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Cycling ◽  
Acid Rain ◽  
Surface Waters ◽  
Nitrate Leaching ◽  
Algal Blooms ◽  
Livestock Farm ◽  
Livestock Farmers ◽  
Porous Strata ◽  
Pollute Groundwater

The environmental or polluting aspects of nitrogen in relation to livestock farms are gaseous losses to the atmosphere, nitrate leaching into water supplies and the eutrophication of surface waters. Gaseous losses of ammonia by volatilisation from organic materials and denitrification losses from soil as nitrogen and nitrous oxide have been at various times implicated in acid rain, photochemical smogs and effects on the ozone layer although the latter is now largely discounted. Nitrate leached from soil may pass rapidly into surface waters where it can affect quality for drinking or encourage algal blooms. Over porous strata nitrate may take many years to percolate downwards so as to pollute groundwater supplies. Restrictions may face livestock farmers in the arable areas of eastern England to restrict nitrate leaching from their land.

Proposal for a New Structure of Enterprise Management Concept for Processing Secondary Raw Materials - Aluminum

2014 ◽  
Vol 708 ◽  
pp. 178-183
Author(s):  
Andrej Hačevský ◽  
Jan Spišák
Keyword(s):  
Raw Materials ◽  
Balance Model ◽  
Enterprise Management ◽  
Analysis And Synthesis ◽  
Management Concept ◽  
Verification Process ◽  
Enterprise Management System ◽  
The Individual ◽  
Production Company ◽  
Verification Plan

From the analysis and synthesis, which consists of a draft of structure of a new enterprise management system concept based on hierarchical balancing optimization model, results clear findings and outputs. The primary benefit is considered to be the fact, that it showed the existence and use of balancing model as a tool for effective management of the production company. This article primarily describes the use of the balance model at the analysis of the production process. HBOM can be involved in the verification process impacts of the individual reversals in the technology and economics of company, at operating in the verification plan, and verification of compliance and reality.

Experimental addition of nitrogen to a whole forest ecosystem at Gårdsjön, Sweden (NITREX): Nitrate leaching during 26 years of treatment

2018 ◽  
Vol 242 ◽  
pp. 367-374 ◽  
Author(s):  
Filip Moldan ◽  
Sara E.A-K. Jutterström ◽  
Jakub Hruška ◽  
Richard F. Wright
Keyword(s):  
Nitrate Leaching ◽  
Forest Ecosystem

scholarly journals Modelling the water balance of Lake Victoria (East Africa) – Part 1: Observational analysis

2018 ◽  
Vol 22 (10) ◽  
pp. 5509-5525 ◽  
Author(s):  
Inne Vanderkelen ◽  
Nicole P. M. van Lipzig ◽  
Wim Thiery
Keyword(s):  
Water Balance ◽  
Lake Level ◽  
Lake Victoria ◽  
Balance Model ◽  
Lake Victoria Basin ◽  
Lake Level Fluctuations ◽  
Lake Evaporation ◽  
In Situ Observations ◽  
The Individual

Abstract. Lake Victoria is the largest lake in Africa and one of the two major sources of the Nile river. The water level of Lake Victoria is determined by its water balance, consisting of precipitation on the lake, evaporation from the lake, inflow from tributary rivers and lake outflow, controlled by two hydropower dams. Due to a scarcity of in situ observations, previous estimates of individual water balance terms are characterized by substantial uncertainties, which means that the water balance is often not closed independently. In this first part of a two-paper series, we present a water balance model for Lake Victoria, using state-of-the-art remote sensing observations, high-resolution reanalysis downscaling and outflow values recorded at the dam. The uncalibrated computation of the individual water balance terms yields lake level fluctuations that closely match the levels retrieved from satellite altimetry. Precipitation is the main cause of seasonal and interannual lake level fluctuations, and on average causes the lake level to rise from May to July and to fall from August to December. Finally, our results indicate that the 2004–2005 drop in lake level can be about half attributed to a drought in the Lake Victoria Basin and about half to an enhanced outflow, highlighting the sensitivity of the lake level to human operations at the outflow dam.

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