Nutrient Balances of Rewetted Fens – Groundwater Lysimeter Results

With the raising of groundwater levels to protect fens and the climate, there may be a risk of nutrients, such as nitrogen or potassium, leaching into the groundwater. Great amounts of nutrients, which are accumulated largely by peat forming plants like Phragmites australis and Carex spec., are conveyed into rewetted fens through high amounts of introduced water. Nitrogen leaching into the groundwater is very low even at the beginning of flooding and there is no sudden, pronounced leaching. Only a portion of potassium is taken up by plants whereas the rest might be found in the groundwater. Increasing nutrient inputs must be expected as soon as more contaminated water is added contributing to the regeneration of groundwater and increasing the pollution with nutrients at once

Evapotranspiration of Rewetted and Drained Fen Soils With Grass – Long Term Lysimeter Studies

In the context of reducing greenhouse gas (GHG) emissions to combat climate change, rewetting of peatlands is of particular importance. High groundwater levels covering organic matter in the soil prevent its oxidation to CO2. The amount of water needed to allow the rewetting of peatlands can be determined in lysimeter studies. The evapotranspiration in fens depends essentially on the groundwater table, the vegetation (transpirational active biomass) and the saturation deficit of the atmosphere. After rewetting, these factors can lead to an evapotranspiration of 1000 l m-2 a-1 and even 2000 l m-2 a-1 in dry years depending on the vegetation. In a long term experiment over 20 years, the lysimeters planted with Phragmites australis showed the highest evapotranspiration rates, followed by those covered with Carex species. Evaluation of these results for a large, flooded, rewetted fen area in the Havelländisches Luch in the federal state of Brandenburg, Germany, with Phragmites confirmed the high values of evapotranspiration measured at the groundwater lysimeter station of ZALF in Paulinenau

Impact of Type of K Fertilizer on DCAD of Fen Grassland in Northeast Germany

A lower DCAD is required in the diet fed during the prepartum period, but increasing the DCAD of diets fed during lactation increased milk yield and dry matter intake (Overton 2020). We conducted 3 cutting date/type of fertilizer trials, harvested with 5, 4 and 3 cuts per year over 3 years. Compared to the chloride based K fertilizer, the application of a sulphate based K fertilizer did not change dry matter yield and fodder quality (NEL-, XP-content) but led to significant higher DCAD in the grass in cut 1 - 3 of all trials over 3 years. The increase of DCAD amounted to approximately 100 to 150 in the first, 50 to 100 in the second and 40 to 80 meq kg-1 DM in the third cut. The findings correspond to results from grassland on other soils in Germany

Electrically-assisted bikes: potential impacts on travel behaviour

This paper reports on a review of the European literature about the impacts of having an electrically-assisted bike available to use, together with results from a trial in the UK city of Brighton, where 80 employees were loaned an electrically-assisted bike for a 6–8 week period. In the Brighton trial, three-quarters of those who were loaned an e-bike used them at least once a week. Across the sample as a whole, average usage was in the order of 15–20 miles per week, and was accompanied by an overall reduction in car mileage of 20%. At the end of the trial, 38% participants expected to cycle more in the future, and at least 70%said that they would like to have an e-bike available for use in the future, and would cycle more if this was the case. This is consistent with the results of the European literature which shows that when e-bikes are made available, they get used; that a proportion of e-bike trips typically substitutes for car use; and that many people who take part in trials become interested in future e-bike use, or cycling more generall

Online Tar Analysis with Laser Mass-Spectrometry for Biomass Gasifiers

The further development of gasification technology for biomass for various sizes of gasifiers and differrent end uses needs detailed information about the product gas com-position. This is especially the case for unwanted by-products like tar. An online analysis system is applied making use of a combination of gas chromatogra-phy (GC) and laser mass spectrometry (LAMS). A conventional tabletop gas chromatograph / ion-trap mass-spectrometer (GC/MS) system (Varian Saturn) was equipped with an additional laser ionization (LI) system. Its applicattion reduces fragmentation of analyte molecules and allows for short analysis times even in complex hydroocarbon matrices. The application of GC/LAMS for tar analysis in biomass gasification provides results in much shorter time compared with other tar analysis methods. The analysis system is set up for carrying out fundamental research on gasification processes mainly at laboratory sites. Its flexible design offers the possibilities of using electron impact (EI) as well as laser ionization in mass spectrometry, being able to perform hot-gas online and liquid offline analyses with the option of gas chroma-tographic separation. It was made mobile to perform field measurements on larger, technical-scale gasifiers as well

Spectrometric fluorescence and Raman lidar: absolute calibration of aerosol fluorescence spectra and fluorescence correction of humidity measurements

RAMSES is the operational spectrometric fluorescence and Raman lidar at the Lindenberg Meteorological Observatory. It employs three spectrometers, with the UVA spectrometer (378–458 nm spectral range) being the latest to be implemented in 2018. The UVA spectrometer extends the fluorescence measurement range to shorter wavelengths than previously accessible, and its water vapor measurements can be corrected for fluorescence effects. First the new experimental setup of the RAMSES near-range receiver, which integrates the UVA spectrometer, is described. Then it is detailed how the fluorescence measurement with the UVA spectrometer is absolutely calibrated and how the fluorescence spectra are merged with those obtained with the second fluorescence spectrometer (440–750 nm spectral range). The second part of this study is dedicated to the effect of aerosol fluorescence on water vapor measurements with Raman lidars. When aerosols are present, a fluorescence-induced error always arises and therefore requires thorough analysis, even though it is particularly significant (in relative terms) only when the atmosphere is dry, the fluorescence signal strong, or the bandwidth of the Raman detection channels wide. For moisture measurements with the UVA spectrometer, a method is introduced that effectively eliminates the systematic fluorescence error. However, the increase in trueness comes at the expense of precision. The investigations further show that an accurate correction for fluorescence is impossible when the Raman lidar is not equipped with a spectrometer but with a single fluorescence receiver channel only, at least for biomass burning aerosol, because for a given fluorescence backscatter coefficient at the wavelength of the auxiliary detection channel, the induced error in humidity can vary widely due to the changing shape of the fluorescence spectrum, which depends on aerosol type and atmospheric state and possibly also on other factors.</p

Determination of myocardial and serum digoxin concentrations in children by specific and nonspecific assay methods

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109866/1/cptclpt198378.pd