Search

Your search keyword '"Schack-Kirchner, Helmer"' showing total 111 results
Start Over Author "Schack-Kirchner, Helmer"
111 results on '"Schack-Kirchner, Helmer"'

16. High-resolution monitoring of surface-flow depth with frequency-domain probes

Author

Schack-Kirchner, Helmer, Schmid, Thomas, and Hildebrand, Ernst

Subjects
Soil chemistry, Earth sciences
Abstract

The need exists for a measurement technique to accurately determine the depth of surface runoff on natural soil surfaces. The objective of this note was to determine the sensitivity to the immersion depth of commercially available frequency-domain probes. Within the range of 0 to 25 mm, measurement accuracies better than 0.5 mm were reached. Interestingly, soiling of the rods or droplets did not influence the results significantly. The influence of the electrical conductivity of the water or internal characteristics of different probes did not lead to a bias of more than 1 mm. A field test with grid-like mounted frequency-domain probes showed a stable output signal and a high sensitivity to hydrograph changes. We concluded that frequency-domain probes were well suited for tracking shallow depths of surface runoff in field studies and allow high spatial and time resolution. They provide higher accuracy than alternative systems in the water-level range

Published
2005

24. Measuring and modeling soil intra-day variability of the 13CO2 & 12CO2 production in a scots pine forest

Author

Longdoz, Bernard, Goffin, Stephanie, Parent, Florian, Plain, Caroline, Epron, Daniel, Wylock, Christophe, Haut, Benoit, Maier, Martin, Schack-Kirchner, Helmer, Aubinet, Marc, Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), AgroBio Tech Gembloux, Université de Liège, Transfers, Interfaces and Processes, Université Libre de Bruxelles [Bruxelles] (ULB), Institute of Soil Science and Forest Nutrition, University of Freiburg, and Université libre de Bruxelles (ULB)

Subjects
[SDV]Life Sciences [q-bio], mesure, production de co2, sol forestier, forêt résineuse, modélisation
Abstract

absent

Published
2015

25. Measuring and modeling soil intra-day variability of the 13CO2 & 12CO2 production and transport in a scots pine forest

Author

Goffin, Stephanie, Parent, Florian, Plain, Caroline, Epron, Daniel, Wylock, Christophe, Haut, Benoit, Maier, Martin, Schack-Kirchner, Helmer, Aubinet, Marc, Longdoz, Bernard, Université de Liège, Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Université libre de Bruxelles (ULB), and University of Freiburg [Freiburg]

Subjects
cycle du carbone, dioxyde de carbone, [SDV]Life Sciences [q-bio], sol forestier, variation journalière, ComputingMilieux_MISCELLANEOUS, forêt tempérée, forêt résineuse
Abstract

International audience

Published
2014

26. Comparison of portable devices for sub-ambient concentration measurements of methane (CH4) and nitrous oxide (N2O) in soil research.

Author

Warlo, Hannes, Machacova, Katerina, Nordstrom, Nenne, Maier, Martin, Laemmel, Thomas, Roos, Aappo, and Schack-Kirchner, Helmer

Subjects
METHANE, NITROUS oxide, SOIL science, PHOTOACOUSTIC spectroscopy, GAS chromatography
Abstract

Production and consumption of methane (CH4) and nitrous oxide (N2O) in soils have a strong influence on global greenhouse gases (GHG) budgets. Therefore, it is crucial to precisely measure GHG fluxes at the soil-atmosphere interface. In upland soils, CH4 and N2O can be consumed by microbiological processes, and the respective concentrations can be lower than in the atmosphere, demanding highly sensitive gas analysing systems. Traditionally, soil air is sampled in vials and analysed in the laboratory by gas chromatography (GC). During the last decade, different technologies have been developed that allowed to build portable gas analysers that are able to measure sub-ambient gas concentration directly in the field. Here, we compared sub-ambient to ambient CH4 and N2O concentration values from four portable devices using different measurement technologies (a portable GHG analyser based on laser absorption spectroscopy [LAS], two portable Fourier transform infrared spectroscopy [FTIR] devices and a field gas analyser using photoacoustic spectroscopy [PAS]) to traditional GC analysis in the laboratory (a GC system equipped with a flame ionisation detector [GC-FID] and an electron capture detector [GC-ECD]). The accuracy and precision of photoacoustic spectroscopy measurements are strongly influenced by the water vapour content and non-target gases in the sampling air. We used an advanced set-up for a widely used PAS analyser enabling N2O measurements at sub-ambient concentrations with similar precision and accuracy as the GC-ECD system. Measurements of CH4 and N2O by FTIR and LAS devices were in good agreement with the GC systems. We conclude that the portable devices are suitable for studies of GHG fluxes in the field. Thanks to their universal and portable character, LAS, PAS and FTIR devices represent useful alternatives to currently used technologies for field studies. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

27. Horizon Partitioning of Soil CO2 Sources and their Isotopic Composition (13C) in a [i]Pinus Sylvestris[/i] Stand

Author

Goffin, S., Parent, Florian, PLAIN, Caroline, Maier, Martin, Schack-Kirchner, Helmer, Aubinet, Marc, Longdoz, Bernard, Faculté Gembloux Agro Bio-Tech, Université de Liège, Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Albert Ludwigs University, University of Freiburg [Freiburg], and American Geophysical Union (AGU). USA.

Subjects
[SDV]Life Sciences [q-bio]
Abstract

absent

Published
2012

30. Measuring and modeling soil intra-day variability of the 13CO2 and 12CO2 production and transport in a scots pine forest

Author

TERENO International Conference 2014 (29/09-02/10 /2014: Rheinische Friedrich-Wilhelms-Universität Bonn (Germany)), Goffin, Stéphanie, Parent, Florian, Plain, Caroline, Epron, Daniel, Wylock, Christophe, Haut, Benoît, Maier, Martin, Schack-Kirchner, Helmer, Aubinet, Marc, Longdoz, Bernard, TERENO International Conference 2014 (29/09-02/10 /2014: Rheinische Friedrich-Wilhelms-Universität Bonn (Germany)), Goffin, Stéphanie, Parent, Florian, Plain, Caroline, Epron, Daniel, Wylock, Christophe, Haut, Benoît, Maier, Martin, Schack-Kirchner, Helmer, Aubinet, Marc, and Longdoz, Bernard

Abstract

info:eu-repo/semantics/nonPublished

Published
2014

31. Measuring and modeling soil intra-day variability of the 13CO2 and 12CO2 production and transport in a scots pine forest

Author

1st ICOS International Conference on Greenhouse Gases and Biogeochemical Cycles (23-25 /09/2014: Brussels), Goffin, Stéphanie, Parent, Florian, Plain, Caroline, Epron, Daniel, Wylock, Christophe, Haut, Benoît, Maier, Martin, Schack-Kirchner, Helmer, Aubinet, Marc, Longdoz, Bernard, 1st ICOS International Conference on Greenhouse Gases and Biogeochemical Cycles (23-25 /09/2014: Brussels), Goffin, Stéphanie, Parent, Florian, Plain, Caroline, Epron, Daniel, Wylock, Christophe, Haut, Benoît, Maier, Martin, Schack-Kirchner, Helmer, Aubinet, Marc, and Longdoz, Bernard

Abstract

info:eu-repo/semantics/nonPublished

Published
2014

32. Volatile soil carbon: joint project PROCOPE

Author

Longdoz, Bernard, Maier, Martin, Schack-Kirchner, Helmer, PLAIN, Caroline, Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), and University of Freiburg [Freiburg]

Subjects
SOIL, CARBON, EDDY COVARIANCE SYSTEM, VARIABILITE, sol, méthode de mesure, flux de co2, [SDV]Life Sciences [q-bio], lorraine, moselle, dioxyde de carbone, forêt, respiration du sol, carbone, isotope
Published
2009

33. Optimization of skidding distance of wood with a forwarder

Author

Malinovski, Ricardo Anselmo [UNESP], Fenrier, Paulo Torres, Schack-Kirchner, Helmer, Malinovski, Jorge Roberto, Malinovski, E Rafael Alexandre, Universidade Estadual Paulista (Unesp), Universidade de Freiburg, and Universidade Federal do Paraná (UFPR)

Subjects
Optimization, Free software, Precision forestry, Technological tools, Timber, Management operations, Forests, Computer Programs, Skidding, Computer graphics, Operation planning, Information systems, Harvesting, Investments, Computational tools, Satellite navigation aids, Wood harvesting, Forestry, Technological resources, Geographic information systems, GIS, Wood, Skidding distances, Different sizes, Investment, Global positioning system
Abstract

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:23:39Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:35:17Z : No. of bitstreams: 1 2-s2.0-58049128920.pdf: 1298071 bytes, checksum: 8f0b2ac511c85a92b27904c377dc0aa2 (MD5) Made available in DSpace on 2014-05-27T11:23:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-09-01 The activities and management operations of wood harvesting do not have good computational tools available to help the forest technicians with the task of cost reduction. In many cases, machines of high investment are used in wood harvesting without adequate operation planning; consequently, the cost per hour of these machines, which is high, could be reduced. Using technological resources such as the Geographic Information Systems (GIS) integrated with the Global Positioning System (GPS), which are the basis of precision harvesting. In this research, a technological tool capable of calculating and optimizing the average skidding distance of the forwarder was developed. It was used in stands of different sizes and formats through mathematical techniques and available functionalities in the Geographic Information System GRASS. The developed tool, called optimized model, divides the stand in small parts in relation to shorter skidding distances. The main variable considered was the alignment of plantation. The model was tested in eucalypt stands located in the State of São Paulo. Sixteen stands were randomly selected: eight with a rectangular polygon form, and eight with irregular polygon form. The main variables were collected in these stands. Results showed that the optimized model developed, is efficient and flexible. It was possible to divide the stands in small parts resulting in smaller skidding medium distances. The stands with irregular form had shorter skidding medium distances than the rectangular stands. Curso de Engenharia Industrial Madeireira Campus Experimental de Itapeva Universidade Estadual Paulista, Rua Geraldo Alckmin, 519, Vila Nossa Sra. de Fátima - Itapeva, SP - 18409-010 Curso de Engenharia Florestal Faculdade de Ciencias Agronomicas Campus de Botucatu, Caixa Postal 237, Botucatu, SP - 18603-970 Institut für Bodenkunde und Waldernahrungslehre Universidade de Freiburg, Bertoldstrasse 17, 79098 Freiburg i.Br Curso de Engenharia Florestal Universidade Federal do Paraná, Rua Lothário Meissner, 632, fardim Botânico - Curitiba, PR - 80210-170 Curso de Pós Graduação em Economia e Política Florestal Universidade Federal do Paraná, Rua Lothário Meissner, 632, Jardim Botãnico - Curitiba, PR - 80210-170 Curso de Engenharia Industrial Madeireira Campus Experimental de Itapeva Universidade Estadual Paulista, Rua Geraldo Alckmin, 519, Vila Nossa Sra. de Fátima - Itapeva, SP - 18409-010

Published
2008

36. Does Juncus effusus L. and Carex brizoides L. help to regenerate a sufficient aeration in compacted forest soils?

Author

HAAS, JOHANNES, KÜHNE, ANKE, SCHACK-KIRCHNER, HELMER, and LANG, FRIEDERIKE

Subjects
SOIL aeration, JUNCUS effusus, SEAGRASSES, LAND cover, SOIL density measurement, SOIL diffusion
Abstract

The article discusses the study that investigates the effect of seagrass (Carex brizoides L.) and soft rush (Juncus effusus L.) on soil aeration in South-West Germany's skid trails. Topics include the determination of the vegetation cover and the microtopograhy of the sites and the measurement of the bulk density and gas diffusivity of the oils. The study concludes that the plants do not have direct effects on soil aeration.

Published
2017
Full Text
View/download PDF

50. The desorption solution — an alternative approach to measure water soluble ions in soils

Author

Blattner, Mario S., Augustin, Sabine, Schack-Kirchner, Helmer, and Hildebrand, Ernst E.

Abstract

Although the composition of the soil solution has important ecological information, there is no general consensus for obtaining and analyzing of the soil solution.  This study presents an alternative procedure to obtain the soil solution and determine all relevant anions and cations. The soil samples are taken with an auger. 10—20 g of field moist soil are desorbed in a pressure chamber at 170 kPa (pF 3.2), with a cellulose acetate membrane filter ( < 0.45 μm) as capillar bridge between the interior and exterior of the chamber. The desorption procedure is performed at 4°C for 24 hours and yields up to 1.0 ml soil solution, depending on the actual water potential. If more soil solution is needed, the soil may be replaced by another aliquot of the same sample. 0.15 ml of soil solution is sufficient for analysing all cations and anions, which account quantitatively for the ion balance with a capillary electrophoresis. Compared with suction cups, ion concentrations in desorption solutions are, although generally lower, in the same order of magnitude. The advantage of this method is that no field equipment is needed, apart from the auger. Even in heterogeneous forest soils, water soluble ions can be monitored with a high spatial resolution and without any dilution effects, which are common in the most laboratory methods. The problem of lacking spatial representativity in stationary lysimeter stations is also overcome. Additionally it is possible to obtain and analyze soil solutions in a suction range where suction cups fail.

Published
2000
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results