TY - GEN A1 - Spröte, Roland A1 - Fischer, Thomas A1 - Veste, Maik A1 - Raab, Thomas A1 - Wiehe, Wolfgang A1 - Lange, Philipp A1 - Bens, Oliver A1 - Hüttl, Reinhard F. T1 - Biological topsoil crusts at early successional stages on recultivated post-mining sites in Brandenburg, NE Germany Y1 - 2010 ER - TY - GEN A1 - Fischer, Thomas A1 - Veste, Maik A1 - Wiehe, Wolfgang A1 - Lange, Philipp T1 - Water repellency and pore clogging at early successional stages of microbiotic crusts on inland dunes, Brandenburg, NE Germany Y1 - 2010 ER - TY - CHAP A1 - Fischer, Thomas A1 - Yair, Aaron A1 - Veste, Maik T1 - Infiltration, water holding capacity and growth patterns of biological soil crusts on sand dunes under arid and temperate climates T2 - EGU General Assembly 2012, held 22-27 April, 2012 in Vienna Y1 - 2012 N1 - EGU2012-5034 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - CHAP A1 - Fischer, Thomas A1 - Veste, Maik T1 - Small scale spatial heterogeneity of biological soil crusts during initial ecosystem development T2 - Abstract Book of the 12th European Ecological Federation Congress, 25-29 September 2011, Avila, Spain Y1 - 2011 UR - http://www.desertconsult.de/abstracts/Veste_EEF2011_2.pdf SP - S. 250 ER - TY - CHAP A1 - Fischer, Thomas A1 - Veste, Maik T1 - Biological soil crusts on inland dunes in NE Germany: Can we link succession with hydrology? T2 - Book of Abstracts Workshop "Biological Soil Crusts in Ecosystems - their Diversity, Ecology, and Management", 22-25. August 2010, Zellingen-Retzbach, Germany Y1 - 2010 UR - http://www.desertconsult.de/abstracts/biocrusts3.pdf SP - S. 52 ER - TY - CHAP A1 - Fischer, Thomas A1 - Veste, Maik A1 - Lange, Philipp A1 - Wiehe, Wolfgang T1 - How biological soil crusts are stabilizing the soil surface? The development of organo-mineral interactions in the initial phase T2 - EGU General Assembly 2009, held in Vienna, Austria, 19 – 24 April 2009 Y1 - 2009 UR - http://meetingorganizer.copernicus.org/EGU2009/EGU2009-8635.pdf N1 - EGU2009-8635 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - GEN A1 - Fischer, Thomas A1 - Veste, Maik A1 - Bens, Oliver A1 - Hüttl, Reinhard F. T1 - Dew formation on the surface of biological soil crusts in central European sand ecosystems T2 - Biogeosciences N2 - Dew formation was investigated in three developmental stages of biological soil crusts (BSC), which were collected along a catena of an inland dune and in the initial substrate. The Penman equation, which was developed for saturated surfaces, was modified for unsaturated surfaces and used for prediction of dewfall rates. The levels of surface saturation required for this approach were predicted using the water retention functions and the thicknesses of the BSCs. During a first field campaign (2–3 August 2011), dewfall increased from 0.042 kg m−2 for the initial sandy substrate to 0.058, 0.143 and 0.178 kg m−2 for crusts 1 to 3, respectively. During a second field campaign (17–18 August 2011), where dew formation was recorded in 1.5 to 2.75-h intervals after installation at 21:30 CEST, dewfall increased from 0.011 kg m−2 for the initial sandy substrate to 0.013, 0.028 and 0.055 kg m−2 for crusts 1 to 3, respectively. Dewfall rates remained on low levels for the substrate and for crust 1, and decreased overnight for crusts 2 and 3 (with crust 3 > crust 2 > crust 1 throughout the campaign). Dew formation was well reflected by the model response. The suggested mechanism of dew formation involves a delay in water saturation in near-surface soil pores and extracellular polymeric substances (EPS) where the crusts were thicker and where the water capacity was high, resulting in elevated vapor flux towards the surface. The results also indicate that the amount of dewfall was too low to saturate the BSCs and to observe water flow into deeper soil. Analysis of the soil water retention curves revealed that, despite the sandy mineral matrix, moist crusts clogged by swollen EPS pores exhibited a clay-like behavior. It is hypothesized that BSCs gain double benefit from suppressing their competitors by runoff generation and from improving their water supply by dew collection. Despite higher amounts of dew, the water availability to the crust community decreases with crust development, which may be compensated by ecophysiological adaptation of crust organisms, and which may further suppress higher vegetation or mosses. Y1 - 2012 U6 - https://doi.org/10.5194/bg-9-4621-2012 SN - 1726-4189 VL - 9 SP - 4621 EP - 4628 ER - TY - GEN A1 - Brankatschk, Robert A1 - Fischer, Thomas A1 - Veste, Maik A1 - Zeyer, Josef T1 - Succession of N Cycling Processes in Biological Soil Crusts on a Central European Inland Dune T2 - FEMS Microbiology Ecology N2 - Biological soil crusts (BSCs) are microbial assemblages that occur worldwide and facilitate ecosystem development by nitrogen (N) and carbon accumulation. N turnover within BSC ecosystems has been intensively studied in the past; however, shifts in the N cycle during BSC development have not been previously investigated. Our aim was to characterise N cycle development first by the abundance of the corresponding functional genes (in brackets) and second by potential enzyme activities; we focussed on the four processes: N fixation (nifH), mineralisation as proteolysis and chitinolysis (chiA), nitrification (amoA) and denitrification (nosZ). We sampled from four phases of BSC development and from a reference located in the rooting zone of Corynephorus canescens, on an inland dune in Germany. BSC development was associated with increasing amounts of chlorophyll, organic carbon and N. Potential activities increased and were highest in developed BSCs. Similarly, the abundance of functional genes increased. We propose and discuss three stages of N process succession. First, the heterotrophic stage (mobile sand without BSCs) is dominated by mineralisation activity. Second, during the transition stage (initial BSCs), N accumulates, and potential nitrification and denitrification activity increases. Third, the developed stage (established BSCs and reference) is characterised by the dominance of nitrification. Y1 - 2013 U6 - https://doi.org/10.1111/j.1574-6941.2012.01459.x SN - 1574-6941 VL - 83 IS - 1 SP - 149 EP - 160 ER - TY - GEN A1 - Xiao, Bo A1 - Wang, Huifang A1 - Fan, Jun A1 - Fischer, Thomas A1 - Veste, Maik T1 - Biological soil crusts decrease soil temperature in summer and increase soil temperature in winter in semiarid environment T2 - Ecological Engineering N2 - In hot and wet conditions in summer, the biological soil crusts (BSCs) decreased soil temperature by up to 11.8 °C, 7.5 °C, 5.4 °C, and 3.2 °C at surface, 5 cm, 15 cm, and 30 cm, respectively; while in cold and dry conditions in winter the BSCs increased soil temperature by up to 1.2 °C, 1.2 °C, and 1.1 °C at 5 cm, 15 cm, and 30 cm, respectively. The daily mean soil temperatures of the BSCs in a whole year were averagely increased by 0.57 ± 0.04 °C, 0.31 ± 0.04 °C, and 0.22 ± 0.04 °C at 5 cm, 15 cm, and 30 cm, respectively. The effects of the BSCs on soil temperature were positively correlated with air temperature and soil moisture, and decreased with soil depth from surface to deep soil. We concluded that BSCs relieved the extreme hot and cold soil micro-environments in desert ecosystem to some extent. Therefore their effects on soil temperature are positive for improving water and nutrient availability and biological community structure, thus decreasing susceptibility to desertification. These results would be helpful for understanding the ecological and hydrological functions of BSCs in semiarid environment. Y1 - 2013 U6 - https://doi.org/10.1016/j.ecoleng.2013.06.009 SN - 0925-8574 VL - 58 SP - 52 EP - 56 ER - TY - GEN A1 - Fischer, Thomas A1 - Yair, Aaron A1 - Veste, Maik A1 - Geppert, Helmut T1 - Hydraulic properties of biological soil crusts on sand dunes studied by 13C-CP/MAS-NMR: a comparison between an arid and a temperate site T2 - Catena N2 - Using principal component analysis (PCA), we studied the relationships between hydraulic properties and 13C-CP/MAS-NMR shift regions of biological soil crusts (BSCs) on sand dunes under arid and temperate conditions. The arid study site was located near Nizzana, in the northwestern Negev, Israel and the temperate site was near Lieberose, Brandenburg, Germany. BSCs were sampled at each site near the dune crest, at the center of the dune slope and at the dune base. The soil texture was finer and water holding capacities (WHCs) were higher in Nizzana, whereas surface wettability was reduced in Lieberose. At both sites, BSCs caused extra WHC compared to the mineral substrate. Infiltration after wetting along both catenas generally reached a maximum after 10 min and decreased after 30 min. Carbohydrates were the dominating components in all of the BSCs studied, where the relative peak areas of carbohydrate-derived structures (60–110 ppm) amounted to 28–46% and to 10–14% of total C-peak areas, respectively. PCA revealed that the WHC of the substrate was closely related to the amount of silt and clay, whereas the BSC induced extra WHC was closely related to carbohydrates. It was further found that water repellency was positively related to carbohydrate C, but negatively related to alkyl C. Infiltration kinetics was attributed to polysaccharide hydration and swelling. Our findings support the hypothesis that hydraulic properties of BSCs are determined by extracellular polymeric substances (EPS) and soil texture. Hydraulic properties in BSCs result from the combination of chemical properties related to C compounds mainly dominated by carbohydrates and physical surface properties related to texture, porosity and water holding capacity. Y1 - 2013 U6 - https://doi.org/10.1016/j.catena.2013.06.002 SN - 0341-8162 VL - 110 SP - 155 EP - 160 ER - TY - CHAP A1 - Fischer, Thomas A1 - Gypser, Stella A1 - Subbotina, Maria A1 - Veste, Maik T1 - Hydraulic and nutritional feedback controls surface patchiness of biological soil crusts at a post-mining site T2 - European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015 Y1 - 2015 N1 - EGU2015-4551 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - CHAP A1 - Kleefeld, Andreas A1 - Veste, Maik T1 - Robuste und strukturerhaltende Bildentrauschung via Medianfilterung und Bildsegmentierung T2 - 20. und 21. Workshop Computer-Bildanalyse in der Landwirtschaft, 26. Mai 2014, Osnabrück N2 - Ein Medianfilter ist ein Werkzeug, das benutzt werden kann, um Bilder zu entrauschen. Allerdings verschwimmen vorhandene Strukturen, und eine gute Bildsegmentierung gestaltet sich schwierig. Daher wird hier ein Medianfilteralgorithmus vorgestellt, der in der Lage ist, Bilder zu entrauschen und gleichzeitig vorhandene Strukturen beizubehalten. Wir zeigen die Anwendbarkeit dieser Methode auf Bilder, die durch ein automatisches Minirhizotronsystem aufgenommen worden sind. Dieses dient zur zerstörungsfreien Observierung von Wurzelwachstum. Die verbesserten Bilder werden dann zur Bildsegmentierung benutzt, um automatisch die Wurzeln in den Bildern zu entdecken. KW - Medianfilter KW - Bildsegmentierung KW - automatisches Minirhizotronsystem Y1 - 2015 UR - http://www.atb-potsdam.de/?id=161 SN - 0947-7314 SP - 92 EP - 100 PB - Leibniz-Institut für Agrartechnik Potsdam-Bornim e.V. CY - Potsdam ER - TY - CHAP A1 - Zaplata, Markus Klemens A1 - Veste, Maik A1 - Pohle, Ina A1 - Schümberg, Sabine A1 - Abreu Schonert, Iballa A1 - Hinz, Christoph T1 - Experimental investigation of the early interaction between cyanobacterial soil crusts and vascular plants T2 - European Geosciences Union, General Assembly 2016, Vienna, Austria N2 - While there are hints that biological soil crusts (BSCs) can constitute physical barriers for the emergence of vascular plants, a conceptual approach for the quantitative evaluation of these effects is still missing. Here we present an experimental design to test the emergence of seedlings in situ with (i) capping natural intact, (ii) destroyed and (iii) removed BSC. The selected field site is directly adjacent to the constructed Hühnerwasser catchment (Lusatia, Germany). This site exists since the end of 2008 and consists of loamy sand. Serving as proxy for seedling thrust, we inserted pre-germinated seeds of three confamiliar plant species with different seed masses (members of the Fabaceae family: Lotus corniculatus L., Ornithopus sativus Brot., and Glycine max (L.) Merr.). In each treatment as well as in the control group planting depths were 10 mm. We took care that experimental plots had identical crust thickness, slightly less than 4 mm, serving as proxy for mechanical resistance. A plot became established as follows: Firstly, the pristine crusted surface was vertically cut. To the windward side the BSC remained intact (i: “with BSC” stripe). To the downwind side soil material was temporarily excavated for laterally inserting the seeds beneath the surface of the first stripe. Then at the thereby disturbed second stripe pulverised BSC material became filled as a top layer (ii: “BSC mix” stripe). From the next stripe the BSC was removed (iii : “no BSC” stripe). Thus each plot had each experimental group in spatial contiguity (within 50 cm * 50 cm). The overall 50 plots were distributed across an area of 40 m * 12 m. When individuals of a species either emerged at all stripes, “XXX”, or at no stripe of a plot, “– – –“, there was no reason to suppose any effect of a crust. The “–XX” emergence pattern (depicting the appearance of seedlings in both stripes possessing manipulated surfaces) points towards hindrance more clearly than “–X–” or “– - X”. Altogether eight possible combinations exist. Combinatorial analysis turned out that seedling emergence had been notably impeded for light-weighted seeds but little for heavy seeds. Repeated recordings enable to account for adaptable emergence of seedlings according to varying crust conditions – in spatial as well as temporal terms. The proposed experimental procedure hence is highly recommended as a viable instrument to further investigate filter and facilitation processes between BSCs and vascular plants. Y1 - 2016 UR - http://meetingorganizer.copernicus.org/EGU2016/EGU2016-8595.pdf N1 - EGU2016-8595 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - CHAP A1 - Fischer, Thomas A1 - Yair, Aaron A1 - Geppert, Helmut A1 - Veste, Maik T1 - Water repellency and infiltration of biological soil crusts on an arid and a temperate dunes T2 - European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April – 02 May 2014 Y1 - 2014 N1 - EGU2014-12175 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - GEN A1 - Gerwin, Werner A1 - Schaaf, Wolfgang A1 - Biemelt, Detlef A1 - Winter, S. A1 - Fischer, A. A1 - Veste, Maik A1 - Hüttl, Reinhard F. T1 - Overview and first results of ecological monitoring at the artificial watershed Chicken Creek (Germany) T2 - Physics and Chemistry of the Earth Y1 - 2011 SN - 1873-5193 VL - 36 IS - 1-4 SP - 61 EP - 73 ER - TY - CHAP A1 - Lippert, Gudrun A1 - Nixdorf, Brigitte A1 - Leßmann, Dieter A1 - Henschke, Ingo A1 - Veste, Maik A1 - Böhme, Michael T1 - Primärsukzession einem Kleingewässer (Hühnerwasserteich) - Teil 2: Vergleich der Produktion von Phytoplankton, Makrophyten und heterotrophen Bakterien T2 - Erweiterte Zusammenfassung der Jahrestagung der DGL 2009 in Oldenburg KW - Primärsukzession KW - Phytoplankton Y1 - 2010 SN - 978-3-9802188-8-7 SP - 84 EP - 89 PB - Eigenverlag der DGL CY - Hardegsen ER - TY - CHAP A1 - Veste, Maik ED - Korn, Horst ED - Schliep, Rainer ED - Stadler, Jutta T1 - Auswirkungen des Klimawandels auf die Waldvegetation: Anpassungsfähigkeit und ihre Grenzen T2 - Biodiversität und Klima - Vernetzung der Akteure in Deutschland IV, Ergebnisse und Dokumentation des 4. Workshops Y1 - 2009 UR - http://www.bfn.de/fileadmin/MDB/documents/service/Skript246.pdf SP - 31 EP - 34 PB - BfN CY - Bonn ER - TY - CHAP A1 - Schaaf, Wolfgang A1 - Gerwin, Werner A1 - Veste, Maik A1 - Biemelt, Detlef A1 - Hüttl, Reinhard F. T1 - Monitoring program at the artificial catchment "chicken creek", Germany Y1 - 2008 ER - TY - CHAP A1 - Fischer, Thomas A1 - Veste, Maik A1 - Mykhailova, Larysa T1 - Ecological Maturity and Drought Stress of Biological Soil Crusts along a Central European Inland Dune Catena T2 - European Geosciences Union, General Assembly 2014, Vienna, Austria, 27 April – 02 May 2014 Y1 - 2014 N1 - EGU2014-11377 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - CHAP A1 - Fischer, Thomas A1 - Veste, Maik A1 - Wiehe, Wolfgang A1 - Lange, Philipp ED - Ukonmaanaho, Liisa ED - Nieminen, Tiina Maileena ED - Starr, Michael T1 - Linking microstructural and spectroscopic analysis of biological soil crusts - investigation of organo-mineral interactions T2 - 6th International Symposium on Ecosystem Behaviour BIOGEOMON 2009 Y1 - 2009 UR - http://www.metla.fi/julkaisut/workingpapers/2009/mwp128.pdf SN - 978-951-40-2177-0 SP - S. 412 PB - Finnish Forest Research Institut CY - Vantaa, Finland ER -