@misc{SproeteFischerVesteetal., author = {Spr{\"o}te, Roland and Fischer, Thomas and Veste, Maik and Raab, Thomas and Wiehe, Wolfgang and Lange, Philipp and Bens, Oliver and H{\"u}ttl, Reinhard F.}, title = {Biological topsoil crusts at early successional stages on recultivated post-mining sites in Brandenburg, NE Germany}, language = {en} } @misc{FischerVesteWieheetal., author = {Fischer, Thomas and Veste, Maik and Wiehe, Wolfgang and Lange, Philipp}, title = {Water repellency and pore clogging at early successional stages of microbiotic crusts on inland dunes, Brandenburg, NE Germany}, language = {en} } @inproceedings{FischerVeste, author = {Fischer, Thomas and Veste, Maik}, title = {Small scale spatial heterogeneity of biological soil crusts during initial ecosystem development}, series = {Abstract Book of the 12th European Ecological Federation Congress, 25-29 September 2011, Avila, Spain}, booktitle = {Abstract Book of the 12th European Ecological Federation Congress, 25-29 September 2011, Avila, Spain}, pages = {S. 250}, language = {en} } @inproceedings{FischerVeste, author = {Fischer, Thomas and Veste, Maik}, title = {Biological soil crusts on inland dunes in NE Germany: Can we link succession with hydrology?}, series = {Book of Abstracts Workshop "Biological Soil Crusts in Ecosystems - their Diversity, Ecology, and Management", 22-25. August 2010, Zellingen-Retzbach, Germany}, booktitle = {Book of Abstracts Workshop "Biological Soil Crusts in Ecosystems - their Diversity, Ecology, and Management", 22-25. August 2010, Zellingen-Retzbach, Germany}, pages = {S. 52}, language = {en} } @inproceedings{FischerVesteLangeetal., author = {Fischer, Thomas and Veste, Maik and Lange, Philipp and Wiehe, Wolfgang}, title = {How biological soil crusts are stabilizing the soil surface? The development of organo-mineral interactions in the initial phase}, series = {EGU General Assembly 2009, held in Vienna, Austria, 19 - 24 April 2009}, booktitle = {EGU General Assembly 2009, held in Vienna, Austria, 19 - 24 April 2009}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @misc{FischerVesteBensetal., author = {Fischer, Thomas and Veste, Maik and Bens, Oliver and H{\"u}ttl, Reinhard F.}, title = {Dew formation on the surface of biological soil crusts in central European sand ecosystems}, series = {Biogeosciences}, volume = {9}, journal = {Biogeosciences}, issn = {1726-4189}, doi = {10.5194/bg-9-4621-2012}, pages = {4621 -- 4628}, abstract = {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.}, language = {en} } @misc{XiaoWangFanetal., author = {Xiao, Bo and Wang, Huifang and Fan, Jun and Fischer, Thomas and Veste, Maik}, title = {Biological soil crusts decrease soil temperature in summer and increase soil temperature in winter in semiarid environment}, series = {Ecological Engineering}, volume = {58}, journal = {Ecological Engineering}, issn = {0925-8574}, doi = {10.1016/j.ecoleng.2013.06.009}, pages = {52 -- 56}, abstract = {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.}, language = {en} } @misc{FischerYairVesteetal., author = {Fischer, Thomas and Yair, Aaron and Veste, Maik and Geppert, Helmut}, title = {Hydraulic properties of biological soil crusts on sand dunes studied by 13C-CP/MAS-NMR: a comparison between an arid and a temperate site}, series = {Catena}, volume = {110}, journal = {Catena}, issn = {0341-8162}, doi = {10.1016/j.catena.2013.06.002}, pages = {155 -- 160}, abstract = {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.}, language = {en} } @inproceedings{FischerGypserSubbotinaetal., author = {Fischer, Thomas and Gypser, Stella and Subbotina, Maria and Veste, Maik}, title = {Hydraulic and nutritional feedback controls surface patchiness of biological soil crusts at a post-mining site}, series = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, booktitle = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @inproceedings{ZaplataVestePohleetal., author = {Zaplata, Markus Klemens and Veste, Maik and Pohle, Ina and Sch{\"u}mberg, Sabine and Abreu Schonert, Iballa and Hinz, Christoph}, title = {Experimental investigation of the early interaction between cyanobacterial soil crusts and vascular plants}, series = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2016, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {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 H{\"u}hnerwasser 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.}, language = {en} }