@inproceedings{SchaafGerwinVesteetal., author = {Schaaf, Wolfgang and Gerwin, Werner and Veste, Maik and Biemelt, Detlef and H{\"u}ttl, Reinhard F.}, title = {Monitoring program at the artificial catchment "chicken creek", Germany}, language = {en} } @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} } @misc{FischerYairVeste, author = {Fischer, Thomas and Yair, Aaron and Veste, Maik}, title = {Microstructure and hydraulic properties of biological soil crusts on sand dunes: a comparison between arid and temperate climates}, series = {Biogeosciences Discuss}, volume = {9}, journal = {Biogeosciences Discuss}, doi = {10.5194/bgd-9-12711-2012}, pages = {12711 -- 12734}, abstract = {We studied the relationships between crust microstructure, infiltration and water holding capacity under arid and temperate conditions (Factor A: Climate) on biological soil crusts (BSCs) sampled along a catena on mobile sand dunes (Factor B: Catena). The arid study site was located near Nizzana, Israel (precipitation: 86mm a-1, PET: ca. 2500mm a-1) and the temperate site near Lieberose, Germany (precipitation: 569mm a-1, PET: ca. 780mm a-1). BSCs were sampled near the dune crest, at the centre of the dune slope and at the dune base at each site. Scanning electron microscopy (SEM) was used to characterize BSC morphology and microstructure. Infiltration was determined using microinfiltrometry under controlled moisture conditions in the lab. Water holding capacities were determined after water saturation of the dry BSCs. Wettability of the crusts was characterized using a "repellency index", which was calculated from water and ethanol sorptivities. Irrespective of the climate, an accumulation of fine particles in the BSCs was found, increasing along the catena from dune crest to dune base. Texture was finer and water holding capacities of the underlying substrate were higher at the arid site, whereas surface wettability was reduced at the temperate site. At both sites, BSCs caused extra water holding capacity compared to the substrate. Infiltration rates decreased along the catena and were generally lower at the dune slope and base of the arid site. A mechanism of crust stabilization is proposed where BSCs benefit from increased texture and biomass mediated water supply, and where the water supply to higher plants was limited due to alteration of physico-chemical surface properties under temperate conditions.}, language = {en} } @inproceedings{FischerYairVeste, author = {Fischer, Thomas and Yair, Aaron and Veste, Maik}, title = {Infiltration, water holding capacity and growth patterns of biological soil crusts on sand dunes under arid and temperate climates}, series = {EGU General Assembly 2012, held 22-27 April, 2012 in Vienna}, booktitle = {EGU General Assembly 2012, held 22-27 April, 2012 in Vienna}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {de} } @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{BrankatschkFischerVesteetal., author = {Brankatschk, Robert and Fischer, Thomas and Veste, Maik and Zeyer, Josef}, title = {Succession of N Cycling Processes in Biological Soil Crusts on a Central European Inland Dune}, series = {FEMS Microbiology Ecology}, volume = {83}, journal = {FEMS Microbiology Ecology}, number = {1}, issn = {1574-6941}, doi = {10.1111/j.1574-6941.2012.01459.x}, pages = {149 -- 160}, abstract = {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.}, language = {de} } @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} }