@misc{GypserHerppichFischeretal., author = {Gypser, Stella and Herppich, Werner B. and Fischer, Thomas and Lange, Philipp and Veste, Maik}, title = {Photosynthetic characteristics and their spatial variance on biological soil crusts covering initial soils of post-mining sites in Lower Lusatia, NE Germany}, series = {Flora}, volume = {Vol. 220}, journal = {Flora}, issn = {0367-2530}, doi = {10.1016/j.flora.2016.02.012}, pages = {103 -- 116}, abstract = {Following surface disturbance, quaternary sands are the basic substrate for soil development in the Lusatian reclamation area. These substrates mostly contain few organic matter and, hence, are nutrient poor. Accumulation of soil carbon is an important factor for ecosystem development, where biological soil crusts initially influence soil processes and promote ecosystem succession. The compositional structures of biological soil crusts at various developmental stages and their photosynthetic properties were investigated on two former open-cast lignite sites, currently under reclamation, an artificial sand dune in Welzow S{\"u}d, and a forest plantation in Schlabendorf S{\"u}d (Brandenburg, Germany). As development of biological soil crusts progressed, their contents of organic carbon and total chlorophyll increased. The ratio of these parameters, however, varied with the relative contribution of lichens and mosses in particular. Also maximum photochemical efficiency, net photosynthesis and respiration increased with crustal development. An additional evaluation of NDVI and chlorophyll fluorescence images showed that especially moss-dominated biocrusts had higher photosynthetic capacity compared to green algae-dominated biocrusts or soil lichens, so the photosynthetic capacity showed to be highly species-specific. The ratio of gross photosynthesis to respiration indicated a higher ecological efficiency of biocrusts dominated by green algae than of lichen-dominated biocrusts. The occurrence of soil lichens reduced net CO2 fixation and increased CO2 release due to the enhanced mycobiontic respiration. During crustal succession, the rise of photosynthesis-related parameters is not necessarily linear as a result of the highly heterogenic distribution of the different crustal organisms between biocrusts of similar developmental stages as well as between those growing at the two study sites. Therefore, the evaluation of relevant ecophysiological parameters highlighted that not all biocrust-forming organisms similarly contribute to the ecophysiological behavior of biological soil crusts. Nevertheless, the occurrence of the biological soil crusts promoted soil formation and accumulation of soil carbon in initial soils.}, language = {en} } @misc{GypserVesteFischeretal., author = {Gypser, Stella and Veste, Maik and Fischer, Thomas and Lange, Philipp}, title = {Infiltration and water retention of biological soil crusts on reclaimed soils of former open-cast lignite mining sites in Brandenburg, north-east Germany}, series = {Journal of hydrology and hydromechanics}, volume = {64}, journal = {Journal of hydrology and hydromechanics}, number = {1}, doi = {10.1515/johh-2016-0009}, pages = {1 -- 11}, abstract = {Investigations were done on two former open-cast lignite mining sites under reclamation, an artificial sand dune in Welzow S{\"u}d, and a forest plantation in Schlabendorf S{\"u}d (Brandenburg, Germany). The aim was to associate the topsoil hydrological characteristics of green algae dominated as well as moss and soil lichen dominated biological soil crusts during crustal succession with their water retention and the repellency index on sandy soils under temperate cli-mate and different reliefs. The investigation of the repellency index showed on the one hand an increase due to the cross-linking of sand parti-cles by green algae which resulted in clogging of pores. On the other hand, the occurrence of moss plants led to a de-crease of the repellency index due to absorption caused by bryophytes. The determination of the water retention curves showed an increase of the water holding capacity, especially in conjunction with the growth of green algae layer. The pore-related van Genuchten parameter indicate a clay-like behaviour of the developed soil crusts. Because of the inho-mogeneous distribution of lichens and mosses as well as the varying thickness of green algae layers, the water retention differed between the study sites and between samples of similar developmental stages. However, similar tendencies of water retention and water repellency related to the soil crust formation were observed. Biological soil crusts should be considered after disturbances in the context of reclamation measures, because the ini-tial development of green algae biocrusts lead to an increasing repellency index, while the occurrence of mosses and a gain in organic matter enhance the water holding capacity. Thus, the succession of biocrusts and their small-scale succes-sion promote the development of soil and ecosystem.}, language = {en} } @misc{GypserVesteFischeretal., author = {Gypser, Stella and Veste, Maik and Fischer, Thomas and Lange, Philipp}, title = {Formation of soil lichen crusts at reclaimed post-mining sites, Lower Lusatia, North-east Germany}, series = {Graphis Scripta}, volume = {27}, journal = {Graphis Scripta}, number = {1-2}, issn = {0901-7593}, pages = {3 -- 14}, abstract = {Biological soil crusts were investigated at reclaimed post-mining sites near Welzow and Schlabendorf in Lower Lusatia (Brandenburg, Germany). Various development stages from initial biological soil crusts built up by green algae, to more developed soil crusts with mosses, as well as moss-soil lichen crusts, were classified. The spatial-temporal dynamics during the development resulted in a moss-lichens cover with discrete patches of pioneer organisms like green algae in between. At the study sites, 13 species of terricolous lichens were identified. The formation of the biological soil crust is important for the accumulation of soil organic matter in the first millimeters of the topsoil of these pioneer ecosystems. A correlation between cryptogamic biomass and soil carbon content were found.}, language = {en} } @misc{FischerVeste, author = {Fischer, Thomas and Veste, Maik}, title = {Carbon cycling of biological soil crusts mirrors ecological maturity along a Central European inland dune catena}, series = {Catena}, volume = {160}, journal = {Catena}, issn = {0341-8162}, doi = {10.1016/j.catena.2017.09.004}, pages = {68 -- 75}, abstract = {Photosynthesis and respiration of biological soil crusts (BSCs) sampled along a mobile inland dune catena were determined to evaluate the applicability of Odum's P/R ratio, determined under controlled conditions, for estimation of ecosystem maturity. The theory is that in the early stages of ecological succession, the total photosynthesis (P) exceeds the rate of community respiration (R), so that the P/R ratio is greater than 1, and that P/R approaches 1 as succession occurs. In the special case of organic pollution, the P/R ratio is typically less than 1. Samples were collected in the deflation zone of the dune near the crest (BSC1, thickness 2-3 mm), at the lee side of grass tussocks at the slope (BSC2, thickness 2-4 mm) and near the base (BSC3, thickness 4-6 mm). Non crusted sand was used as control (BSC0). Photosynthesis, respiration, crust biomass, as well as fossil and allochthonous pedogenic carbon entering the system with mineral substrate were determined. The respiration of the BSC1 was dominated by the degradation of allochthonous organic matter, leading to a diminished P/R ratio. The better developed BSC2 and BSC3 were less influenced by allochthonous organic matter, where BSC maturity increased downslope with biomass increase. No significant relation between the P/R ratio and soil water tension was found. Crust carbon pools increased and flows intensified, but mineralization constants decreased with system maturation. It was concluded that Odum's P/R ratio and accumulation of recalcitrant to biodegradation organic matter are indicative for biocrust maturity.}, language = {en} } @misc{HuettlFischer, author = {H{\"u}ttl, Reinhard F. and Fischer, Thomas}, title = {Carbon sequestration and landscape ecology in Western Europe - editorial}, series = {Ecological Engineering}, volume = {29}, journal = {Ecological Engineering}, number = {4}, issn = {0925-8574}, doi = {10.1016/j.ecoleng.2006.10.001}, pages = {317 -- 318}, language = {en} } @misc{FischerVesteEiseleetal., author = {Fischer, Thomas and Veste, Maik and Eisele, Andreas and Bens, Oliver and Spyra, Wolfgang and H{\"u}ttl, Reinhard F.}, title = {Small Scale Spatial Heterogeneity of Normalized Difference Vegetation Indices (NDVI) and Hot Spots of Photosynthesis in Biological Soil Crusts}, series = {Flora}, volume = {207}, journal = {Flora}, number = {3}, doi = {10.1016/j.flora.2012.01.001}, pages = {159 -- 167}, abstract = {Normalized Difference Vegetation Indices (NDVIs) are typically determined using satellite or airborne remote sensing, or field portable spectrometers, which give an averaged signal on centimetre to metre scale plots. Biological soil crust (BSC) patches may have smaller sizes, and ecophysiological, hydrological as well as pedological processes may be heterogeneously distributed within this level of resolution. A ground-based NDVI imaging procedure using low-cost equipment (Olympus Camedia 5000z digital camera equipped with a Hoya R72 infrared filter) was developed in this study to fill this gap at the level of field research, where carrying costly and bulky equipment to remote locations is often the limiting factor for data collection. Method principle and field data are presented, and the field experiment was deepened comparing NDVI measurements and CO2 turnover of soil crust samples in the laboratory, backing the reliability of the approach. A commercially available colour rendition chart with known red (600-700 nm) and NIR (800-900 nm) reflectances was placed into each scene and used for calibration purposes on a per-image basis. Generation of NDVI images involved (i) determination of red and NIR reflectances from the pixel values of the red and NIR channels, respectively, and (ii) calculation and imaging of the NDVI, where NDVI values of -1 to +1 were mapped to grey values of 0 to 255. The correlation between NDVI values retrieved from these images and NDVI values determined using field spectrometry was close (r2 = 0.91), the 95\% confidence interval amounted to 0.10 NDVI units. The pixel resolution was 0.8 mm in the field and 0.2 mm in the laboratory, but can still be improved significantly with closer distance to the crust or with higher camera resolution. NDVI values obtained using the new method were related to the net CO2 uptake of BSCs, where both slope and correlation coefficient of the respective regression function conformed with literature data. Geostatistical analysis revealed that both spatial variability of net CO2 uptake as well as size of individual hot spots of this parameter increased with crust development. The latter never exceeded 4 mm in the investigated crusts, which points to the necessity of high resolution imaging for linking remote sensing with ecophysiology. Perspectively, the new method could be used for field monitoring of both biological soil crusts and vascular vegetation.}, language = {en} } @misc{FischerVesteSchaafetal., author = {Fischer, Thomas and Veste, Maik and Schaaf, Wolfgang and D{\"u}mig, Alexander and K{\"o}gel-Knabner, Ingrid and Wiehe, Wolfgang and Bens, Oliver and H{\"u}ttl, Reinhard F.}, title = {Initial pedogenesis in a topsoil crust 3 years after construction of an artificial water catchment in Brandenburg, NE Germany}, series = {Biogeochemistry}, volume = {101}, journal = {Biogeochemistry}, number = {1-3}, issn = {1573-515X}, doi = {10.1007/s10533-010-9464-z}, pages = {165 -- 176}, abstract = {Cyanobacteria and green algae present in biological soil crusts are able to colonize mineral substrates even under extreme environmental conditions. As pioneer organisms, they play a key role during the first phases of habitat colonization. A characteristic crust was sampled 3 years after installation of the artificial water catchment "Chicken creek", thus representing an early successional stage of ecosystem development. Mean annual rainfall and temperature were 559 mm and 9.3°C, respectively. We combined scanning electron microscopy (SEM/EDX) and infrared (FTIR) microscopy to study the contact zone of algal and cyanobacterial mucilage with soil minerals in an undisturbed biological soil crust and in the subjacent sandy substrate. The crust was characterized by an approximately 50 μm thick surface layer, where microorganisms resided and where mineral deposition was trapped, and by an approximately 2.5 mm thick lower crust where mineral particles were stabilized by organo-mineral structures. SEM/EDX microscopy was used to determine the spatial distribution of elements, organic compounds and minerals were identified using FTIR microscopy and X-ray diffraction (XRD). The concentration of organic carbon in the crust was about twice as much as in the parent material. Depletion of Fe, Al and Mn in the lower crust and in the subjacent 5 mm compared to the geological substrate was observed. This could be interpreted as the initial phase of podzolization. Existence of bridging structures between mineral particles of the lower crust, containing phyllosilicates, Fe compounds and organic matter (OM), may indicate the formation of organo-mineral associations. pH decreased from 8.1 in the original substrate to 5.1 on the crust surface 3 years after construction, pointing to rapid weathering of carbonates. Weathering of silicates could not be detected.}, language = {en} } @misc{DillyNiiAnnangFrankeetal., author = {Dilly, Oliver and Nii-Annang, Seth and Franke, Gabriele and Fischer, Thomas and Buegger, Franz and Zyakun, Anatoly}, title = {Resilience of microbial respiration, respiratory quotient and stable isotope characteristics to soil hydrocarbon addition}, series = {Soil Biology and Biochemistry}, volume = {43}, journal = {Soil Biology and Biochemistry}, number = {9}, issn = {0038-0717}, doi = {10.1016/j.soilbio.2010.09.026}, pages = {1808 -- 1811}, abstract = {On the basis of CO2 evolution rate, O2 uptake rate, and 13C isotopic signature of respired CO2, the metabolic response to the addition of 13C labelled n-hexadecane and palmitic acid each with supplementary nitrogen was studied for two topsoils, one under continuous agricultural management and the other under beech forest. The CO2 evolution rate was immediately stimulated in the agricultural soil and the respiratory quotient (RQ) decreased from 0.8 to 0.4 mol CO2 evolution rate per mol O2 uptake rate, which was below the theoretically expected value of 0.65 and 0.70 for the degradation of n-hexadecane and palmitic acid, respectively. The microbial response was delayed in the forest soil, but developed better than in the agricultural soil throughout the subsequent 2-4 weeks. Consequently, the respiration rate returned earlier to the initial level for the beech forest soil and the δ13C of respired CO2 and RQ approached values before hydrocarbon addition. Based on the link among respiration rates, RQ and 13C-CO2 value, the added oil-analogue compounds induced a more rapid response in the agricultural soil and were degraded more completely in the forest soil. We concluded that the resilience, which we defined here as the capacity of the soil microbiota to buffer perturbance and to reorganise in response to change resulting in a more desirable system, was higher in our forest soil than for the agricultural soil.}, language = {de} } @incollection{BergmannFischerHuettl, author = {Bergmann, Charlotte and Fischer, Thomas and H{\"u}ttl, Reinhard F.}, title = {Decomposition of needle-, herb- and root- litter and Of-layer humus in three scots pine stands}, series = {Changes of atmospheric chemistry and effects on forest ecosystems: A roof experiment without roof.}, booktitle = {Changes of atmospheric chemistry and effects on forest ecosystems: A roof experiment without roof.}, editor = {H{\"u}ttl, Reinhard F. and Bellmann, Klaus}, publisher = {Kluwer Academic Publishers}, address = {Dordrecht}, isbn = {0-7923-5713-2}, pages = {151 -- 176}, language = {en} } @incollection{BergmannFischerHuettl, author = {Bergmann, Charlotte and Fischer, Thomas and H{\"u}ttl, Reinhard F.}, title = {Seasonal variability of organic matter and N input with litterfall in three scots pine stands}, series = {Changes of atmospheric chemistry and effects on forest ecosystems: A roof experiment without roof}, booktitle = {Changes of atmospheric chemistry and effects on forest ecosystems: A roof experiment without roof}, editor = {H{\"u}ttl, Reinhard F. and Bellmann, Klaus}, publisher = {Kluwer Academic Publishers}, address = {Dordrecht}, isbn = {0-7923-5713-2}, pages = {177 -- 186}, language = {en} } @incollection{HuettlFischer, author = {H{\"u}ttl, Reinhard F. and Fischer, Thomas}, title = {Wirkungen auf Boden und Bodenorganismen}, language = {de} } @inproceedings{FischerSchneiderBaumannetal., author = {Fischer, Thomas and Schneider, Bernd Uwe and Baumann, Karen and H{\"u}ttl, Reinhard F.}, title = {Spatial Distribution of Black pine (Pinus nigra L.) roots and its relationship to chemical properties of bulk and rhizosphere soil equilibrium solution}, series = {Woody Root Processes: Revealing the Hidden Half : Sade Boqer, Israel, 4-6 February 2006}, booktitle = {Woody Root Processes: Revealing the Hidden Half : Sade Boqer, Israel, 4-6 February 2006}, language = {en} } @inproceedings{GypserFischerLangeetal., author = {Gypser, Stella and Fischer, Thomas and Lange, Philipp and Veste, Maik}, title = {Impact of biocrust succession on water retention and repellency on open-cast lignite mining sites under reclamation in Lower Lusatia, NE-Germany}, 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 = {Mining activities can strongly affect ecosystem properties by destruction of naturally developed soils and removal of vegetation. The unstructured substrates show high bulk densities, compaction, low water infiltration rates, reduced water holding capacities and higher susceptibility to wind and water erosion. In the initial stage of the ecosystem development, the post-mining sites are open areas without or with a low cover of higher vegetation. It is well-known that biocrusts are able to colonize the soil surface under such extreme conditions without human support and affect soil hydrological processes such as water infiltration, run-off or re-distribution. Investigations were conducted on two former lignite open-cast mining sites, an artificial sand dune on the reclaimed watershedWelzow "Neuer Lugteich" and a reforestation area in Schlabendorf (Brandenburg, north-east Germany). The aim was to relate the hydrological characteristics of the topsoil to successional stages of biological soil crusts on reclaimed soils and their influence on repellency index and water holding capacity compared to pure mining substrate. Our study emphasized the influence of changing successional stages and species composition of biological soil crusts, forming a small-scale crust pattern, on water repellency and retention on sandy soils in temperate climate. Different successional stages of soil crusts were identified from initial scattered green algae crusts, dominated by Zygogonium spec. and Ulothrix spec., and more developed soil crusts containing mosses such as Ceratodon purpureus and Polytrichum piliferum. Lichens of the Genus Cladonia were more pronouncedly contributed to biocrusts at later and mature stages of development. The repellency index on the one hand increased due to the cross-linking of sand particles by the filamentous green algae Zygogonium spec. which resulted in clogging of pores, and on the other hand decreased with the occurrence of moss plants due to absorption caused by bryophytes. The determination of the water retention curves showed an increase of the water holding capacity, especially in conjunction with the growth of green algae layer. The absorption capacity of soil crust biota as well as a decreased pore diameter in the green algae layers positively affected the water retention of crusted soil compared to pure substrate. The occurrence of bryophytes with later succession weakened the repellent behavior of the biocrusts, increased infiltration, and might have affected the run-off at small-scale on biocrusts. Certainly, the biological soil crusts showed water repellent properties but no distinctive hydrophobic characteristics. On both locations, similar trends of water repellency and retention related to crustal formation were observed, in spite of different relief, reclamation time and inhomogeneous distribution of crustal organisms.}, language = {en} }