@misc{FischerKholiavkoSchaafetal., author = {Fischer, Thomas and Kholiavko, Tatiana and Schaaf, Wolfgang and Veste, Maik}, title = {Soil respiration responses of moss and lichen biocoenoses to moderate and severe rain events after summer drought in a temperate early-successional ecosystem}, series = {Ecohydrology}, volume = {16}, journal = {Ecohydrology}, number = {7}, issn = {1936-0592}, doi = {10.1002/eco.2578}, abstract = {It is commonly accepted that CO2 efflux increases with soil water content in aerated soils and that rewetting after periods of soil drying can result in respiration pulses. It has further been shown that soil pores may become water logged which can impede soil gas exchange. The present study aimed to quantify the carbon response of moss (Polytrichum piliferum) and lichen (Cladonia coniocraea) biocoenoses to different quantities of rain in an artificial catchment, which granted that the starting point of the development of both biocoenoses was the same. To address this aim, we conducted in situ soil moisture and soil respiration measurements, where soil respiration was hypothesised to emerge from a cryptogamic vegetation layer and from mineral soil beneath. We found that higher water-holding capacity of the moss layer and higher accumulation of organic matter in the upper mineral soil under mosses result in higher amounts of water stored near the surface. As a consequence, evaporation of water as well as pulses of CO2 efflux after moderate rain following a period of drought were higher in the moss biocoenosis, where the upper mineral soil was of key importance. In contrast, the lichen biocoenosis facilitated penetration of rainwater into the deep soil. Superimposing rewetting pulses, near-saturation of soil pores with water after severe rain resulted in gas exchange inhibition and diminished soil respiration until subsequent aeration in both biocoenoses}, language = {en} } @misc{RisseBuhlHagedornDuemigetal., author = {Risse-Buhl, Ute and Hagedorn, Frank and D{\"u}mig, Alexander and Gessner, Mark O. and Schaaf, Wolfgang and Nii-Annang, Seth and Gerull, Linda and Mutz, Michael}, title = {Dynamics, chemical properties and bioavailability of DOC in an early successional catchment}, series = {Biogeosciences}, volume = {10}, journal = {Biogeosciences}, issn = {1726-4189}, doi = {doi:10.5194/bg-10-4751-2013}, pages = {4751 -- 4765}, language = {en} } @misc{KwakChangNaethetal., author = {Kwak, Jin-Hyeob and Chang, Scott X. and Naeth, M. Anne and Schaaf, Wolfgang}, title = {Coarse Woody Debris Increases Microbial Community Functional Diversity but not Enzyme Activities in Reclaimed Oil Sands Soils}, series = {PLoS One}, volume = {10}, journal = {PLoS One}, issn = {1932-6203}, doi = {10.1371/journal.pone.0143857}, pages = {0143857}, abstract = {Forest floor mineral soil mix (FMM) and peat mineral soil mix (PMM) are cover soils commonly used for upland reclamation post open-pit oil sands mining in northern Alberta, Canada. Coarse woody debris (CWD) can be used to regulate soil temperature and water content, to increase organic matter content, and to create microsites for the establishment of microorganisms and vegetation in upland reclamation. We studied the effects of CWD on soil microbial community level physiological profile (CLPP) and soil enzyme activities in FMM and PMM in a reclaimed landscape in the oil sands. This experiment was conducted with a 2 (FMM vs PMM) × 2 (near CWD vs away from CWD) factorial design with 6 replications. The study plots were established with Populus tremuloides (trembling aspen) CWD placed on each plot between November 2007 and February 2008. Soil samples were collected within 5 cm from CWD and more than 100 cm away from CWD in July, August and September 2013 and 2014. Microbial biomass was greater (p<0.05) in FMM than in PMM, in July, and August 2013 and July 2014, and greater (p<0.05) near CWD than away from CWD in FMM in July and August samplings. Soil microbial CLPP differed between FMM and PMM (p<0.01) according to a principal component analysis and CWD changed microbial CLPP in FMM (p<0.05) but not in PMM. Coarse woody debris increased microbial community functional diversity (average well color development in Biolog Ecoplates) in both cover soils (p<0.05) in August and September 2014. Carbon degrading soil enzyme activities were greater in FMM than in PMM (p<0.05) regardless of distance from CWD but were not affected by CWD. Greater microbial biomass and enzyme activities in FMM than in PMM will increase organic matter decomposition and nutrient cycling, improving plant growth. Enhanced microbial community functional diversity by CWD application in upland reclamation has implications for accelerating upland reclamation after oil sands mining.}, language = {en} } @misc{HerbrichZoennchenSchaaf, author = {Herbrich, Marcus and Z{\"o}nnchen, Claudia and Schaaf, Wolfgang}, title = {Short-term effects of plant litter addition on mineral surface characteristics of young sandy soils}, series = {Geoderma}, volume = {239-240}, journal = {Geoderma}, issn = {0016-7061}, doi = {10.1016/j.geoderma.2014.10.017}, pages = {206 -- 212}, abstract = {Initial stages of soil development are characterized by structural changes of mineral surfaces over time. The specific surface area (SSA) is closely related to pedogenic properties and soil organic matter (SOM). Interactions between SOM and mineral surfaces induce quantitative and qualitative changes in SSA and corresponding soil properties. However, the knowledge about ranges, effects and mechanisms of organic coverage in the very initial phase of pedogenesis is very limited. Therefore, our objective was to study these processes in young sandy soils and the effects of plant litter addition. Soil samples taken from the constructed catchment "Chicken Creek" were used in a microcosm experiment over 80 weeks. The silt and clay fractions of samples (b63 μm) were analyzed before the experiment and after 40 and 80 weeks. The effects of litter addition and weathering on SSA were assessed using the BET-N2 sorption approach. We found increases of SSA between 16.4\% and 41.6\% within the 80 week experimental period, but a relative reduction in S. A due to organic coverage of these new surfaces after plant litter addition. The removal of the soil organic matter (SOM) by muffling increased SSA (6.8-12.9\%). The results for SSA corresponded to changes in surface specific parameters like cation exchange capacity (CEC), surface enthalpy and the fractional coverage of mineral surfaces by SOM. In conclusion, the results showed that the soilswere clearly in a very initial state of soil development. However, the potential of these young sandy soils to adsorb nutrients and soil organic matter as one of the main important soil functions clearly increased within the relatively short experimental period and changes in SSA indicate relatively large increases in mineral surfaces within short time periods during the initial phase of soil development compared to long-term pedogenesis.}, language = {en} } @misc{ZoennchenSchaafEsperschuetz, author = {Z{\"o}nnchen, Claudia and Schaaf, Wolfgang and Espersch{\"u}tz, J{\"u}rgen}, title = {Effect of litter addition on element leaching in young sandy soils}, series = {Journal of Plant Nutrition and Soil Science}, volume = {177}, journal = {Journal of Plant Nutrition and Soil Science}, number = {4}, issn = {1522-2624}, doi = {10.1002/jpln.201300383}, pages = {585 -- 595}, abstract = {The knowledge about element leaching and biogeochemical cycles during initial stages of soil development is very limited. Therefore, we studied the effects of parent material characteristics and plant litter addition on element leaching from young sandy soils in a microcosm experiment. Our objective was to evaluate the function of young soils as a source and/or sink for nutrients during initial pedogenesis and to identify main processes which are involved in the initial development of biogeochemical cycles. The main research questions were: (1) How do differences in parent material characteristics affect nutrient leaching?; and (2) How is nutrient leaching of young soils influenced by litter addition of different plant functional groups (e.g., legume and grass species)? Combined treatments of two minimally weathered parent materials (pure sand and loamy sand) with plant litter of two plant species (Lotus corniculatus L. and Calamagrostis epigejos L.) were investigated in a soil column experiment. In addition, control columns with parent material or plant litter only were included. Carbonate weathering as a main source for calcium leaching was induced by the moderately acidic irrigation solution used in the experiment. It was 7.5 fold greater for the loamy sand parent material compared to the pure sand despite lower carbonate contents in the loamy sand. Leaching of K was very low for both parent materials but greater for the loamy sand parent material, likely due to transfer processes from fixed to exchangeable potassium forms in the clay minerals of the loamy sand. Plant litter addition generally increased leaching losses. Carbonate dissolution was intensified by both plant litter types, especially by L. corniculatus, very likely due to H+ released during nitrification of N released from plant litter and an increase in partial pressure of CO2 from microbial respiration. In contrast, K was largely retained in the soils, probably due to fixation by clay minerals and microbial immobilization. Only the pure sand treated with L. corniculatus litter leached K, resulting in 4-6 fold greater leaching losses compared to all other treatments. Nitrogen released from L. corniculatus litter was almost completely nitrified and was nearly doubled as compared to that from C. epigejos, resulting in greater N leaching. The results of our study allow identifying the general function and processes of vegetation patches in young ecosystems formed as a result of initial parent material characteristics and invading vegetation with respect to litter decomposition, soil solution composition, nutrient retention and leaching, and effects on the soil mineral phase. These patterns are not mere additive effects of parent materials plus plant litter, but reflect differences in biogeochemical process intensities and could result in an increasing heterogeneity of soil properties, nutrient availability, and element leaching fluxes with time.}, language = {en} } @misc{UlrichPiwczynskiZaplataetal., author = {Ulrich, Werner and Piwczynski, Marcin and Zaplata, Markus K. and Winter, Susanne and Schaaf, Wolfgang and Fischer, Anton}, title = {Small-scale spatial variability in phylogenetic community structure during early plant succession depends on soil properties}, series = {Oecologia}, volume = {175}, journal = {Oecologia}, number = {3}, doi = {10.1007/s00442-014-2954-2}, pages = {985 -- 995}, abstract = {During early plant succession, the phylogenetic structure of a community changes in response to important environmental filters and emerging species interactions. We traced the development of temperate-zone plant communities during the first 7 years of primary succession on catchment soils to explore patterns of initial species assembly. We found pronounced small-scale differences in the phylogenetic composition of neighbouring plant assemblages and a large-scale trend towards phylogenetic evenness. This small-scale variability appears to be mediated by soil properties, particularly carbonate content. Therefore, abiotic environmental conditions might counteract or even supersede the effects of interspecific competition among closely related species, which are usually predicted to exhibit patterns of phylogenetic evenness. We conclude that theories on phylogenetic community composition need to incorporate effects of small-scale variability of environmental factors.}, language = {en} } @misc{SchaafHuettlScullion, author = {Schaaf, Wolfgang and H{\"u}ttl, Reinhard F. and Scullion, John}, title = {Preface: EUROSOIL 2004 Symposium in Freiburg, Germany}, series = {Water, Air \& Soil Pollution: Focus}, volume = {6}, journal = {Water, Air \& Soil Pollution: Focus}, number = {3-4}, issn = {1573-2940}, doi = {10.1007/s11267-005-9020-3}, pages = {233 -- 234}, language = {en} } @misc{SchaafHuettl, author = {Schaaf, Wolfgang and H{\"u}ttl, Reinhard F.}, title = {Direct and indirect effects of soil pollution by lignite mining}, series = {Water, Air \& Soil Pollution: Focus}, volume = {6}, journal = {Water, Air \& Soil Pollution: Focus}, number = {3-4}, issn = {1573-2940}, doi = {10.1007/s11267-005-9028-8}, pages = {353 -- 364}, language = {en} } @misc{BiberSeifertZaplataetal., author = {Biber, Peter and Seifert, Stefan and Zaplata, Markus K. and Schaaf, Wolfgang and Pretzsch, Hans and Fischer, Anton}, title = {Relationships between substrate, surface characteristics, and vegetation in an initial ecosystem}, series = {Biogeosciences}, volume = {10}, journal = {Biogeosciences}, doi = {10.5194/bg-10-8283-2013}, pages = {8283 -- 8303}, abstract = {We investigated surface and vegetation dynamics in the artificial initial ecosystem "Chicken Creek" (Lusatia, Germany) in the years 2006-2011 across a wide spectrum of empirical data. We scrutinized three overarching hypotheses concerning (1) the relations between initial geomorphological and substrate characteristics with surface structure and terrain properties, (2) the effects of the latter on the occurrence of grouped plant species, and (3) vegetation density effects on terrain surface change. Our data comprise and conflate annual vegetation monitoring results, biennial terrestrial laser scans (starting in 2008), annual groundwater levels, and initially measured soil characteristics. The empirical evidence mostly confirms the hypotheses, revealing statistically significant relations for several goal variables: (1) the surface structure properties, local rill density, local relief energy and terrain surface height change; (2) the cover of different plant groups (annual, herbaceous, grass-like, woody, Fabaceae), and local vegetation height; and (3) terrain surface height change showed significant time-dependent relations with a variable that proxies local plant biomass. Additionally, period specific effects (like a calendar-year optimum effect for the occurrence of Fabaceae) were proven. Further and beyond the hypotheses, our findings on the spatiotemporal dynamics during the system's early development grasp processes which generally mark the transition from a geo-hydro-system towards a bio-geo-hydro system (weakening geomorphology effects on substrate surface dynamics, while vegetation effects intensify with time), where pure geomorphology or substrate feedbacks are changing into vegetation-substrate feedback processes.}, language = {en} } @misc{SchaafHuettl, author = {Schaaf, Wolfgang and H{\"u}ttl, Reinhard F.}, title = {Experiences with liming in European countries - results of long-term experiments}, series = {Journal of Forest Science}, volume = {52}, journal = {Journal of Forest Science}, number = {Special Issue}, pages = {35 -- 44}, language = {en} } @misc{NsiahSchaaf, author = {Nsiah, Paul Kofi and Schaaf, Wolfgang}, title = {The potentials of biological geotextiles in erosion and sediment control during gold mine reclamation in Ghana}, series = {Journal of Soils and Sediments}, volume = {19}, journal = {Journal of Soils and Sediments}, number = {4}, issn = {1614-7480}, doi = {10.1007/s11368-018-2217-7}, pages = {1995 -- 2006}, abstract = {Purpose Soil erosion is a significant environmental impact of surface mining affecting the initial establishment of vegetation, especially on steep slopes, during reclamation. Consequently, we investigated the potentials of biological geotextiles constructed from two local plants, Pennisetum purpureum and Broussonetia papyrifera, in reducing erosion and sedimentation during reclamation at Newmont Ghana Gold Limited. Materials and methods Six experimental plots were constructed on a 33\% slope waste rock, covered with a 70-cm layer of stockpiled subsoil. Concrete gutters, lined with silt fence, were installed at the lower end of each plot to collect eroded sediment. The two kinds of biological geotextiles, BYork^ mat and elephant grass mat, were used with bare ground as control in a randomized block design with two replicates each. Data on sediment yield was collected after each substantial rainfall. The performance of each geotextile in reducing soil loss was expressed as a percentage from the mean total sediment yield. Results and discussion With total precipitation of 306 mm in the period April 18, to July 4, 2016, both elephant grass mat and York mat significantly (p < 0.05) reduced soil loss by 56.6\% and 97.3\%, respectively, compared to the control, indicating both mats were effective in erosion and sediment control. The relatively high performance of York mat was mainly attributed to its more fibers that provided less surface cover (70\%) as well as flexibility of the fibers which enabled the mat to absorb more water during rainfall thus increasing its weight. This increase in weight promoted better drapability, with better erosion and sediment control. Gully formations at the site were primarily due to high concentrated runoff flows from the top of reclaiming benches, with time delays between completion of earthworks, geotextile placement, and seeding of plants as predisposing factors. Conclusions The York mat (YM) and the elephant grass mat (EM) individually acted as cover and protected the highly erodible graded mine slope against the erosive forces of tropical rain and runoff until vegetation establishment. Even so, planning and coordinating the reclamation program such that all earthworks are completed at the end of the dry season to enable geotextile installation and plant seeding at the onset of rains, together with installation of temporary slope drains in preventing gully formations from concentrated runoff flows, are considered to contribute significantly to the general reclamation success at Newmont Ghana Gold Limited (NGGL) and similar mine sites.}, language = {en} } @misc{WinterZaplataRzannyetal., author = {Winter, Susanne and Zaplata, Markus K. and Rzanny, Michael and Schaaf, Wolfgang and Fischer, Anton and Ulrich, Werner}, title = {Increasing ecological multifunctionality during early plant succession}, series = {Plant Ecology}, volume = {220}, journal = {Plant Ecology}, number = {4-5}, issn = {1573-5052}, doi = {10.1007/s11258-019-00930-3}, pages = {499 -- 509}, abstract = {Ecological multifunctionality quantifies the functional performance of various important plant traits and increases with growing structural habitat heterogeneity, number of plant functional traits, and species richness. However, the successional changes in multifunctionality have not been traced so far. We use quantitative plant samples of 1 m2 plots from the first 6 years of initial vegetation dynamics in a German created catchment to infer the temporal changes in plant functional trait space and multifunctionality. Multifunctionality at the plot level was in all study years lower than expected from a random sample of the local pool of potential colonizers and was lowest at intermediate states of succession. In each year species containing a specific set of traits occurred with limited but focused functionality. The observed average low degree of multifunctionality contrasts with recent models predicting a tendency towards maximum multifunctionality during plant community development. However, variability in multifunctionality among plots increased during succession and the respective multifunctionality distribution among plots was increasingly right skewed indicating an excess of plots with relatively high multifunctionality. This relative excess of plots with high multifunctionality might act as an important trigger of community development paving the way for new species and functions to become established.}, language = {en} } @misc{NsiahSchaaf, author = {Nsiah, Paul Kofi and Schaaf, Wolfgang}, title = {Subsoil Amendment With Poultry Manure as Topsoil Substitute for Promoting Successful Reclamation of Degraded Mine Sites in Ghana}, series = {Journal of Natural Resources and Development}, volume = {10}, journal = {Journal of Natural Resources and Development}, issn = {0719-2452}, pages = {1 -- 12}, abstract = {Background: Despite the key role topsoil plays in reclamation, there are situations where topsoil is in deficit or unavailable, especially at degraded and abandoned mine sites in Ghana. The sites pose serious ecological and safety risks, underscoring the urgent need to finding alternative substrate for restoration. This study investigated the feasibility of using amended-subsoil as topsoil substitute for reclamation. The hypothesis was that amendment of stockpiled-subsoil with poultry manure positively influences tree growth and ground vegetation cover (GVC), which promote better soil stabilization at degraded mine sites. A graded waste-rock dump was covered with a 70 cm layer of the stockpiled subsoil at Newmont Ghana Gold Limited. Two experimental plots (24 × 15 m) were established with the treatments poultry manure (PLM 23 t ha-1) and control (no PLM), followed by seeding of Cowpea (Vigna unguiculata) and planting of potted-seedlings of five forest tree species. The Laser-point-quadrat method was used to estimate GVC, whereas erosion was visually observed. Diameter and height data of planted trees and surviving numbers were collected. Results: There was significant increase in tree growth and in GVC for the poultry manure treatment compared to the control. The manure provided sufficient nitrogen to overcome nitrogen deficiency and facilitated quicker and stronger vegetation growth that yielded superior soil stabilization. Conclusions: The findings demonstrate the potential of manure application in promoting successful restoration of the many degraded and abandoned mine sites in Ghana to productive uses.}, language = {en} } @misc{MoghadasSchaafGerwinetal., author = {Moghadas, Davood and Schaaf, Wolfgang and Gerwin, Werner and Badorreck, Annika and H{\"u}ttl, Reinhard F.}, title = {A web-based platform for terrestrial data repository from Chicken Creek catchment}, series = {Earth Science Informatics}, volume = {12}, journal = {Earth Science Informatics}, number = {4}, issn = {1865-0481}, doi = {10.1007/s12145-019-00385-0}, pages = {671 -- 684}, abstract = {Exploring hydrological and ecological processes plays a key role in understanding ecosystem developments. In this respect, the constructed catchment, Chicken Creek, has been established for fundamental and interdisciplinary scientific research. Since 2005, an ongoing monitoring program has been launched to measure hydrological, biological, meteorological, and pedological parameters during the ecological development of the site. This comprehensive and multidisciplinary monitoring program has produced a diverse large data set. Handling such complex data for research purposes can be a cumbersome task. Consequently, we developed an online data portal (https://www.b-tu.de/chicken-creek/apps/datenportal/) to efficiently handle the data from Chicken Creek catchment. The portal was constructed using Shiny package of the R programming language. This platform provides a web-based data repository allowing for data discovery, download, visualization, and analysis. The data include time series of different parameters from installed sensors, data from laboratory analyses, vegetation data, data from sampling campaigns, and aerial photos. This platform demonstrates the relevancy and potentiality of the R-Shiny for constructing an online data portal to be used for multidisciplinary scientific purposes. The Chicken Creek data portal thus provides a comprehensive and reliable database to give scientists a fast and easy access to all collected data.}, language = {en} } @misc{KwakChangNaethetal., author = {Kwak, Jin-Hyeob and Chang, Scott X. and Naeth, M. Anne and Schaaf, Wolfgang}, title = {Coarse woody debris effects on greenhouse gas emission rates depend on cover soil type in oil sands reclamation}, series = {Applied Soil Ecology}, volume = {100}, journal = {Applied Soil Ecology}, issn = {0929-1393}, doi = {10.1016/j.apsoil.2015.12.006}, pages = {124 -- 134}, abstract = {Peat mineral soil mix (PMM) and forest floor mineral soil mix (FMM) are cover soils commonly used for land reclamation, while coarse woody debris (CWD) can be added to create structural diversity and provide an additional source of organic matter. However, the effect of cover soil type and CWD on emission rates of greenhouse gases, such as carbon dioxide (CO₂) methane (CH₄) and nitrous oxide (N₂O) in reclaimed oil sands soils has not been studied. Soil respiration, CH₄ uptake and N₂O emission rates were studied in a factorial experiment consisting of 2 cover soils (FMM vs PMM) × 2 sampling distances from the CWD (near vs away from CWD). Greenhouse gas emission rates were measured in July, August, and September 2012 and 2013 using static chambers. Soil respiration rates were greater in FMM than in PMM regardless of the distance from CWD at each sampling time (p < 0.05). Rates ranged from 461 to 1148 and 293 to 677 mg CO2 m⁻²h⁻¹for FMM and PMM, respectively, in 2012, and from 355 to 1318 and 235 to 700 mg CO2 m⁻²h⁻¹, respectively, in 2013. The CWD increased soil respiration by 22-33\% in FMM but not in PMM. Soil respiration rates were positively related to microbial biomass carbon (p = 0.004) and nitrogen (p < 0.001). Soil respiration rates decreased from July to September in 2012 and 2013, and were positively related to soil temperature (p < 0.01) but not with soil water content measured at 5 cm depth. Methane uptake rates were greater in FMM (0.026-0.037) than in PMM (0.015-0.028 mg CH₄⁻²h⁻¹. The CWD increased CH4 uptake rates only in July and August 2012 in FMM, and were negatively related to soil water content (p < 0.001) but not to soil temperature. Nitrous oxide emission rates (0.001-0.016 mg N₂O m⁻²h⁻¹) were not affected by either cover soil type or CWD. Global warming potential of CO₂, CH₄ and N₂O effluxes was greater in FMM than in PMM and near CWD than away from CWD, especially in FMM. Our study demonstrates that applying CWD for oil sands reclamation increases organic matter decomposition (increased CO₂ evolution), driven by the effect on microbial populations. Results from this study provide support to findings in earlier studies that CWD application benefits vegetation establishment through enhancing soil processes in reclaimed oil sands lands.}, language = {en} } @misc{ChabbiSebiloRumpeletal., author = {Chabbi, Abad and Sebilo, Mathieu and Rumpel, Cornelia and Schaaf, Wolfgang and Mariotti, Andr{\´e}}, title = {Origin of Nitrogen in Reforested Lignite-Rich Mine Soils Revealed by Stable Isotope Analysis}, series = {Environmental Science \& Technology}, volume = {42}, journal = {Environmental Science \& Technology}, number = {8}, issn = {1520-5851}, doi = {10.1021/es702377k}, pages = {2787 -- 2792}, language = {en} } @misc{PapritzDuemigZimmermannetal., author = {Papritz, Andreas and D{\"u}mig, Alexander and Zimmermann, Claudia and Gerke, Horst H. and Felderer, Bernd and K{\"o}gel-Knabner, Ingrid and Schaaf, Wolfgang and Schulin, Rainer}, title = {Uncertainty of variance component estimates in nested sampling: a case study on the field-scale spatial variability of a restored soil}, series = {European Journal of Soil Science}, volume = {62}, journal = {European Journal of Soil Science}, number = {3}, issn = {1365-2389}, pages = {479 -- 495}, language = {en} }