@inproceedings{PohleHuSchaafetal., author = {Pohle, Ina and Hu, Yuzhu and Schaaf, Wolfgang and Gerwin, Werner and Maurer, Thomas and Hinz, Christoph}, title = {Hydrogeochemische Signaturen der Einzugsgebietsentwicklung - die Rolle der Calcium- und Sulfatfreisetzung im H{\"u}hnerwassereinzugsgebiet}, series = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, booktitle = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, pages = {S. 5}, language = {de} } @inproceedings{HinzSchaafGerwinetal., author = {Hinz, Christoph and Schaaf, Wolfgang and Gerwin, Werner and Pohle, Ina}, title = {Entwicklung eines transienten hydrologischen Systems: Zustands{\"a}nderungen des k{\"u}nstlichen Einzugsgebiets H{\"u}hnerwasser}, series = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, booktitle = {Abstract-Sammlung zu Posterbeitr{\"a}gen, eingereicht zum Tag der Hydrologie in Trier 2017, 23. 03. - 24. 03. 2017}, pages = {S. 1}, language = {de} } @incollection{SchaafWeckerHuettl, author = {Schaaf, Wolfgang and Wecker, Birgit and H{\"u}ttl, Reinhard F.}, title = {Ver{\"a}nderungen der Oberbodeneigenschaften von Waldb{\"o}den im nordostdeutschen Tiefland druch langj{\"a}hrige atmogene Stoffakkumulation}, series = {Landschaft im Wandel - {\"O}kologie im Wandel}, booktitle = {Landschaft im Wandel - {\"O}kologie im Wandel}, editor = {Petschel, Tim}, publisher = {Verl. Die Werkstatt}, address = {G{\"o}ttingen}, isbn = {3-89533-379-4}, pages = {S. 211}, language = {de} } @inproceedings{ZaplataKollmannUlrichetal., author = {Zaplata, Markus K. and Kollmann, Johannes and Ulrich, Werner and Winter, Susanne and Schaaf, Wolfgang and Elmer, Michael and Gerwin, Werner and Fischer, Anton}, title = {Cover balance or degree of autocorrelation? It is the same and integratively traces pattern formation during succession}, series = {Gf{\"O} 43rd Annual Meeting, Building bridges in ecology, linking systems, scales and disciplines, September 9 to 13, 2013, Potsdam, Germany}, booktitle = {Gf{\"O} 43rd Annual Meeting, Building bridges in ecology, linking systems, scales and disciplines, September 9 to 13, 2013, Potsdam, Germany}, editor = {Jeltsch, Florian and Joshi, Jasmin}, pages = {228 -- 229}, abstract = {It is widely acknowledged that increasing complexity is a key attribute of ecosystem genesis. This is particularly true for primary succession on homogeneous substrates. However, a mechanistic understanding of spatial colonisation and pattern formation during primary succession has not been achieved yet. Thus, we studied this topic for 7 years within an experimental catchment (6 ha) established in the post-mining landscape of eastern Germany. Equidistant permanent plots (120 plots {\`a} 25m²) allowed for autocorrelation analyses, and thus tracing the spatial development of species cover performance. For each species tested, the "cover balance" first increased due to colonization, while decreasing in the course of succession. Drawing a benefit from these temporal trends, we suggested cover balance levels revealed by autocorrelation analyses to best indicate well-defined phases in primary succession at spatial entities. Hence, with the help of this spatial approach, terrestrial succession can be understood now much better at the most general level of the hierarchy provided by Pickett et al. (1987). In accordance with these authors, at subordinated levels of the causal hierarchy differential species performance might get collectively explained by contributing processes or conditions, such as ecophysiological traits, life history strategies, competition and allelopathy of the occurring plant species. Further research is needed to understand their relative contributions to the pattern formation.}, language = {en} } @article{WeckerSchaafHuettl, author = {Wecker, Birgit and Schaaf, Wolfgang and H{\"u}ttl, Reinhard F.}, title = {Einfluss kohliger Substanz auf den Stoffaustrag gest{\"o}rter Standorte}, language = {de} } @article{SchaafNeumannHuettl, author = {Schaaf, Wolfgang and Neumann, C. and H{\"u}ttl, Reinhard F.}, title = {Actual cation exchange capacity in lignite containing pyritic mine spoils.}, language = {en} } @inproceedings{SchaafGerwinKoegelKnabneretal., author = {Schaaf, Wolfgang and Gerwin, Werner and K{\"o}gel-Knabner, Ingrid and Zeyer, Josef and H{\"u}ttl, Reinhard F.}, title = {The artificial catchment 'Chicken Creek': A research site to study the development of biogeochemical cycles in initial ecosystems}, series = {EGU General Assembly 2009, Vienna, Austria, 19 - 24 April 2009}, booktitle = {EGU General Assembly 2009, Vienna, Austria, 19 - 24 April 2009}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @inproceedings{SchaafPohleMaureretal., author = {Schaaf, Wolfgang and Pohle, Ina and Maurer, Thomas and Gerwin, Werner and Hinz, Christoph and Badorreck, Annika}, title = {Water balance dynamics of the constructed Chicken Creek catchment as influenced by 12 years of ecological development}, series = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, booktitle = {European Geosciences Union, General Assembly 2018, Vienna, Austria}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Experimental catchments with well-known boundaries and characteristics may contribute valuable data to hydrological, critical zone and landscape evolution research. One of the most well-established and largest constructed catchments is the Chicken Creek catchment (6 ha area including a 0.4 ha pond, Brandenburg, Germany) representing an initial ecosystem undergoing a highly dynamic ecological development starting from clearly defined starting conditions. The water balance dynamics of the catchment was calculated using a simple mass balance approach to reveal the impact of ecological development during 12 years. Water storage in the catchment was calculated from a 3D-model of groundwater volumes, soil moisture measurements and water level recordings of the pond. The catchment water balance equation was resolved for evapotranspiration, the only part that was not measured directly. Due to the known boundary conditions and the inner structure of the catchment, we were able to quantify the different storage compartments and their role in hydrologic response. Our results indicate that for small catchments with a highly dynamic ecological development like the Chicken Creek, the knowledge about saturated and unsaturated storage volumes enables a good estimate and closure of the water balance using a rather simple approach, at least in annual resolution. We found a significant relationship between vegetation cover in the catchment and calculated ET. Time series of meteorological, hydrological, soil and vegetation data over 12 years enabled us to characterize the transient development of the catchment and to evaluate the effect of different feedback mechanisms on catchment hydrology. The dataset from the Chicken Creek catchment indicate at least three phases in ecosystem development, where initial abiotic feedbacks (e.g. erosion) were followed by more and more biotic controls (e.g. biological soil crusts, vegetation succession and growth). Data from Chicken Creek in high spatial and temporal resolution provide a valuable database underlining the high importance of abiotic/biotic feedback effects that change the hydrologic functioning and response of the catchment more than the water balance itself revealed and thus have to be included in catchment models.}, language = {en} } @misc{SchaafPohleMaureretal., author = {Schaaf, Wolfgang and Pohle, Ina and Maurer, Thomas and Gerwin, Werner and Hinz, Christoph and Badorreck, Annika}, title = {Water Balance Dynamics during Ten Years of Ecological Development at Chicken Creek Catchment}, series = {Vadose Zone Journal}, volume = {16}, journal = {Vadose Zone Journal}, number = {11}, issn = {1539-1663}, doi = {10.2136/vzj2017.04.0074}, pages = {14}, abstract = {Difficulties in quantitatively closing the water balance of catchments arise when upscaling point measurements and from insufficient knowledge of the physical boundaries, inner structure, and storage volumes of natural catchments. In addition, there is a strong need for generalizing the relationship between catchment characteristics and hydrological response. Therefore, experimental catchments with well-known boundaries and conditions could contribute valuable data to hydrological and critical zone research. One of the most well-established and largest constructed catchments is the Chicken Creek catchment (6 ha including a pond, Brandenburg, Germany) representing an initial ecosystem undergoing highly dynamic ecological development starting from clearly defined starting conditions. Directly after completion of the construction, extensive monitoring equipment was installed to track the ecosystem development and to capture the spatiotemporal variability of meteorological, hydrological, ecological, and soil conditions and vegetation succession. In this study, we focused on the water balance dynamics of the Chicken Creek catchment for the period 2005 to 2015 as influenced by ecological development. Water storage in the catchment was calculated from a three-dimensional model of groundwater volumes, soil moisture measurements, and water level recordings of the pond. The catchment water balance equation was resolved for evapotranspiration, the only part that was not measured directly. Time series of meteorological, hydrological, and ecological data for 10 yr enabled us to characterize the transient development of the catchment and to evaluate the effect of different feedback mechanisms on catchment hydrology.}, language = {en} } @incollection{SchaafHinzGerwinetal., author = {Schaaf, Wolfgang and Hinz, Christoph and Gerwin, Werner and Zaplata, Markus K. and H{\"u}ttl, Reinhard F.}, title = {Ecosystem Development in the Constructed Catchment "Chicken Creek"}, series = {Hydrology of Artificial and Controlled Experiments}, booktitle = {Hydrology of Artificial and Controlled Experiments}, editor = {Liu, Jiu-Fu and Gu, Wei-Zu}, publisher = {Intech Open}, address = {London}, isbn = {978-1-78923-559-3}, pages = {75 -- 93}, abstract = {Landscapes and ecosystems are complex systems with many feedback mechanisms acting between the various abiotic and biotic components. The knowledge about these interacting processes is mainly derived from mature ecosystems. The initial development of ecosystem complexity may involve state transitions following catastrophic shifts, disturbances, or transgression of thresholds. We propose a conceptual framework of feedback processes in early states of ecosystem development affected by spatiotemporal environmental drivers. To test this concept, we used 10-year time series of hydrological, biological, geomorphological, and soil data from the constructed catchment Chicken Creek." The 6ha site was left to unrestricted development since 2005 and was intensively monitored. The data showed a very rapid development of the site with an increasing complexity and heterogeneity. In the first years, stochastic signals like the initial substrate conditions and external drivers like extreme weather events were the most important factors resulting in abiotic/abiotic feedback mechanisms shaping the morphology of the site and creating site diversity. Initial abiotic feedback mechanisms between water and substrate were soon followed by abiotic/biotic feedbacks between biological soil crusts, invading vegetation, geomorphology, and hydrology resulting in state transitions of catchment functioning.}, language = {en} } @misc{UlrichZaplataWinteretal., author = {Ulrich, Werner and Zaplata, Markus K. and Winter, Susanne and Schaaf, Wolfgang and Fischer, Anton and Soliveres, Santiago and Gotelli, Nicholas J.}, title = {Species interactions and random dispersal rather than habitat filtering drive community assembly during early plant succession}, series = {Oikos}, volume = {125}, journal = {Oikos}, number = {5}, doi = {10.1111/oik.02658}, pages = {698 -- 707}, abstract = {Theory on plant succession predicts a temporal increase in the complexity of spatial community structure and of competitive interactions: initially random occurrences of early colonising species shift towards spatially and competitively structured plant associations in later successional stages. Here we use long-term data on early plant succession in a German post mining area to disentangle the importance of random colonisation, habitat filtering, and competition on the temporal and spatial development of plant community structure. We used species co-occurrence analysis and a recently developed method for assessing competitive strength and hierarchies (transitive versus intransitive competitive orders) in multispecies communities. We found that species turnover decreased through time within interaction neighbourhoods, but increased through time outside interaction neighbourhoods. Successional change did not lead to modular community structure. After accounting for species richness effects, the strength of competitive interactions and the proportion of transitive competitive hierarchies increased through time. Although effects of habitat filtering were weak, random colonization and subsequent competitive interactions had strong effects on community structure. Because competitive strength and transitivity were poorly correlated with soil characteristics, there was little evidence for context dependent competitive strength associated with intransitive competitive hierarchies.}, language = {en} }