Forschungszentrum Landschaftsentwicklung und Bergbaulandschaften (FZLB)
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- ecosystem development (2)
- Hühnerwasser (1)
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- lingite mining (1)
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Die zurückliegenden trocken-heißen Sommer haben im Süden Brandenburgs zu zahlreichen Bränden in den dominierenden Kiefernwäldern geführt, einige davon mit katastrophalen Ausmaßen. Dazu gehören die extremen Brandereignisse 2018 bei Treuenbrietzen sowie 2019 bei Jüterbog und Lieberose, die zusammen weit über 1000 ha Waldfläche zerstört und dabei auch Veränderungen der betroffenen Waldböden verursacht haben.
Das seit Mai 2020 von der FNR geförderte Verbundvorhaben Pyrophob befasst sich mit den Auswirkungen von Waldbränden im Süden Brandenburgs auf die Waldökosysteme und mit waldbaulichen Maßnahmen, die mittelfristig zu einer Verringerung der Brandanfälligkeit der Wälder beitragen sollen. Im Rahmen des auf eine fünfjährige Laufzeit ausgelegten Verbundvorhabens finden bodenkundliche Untersuchungen auf zwölf Versuchsflächen bei Treuenbrietzen und Jüterbog statt. An beiden Standorten werden unverbrannte Referenzflächen mit einbezogen. Ergänzend konnten bei Lieberose bereits 2019 nur kurz nach dem Brandgeschehen erste Bodenuntersuchungen durchgeführt werden. Die untersuchten Brandflächen bei Jüterbog und Lieberose sind als Totalreservate ausgewiesen, auf denen auch nach dem Brand waldbauliche Maßnahmen vollständig unterbleiben. Auf den Flächen bei Treuenbrietzen wurden verschiedene Behandlungsvarianten durchgeführt, zu denen auf einem Teil der Flächen die vollständige Entfernung der abgestorbenen Bäume gehörte, während auf anderen Teilflächen Totholz auf der Fläche verblieb.
Ziel der bodenkundlichen Arbeiten in Pyrophob ist zum einen eine Charakterisierung der direkten Auswirkungen des Brandes auf Humus und Mineralboden hinsichtlich des Stoffbestandes und bodenbiologischer Prozesse. Zum anderen wird der Stoffaustrag aus dem Oberboden erfasst. Der etwaige Einfluss der unterschiedlichen waldbaulichen Vorgehensweise auf die Bodenverhältnisse wird dabei als ein Indikator für die Auswahl geeigneter Maßnahmen berücksichtigt.
In den verschiedenen Untersuchungsvarianten des Vorhabens wurden zu diesem Zweck Humus- und Mineralbodenprofile untersucht. Zudem wurden Mischproben aus dem Ober- und Unterboden entnommen und auf ihren Stoffhaushalt hin analysiert. Auf jeder Untersuchungsfläche wurden je drei frei dränende Kleinlysimeter in 10 cm Bodentiefe installiert, um die zeitlichen Veränderungen der Sickerwasserzusammensetzung und die durch den Brand initiierten Stoffausträge aus dem Oberboden zu quantifizieren. Ergänzend finden Untersuchungen zu möglichen Auswirkungen der Brände auf bodenbiologische Prozesse wie Streuabbau und Stickstoffmineralisation statt.
Die Lausitz zählt schon heute zu einer der niederschlagärmsten Regionen in Deutschland. Durch den Klimawandel wird diese Situation noch weiter verstärkt und die Wahrscheinlichkeit von extremen Trockenperioden während der Hauptvegetationsphase wird zunehmen. Einer der zentralen bodenkundlichen Herausforderungen wird es somit sein, die geringe Wasserhaltekapazität der vor allem sandigen Böden der Region zu steigern. In dem Verbundvorhaben StabilOrg wird daher die Entwicklung neuartiger Bodenhilfsstoffe auf der Basis regional in der Lausitz verfügbarer Ressourcen untersucht.
Durch die Tagebauaktivitäten in der Region fallen große Mengen an Eisenhydroxidschlämmen (EHS) an. Hierbei lassen sich 3 Herkunftsschwerpunkte definieren: I) natürliche Eisenhydroxidsedimente aus Fließen, II) EHS aus Grubenwasserbehandlungsanlagen, die durch Kalkung gefällt wurden und III) EHS aus Trinkwassergewinnungsstätten, die gekalkt und zusätzlich durch chemische Flockungsmittel behandelt wurden. Diese sollen mit verschiedenen Tonen und Lehmen als weitere anorganische Komponenten, sowie mit organischem Material (Kompost) gemischt werden. Ziel ist die Herstellung von anorganisch-organische Mischsubstraten, die die bodenphysikalischen Eigenschaften positiv beeinflussen.
Erste Untersuchungsergebnisse zeigen, dass sich die untersuchten EHS je nach Behandlung in ihrer mineralogischen Zusammensetzung, sowie den physikochemischen Parametern deutlich unterscheiden. In ersten Experimenten wird untersucht, wie sich diese Mischungen auf die Wasserhaltekapazität von sandigen Böden auswirken und ob sich dabei Unterschiede zwischen den EHS und in Kombination mit den anderen Ausgangssubstanzen aufzeigen lassen.
Exploring hydrological and ecological processes plays a key role in understanding ecosystem development. In this respect, the constructed catchment, Chicken Creek (Hühnerwasser), has been established to promote fundamental and interdisciplinary scientific research. Since 2005, an on-going monitoring program has been established in this catchment to measure hydrological, biological, meteorological, and pedological parameters during the ecological development of the site. This comprehensive and multidisciplinary monitoring program has produced a large and diverse data set. Managing and exploring such a complex data set for research purposes can be a cumbersome task. As a consequence, 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 R programming language, Shiny package, and the accompanying local Linux server. This platform allows for efficient data discovery, download, visualization, and analysis. Data visualizations are freely available, while data storage is limited to the authorized users. In comparison with the commonly used data base tools, R-Shiny offers several advantages. As an open source package, this platform allows for constructing a web data platform in an interactive way taking into account the complexity and diversity of the data. The flexibility of this routine enables to make an efficient user-demand data portal rather than relying on predetermined outputs. It also offers flexibility in data handling by using many different R packages, rendering versatile and extensive functionalities. R-Shiny is particularly powerful in terms of statistical analyses. Although the Chicken Creek online data portal is complete and available, new features, and extended capabilities are under active development. The Chicken Creek data portal provides a comprehensive and reliable database to give scientists a fast and easy access to all collected data.
Consequently, R-Shiny offers a great potential for future development of the web-based data portals to efficiently handle scientific data collected at different scales.
After completion of the construction in 2005 (Gerwin et al. 2009), a major challenge was to develop and install a cross-disciplinary long-term monitoring program for the 6 ha area to record major environmental parameters adapted to the development of the site (Schaaf et al. 2013).
During its first 15 years, Chicken Creek showed a very dynamic development (Elmer et al 2013). Whereas the abiotic geosystem of the first 2-3 years was characterized by heavy erosion and sediment transport, primary succession by invading vegetation and the unexpected formation of soil crusts within few years resulted in more biotic-abiotic feedbacks that controlled catchment hydrology. Our observations over a period of 15 years indicate that even minor variations in initial substrate characteristics (e.g. texture) can have lasting impacts on geomorphical, hydrological and biological development like erosion intensity, groundwater levels or establishment of vegetation patterns. The time-series of monitoring data combined with a structure model of the catchment (Gerke et al. 2013) allowed the closure of the water balance by relatively simple calculations of water storage volumes and the estimation of evapotranspiration (Schaaf et al. 2017). From these data three stages of ecosystem development were derived which are characterized by increasing influence of biota and increasing system complexity.
Ecosystems are characterized by high complexity and are dynamically changing by abiotic and biotic drivers such as climate, vegetation and soil fauna. Due to feedback processes between compartments, ecosystems show an inherent degree of locally heterogeneous properties and structures at multiple spatial and temporal scales.
The constructed catchment “Chicken Creek” represents a unique and outstanding site to study an ecosystem at the initial stage of development. The catchment is located about 20 km south of the city of Cottbus (Germany). The 6-ha catchment area was built in 2005 of coarse-textured quaternary sediments from the adjacent lignite mine and forms a back- and foot-slope that flattens out to a pond. A clay liner of 2-3 m thickness seals the catchment at the bottom, allowing for the formation of a local water body fed by precipitation. After construction the site was left to an unrestricted and unmanaged succession to elucidate the role of structures und processes during the initial establishment of an ecosystem. To study processes of ecosystem development and newly emerging structures the Chicken Creek catchment is equipped with a comprehensive ecological monitoring network. A network of more than 40 wells and two weirs allow for recording groundwater levels, surface runoff and discharge. Meteorological parameters are recorded at three weather stations. Annual aerial photos and vegetation monitoring reveal the floral colonisation of the area. Here, we present the 12 years of diverse and extensive monitoring program which has been launched to measure hydrological, biological, meteorological, and pedological parameters during the ecological development of the catchment area.
The Huehnerwasser catchment was constructed 2004-2005 in a post-mining landscape in Eastern Germany and was left for an unmanaged primary ecosystem succession. At the same time a comprehensive monitoring program was launched for observing the expected dynamic development of this 6 ha site. During the following years this artificially created system was subject to a series of fast changes with regard to morphology, hydrology or vegetation cover. In summary, these processes resulted in significant alterations of the original, initial system within a short period of time. This development can be divided up into single phases with dominating processes or groups of processes. A first phase was mainly characterized by interactions between abiotic system components such as water and substrate. However, already in this very early developmental phase biotic components in the form of microorganisms were a crucial system forming factor by means of biological soil crusts. This period was quickly replaced by a second phase with dominating hydrological processes. During this phase the local groundwater body of the system developed to its full extent. With the beginning of the present phase biota gained control of the system behavior. Particularly plants and related processes such as water uptake and evapotranspiration are now responsible for new modifications of the system. The Huehnerwasser site offers an example of young and highly dynamic ecological systems. This transitional development of a very young ecosystem contrasts with the behavior of mature ecosystems with slow and less pronounced changes unless the system is disturbed. In this paper we present insights into a unique landscape observatory which illustrates the dynamic nature of natural systems in fast motion.
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.
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.
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.