TY - GEN A1 - Lehmkuhl, Frank A1 - Gerwin, Werner A1 - Raab, Thomas A1 - Birkhofer, Klaus A1 - Hinz, Christoph A1 - Letmathe, Peter A1 - Leuchner, Michael A1 - Roß-Nickoll, Martina A1 - Rüde, Thomas R. A1 - Trachte, Katja A1 - Wätzold, Frank T1 - Perspectives for the lignite post-mining landscapes of the lignite mining landscapes under changing environmental conditions - what can we learn from a comparison between the Rhenish and the Lusatian regions in Germany? : EGU General Assembly 2024, Vienna, Austria & Online | 14–19 April 2024 N2 - The German government's decision to phase out lignite mining by 2038 or earlier, as recently 2030 has been agreed for the Rhineland, will trigger a number of transition processes in Germany's remaining lignite mining areas. The two largest lignite mining areas are located in geographically different regions: Rhineland in the west and Lusatia in the east. As the socio-economic and environmental conditions in these two mining areas are set to change dramatically, the German government has adopted extensive economic support measures. However, the environmental changes will also lead to changes in the ecosystem functions and services provided by the future post-mining landscapes. Gerwin et al. (2023) compare the two main lignite producing regions of Germany in terms of their natural and cultural environments. The economic situation and its history are reflected and differences are outlined. Part of the differences in cultural development can be explained by the natural conditions, especially the edaphic factors and the climatic situation. Because of the specific geological settings, tailored mining technologies were developed and used in the two regions, with different effects on the resulting post-mining landscapes. We conclude that the landscapes of Lusatia and the Rhineland have been radically restructured by the long and varied history of lignite mining. Both regions will change significantly as the mining industry continues to decline and is expected to cease altogether within the next decade. These changes in the post-mining landscapes and the ecosystem services will provide both challenges and opportunities. The preconditions for positive socio-economic development and for sustainable land use concepts that also consider ecological aspects are different for the two regions. The exchange of knowledge and experience between the two mining regions is crucial to the success of this major transformation process, despite, or perhaps because of, these differences. Gerwin, W., Raab, T., Birkhofer, K., Hinz, C., Letmathe, P., Leuchner, M., Roß-Nickoll, M., Rüde, T., Trachte, K., Wätzold, F., Lehmkuhl, F. (2023): Perspectives of lignite post-mining landscapes under changing environmental conditions: what can we learn from a comparison between the Rhenish and Lusatian region in Germany? Environmental Sciences Europe 35:36. https://doi.org/10.1186/s12302-023-00738-z Y1 - 2024 U6 - https://doi.org/10.5194/egusphere-egu24-2791 PB - Copernicus GmbH ER - TY - GEN A1 - Gerwin, Werner A1 - Raab, Thomas A1 - Hinz, Christoph A1 - Letmathe, Peter A1 - Leuchner, Michael A1 - Roß-Nickoll, Martina A1 - Rüde, Thomas A1 - Trachte, Katja A1 - Wätzold, Frank A1 - Lehmkuhl, Frank T1 - Perspectives of lignite post‑mining landscapes under changing environmental conditions: what can we learn from a comparison between the Rhenish and Lusatian region in Germany? T2 - Environmental Sciences Europe N2 - Background The decision of the German federal government to cease lignite mining until 2038 or—if possible— already earlier until 2030, will cause manifold transition processes in the remaining lignite mining districts of Germany. The two largest districts are located in geographically opposite regions: The Rhineland in the western part and Lusatia in the east of Germany. As particularly these two mining districts will experience severe changes in their socioeconomic as well environmental conditions, the federal government has adopted comprehensive economic support measures. However, the environmental changes will also cause altered ecosystem functions and services to be provided by the future post-mining landscapes. Results In this paper, the two main lignite-producing regions of Germany are compared with regard to their natural and cultural settings. The economic situation and its history are reflected and differences are outlined. Part of the disparities in the cultural development can be explained by very different natural conditions, especially edaphic factors and climatic situation. Because of dissimilar geological settings, different mining technologies were developed and are in use in the two regions with distinct effects on the resulting post-mining landscapes. Conclusion The long-standing and manifold lignite mining activities have radically restructured the landscapes in Lusatia and the Rhineland. With the ongoing decline of the mining industry and its complete cessation, presumably within the next decade, both regions will alter their faces significantly. These changes offer both challenges but also opportunities with respect to the post-mining landscapes and their ecosystem services they are going to provide. The prerequisites for a positive socioeconomic development and for sustainable land-use concepts that also consider ecological aspects are different for both regions. However, or especially because of these differences, the knowledge exchange and experience transfer between both mining regions are pivotal for the success of this extensive transformation process. KW - Lignite mining KW - Ecosystem services KW - Post-mining landscapes KW - Transformation processes Y1 - 2023 U6 - https://doi.org/10.1186/s12302-023-00738-z SN - 2190-4715 VL - 35 ER - TY - GEN A1 - Bendix, Jörg A1 - Aguire, Nicolay A1 - Beck, Erwin A1 - Bräuning, Achim A1 - Brandl, Roland A1 - Breuer, Lutz A1 - Böhning‑Gaese, Katrin A1 - Paula, Mateus Dantas de A1 - Hickler, Thomas A1 - Homeier, Jürgen A1 - Inclan, Diego A1 - Leuschner, Christoph A1 - Neuschulz, Eike L. A1 - Schleuning, Matthias A1 - Suarez, Juan P. A1 - Trachte, Katja A1 - Wilcke, Wolfgang A1 - Windhorst, David A1 - Farwig, Nina T1 - A research framework for projecting ecosystem change in highly diverse tropical mountain ecosystems T2 - Oecologia N2 - Tropical mountain ecosystems are threatened by climate and land-use changes. Their diversity and complexity make projections how they respond to environmental changes challenging. A suitable way are trait-based approaches, by distinguishing between response traits that determine the resistance of species to environmental changes and effect traits that are relevant for species' interactions, biotic processes, and ecosystem functions. The combination of those approaches with land surface models (LSM) linking the functional community composition to ecosystem functions provides new ways to project the response of ecosystems to environmental changes. With the interdisciplinary project RESPECT, we propose a research framework that uses a trait-based response-effect-framework (REF) to quantify relationships between abiotic conditions, the diversity of functional traits in communities, and associated biotic processes, informing a biodiversity-LSM. We apply the framework to a megadiverse tropical mountain forest. We use a plot design along an elevation and a land-use gradient to collect data on abiotic drivers, functional traits, and biotic processes. We integrate these data to build the biodiversity-LSM and illustrate how to test the model. REF results show that aboveground biomass production is not directly related to changing climatic conditions, but indirectly through associated changes in functional traits. Herbivory is directly related to changing abiotic conditions. The biodiversity-LSM informed by local functional trait and soil data improved the simulation of biomass production substantially. We conclude that local data, also derived from previous projects (platform Ecuador), are key elements of the research framework. We specify essential datasets to apply this framework to other mountain ecosystems. KW - Biodiversity-land surface model KW - Functional traits KW - High mountains KW - Research framework KW - Response-effect-framework Y1 - 2021 U6 - https://doi.org/10.1007/s00442-021-04852-8 SN - 0029-8549 SN - 1432-1939 VL - 195 IS - 3 SP - 589 EP - 600 ER - TY - GEN A1 - Juhlke, Tobias R. A1 - Geldern, Robert van A1 - Barth, Johannes A. C. A1 - Bendix, Jörg A1 - Bräuning, Achim A1 - Garel, Emilie A1 - Häusser, Martin A1 - Huneau, Frédéric A1 - Knerr, Isabel A1 - Santoni, Sébastien A1 - Szymczak, Sonja A1 - Trachte, Katja T1 - Temporal offset between precipitation and water uptake of Mediterranean pine trees varies with elevation and season T2 - Science of the Total Environment N2 - For climate models that use paleo-environment data to predict future climate change, tree-ring isotope variations are one important archive for the reconstruction of paleo-hydrological conditions. Due to the rather complicated pathway of water, starting from precipitation until its uptake by trees and the final incorporation of its components into tree-ring cellulose, a closer inspection of seasonal variations of tree water uptake is important. In this study, branch and needle samples of two pine species (Pinus pinaster and Pinus nigra subsp. laricio) and several water compartments (precipitation, creek, soil) were sampled over a two-year period and analyzed for the temporal variations of their oxygen and hydrogen stable isotope ratios (δ18O and δ2H) at five sites over an elevation gradient from sea level to around 1600 m a.s.l. on the Mediterranean island of Corsica (France). A new model was established to disentangle temporal relationships of source water uptake of trees. It uses a calculation method that incorporates the two processes mostly expected to affect source water composition: mixing of waters and evaporation. The model results showed that the temporal offset from precipitation to water uptake is not constant and varies with elevation and season. Overall, seasonal source water origin was shown to be dominated by precipitation from autumn and spring. While autumn precipitation was a more important water source for trees growing at mid- (~800–1000 m a.s.l) and high-elevation (~1600 m a.s.l.) sites, trees at coastal sites mostly took up water from late winter and spring. These findings show that predicted decreases in precipitation amounts during the wet season in the Mediterranean can have strong impacts on water availability for pine trees, especially at higher elevations. KW - Oxygen isotopes KW - Hydrogen isotopes KW - Mediterranean KW - Soil water KW - Water uptake KW - Pine trees Y1 - 2021 U6 - https://doi.org/10.1016/j.scitotenv.2020.142539 VL - 755 IS - 2 ER - TY - GEN A1 - Knerr, Isabel A1 - Trachte, Katja A1 - Egli, Sebastian A1 - Barth, Johannes A. C. A1 - Bräuning, Achim A1 - Garel, Emilie A1 - Häusser, Martin A1 - Huneau, Frédéric A1 - Juhlke, Tobias R. A1 - Santoni, Sébastien A1 - Szymczak, Sonja A1 - Geldern, Robert van A1 - Bendix, Jörg T1 - Fog - low stratus (FLS) regimes on Corsica with wind and PBLH as key drivers T2 - Atmospheric Research N2 - The French Mediterranean island of Corsica is already today confronted with a clear tendency towards water shortage, leading not only to socio-economical, but also to ecological problems. A potential, but not very widespread source of water is the presence of near-ground clouds, mostly fog. In this study, we investigate fog-low stratus (FLS) frequencies in Corsica, derived from a data set of Meteosat Second Generation SEVIRI, whereby a distinction between fog and low stratus is hardly feasible using remote sensing data. The FLS frequency was studied with respect to its interaction with distinct locally-generated wind and its dependence on the planetary boundary layer height (PBLH) obtained by ERA5 reanalysis (the fifth generation of the European Centre for Medium-Range Weather Forecasts, ECMWF). Results show that radiation FLS is formed in coastal areas at sunrise, with low PBLH. On the other hand, in the interior of the island at sunset, a maximum of advection FLS is formed, fostered by locally-generated and related transport of moisture. On the east side of the island, FLS frequency is lower throughout the year due to frequent lee situations. This situation is reinforced by reduced synoptic moisture transport by westerly winds, so that westerly exposed slopes benefit from moisture input by FLS formation. KW - Corsica KW - Mediterranean KW - Fog Low Stratus KW - Meteosat Second Generation (MSG) KW - Planetary Boundary Layer KW - Locally-generated wind Y1 - 2021 U6 - https://doi.org/10.1016/j.atmosres.2021.105731 SN - 0169-8095 VL - 261 ER - TY - GEN A1 - Urgilés, Gabriela A1 - Célleri, Rolando A1 - Trachte, Katja A1 - Bendix, Jörg A1 - Orellana-Alvear, Johanna T1 - Clustering of Rainfall Types Using Micro Rain Radar and Laser Disdrometer Observations in the Tropical Andes T2 - Remote Sensing N2 - Lack of rainfall information at high temporal resolution in areas with a complex topography as the Tropical Andes is one of the main obstacles to study its rainfall dynamics. Furthermore, rainfall types (e.g., stratiform, convective) are usually defined by using thresholds of some rainfall characteristics such as intensity and velocity. However, these thresholds highly depend on the local climate and the study area. In consequence, these thresholds are a constraining factor for the rainfall class definitions because they cannot be generalized. Thus, this study aims to analyze rainfall-event types by using a data-driven clustering approach based on the k-means algorithm that allows accounting for the similarities of rainfall characteristics of each rainfall type. It was carried out using three years of data retrieved from a vertically pointing Micro Rain Radar (MRR) and a laser disdrometer. The results show two main rainfall types (convective and stratiform) in the area which highly differ in their rainfall features. In addition, a mixed type was found as a subgroup of the stratiform type. The stratiform type was found more frequently throughout the year. Furthermore, rainfall events of short duration (less than 70 min) were prevalent in the study area. This study will contribute to analyze the rainfall formation processes and the vertical profile. KW - rainfall types KW - k-means KW - micro rain radar KW - laser disdrometer KW - rainfall characteristics KW - tropical Andes Y1 - 2021 U6 - https://doi.org/10.3390/rs13050991 VL - 13 IS - 5 ER - TY - GEN A1 - Herrmann, Frank A1 - Keuler, Klaus A1 - Wolters, Tim A1 - Bergmann, Sabine A1 - Eisele, Michael A1 - Wendland, Frank T1 - Mit der Modellkette RCP-GCM-RCM-mGROWA projizierte Grundwasserneubildung als Datenbasis für zukünftiges Grundwassermanagement in Nordrhein-Westfalen T2 - Grundwasser N2 - Mit einem Multi-Modell-Ensemble wurde analysiert, wie sich der Klimawandel auf den Grundwasserhaushalt in Nordrhein-Westfalen (NRW) auswirkt. Hierzu wurden Projektionen der zukünftigen Grundwasserneubildung für insgesamt 36 Mitglieder der Modellkette RCP-GCM-RCM-mGROWA, bestehend aus 3 RCP-Szenarien zukünftiger globaler Erwärmung, 6 globalen und 5 dynamischen regionalen Klimamodellen sowie dem Wasserhaushaltsmodell mGROWA, vorgenommen. Mit dem Ensemble wurden für die hydrogeologischen Großräume NRWs nur teilweise signifikante Änderungen der jährlichen Grundwasserneubildung in den Perioden 2011–2040, 2041–2070 und 2071–2100 projiziert. Ein Robustheitstest mit zwei Kriterien (Übereinstimmung und Signifikanz der Änderungssignale) liefert keine belastbare Begründung dafür, dass sich die Grundwasserneubildung bis 2100 systematisch und signifikant ändern wird. Aus statistischer Perspektive wird deshalb die Schlussfolgerung gezogen, dass in NRW langfristig eine Grundwasserneubildung erwartet werden kann, die sich nicht grundlegend vom Niveau der Periode 1971–2000 unterscheidet. Hydro-meteorologisch befindet sich NRW in einer Übergangszone, in der eine Zunahme der Winterniederschläge die Wirkung der Erwärmung auf die Grundwasserneubildung wahrscheinlich kompensiert. KW - Grundwasserneubildung KW - Nordrhein-Westfalen KW - mGROWA KW - Klimawandel KW - Multi-Modell-Ensemble KW - Robustheit KW - Groundwater recharge KW - North Rhine-Westphalia KW - Climate change impact KW - Multi-model ensemble KW - Robustness Y1 - 2021 U6 - https://doi.org/10.1007/s00767-020-00471-x SN - 1430-483X SN - 1432-1165 VL - 26 IS - 1 SP - 17 EP - 31 ER - TY - GEN A1 - Veste, Maik A1 - Grey, Kerry-Anne A1 - Gottschalk, Nadine A1 - Trachte, Katja A1 - Midgley, Guy F. T1 - Can shelterbelt trees reduce evapotranspiration and ecophysiological stress in irrigated vineyards and citrus orchards? A transcontinental experiment in the Western Cape, South Africa and Lower Lusatia, Germany T2 - Landscape 2021 - Diversity for Sustainable and Resilient Agriculture N2 - In the context of ongoing climate change and increasing population, there is an urgent need to optimize the water consumption of surface and groundwater in agricultural production. In recent years, intensive irrigated viticulture and horticulture have faced increasing demand pressure in many water-limited areas including the Western Cape Province in South Africa. Shelterbelts of trees are often used to reduce wind speed and water demands as an eco-engineering measure directly influencing soil evaporation and crop transpiration. Objectives are (i) to evaluate the extent of impacts of wind speed from shelterbelts at canopy level in citrus orchards and vineyards (ii) to assess the wind effects at leaf level including leaf temperature and related ecophysiological performance in irrigated vineyards. Y1 - 2021 U6 - https://doi.org/10.13140/RG.2.2.34333.03043 ER - TY - GEN A1 - Limberger, Oliver A1 - Homeier, Jürgen A1 - Farwig, Nina A1 - Pucha-Cofrep, Franz A1 - Fries, Andreas A1 - Leuschner, Christoph A1 - Trachte, Katja A1 - Bendix, Jörg T1 - Classification of Tree Functional Types in a Megadiverse Tropical Mountain Forest from Leaf Optical Metrics and Functional Traits for Two Related Ecosystem Functions T2 - Forests N2 - Few plant functional types (PFTs) with fixed average traits are used in land surface models (LSMs) to consider feedback between vegetation and the changing atmosphere. It is uncertain if highly diverse vegetation requires more local PFTs. Here, we analyzed how 52 tree species of a megadiverse mountain rain forest separate into local tree functional types (TFTs) for two functions: biomass production and solar radiation partitioning. We derived optical trait indicators (OTIs) by relating leaf optical metrics and functional traits through factor analysis. We distinguished four OTIs explaining 38%, 21%, 15%, and 12% of the variance, of which two were considered important for biomass production and four for solar radiation partitioning. The clustering of species-specific OTI values resulted in seven and eight TFTs for the two functions, respectively. The first TFT ensemble (P-TFTs) represented a transition from low to high productive types. The P-TFT were separated with a fair average silhouette width of 0.41 and differed markedly in their main trait related to productivity, Specific Leaf Area (SLA), in a range between 43.6 to 128.2 (cm2/g). The second delineates low and high reflective types (E-TFTs), were subdivided by different levels of visible (VIS) and near-infrared (NIR) albedo. The E-TFTs were separated with an average silhouette width of 0.28 and primarily defined by their VIS/NIR albedo. The eight TFT revealed an especially pronounced range in NIR reflectance of 5.9% (VIS 2.8%), which is important for ecosystem radiation partitioning. Both TFT sets were grouped along elevation, modified by local edaphic gradients and species-specific traits. The VIS and NIR albedo were related to altitude and structural leaf traits (SLA), with NIR albedo showing more complex associations with biochemical traits and leaf water. The TFTs will support LSM simulations used to analyze the functioning of mountain rainforests under climate change. KW - ecosystem productivity KW - energy fluxes KW - leaf hyperspectra KW - functional traits KW - tree functional types KW - tropical forest Y1 - 2021 U6 - https://doi.org/10.3390/f12050649 SN - 1999-4907 VL - 12 IS - 5 ER - TY - GEN A1 - Knerr, Isabel A1 - Trachte, Katja A1 - Garel, Emilie A1 - Huneau, Frédéric A1 - Santoni, Sébastien A1 - Bendix, Jörg T1 - Partitioning of Large-Scale and Local-Scale Precipitation Events by Means of Spatio-Temporal Precipitation Regimes on Corsica T2 - Atmosphere N2 - The island of Corsica in the western Mediterranean is characterized by a pronounced topography in which local breeze systems develop in the diurnal cycle. In interaction with the large-scale synoptic situation, various precipitation events occur, which are classified in this study with regard to their duration and intensity. For this purpose, the island was grouped into five precipitation regimes using a cluster analysis, namely the western coastal area, the central mountainous region, the southern coastal area, the northeast coastal area, and the eastern coastal area. Based on principal component analysis using mean sea level pressure (mslp) obtained from ERA5 reanalysis (the fifth generation of the European Centre for Medium-Range Weather Forecasts, ECMWF), six spatial patterns were identified which explain 98% of the large-scale synoptic situation, while the diurnal breeze systems within the regimes characterize local drivers. It is shown that on radiation days with weak large-scale pressure gradients, pronounced local circulations in mountainous regions are coupled with sea breezes, leading to a higher number of short and intense precipitation events. Meridional circulation patterns lead to more intensive precipitation events on the eastern part of the island (30% intensive events with meridional patterns on the east side compared to 11% on the west side). On the west side of Corsica, however, coastal precipitation events are seldom and less intense than further inland, which can be attributed to the influence of the topography in frontal passages. KW - Corsica KW - Mediterranean KW - precipitation KW - principal component analysis KW - ERA-5 KW - clustering KW - local wind systems Y1 - 2020 U6 - https://doi.org/10.3390/atmos11040417 VL - 11 IS - 4 ER -