@misc{RisseBuhlOpreiMutz, author = {Risse-Buhl, Ute and Oprei, Anna and Mutz, Michael}, title = {Streambed migration frequency drives ecology and biogeochemistry across spatial scales}, series = {WIREs Water}, volume = {10}, journal = {WIREs Water}, number = {3}, issn = {2049-1948}, doi = {10.1002/wat2.1632}, language = {en} } @misc{OpreiSchreckingerFranzmannetal., author = {Oprei, Anna and Schreckinger, Jose and Franzmann, Insa and Lee, Hayoung and Mutz, Michael and Risse-Buhl, Ute}, title = {Light over mechanics: microbial community structure and activity in simulated migrating bedforms are controlled by oscillating light rather than by mechanical forces}, series = {FEMS Microbiology Ecology}, volume = {100}, journal = {FEMS Microbiology Ecology}, number = {6}, issn = {0168-6496}, doi = {10.1093/femsec/fiae073}, pages = {15}, language = {en} } @misc{OpreiSchreckingerMutzetal., author = {Oprei, Anna and Schreckinger, Jos{\´e} and Mutz, Michael and Kamjunke, Norbert and Worrich, Anja and Risse-Buhl, Ute}, title = {Migrating ripples create streambed heterogeneity altering microbial diversity and metabolic activity}, series = {Limnology and Oceanography}, volume = {69}, journal = {Limnology and Oceanography}, number = {8}, issn = {1939-5590}, doi = {10.1002/lno.12631}, pages = {1882 -- 1899}, language = {en} } @misc{OpreiSchreckingerKholiavkoetal., author = {Oprei, Anna and Schreckinger, Jos{\´e} and Kholiavko, Tatiana and Frossard, Aline and Mutz, Michael and Risse-Buhl, Ute}, title = {Long-term functional recovery and associated microbial community structure after sediment drying and bedform migration}, series = {Frontiers in Ecology and Evolution}, volume = {Vol. 11}, journal = {Frontiers in Ecology and Evolution}, issn = {2296-701X}, doi = {10.3389/fevo.2023.1112519}, abstract = {Climate change and erosion from agricultural areas cause increased drying periods and bedform migration of riverbeds, respectively, worldwide. Both sediment drying and bedform migration can independently stress the microbial community residing in the riverbed. Here, we investigated the microbial response after exposure to these stressors with a focus on long-term recovery. We conducted an in situ experiment to investigate the long-term (8 months) functional and structural recovery of benthic microbial communities from either sediment drying (episodic severe stressor) or bedform migration (frequent moderate stressor). Stressed sediment associated communities were rewetted (dried sediments) and immobilized (migrated sediments) and exposed in the River Spree (north-eastern Germany) to initiate the recovery process. We then evaluated the microbial function (community respiration, net community production and extracellular enzymatic activities) as well as the bacterial, fungal and diatom community structure (16S rRNA gene and ITS region metabarcoding, and microscopic diatom morphotype classification). We observed different recovery times for community respiration (less than 7 days) and gross primary production (more than 5 months), implying a shift toward net heterotrophy in the first few months after stress exposure. Similarly, we observed a strong autotrophic community response (particularly associated with the diatoms Navicula and Fragilaria), especially in migrated sediments. The bacterial and fungal community response to sediment drying was stronger than to bedform migration (particularly associated with the bacterium Flavobacterium and the fungi Alternaria sp. and Aureobasidium pullulans). Our results show that sediment drying and bedform migration had a significant impact on the microbial community function and structure, which persisted for several months after the stress. Due to the surprising long period of recovery, successive stress events combined with seasonal effects will likely hamper the ongoing recovery process with severe alterations to the microbial function and structure. These findings extend the concept of ecosystem resilience and stability on the dimensions of timescale and seasonal environmental variations. Legacy effects are expected to play a key role when facing future stress.}, language = {en} } @misc{OpreiSchreckingerKholiavkoetal., author = {Oprei, Anna and Schreckinger, Jos{\´e} and Kholiavko, Tatiana and Frossard, Aline and Mutz, Michael}, title = {Functional and structural recovery of stream biofilms at the habitat scale is based on the individual disturbance history}, series = {Ergebnisse der Jahrestagung 2019 in M{\"u}nster}, journal = {Ergebnisse der Jahrestagung 2019 in M{\"u}nster}, publisher = {Eigenverlag der DGL}, address = {Essen}, isbn = {978-3-9818302-4-8}, pages = {216}, language = {en} } @misc{OpreiFranzmannSchreckingeretal., author = {Oprei, Anna and Franzmann, Insa and Schreckinger, Jos{\´e} and Mutz, Micheal}, title = {From soil to sediment : bedform migration shapes microbial communities from eroding bank soil during terrestrial-aquatic regime shift}, series = {Journal of geophysical research: biogeosciences}, volume = {130}, journal = {Journal of geophysical research: biogeosciences}, number = {10}, publisher = {Wiley}, address = {Hoboken, NJ}, issn = {2169-8961}, doi = {10.1029/2024JG008549}, pages = {1 -- 18}, abstract = {Soil erosion from riverbanks is a common phenomenon in sandy streams and rivers and has intensified in the last decades due to land use change. When entering the aquatic environment, incoming soil is mixed with benthic sediments, and the microbial community undergoes a terrestrial-aquatic transition. Aquatic sediments in sand-dominated streams are frequently transported as migrating ripples, where microbes adhering to sand grains experience migrating-resting cycles in the range of minutes to hours. Despite the ubiquitous co-occurrence of riverbank erosion and migrating bedforms in sand-dominated streams, we lack a general understanding of how sediment transport at low flow influences the terrestrial-aquatic habitat transition. In a microcosm experiment, we compared purely aquatic sediment with a mix from riverbank soil and aquatic sediment. We tested the effect of simulated ripple migration on both sediment types compared to stationary conditions. We estimated α- and β-diversity, abundance, community respiration, and net ecosystem production for bacteria, fungi, and diatoms. Our results show that high richness and abundance of the terrestrial community, especially fungi, were lost after the aquatic transition. The succession of bacteria and fungi, which behaved more like habitat specialists, was not measurably influenced by sediment transport, but showed a distinct shift from a terrestrial to an aquatic community. In contrast, the diatom community was dominated by habitat generalists. Final community respiration and net ecosystem production in the mixed sediments were lower compared to aquatic sediments. Our findings highlight that further studies need to include spatiotemporal patterns of sediment transport when investigating terrestrial-aquatic habitat transitions.}, language = {en} }