@article{NwosuBrauerKaiseretal.2021, author = {Nwosu, Ebuka Canisius and Brauer, Achim and Kaiser, J{\´e}r{\^o}me and Horn, Fabian and Wagner, Dirk and Liebner, Susanne}, title = {Evaluating sedimentary DNA for tracing changes in cyanobacteria dynamics from sediments spanning the last 350 years of Lake Tiefer See, NE Germany}, series = {Journal of paleolimnology}, volume = {66}, journal = {Journal of paleolimnology}, number = {3}, publisher = {Springer}, address = {Dordrecht}, issn = {0921-2728}, doi = {10.1007/s10933-021-00206-9}, pages = {279 -- 296}, year = {2021}, abstract = {Since the beginning of the Anthropocene, lacustrine biodiversity has been influenced by climate change and human activities. These factors advance the spread of harmful cyanobacteria in lakes around the world, which affects water quality and impairs the aquatic food chain. In this study, we assessed changes in cyanobacterial community dynamics via sedimentary DNA (sedaDNA) from well-dated lake sediments of Lake Tiefer See, which is part of the Klocksin Lake Chain spanning the last 350 years. Our diversity and community analysis revealed that cyanobacterial communities form clusters according to the presence or absence of varves. Based on distance-based redundancy and variation partitioning analyses (dbRDA and VPA) we identified that intensified lake circulation inferred from vegetation openness reconstructions, delta C-13 data (a proxy for varve preservation) and total nitrogen content were abiotic factors that significantly explained the variation in the reconstructed cyanobacterial community from Lake Tiefer See sediments. Operational taxonomic units (OTUs) assigned to Microcystis sp. and Aphanizomenon sp. were identified as potential eutrophication-driven taxa of growing importance since circa common era (ca. CE) 1920 till present. This result is corroborated by a cyanobacteria lipid biomarker analysis. Furthermore, we suggest that stronger lake circulation as indicated by non-varved sediments favoured the deposition of the non-photosynthetic cyanobacteria sister clade Sericytochromatia, whereas lake bottom anoxia as indicated by subrecent- and recent varves favoured the Melainabacteria in sediments. Our findings highlight the potential of high-resolution amplicon sequencing in investigating the dynamics of past cyanobacterial communities in lake sediments and show that lake circulation, anoxic conditions, and human-induced eutrophication are main factors explaining variations in the cyanobacteria community in Lake Tiefer See during the last 350 years.}, language = {en} } @article{SteffenRoeckstromRichardsonetal.2018, author = {Steffen, Will and R{\"o}ckstrom, Johan and Richardson, Katherine and Lenton, Timothy M. and Folke, Carl and Liverman, Diana and Summerhayes, Colin P. and Barnosky, Anthony D. and Cornell, Sarah E. and Crucifix, Michel and Donges, Jonathan Friedemann and Fetzer, Ingo and Lade, Steven J. and Scheffer, Marten and Winkelmann, Ricarda and Schellnhuber, Hans Joachim}, title = {Trajectories of the Earth System in the Anthropocene}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {33}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1810141115}, pages = {8252 -- 8259}, year = {2018}, abstract = {We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a "Hothouse Earth" pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene. We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies. Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System-biosphere, climate, and societies-and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values.}, language = {en} } @article{HegerBernardVerdierGessleretal.2019, author = {Heger, Tina and Bernard-Verdier, Maud and Gessler, Arthur and Greenwood, Alex D. and Grossart, Hans-Peter and Hilker, Monika and Keinath, Silvia and Kowarik, Ingo and K{\"u}ffer, Christoph and Marquard, Elisabeth and Mueller, Johannes and Niemeier, Stephanie and Onandia, Gabriela and Petermann, Jana S. and Rillig, Matthias C. and Rodel, Mark-Oliver and Saul, Wolf-Christian and Schittko, Conrad and Tockner, Klement and Joshi, Jasmin Radha and Jeschke, Jonathan M.}, title = {Towards an Integrative, Eco-Evolutionary Understanding of Ecological Novelty: Studying and Communicating Interlinked Effects of Global Change}, series = {Bioscience}, volume = {69}, journal = {Bioscience}, number = {11}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0006-3568}, doi = {10.1093/biosci/biz095}, pages = {888 -- 899}, year = {2019}, abstract = {Global change has complex eco-evolutionary consequences for organisms and ecosystems, but related concepts (e.g., novel ecosystems) do not cover their full range. Here we propose an umbrella concept of "ecological novelty" comprising (1) a site-specific and (2) an organism-centered, eco-evolutionary perspective. Under this umbrella, complementary options for studying and communicating effects of global change on organisms, ecosystems, and landscapes can be included in a toolbox. This allows researchers to address ecological novelty from different perspectives, e.g., by defining it based on (a) categorical or continuous measures, (b) reference conditions related to sites or organisms, and (c) types of human activities. We suggest striving for a descriptive, non-normative usage of the term "ecological novelty" in science. Normative evaluations and decisions about conservation policies or management are important, but require additional societal processes and engagement with multiple stakeholders.}, language = {en} }