TY - JOUR A1 - Steffen, Will A1 - Röckstrom, Johan A1 - Richardson, Katherine A1 - Lenton, Timothy M. A1 - Folke, Carl A1 - Liverman, Diana A1 - Summerhayes, Colin P. A1 - Barnosky, Anthony D. A1 - Cornell, Sarah E. A1 - Crucifix, Michel A1 - Donges, Jonathan A1 - Fetzer, Ingo A1 - Lade, Steven J. A1 - Scheffer, Marten A1 - Winkelmann, Ricarda A1 - Schellnhuber, Hans Joachim T1 - Trajectories of the Earth System in the Anthropocene JF - Proceedings of the National Academy of Sciences of the United States of America N2 - 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. KW - Earth System trajectories KW - climate change KW - Anthropocene KW - biosphere feedbacks KW - tipping elements Y1 - 2018 U6 - https://doi.org/10.1073/pnas.1810141115 SN - 0027-8424 VL - 115 IS - 33 SP - 8252 EP - 8259 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Heger, Tina A1 - Bernard-Verdier, Maud A1 - Gessler, Arthur A1 - Greenwood, Alex D. A1 - Grossart, Hans-Peter A1 - Hilker, Monika A1 - Keinath, Silvia A1 - Kowarik, Ingo A1 - Küffer, Christoph A1 - Marquard, Elisabeth A1 - Mueller, Johannes A1 - Niemeier, Stephanie A1 - Onandia, Gabriela A1 - Petermann, Jana S. A1 - Rillig, Matthias C. A1 - Rodel, Mark-Oliver A1 - Saul, Wolf-Christian A1 - Schittko, Conrad A1 - Tockner, Klement A1 - Joshi, Jasmin Radha A1 - Jeschke, Jonathan M. T1 - Towards an Integrative, Eco-Evolutionary Understanding of Ecological Novelty: Studying and Communicating Interlinked Effects of Global Change JF - Bioscience N2 - 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. KW - Anthropocene KW - eco-evolutionary experience KW - global change KW - novel ecosystems KW - shifting baselines Y1 - 2019 U6 - https://doi.org/10.1093/biosci/biz095 SN - 0006-3568 SN - 1525-3244 VL - 69 IS - 11 SP - 888 EP - 899 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Nwosu, Ebuka Canisius A1 - Brauer, Achim A1 - Kaiser, Jérôme A1 - Horn, Fabian A1 - Wagner, Dirk A1 - Liebner, Susanne T1 - Evaluating sedimentary DNA for tracing changes in cyanobacteria dynamics from sediments spanning the last 350 years of Lake Tiefer See, NE Germany JF - Journal of paleolimnology N2 - 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. KW - Late Holocene KW - Methylheptadecanes KW - Varves KW - Anthropocene KW - Sericytochromatia KW - Melainabacteria Y1 - 2021 U6 - https://doi.org/10.1007/s10933-021-00206-9 SN - 0921-2728 SN - 1573-0417 VL - 66 IS - 3 SP - 279 EP - 296 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Schittko, Conrad A1 - Onandia, Gabriela A1 - Bernard-Verdier, Maud A1 - Heger, Tina A1 - Jeschke, Jonathan M. A1 - Kowarik, Ingo A1 - Maaß, Stefanie A1 - Joshi, Jasmin T1 - Biodiversity maintains soil multifunctionality and soil organic carbon in novel urban ecosystems JF - Journal of ecology N2 - Biodiversity in urban ecosystems has the potential to increase ecosystem functions and support a suite of services valued by society, including services provided by soils. Specifically, the sequestration of carbon in soils has often been advocated as a solution to mitigate the steady increase in CO2 concentration in the atmosphere as a key driver of climate change. However, urban ecosystems are also characterized by an often high level of ecological novelty due to profound human-mediated changes, such as the presence of high numbers of non-native species, impervious surfaces or other disturbances. Yet it is poorly understood whether and how biodiversity affects ecosystem functioning and services of urban soils under these novel conditions. In this study, we assessed the influence of above- and below-ground diversity, as well as urbanization and plant invasions, on multifunctionality and organic carbon stocks of soils in non-manipulated grasslands along an urbanization gradient in Berlin, Germany. We focused on plant diversity (measured as species richness and functional trait diversity) and, in addition, on soil organism diversity as a potential mediator for the relationship of plant species diversity and ecosystem functioning. Our results showed positive effects of plant diversity on soil multifunctionality and soil organic carbon stocks along the entire gradient. Structural equation models revealed that plant diversity enhanced soil multifunctionality and soil organic carbon by increasing the diversity of below-ground organisms. These positive effects of plant diversity on soil multifunctionality and soil fauna were not restricted to native plant species only, but were also exerted by non-native species, although to a lesser degree. Synthesis. We conclude that enhancing diversity in plants and soil fauna of urban grasslands can increase the multifunctionality of urban soils and also add to their often underestimated but very valuable role in mitigating effects of climate change. KW - Anthropocene KW - biological invasions KW - ecosystem function and services; KW - functional diversity KW - global change KW - non-native species KW - novel KW - ecosystems KW - urbanization Y1 - 2022 U6 - https://doi.org/10.1111/1365-2745.13852 SN - 0022-0477 SN - 1365-2745 VL - 110 IS - 4 SP - 916 EP - 934 PB - Wiley CY - Hoboken ER -