TY - JOUR A1 - Schittko, Conrad A1 - Bernard-Verdier, Maud A1 - Heger, Tina A1 - Buchholz, Sascha A1 - Kowarik, Ingo A1 - von der Lippe, Moritz A1 - Seitz, Birgit A1 - Joshi, Jasmin Radha A1 - Jeschke, Jonathan M. T1 - A multidimensional framework for measuring biotic novelty: How novel is a community? JF - Global Change Biology N2 - Anthropogenic changes in climate, land use, and disturbance regimes, as well as introductions of non-native species can lead to the transformation of many ecosystems. The resulting novel ecosystems are usually characterized by species assemblages that have not occurred previously in a given area. Quantifying the ecological novelty of communities (i.e., biotic novelty) would enhance the understanding of environmental change. However, quantification remains challenging since current novelty metrics, such as the number and/or proportion of non-native species in a community, fall short of considering both functional and evolutionary aspects of biotic novelty. Here, we propose the Biotic Novelty Index (BNI), an intuitive and flexible multidimensional measure that combines (a) functional differences between native and non-native introduced species with (b) temporal dynamics of species introductions. We show that the BNI is an additive partition of Rao's quadratic entropy, capturing the novel interaction component of the community's functional diversity. Simulations show that the index varies predictably with the relative amount of functional novelty added by recently arrived species, and they illustrate the need to provide an additional standardized version of the index. We present a detailed R code and two applications of the BNI by (a) measuring changes of biotic novelty of dry grassland plant communities along an urbanization gradient in a metropolitan region and (b) determining the biotic novelty of plant species assemblages at a national scale. The results illustrate the applicability of the index across scales and its flexibility in the use of data of different quality. Both case studies revealed strong connections between biotic novelty and increasing urbanization, a measure of abiotic novelty. We conclude that the BNI framework may help building a basis for better understanding the ecological and evolutionary consequences of global change. KW - alien species KW - biological invasions KW - coexistence KW - ecological novelty KW - functional diversity KW - novel ecosystems KW - novel species KW - standard metrics Y1 - 2019 VL - 26 IS - 8 PB - John Wiley & Sons, Inc. CY - New Jersey ER - TY - GEN A1 - Schittko, Conrad A1 - Bernard-Verdier, Maud A1 - Heger, Tina A1 - Buchholz, Sascha A1 - Kowarik, Ingo A1 - von der Lippe, Moritz A1 - Seitz, Birgit A1 - Joshi, Jasmin Radha A1 - Jeschke, Jonathan M. T1 - A multidimensional framework for measuring biotic novelty: How novel is a community? T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Anthropogenic changes in climate, land use, and disturbance regimes, as well as introductions of non-native species can lead to the transformation of many ecosystems. The resulting novel ecosystems are usually characterized by species assemblages that have not occurred previously in a given area. Quantifying the ecological novelty of communities (i.e., biotic novelty) would enhance the understanding of environmental change. However, quantification remains challenging since current novelty metrics, such as the number and/or proportion of non-native species in a community, fall short of considering both functional and evolutionary aspects of biotic novelty. Here, we propose the Biotic Novelty Index (BNI), an intuitive and flexible multidimensional measure that combines (a) functional differences between native and non-native introduced species with (b) temporal dynamics of species introductions. We show that the BNI is an additive partition of Rao's quadratic entropy, capturing the novel interaction component of the community's functional diversity. Simulations show that the index varies predictably with the relative amount of functional novelty added by recently arrived species, and they illustrate the need to provide an additional standardized version of the index. We present a detailed R code and two applications of the BNI by (a) measuring changes of biotic novelty of dry grassland plant communities along an urbanization gradient in a metropolitan region and (b) determining the biotic novelty of plant species assemblages at a national scale. The results illustrate the applicability of the index across scales and its flexibility in the use of data of different quality. Both case studies revealed strong connections between biotic novelty and increasing urbanization, a measure of abiotic novelty. We conclude that the BNI framework may help building a basis for better understanding the ecological and evolutionary consequences of global change. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1209 KW - alien species KW - biological invasions KW - coexistence KW - ecological novelty KW - functional diversity KW - novel ecosystems KW - novel species KW - standard metrics Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-525657 SN - 1866-8372 IS - 8 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 -