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 - INPR A1 - Cierjacks, Arne A1 - Kowarik, Ingo A1 - Joshi, Jasmin Radha A1 - Hempel, Stefan A1 - Ristow, Michael A1 - von der Lippe, Moritz A1 - Weber, Ewald T1 - Biological flora of the british isles: robinia pseudoacacia T2 - The journal of ecology N2 - This account presents information on all aspects of the biology of Robinia pseudoacacia L. that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, and history and conservation.Robinia pseudoacacia, false acacia or black locust, is a deciduous, broad-leaved tree native to North America. The medium-sized, fast-growing tree is armed with spines, and extensively suckering. It has become naturalized in grassland, semi-natural woodlands and urban habitats. The tree is common in the south of the British Isles and in many other regions of Europe.Robinia pseudoacacia is a light-demanding pioneer species, which occurs primarily in disturbed sites on fertile to poor soils. The tree does not tolerate wet or compacted soils. In contrast to its native range, where it rapidly colonizes forest gaps and is replaced after 15-30years by more competitive tree species, populations in the secondary range can persist for a longer time, probably due to release from natural enemies.Robinia pseudoacacia reproduces sexually, and asexually by underground runners. Disturbance favours clonal growth and leads to an increase in the number of ramets. Mechanical stem damage and fires also lead to increased clonal recruitment. The tree benefits from di-nitrogen fixation associated with symbiotic rhizobia in root nodules. Estimated symbiotic nitrogen fixation rates range widely from 23 to 300kgha(-1)year(-1). The nitrogen becomes available to other plants mainly by the rapid decay of nitrogen-rich leaves.Robinia pseudoacacia is host to a wide range of fungi both in the native and introduced ranges. Megaherbivores are of minor significance in Europe but browsing by ungulates occurs in the native range. Among insects, the North American black locust gall midge (Obolodiplosis robiniae) is specific to Robinia and is spreading rapidly throughout Europe. In parts of Europe, Robinia pseudoacacia is considered an invasive non-indigenous plant and the tree is controlled. Negative impacts include shading and changes of soil conditions as a result of nitrogen fixation. KW - climatic limitation KW - ecophysiology KW - geographical and altitudinal distribution KW - germination KW - invasive KW - mycorrhiza KW - nitrogen fixation KW - parasites and diseases KW - reproductive biology KW - soils Y1 - 2013 U6 - https://doi.org/10.1111/1365-2745.12162 SN - 0022-0477 SN - 1365-2745 VL - 101 IS - 6 SP - 1623 EP - 1640 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Jaric, Ivan A1 - Heger, Tina A1 - Monzon, Federico Castro A1 - Jeschke, Jonathan M. A1 - Kowarik, Ingo A1 - McConkey, Kim R. A1 - Pysek, Petr A1 - Sagouis, Alban A1 - Essl, Franz T1 - Crypticity in Biological Invasions JF - Trends in Ecology & Evolution N2 - Ecological effects of alien species can be dramatic, but management and prevention of negative impacts are often hindered by crypticity of the species or their ecological functions. Ecological functions can change dramatically over time, or manifest after long periods of an innocuous presence. Such cryptic processes may lead to an underestimation of long-term impacts and constrain management effectiveness. Here, we present a conceptual framework of crypticity in biological invasions. We identify the underlying mechanisms, provide evidence of their importance, and illustrate this phenomenon with case studies. This framework has potential to improve the recognition of the full risks and impacts of invasive species. Y1 - 2019 U6 - https://doi.org/10.1016/j.tree.2018.12.008 SN - 0169-5347 SN - 1872-8383 VL - 34 IS - 4 SP - 291 EP - 302 PB - Elsevier CY - London ER - TY - JOUR A1 - Schulz, Katharina A1 - Voigt, Karsten A1 - Beusch, Christine A1 - Almeida-Cortez, Jarcilene S. A1 - Kowarik, Ingo A1 - Walz, Ariane A1 - Cierjacks, Arne T1 - Grazing deteriorates the soil carbon stocks of Caatinga forest ecosystems in Brazil JF - Forest ecology and management N2 - Grazing by domestic ungulates can have substantial impacts on forests in arid and semi-arid regions, possibly including severe loss of carbon from the soil. Predicting net livestock impacts on soil organic carbon stocks remains challenging, however, due to the dependence on animal loads and on soil and environmental parameters. The objective of this study was to better understand grazing effects on soil organic carbon in seasonal tropical dry forests of north-eastern Brazil (Caatinga) by quantifying carbon stocks of the upper soil profile (0–5 cm depth) and greater soil depths (>5 cm depth down to bedrock) along a gradient of grazing intensity while accounting for other influencing factors such as soil texture, vegetation, landscape topography, and water availability. We analysed soil organic carbon, soil clay content, altitude above sea level, soil depth to bedrock, distance to the nearest permanent water body, species diversity of perennial plants and aboveground biomass on 45 study plots located in the vicinity of the Itaparica Reservoir, Pernambuco, Brazil. Livestock (mainly goats and cattle) are unevenly distributed in the studied ecosystem, thus grazing intensity was accounted for based on the weight of livestock droppings per square metre and classified as no or light, intermediate, or heavy grazing. The mean soil organic carbon in the area was 16.86 ± 1.28 Mg ha−1 C with approximately one-quarter found in the upper 5 cm of the soil profile (4.14 ± 0.43 Mg ha−1 C) and the remainder (12.57 ± 0.97 Mg ha−1 C) in greater soil depths (>5 cm). Heavy grazing led to significantly lower soil organic carbon stocks in the upper 5 cm, whereas no effect on soil organic carbon of the soil overall or in greater soil depths was detectable. The soil’s clay content and the altitude proved to be the most relevant factors influencing overall soil organic carbon stocks and those in greater soil depths (>5 cm). Our findings suggest that grazing causes substantial release of carbon from Brazilian dry forest soils, which should be addressed through improved grazing management via a legally compulsory rotation system. This would ultimately contribute to the conservation of a unique forest system and associated ecosystem services. KW - Carbon cycle KW - Degradation KW - Desertification KW - Livestock KW - Semi-arid KW - Soil Y1 - 2016 U6 - https://doi.org/10.1016/j.foreco.2016.02.011 SN - 0378-1127 SN - 1872-7042 VL - 367 SP - 62 EP - 70 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - von der Lippe, Moritz A1 - Bullock, James M. A1 - Kowarik, Ingo A1 - Knopp, Tatjana A1 - Wichmann, Matthias T1 - Human-mediated dispersal of seeds by the airflow of vehicles JF - PLoS one N2 - Human-mediated dispersal is known as an important driver of long-distance dispersal for plants but underlying mechanisms have rarely been assessed. Road corridors function as routes of secondary dispersal for many plant species but the extent to which vehicles support this process remains unclear. In this paper we quantify dispersal distances and seed deposition of plant species moved over the ground by the slipstream of passing cars. We exposed marked seeds of four species on a section of road and drove a car along the road at a speed of 48 km/h. By tracking seeds we quantified movement parallel as well as lateral to the road, resulting dispersal kernels, and the effect of repeated vehicle passes. Median distances travelled by seeds along the road were about eight meters for species with wind dispersal morphologies and one meter for species without such adaptations. Airflow created by the car lifted seeds and resulted in longitudinal dispersal. Single seeds reached our maximum measuring distance of 45 m and for some species exceeded distances under primary dispersal. Mathematical models were fit to dispersal kernels. The incremental effect of passing vehicles on longitudinal dispersal decreased with increasing number of passes as seeds accumulated at road verges. We conclude that dispersal by vehicle airflow facilitates seed movement along roads and accumulation of seeds in roadside habitats. Dispersal by vehicle airflow can aid the spread of plant species and thus has wide implications for roadside ecology, invasion biology and nature conservation. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0052733 SN - 1932-6203 VL - 8 IS - 1 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Horn, Sebastian A1 - Hempel, Stefan A1 - Ristow, Michael A1 - Rillig, Matthias C. A1 - Kowarik, Ingo A1 - Caruso, Tancredi T1 - Plant community assembly at small scales: Spatial vs. environmental factors in a European grassland JF - Acta oecologica : international journal of ecology N2 - Dispersal limitation and environmental conditions are crucial drivers of plant species distribution and establishment. As these factors operate at different spatial scales, we asked: Do the environmental factors known to determine community assembly at broad scales operate at fine scales (few meters)? How much do these factors account for community variation at fine scales? In which way do biotic and abiotic interactions drive changes in species composition? We surveyed the plant community within a dry grassland along a very steep gradient of soil characteristics like pH and nutrients. We used a spatially explicit sampling design, based on three replicated macroplots of 15 x 15, 12 x 12 and 12 x 12 m in extent. Soil samples were taken to quantify several soil properties (carbon, nitrogen, plant available phosphorus, pH, water content and dehydrogenase activity as a proxy for overall microbial activity). We performed variance partitioning to assess the effect of these variables on plant composition and statistically controlled for spatial autocorrelation via eigenvector mapping. We also applied null model analysis to test for non-random patterns in species co-occurrence using randomization schemes that account for patterns expected under species interactions. At a fine spatial scale, environmental factors explained 18% of variation when controlling for spatial autocorrelation in the distribution of plant species, whereas purely spatial processes accounted for 14% variation. Null model analysis showed that species spatially segregated in a non-random way and these spatial patterns could be due to a combination of environmental filtering and biotic interactions. Our grassland study suggests that environmental factors found to be directly relevant in broad scale studies are present also at small scales, but are supplemented by spatial processes and more direct interactions like competition. (C) 2015 Elsevier Masson SAS. All rights reserved. KW - Assembly pattern KW - Dispersal limitation KW - Festuca brevipila KW - Niche partitioning KW - Null model KW - Plant community ecology KW - Variance partitioning Y1 - 2015 U6 - https://doi.org/10.1016/j.actao.2015.01.004 SN - 1146-609X SN - 1873-6238 VL - 63 SP - 56 EP - 62 PB - Elsevier CY - Paris 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 -