Browsing by Author "Dawson, W."

Now showing 1 - 4 of 4
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    A conceptual framework for prioritization of invasive alien species for management according to their impact
    (Pensoft, 2012-12-14) Kumschick, S.; Bacher, S.; Dawson, W.; Heikkila, J.; Sendek, A.; Pluess, T.; Robinson, T. B.; Kuhn, I.
    The number of invasive alien species is increasing and so are the impacts these species cause to the environment and economies. Nevertheless, resources for management are limited, which makes prioritization unavoidable. We present a prioritization framework which can be useful for decision makers as it includes both a scientific impact assessment and the evaluation of impact importance by affected stakeholders. The framework is divided into five steps, namely 1) stakeholder selection and weighting of stakeholder importance by the decision maker, 2) factual description and scoring of changes by scientists, 3) evaluation of the importance of impact categories by stakeholders, 4) calculation of weighted impact categories and 5) calculation of final impact score and decision making. The framework could be used at different scales and by different authorities. Furthermore, it would make the decision making process transparent and retraceable for all stakeholders and the general public.
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    Drivers of the relative richness of naturalized and invasive plant species on Earth
    (Oxford University Press, 2019) Essl, F.; Dawson, W.; Kreft, H.; Pergl, J.; Pysek, P.; Van Kleunen, M.; Weigelt, P.; Mang, T.; Dullinger, S.; Lenzner, B.; Moser, D.; Maurel, N.; Seebens, H.; Stein, A.; Weber, E.; Chatelain, C.; Inderjit; Genovesi, P.; Kartesz, J.; Morozova, O.; Nishino, M.; Nowak, P.; Pagad, S.; Shu, W.S.; Winter, M.
    ENGLISH ABSTRACT: Biological invasions are a defining feature of the Anthropocene, but the factors that determine the spatially uneven distribution of alien plant species are still poorly understood. Here, we present the first global analysis of the effects of biogeographic factors, the physical environment and socio-economy on the richness of naturalized and invasive alien plants. We used generalized linear mixed-effects models and variation partitioning to disentangle the relative importance of individual factors, and, more broadly, of biogeography, physical environment and socio-economy. As measures of the magnitude of permanent anthropogenic additions to the regional species pool and of species with negative environmental impacts, we calculated the relative richness of naturalized (= RRN) and invasive (= RRI) alien plant species numbers adjusted for the number of native species in 838 terrestrial regions. Socio-economic factors (per-capita gross domestic product (GDP), population density, proportion of agricultural land) were more important in explaining RRI (~50 % of the explained variation) than RRN (~40 %). Warm-temperate and (sub)tropical regions have higher RRN than tropical or cooler regions. We found that socio-economic pressures are more relevant for invasive than for naturalized species richness. The expectation that the southern hemisphere is more invaded than the northern hemisphere was confirmed only for RRN on islands, but not for mainland regions nor for RRI. On average, islands have ~6-fold RRN, and >3-fold RRI compared to mainland regions. Eighty-two islands (=26 % of all islands) harbour more naturalized alien than native plants. Our findings challenge the widely held expectation that socio-economic pressures are more relevant for plant naturalization than for invasive plants. To meet international biodiversity targets and halt the detrimental consequences of plant invasions, it is essential to disrupt the connection between socio-economic development and plant invasions by improving pathway management, early detection and rapid response.
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    No saturation in the accumulation of alien species worldwide
    (Nature Research (part of Springer Nature), 2017) Seebens, Hanno; Blackburn, T. M.; Dyer, E. E.; Genovesi, P.; Hulme, P. E.; Jeschke, J. M.; Pagad, S.; Pysek, P.; Winter, M.; Arianoutsou, M.; Bacher, S.; Blasius, B.; Brundu, G.; Capinha, G.; Celesti-Grapow, L.; Dawson, W.; Dullinger, S.; Fuentes, N.; Jager, H.; Kartesz, J.; Kenis, M.; Kreft, H.; Kuhn, I; Lenzner, B.; Liebhold, A.; Mosena, A.; Moser, D.; Nishino, M.; Pearman, D.; Pergl, J.; Rabitsch, W.; Rojas-Sandoval, J.; Roques, A.; Rorke, S.; Rossinelli, S.; Roy, H. E.; Scalera, R.; Schindler, S.; Stajerova, K.; Tokarska-Guzik, B.; Van Kleunen, M.; Walker, K.; Weigelt, P.; Yamanaka, T.; Essl, F.
    Although research on human-mediated exchanges of species has substantially intensified during the last centuries, we know surprisingly little about temporal dynamics of alien species accumulations across regions and taxa. Using a novel database of 45,813 first records of 16,926 established alien species, we show that the annual rate of first records worldwide has increased during the last 200 years, with 37% of all first records reported most recently (1970–2014). Inter-continental and inter-taxonomic variation can be largely attributed to the diaspora of European settlers in the nineteenth century and to the acceleration in trade in the twentieth century. For all taxonomic groups, the increase in numbers of alien species does not show any sign of saturation and most taxa even show increases in the rate of first records over time. This highlights that past efforts to mitigate invasions have not been effective enough to keep up with increasing globalization.
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    Plants capable of selfing are more likely to become naturalized
    (Nature Publishing Group, 2016) Razanajatovo, M.; Maurel, N.; Dawson, W.; Essl, F.; Kreft, H.; Pergl, J.; Pysek, P.; Weigelt, P.; Winter, M.; Van Kleunen, M.
    Many plant species have established self-sustaining populations outside their natural range because of human activities. Plants with selfing ability should be more likely to establish outside their historical range because they can reproduce from a single individual when mates or pollinators are not available. Here, we compile a global breeding-system database of 1,752 angiosperm species and use phylogenetic generalized linear models and path analyses to test relationships between selfing ability, life history, native range size and global naturalization status. Selfing ability is associated with annual or biennial life history and a large native range, which both positively correlate with the probability of naturalization. Path analysis suggests that a high selfing ability directly increases the number of regions where a species is naturalized. Our results provide robust evidence across flowering plants at the global scale that high selfing ability fosters alien plant naturalization both directly and indirectly.