Browsing by Author "Pysek, P."

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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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    Four priority areas to advance invasion science in the face of rapid environmental change
    (Canadian Science Publishing, 2021) Ricciardi, A.; Iacarella, J. C.; Aldridge, D. C.; Blackburn, T. M.; Carlton, J. T.; Catford, J. A.; Dick, J. T. A.; Hulme, P. E.; Jeschke, J. M.; Liebhold, A. M.; Lockwood, J. L.; MacIsaac, H. J.; Meyerson, L. A.; Pysek, P.; Richardson, D. M.; Ruiz, G. M.; Simberloff, D.; Vila, M.; Wardle, D. A.
    Unprecedented rates of introduction and spread of non-native species pose burgeoning challenges to biodiversity, natural resource management, regional economies, and human health. Current biosecurity efforts are failing to keep pace with globalization, revealing critical gaps in our understanding and response to invasions. Here, we identify four priority areas to advance invasion science in the face of rapid global environmental change. First, invasion science should strive to develop a more comprehensive framework for predicting how the behavior, abundance, and interspecific interactions of non-native species vary in relation to conditions in receiving environments and how these factors govern the ecological impacts of invasion. A second priority is to understand the potential synergistic effects of multiple co-occurring stressors— particularly involving climate change—on the establishment and impact of non-native species. Climate adaptation and mitigation strategies will need to consider the possible consequences of promoting non-native species, and appropriate management responses to non-native species will need to be developed. The third priority is to address the taxonomic impediment. The ability to detect and evaluate invasion risks is compromised by a growing deficit in taxonomic expertise, which cannot be adequately compensated by new molecular technologies alone. Management of biosecurity risks will become increasingly challenging unless academia, industry, and governments train and employ new personnel in taxonomy and systematics. Fourth, we recommend that internationally cooperative biosecurity strategies consider the bridgehead effects of global dispersal networks, in which organisms tend to invade new regions from locations where they have already established. Cooperation among countries to eradicate or control species established in bridgehead regions should yield greater benefit than independent attempts by individual countries to exclude these species from arriving and establishing.
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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.
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    Predicting incursion of plant invaders into Kruger National Park, South Africa : the interplay of general drivers and species-specific factors
    (PLOS, 2011-12) Jarosik, V.; Pysek, P.; Foxcroft, L. C.; Richardson, David M.; Rouget, M.; MacFadyen, S.
    Background: Overcoming boundaries is crucial for incursion of alien plant species and their successful naturalization and invasion within protected areas. Previous work showed that in Kruger National Park, South Africa, this process can be quantified and that factors determining the incursion of invasive species can be identified and predicted confidently. Here we explore the similarity between determinants of incursions identified by the general model based on a multispecies assemblage, and those identified by species-specific models. We analyzed the presence and absence of six invasive plant species in 1.061.5 km segments along the border of the park as a function of environmental characteristics from outside and inside the KNP boundary, using two data-mining techniques: classification trees and random forests. Principal Findings: The occurrence of Ageratum houstonianum, Chromolaena odorata, Xanthium strumarium, Argemone ochroleuca, Opuntia stricta and Lantana camara can be reliably predicted based on landscape characteristics identified by the general multispecies model, namely water runoff from surrounding watersheds and road density in a 10 km radius. The presence of main rivers and species-specific combinations of vegetation types are reliable predictors from inside the park. Conclusions: The predictors from the outside and inside of the park are complementary, and are approximately equally reliable for explaining the presence/absence of current invaders; those from the inside are, however, more reliable for predicting future invasions. Landscape characteristics determined as crucial predictors from outside the KNP serve as guidelines for management to enact proactive interventions to manipulate landscape features near the KNP to prevent further incursions. Predictors from the inside the KNP can be used reliably to identify high-risk areas to improve the costeffectiveness of management, to locate invasive plants and target them for eradication.