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The management of invasive alien species (IAS) in protected areas has become increasingly important in recent years. In this study, we analyse IAS management in the bilateral National Park Thayatal-Podyjí at the Austrian-Czech border. Based on two surveys from the years 2001 and 2010 and on annual management data from 2001-2010 we analyse changes in distribution and the efficiency of IAS management of three invasive alien plants (Fallopia × bohemica, Impatiens glandulifera, Robinia pseudoacacia). In 2010, the three study species had invaded 161 ha (2%) of the study area. Despite a decade of management, F. × bohemica has become widespread, whereas I. glandulifera distribution has decreased strongly. The most widespread species, R. pseudoacacia, has declined substantially in cover, but the area invaded has increased. From 2001 to 2010, annual management effort declined by about half. Management effort per hectare and decade was highest for F. × bohemica (2,657 hours), followed by R. pseudoacacia (1,473 hours) and I. glandulifera (270 hours). Management effort for achieving the same amount of reduction in population size and cover was highest for R. pseudoacacia, followed by F. × bohemica and I. glandulifera. We conclude that substantial effort and resources are necessary to successfully manage the study species and have to be provided over prolonged time periods, and thus continued management of these species is recommended. We highly recommend a systematic approach for monitoring the efficiency of IAS management projects in protected areas.
The Editorial presents the focus, scope, policies, and the inaugural issue of NeoBiota, a new open access peer-reviewed journal of biological invasions. The new journal NeoBiota is a continuation of the former NEOBIOTA publication series. The journal will deal with all aspects of invasion biology and impose no restrictions on manuscript size neither on use of color. NeoBiota implies an XML-based editorial workflow and several cutting-edge innovations in publishing and dissemination, such as semantic markup of and enhancements to published texts, data publication, and extensive cross-linking within the journal and to external sources.
Central European temperate forests are – with the exception of floodplain forests – relatively little invaded by alien plants. However, despite substantial recent progress, there is still a lack of using vege-tation plot data for analyzing spatio-temporal patterns of alien tree species invasions.
We calculated relevé-based metrics of tree species’ ecological preferences using 19,413 phytosociological forest relevés of the Austrian vegetation database. We focused on the five most widely distributed alien trees, i.e. two archaeophytes (Castanea sativa, Juglans regia) and three neophytes (Acer negundo, Ailanthus altissima, Robinia pseudoacacia). For each of these species we analyzed the mean cover in the tree layer and the occurrence in the herb and shrub layers in relevés colonized by adult trees as a measure for persistence. Further, we evaluated the intergenerational ecological plasticity (= the ability of young trees to grow under different site conditions than adults) for the tree species, and the mean relevé indicator values for light, nutrients, moisture and hemeroby. We then compared these alien and native tree species metrics.
We found that A. altissima and R. pseudoacacia build up high mean cover values in invaded forests, but this was not the case for the other alien trees. Thus, both species strongly affected forest communities of invaded sites. Similarly, the two species were common in the lower vegetation layers indicating recruitment under the canopy of adult conspecifics; this was facilitated by their ability to produce root suckers. Highest values of inter-generational ecological plasticity occurred in native pioneer trees and species of softwood floodplain forests, while alien trees had moderately high (A. negundo, A. altissima, J. regia) to low values (C. sativa, R. pseudoacacia). With the exception of C. sativa, all alien species showed high mean Ellenberg indicator values for light and nutrients, and were more common in sites with high hemeroby and high mean Ellenberg indicator values for temperature. Distinct from the ecological preferences of alien trees, and thus rarely invaded, were montane beech forests, coniferous mountain forests and forests at extremely dry sites, as well as swamp and bog forests dominated by willows and ash.
We conclude that relevé-based metrics of the behavior of alien tree species allow new insights into the spatio-temporal dynamics of invasion of woody species in forests. Future work should expand this approach, e.g., by considering the role of life history traits and actual site conditions.
Im allgemeinen Teil der Arbeit wird ein ausführlicher Literaturüberblick über den Verlauf der Ausbreitung der Aleppohirse (Sorghum halepense) in Mitteleuropa mit besonderer Berücksichtigung von Österreich gegeben. Aus der floristischen Literatur lässt sich seit Mitte der 1990er Jahre eine zunehmende Ausbreitung in Österreich und Deutschland ableiten. Diese wird begleitet von einer zunehmenden Einbürgerung in den warmen Gebieten Mitteleuropas. Eine wesentliche Ursache für diese Ausbreitung wird in den steigenden Jahresmitteltemperaturen vermutet.
Im speziellen Teil werden die Ergebnisse einer regionalen Fallstudie aus einem etwa 215 km2 großen Untersuchungsgebiet im östlichen oberösterreichischen Alpenvorland vorgestellt. Dort ist die Aleppohirse erstmals im Jahr 2000 mit zwei Beständen aufgetreten, im Jahr 2003 wurden 13 Vorkommen dokumentiert. Die Ausbreitung erfolgte v.a. entlang von Straßen, die Länge der von Sorghum halepense besiedelten Straßenbankette stieg von 600 m (2000) auf 7800 m (2003) an. Im gleichen Zeitraum nahm der Gesamtbestand von 15 auf 232 blühende Pflanzen zu.
Für die Ausbreitung im Untersuchungsgebiet kommt Straßenbanketten eine zentrale Rolle zu. Es wird vermutet, dass die Korridorfunktion, die günstigen Standortseigenschaften (Nährstoffgehalt, Wasserversorgung), das Störungsregime (gelegentliche Bodenverwundung, Mahd) und eventuell auch die Verschleppung von Diasporen durch Häckseln die große Bedeutung der Straßenbankette begründen. Dabei wird eine ein- bis zweischürige Mahd toleriert und hindert die Art nicht an einer raschen Ausbreitung. Der pflanzensoziologische Anschluss wurde mit 18 Vegetationsaufnahmen dokumentiert. Im Untersuchungsgebiet liegt der Verbreitungsschwerpunkt im Tanaceto-Arrhenatheretum von Straßenbanketten. Deutlich seltener tritt die Art im Echinochloo-Setarietum pumilae von Ackerbrachen auf.
Die Aleppohirse tritt in Mitteleuropa in nährstoffreichen Lebensräumen auf, die naturschutzfachlich von geringer Bedeutung und nicht gefährdet sind. Somit sind auch bei weiterer Ausbreitung keine Naturschutzprobleme zu erwarten. Bei häufigem Auftreten gilt die Aleppohirse in Ackern Südeuropas als problematisches Unkraut. Daher sind bei einer weiteren starken Ausbreitung ökonomische Probleme v.a. im Maisanbau wenigstens regional in Mitteleuropa nicht auszuschließen.
Impacts of alien species on human health have recently become a major issue in medical research and invasion ecology, but comprehensive assessments of this subject are largely lacking. Here, we provide a literature review of alien species with public health impacts in Europe based on a systematic search in the Thomson Reuters Web of Science. We detected 77 relevant articles, of which 21 were reviews and 56 were original research articles. The taxonomic focus was on vascular plants (n=31 articles) and dipterans (n=25 articles). The original research articles mainly covered the spread of the study species, while early invasion stages (introduction, establishment) as well as impact and management were less investigated. Alien species of health concern in Europe are mostly introduced as contaminants, and mostly originate from climatically similar regions of the Northern Hemisphere. In those cases (36% of all articles) when information on the trend in range and abundance was provided, this trend was mostly increasing. We detected little information on the severity of the impacts (two articles) and the interaction with climate change (three articles). In 15 original articles (28%) specific management measures were suggested, in only one article the socioeconomic costs were assessed. We conclude that European research on human health impacts of alien species is biased towards few species, and that several important aspects such as early invasion stages, severity of impact and its temporal trends, and the scale of the socioeconomic costs caused are poorly understood. Interdisciplinary projects bridging gaps between ecologists medical researchers, socioeconomists and public health authorities are required to link alien species to severity and trends of impacts, which is a crucial requisite for risk assessment and decision making.
Robust predictions of alien species richness are useful to assess global biodiversity change. Nevertheless, the capacity to predict spatial patterns of alien species richness remains largely unassessed. Using 22 data sets of alien species richness from diverse taxonomic groups and covering various parts of the world, we evaluated whether different statistical models were able to provide useful predictions of absolute and relative alien species richness, as a function of explanatory variables representing geographical, environmental and socio-economic factors. Five state-of-the-art count data modelling techniques were used and compared: Poisson and negative binomial generalised linear models (GLMs), multivariate adaptive regression splines (MARS), random forests (RF) and boosted regression trees (BRT). We found that predictions of absolute alien species richness had a low to moderate accuracy in the region where the models were developed and a consistently poor accuracy in new regions. Predictions of relative richness performed in a superior manner in both geographical settings, but still were not good. Flexible tree ensembles-type techniques (RF and BRT) were shown to be significantly better in modelling alien species richness than parametric linear models (such as GLM), despite the latter being more commonly applied for this purpose. Importantly, the poor spatial transferability of models also warrants caution in assuming the generality of the relationships they identify, e.g. by applying projections under future scenario conditions. Ultimately, our results strongly suggest that predictability of spatial variation in richness of alien species richness is limited. The somewhat more robust ability to rank regions according to the number of aliens they have (i.e. relative richness), suggests that models of aliens species richness may be useful for prioritising and comparing regions, but not for predicting exact species numbers.
Prioritization of introduction pathways is seen as an important component of the management of biological invasions. We address whether established alien plants, mammals, freshwater fish and terrestrial invertebrates with known ecological impacts are associated with particular introduction pathways (release, escape, contaminant, stowaway, corridor and unaided). We used the information from the European alien species database DAISIE (www.europe-aliens.org) supplemented by the EASIN catalogue (European Alien Species Information Network), and expert knowledge. Plants introduced by the pathways release, corridor and unaided were disproportionately more likely to have ecological impacts than those introduced as contaminants. In contrast, impacts were not associated with particular introduction pathways for invertebrates, mammals or fish. Thus, while for plants management strategies should be targeted towards the appropriate pathways, for animals, management should focus on reducing the total number of taxa introduced, targeting those pathways responsible for high numbers of introductions. However, regardless of taxonomic group, having multiple introduction pathways increases the likelihood of the species having an ecological impact. This may simply reflect that species introduced by multiple pathways have high propagule pressure and so have a high probability of establishment. Clearly, patterns of invasion are determined by many interacting factors and management strategies should reflect this complexity.
Die Strobe (Pinus strobus) ist in Mitteleuropa eine der forstwirtschaftlich bedeutendsten nichteinheimischen Baumarten. Einleitend wird in dieser Arbeit die Einfuhr- und Ausbreitungsgeschichte in Mitteleuropa dargestellt. Im speziellen Teil wird für Österreich eine Analyse der Ausbreitung durchgeführt. Derzeit kommt die Strobe in Österreich nur selten verwildert vor. Die Vorkommen beschränken sich auf einige Gebiete in den Bundesländern Oberösterreich, Niederösterreich, Steiermark und Kärnten. Im Kobernaußer Wald treten Verwilderungen der Strobe auf etwa 150 km2 auf, in den übrigen Gebieten sind sie auf kleine Flächen beschränkt. Vorkommen sind aus 17 Quadranten der Kartierung der Gefäßpflanzen Österreichs bekannt. Die Ausbreitung begann in Österreich spätestens ca. 1965. Die Anzahl der besiedelten Quadranten der floristischen Kartierung nimmt seit den 1960er Jahren linear zu. Die pflanzensoziologische Charakterisierung der besiedelten Lebensräume erfolgte mit 25 Vegetationsaufnahmen. In Österreich treten Verwilderungen besonders in Nadelbaum-Forstgesellschaften auf. Unter den naturnahen Waldbeständen sind bodensaure Buchenwälder (Luzulo-Fagetum) vom Eindringen der Strobe betroffen. Altere Kahlschläge mit Nadelbaumjungwuchs und Forststraßenböschungen stellen ebenfalls wichtige Standorte dar. Auf Grund der Erfahrungen zum Ausbreitungsverlauf im übrigen Mitteleuropa und den naturräumlichen Gegebenheiten erscheint für einige Gebiete Österreichs eine Ausbreitung in den nächsten Jahrzehnten wahrscheinlich. Dies sind v. a. submontane Lagen in den Hauptanbaugebieten, v. a. im Kobernaußer Wald und angrenzenden Gebieten.
