Franz Essl

ABSTRACT Aim To analyse if the historical species description process in 10 animal groups differed among widespread and endemic species and to evaluate whether our current knowledge about the diversity of these groups is complete. Location Sixty-nine terrestrial regions (countries, large islands, archipelagos) covering all of Europe. Methods Based on data from the Fauna Europaea project, we reconstructed the description histories of four vertebrate groups (amphibians, fish, mammals, reptiles) and six well-studied invertebrate groups (butterflies, grasshoppers, ground beetles, snails, spiders, true bugs) living in terrestrial and freshwater environments. We used accelerated failure time models to test for a possible delay of endemic species detection and to provide conservative estimates of the as yet undescribed proportions of the existing diversity. Results Our data set includes 24,092 species, of which 7202 (30%) are endemic to one Fauna Europaea region. Species descriptions over time follow different trajectories for endemic and widespread species,with endemic species being described 79 years later than widespread ones, on average. Rates of widespread species descriptions have been low throughout the 20th century despite increasing numbers of active taxonomists, and models indicate that only a minor fraction of extant species is unknown (0.4–3%). By contrast, endemic species accumulation curves do not seem to have levelled off yet. Conservative model predictions suggest that up to 19% of the existing endemic diversity still awaits description in some taxonomic groups. Conclusions Our results suggest that even for well-studied groups in the world’s biogeographically best-known continent, scientific knowledge of species richness is far from complete and is biased towards widespread species. Research and conservation priorities may thus be misdirected, as, for example, regions with high numbers of as yet unrecognized endemics may not be adequately considered when setting conservation priorities. This is particularly problematic as their mostly small populations make endemic species especially vulnerable to human-induced pressures.

In Europe, a unique alien species inventory with almost 11.000 alien species was established in 2009 through the EU funded Delivering Alien Invasive Species Inventories for Europe (DAISIE) project (http://www. europe-aliens. org). Several high impact publications as well as ground-breaking handbook (DAISIE 2009) documented alarming trends of increasing numbers of newly introduced and naturalized/established species across all groups of organisms. These data enabled to analyse various aspects of invasions at large ...

The European Union's (EU) new legislation concerning Invasive Alien Species (IAS) is a groundbreaking and commendable attempt to set a common standard for combating IAS across political jurisdictions at a multinational scale. However, the regulation, underpinned by a list of IAS of Union concern, affords Member States a degree of operational flexibility and its successful implementation will be dictated by appropriate national enforcement and resource use. In evaluating this EU legislation, we provide pragmatic recommendations based upon a geo-political analysis of the pan-European capabilities to combat IAS and discuss measures to avoid the risk that the regulation will promote a piecemeal response by stakeholders instead of a truly collaborative effort. We highlight a major deficit in the funding mechanisms to support a comprehensive implementation of the legislation and stress the importance of consultation with the broader scientific community, including with key stakeholders, businesses and the general public. Our recommendations will create incentives for industries, raise awareness among citizens and stakeholders, and help establish a social norm for the EU and further afield. The legislation offers a collaborative Europe the chance to demonstrate its commitment to tackling the problems of IAS and to achieve a successful conservation breakthrough of international importance.

Biological invasions can be associated with shifts of the species' climatic niches but the incidence of such shifts is under debate. The reproductive system might be a key factor controlling such shifts because it influences a species' evolutionary flexibility. However, the link between reproductive systems and niche dynamics in plant invasions has been little studied so far. We compiled global occurrence data sets of 13 congeneric sexual and apomictic species pairs, and used principal components analysis (PCA) and kernel smoothers to compare changes in climatic niche optima, breadths and unfilling/expansion between native and alien ranges. Niche change metrics were compared between sexual and apomictic species. All 26 species showed changes in niche optima and/or breadth and 14 species significantly expanded their climatic niches. However, we found no effect of the reproductive system on niche dynamics. Instead, species with narrower native niches showed higher rates of nic...

All around the globe, humans have greatly altered the abiotic and biotic environment with ever-increasing speed. One defining feature of the Anthropocene epoch is the erosion of biogeographical barriers by human-mediated dispersal of species into new regions, where they can naturalize and cause ecological, economic and social damage. So far, no comprehensive analysis of the global accumulation and exchange of alien plant species between continents has been performed, primarily because of a lack of data. Here we bridge this knowledge gap by using a unique global database on the occurrences of naturalized alien plant species in 481 mainland and 362 island regions. In total, 13,168 plant species, corresponding to 3.9% of the extant global vascular flora, or approximately the size of the native European flora, have become naturalized somewhere on the globe as a result of human activity. North America has accumulated the largest number of naturalized species, whereas the Pacific Islands show the fastest increase in species numbers with respect to their land area. Continents in the Northern Hemisphere have been the major donors of naturalized alien species to all other continents. Our results quantify for the first time the extent of plant naturalizations worldwide, and illustrate the urgent need for globally integrated efforts to control, manage and understand the spread of alien species.

To support the 'Streamlining European 2010 Biodiversity Indicators' (SEBI 2010) process, the European Environment Agency (EEA) commissioned a study to revisit and further develop the indicator 'Invasive alien species in Europe'. The aim of the current project is to critically review and improve this indicator, and propose an updated methodology. Further, options for methodologies of new indicators, which monitor IAS over time across Europe, will be discussed. Particular attention is given to closely linking the indicator(s) to recent biodiversity policy goals and developments.

The search for traits that make alien species invasive has mostly concentrated on comparing successful invaders and different comparison groups with respect to average trait values. By contrast, little attention has been paid to trait variability among invaders. Here, we combine an analysis of trait differences between invasive and non-invasive species with a comparison of multidimensional trait variability within these two species groups. We collected data on biological and distributional traits for 1402 species of the native, non-woody vascular plant flora of Austria. We then compared the subsets of species recorded and not recorded as invasive aliens anywhere in the world, respectively, first, with respect to the sampled traits using univariate and multiple regression models; and, second, with respect to their multidimensional trait diversity by calculating functional richness and dispersion metrics. Attributes related to competitiveness (strategy type, nitrogen indicator value),...

Climate change represents a substantial challenge for the management, use and protection of terrestrial and aquatic ecosystems as well as the sustainable use of the key water resources. Numerous feedbacks exist between agriculture, forestry, and water management sectors as well as the conservation of ecosystems and biodiversity. Almost all options to reduce greenhouse gas (GHG) emissions or to adapt to climate change in these sectors also have other socioeconomic or ecological consequences than the intended ones. Such feedbacks can also affect the GHG reduction potentials of climate-change mitigation measures. One example are the GHG emission reductions associated with a substitution of bioenergy for fossil fuels, which are substantially influenced by direct and indirect systemic feedbacks in land use, such as changes in forest area that may result from changes in cultivated areas. A multitude of options exist in the agricultural sector to reduce GHG emissions, in particular in rumi...

Delayed biodiversity responses to environmental forcing mean that rates of contemporary biodiversity changes are underestimated, yet these delays are rarely addressed in conservation policies. Here, we identify mechanisms that lead to such time lags, discuss shifting human perceptions, and propose how these phenomena should be addressed in biodiversity management and science.

ABSTRACT The introduction of alien species into new regions has become a defining feature of global environmental change. It has been argued that greenhouses and polytunnels may serve as invasion foci for emerging plant invaders of agricultural ecosystems under future warmer climates. To test this hypothesis we selected 15 organically producing plant nurseries in lowland eastern Austria. There species coverage was recorded in 73 plots inside and in 60 plots outside polytunnels. In total, 109 species were identified (including plant seedlings which could only be determined to the genus level), consisting of 27 neophytes, 6 archaeophytes and 76 native plant species. Although average weed species numbers were significantly higher inside polytunnels compared to reference plots outdoor, nonmetric multidimensional scaling revealed no significant differences in species composition. Similarly, we found no differences in the weed community indices, i.e., the proportion of species preferring low or high temperatures, low or high precipitation, and low or high soil fertility, between plots located in polytunnels and outdoor. This holds true for total species number as well as for subsets of species of different residence time. The recorded neophytes are native to Asia, Europe, North and South America at almost equal proportions, most neophytes (22 species) are introduced intentionally, while unintentionally introduced species were more abundant on average. In polytunnels, neophyte species number was dependent on the crop category only, and archaeophyte species numbers were influenced by size of the polytunnels, whereas native and total species numbers were again influenced by the crop species. In outdoor plots, archaeophyte numbers were influenced by mean annual temperature. Overall, weed vegetation in polytunnels and outdoors differs only little in terms of species composition and abundance. We thus conclude that sheltered environments (as polytunnels), which mimic warmer climates, do not serve as entry points for emerging neophytes of agricultural ecosystems.

This study improves the spatial coverage of top-down Ambrosia pollen source inventories for Europe by expanding the methodology to Austria, a country that is challenging in terms of topography and the distribution of ragweed plants. The inventory combines annual ragweed pollen counts from 19 pollen-monitoring stations in Austria (2004-2013), 657 geographical observations of Ambrosia plants, a Digital Elevation Model (DEM), local knowledge of ragweed ecology and CORINE land cover information from the source area. The highest mean annual ragweed pollen concentrations were generally recorded in the East of Austria where the highest densities of possible growth habitats for Ambrosia were situated. Approximately 99% of all observations of Ambrosia populations were below 745m. The European infection level varies from 0.1% at Freistadt in Northern Austria to 12.8% at Rosalia in Eastern Austria. More top-down Ambrosia pollen source inventories are required for other parts of Europe. A metho...