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Recent critics of invasion biology advocate reduced efforts against nonnative species, arguing that attempts to manage invasions are often costly and futile and that managers are indiscriminately managing species regardless of their impact. Whether this criticism has affected ground-level operations is unknown. A survey of land stewards of a major conservation NGO reveals that this plea has not been heeded; in fact, managers report that they would increase nonnative species management if more resources were available. While respondents overwhelmingly listed nonnative, invasive species as their highest priority for management, we found little evidence supporting the criticism that practitioners focus on nonnative species with minimal ecological impact. Additionally, we found that more conservation practitioners reported managing problematic "weedy" native species over nonnative species that are not invasive. Our results indicate that these managers are selective rather than profligate, targeting species that are having a demonstrable impact or are likely to do so. They feel hamstrung by resource shortages despite their rigorous target selection. Why the increasing literature calling for changed treatment of nonnatives has not led to changed operations is uncertain. Possible reasons are that the critics are not prescriptive or unified about management prioritization, or that these managers simply reject the proposed new paradigm.
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.
We performed a survey of grassland communities in the Ukrainian Carpathians with the aim of: (1) syntaxonomically classifying the meso- and subxerophilous grassland vegetation; (2) analysing the main gradients in their species composition; (3) estimating the effect of selected environmental factors on grassland species composition; (4) assessing the species richness of vascular plants and bryophytes in relation to the measured environmental variables. We collected 46 phytosociological relevés during the growing seasons of 2010 and 2011. Species composition and species richness were studied at two spatial scales (1 m² and 16 m²) in relation to soil parameters (soil depth, pH (KCl), content of P, K, Mg, N and C), management regime (mowing, grazing, ploughing in the past and burning), and other factors (altitude, litter cover, open soil, inclination, solar radiation and animal excrement). Seven grassland types were distinguished belonging to 3 classes and 4 alliances, namely the Nardetea strictae including the Violion caninae (mesic pastures at altitudes of 400–600 m mostly on moderate slopes) and the Nardo strictae-Agrostion tenuis (grasslands on moderate slopes at altitudes of 700–900 m usually managed by mowing and grazing the aftermath); the Molinio-Arrhenatheretea, including the Arrhenatherion elatioris (submontane grasslands originated mostly on former fields after their abandonment in the past) and the Cynosurion cristati (intensive pastures); and the Festuco-Brometea including the Cirsio-Brachypodion pinnati (abandoned grasslands dominated by Brachypodium pinnatum and Inula salicina). Detrended correspondence analysis indicated that the major compositional turnover was related to altitude and soil reaction. A canonical correspondence analysis confirmed that altitude had the strongest effect on species composition in the analysed dataset, followed by management treatments (former ploughing, grazing intensity). For vascular plant species richness, regression tree analysis identified grazing intensity as the most important predictor at the 1 m² scale. At the 16 m² scale, soil humus content was evaluated as the most important predictor of vascular plant species richness, followed by litter cover and grazing intensity. The number of bryophytes was not determined by the studied environmental factors at either of the two spatial scales. Although the number of analysed relevés in this study was limited, our results significantly contribute to the understanding of submontane grasslands in the Ukrainian Carpathians.