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One specimen of the jumping spider Evarcha jucunda was discovered in the fruit department of a general store in Gießen, Germany. The species has obviously been introduced with transported fruit from mediterranean countries.
The African species Cheiracanthium furculatum Karsch, 1879 was recognised as being introduced to Germany and is re-described and illustrated in the present study. C. tenuipes Roewer, 1961 is recognised as a junior synonym of C. africanum Lessert, 1921 (new synonymy); both subspecies of C. strasseni Strand, 1915, namely C. strasseni strasseni Strand, 1915 and C. strasseni aharonii Strand, 1915, are recognised as junior synonyms of C. mildei L. Koch, 1864 (new synonymies). Photographic images of the copulatory organs of the types of C. cretense Roewer, 1928, recently synonymised with C. mildei, are provided and discussed in the course of intraspecific variation in C. mildei. The female holotype of C. rehobothense Strand, 1915 is re-described and illustrated. Relations of C. rehobothense to other Cheiracanthium species are discussed.
We argue that human-mediated invasions are part of the spectrum of species movements, not a unique phenomenon, because species self-dispersing into novel environments are subject to the same barriers of survival, reproduction, dispersal and further range expansion as those assisted by people. Species changing their distributions by human-mediated and non-human mediated modes should be of identical scientific interest to invasion ecology and ecology. Distinctions between human-mediated invasions and natural colonisations are very valid for management and policy, but we argue that these are value-laden distinctions and not necessarily an appropriate division for science, which instead should focus on distinctions based on processes and mechanisms. We propose an all-encompassing framework of species range expansion. This does not detract from the importance of invasion biology as a discipline, but instead will help bring together research being conducted on multiple taxa, and by multiple disciplines, including epidemiology, that are often focused on an identical phenomenon: colonisation.
In our recent Discussion paper, we presented our view that the only real distinction between biological invasions and natural colonisations is the human element. We agree that invasion science is a very important science, not only to better understand the role that human mediation plays for colonisation, but also for many other science fields. We agree with all invasion researchers that the human influence can result in spectacular differences, including in rates of species movement, rates of successful colonisation, the particular species being moved, the biogeography of dispersal pathways and rates of any resulting ecological disturbance and biodiversity loss. Our deep point is that that species dispersed by human-mediation or natural colonisation are all subject to the same basic laws and rules of ecology, identical to many other phenomenon that occur naturally and can be greatly influenced by people. The human dimension is merely a mechanistic distinction, albeit important because it exposes insights about the colonisation process that cannot be seen by the study of natural colonisations alone. We provide 10 hypotheses that can be scientifically tested to determine whether biological invasions and natural colonisations are two separate processes or the same process being influenced by different mechanisms.
The influence of the Eastern migration route on the Slovak flora – a comparison after 40 years
(2017)
Transport is an important source of introduction and spread of alien plants into new areas and countries. This study provides comprehensive research of selected railway localities in South-Eastern Slovakia to determine the influence of the Eastern Migration Route on the Slovak flora. Railway transshipment yards in Čierna nad Tisou, Dobrá, Velké Kapušany and Matovce were studied from 1964 to 2013; with historic data sampled 1964–1998 and recent data sampled 2012–2013. These data sets were compared to determine differences in species structure following the decreased use of the transshipment yards.
A total of 657 vascular plant taxa were recorded in all localities (566 taxa in the historic and 431 taxa in the recent data set). Native species prevailed over aliens and archaeophytes over neophytes in both time periods. The most frequent aliens were naturalised taxa, where Asiatic and European species prevailed. The most frequent families were Poaceae, Asteraceae and Brassicaceae, and while many species introduced with Russian wheat were recorded only in the past, several taxa are also recorded only recently. Hemicryptophytes were the most abundant life form. Most recorded species were competitors, reproducing by seed and pollinated by insects. Zoochory and hemerochory were the most frequent dispersal types. The proportion of species traits has not changed over time. We identified 49 threatened taxa (38 in the historic and 27 in the recent data set). The Eastern migration route significantly increases the species number of alien vascular plants in the Slovak flora. Although this route had much greater importance in the past, when the role of the Eastern Slovak trans-shipment railway yards was much higher, the studied yards remain an important gateway to Eastern Central Europe and they continue to support agestochory migration of adventive plants.
Islands are particularly noteworthy for global conservation because of the high number of species they host, the high levels of species endemism, and the large number and proportion of species at risk of extinction. Much of the conservation threat on islands is from invasive species. Whilst biosecurity is an increasing focus of attention for authorities globally, species are continuing to establish in new locations outside of their native ranges. Among invasive species, ants are a prominent taxon, especially on islands. Over the past decade, following the detection of one of the world’s worst invasive ant species, African big-headed ant Pheidole megacephala, the environmental management authority on world-heritage-listed Lord Howe Island has focused attention on invasive ants. This detection influenced the creation of biosecurity measures to prevent further incursions of exotic species, particularly ants. Despite these efforts, over the following decade numerous ant species were collected on the island for the first time, indicating a serious biosecurity problem. Here, we investigate the chronosequence of ant introductions to Lord Howe Island to quantify the extent and nature of the island’s ant biosecurity problem. A total of 45 species have been collected on the island and of these, 12 are considered to be endemic, and a further seven are possibly native. Nineteen of the 26 introduced species (42% of the total fauna and 73% of the introduced fauna) were only found for the first time in the last 15 years. All but two of the species that are not native to Lord Howe Island are native to the Australian mainland, indicating that the biosecurity threat comes from the transport of goods from the Australian mainland. We suggest that the pattern of accelerating ant species accumulation on Lord Howe Island is probably not an isolated phenomenon, and that it is probably occurring on most islands globally that are habitable by ants and visited by people.