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Introduced species, those dispersed outside their natural ranges by humans, now cause almost all biological invasions, i.e., entry of organisms into habitats with negative effects on organisms already there. Knowing whether introduction tends to give organisms specific ecological advantages or disadvantages in their new habitats could help understand and control invasions. Even if no specific species traits are associated with introduction, introduced species might out-compete native ones just because the pool of introduced species is very large (“global competition hypothesis”). Especially in the case of intentional introduction, high initial propagule pressure might further increase the chance of establishment, and repeated introductions from different source populations might increase the fitness of introduced species through hybridization. Intentional introduction screens species for usefulness to humans and so might select for rapid growth and reproduction or carry species to suitable habitats, all which could promote invasiveness. However, trade offs between growth and tolerance might make introduced species vulnerable to extreme climatic events and cause some invasions to be transient (“reckless invader hypothesis”). Unintentional introduction may screen for species associated with human-disturbed habitats, and human disturbance of their new habitats may make these species more invasive. Introduction and natural long-distance dispersal both imply that species have neither undergone adaptation in their new habitats nor been adapted to by other species there. These two characteristics are the basis for many well-known hypotheses about invasion, including the “biotic resistance”, “enemy release”, “evolution of increased competitive ability” and “novel weapon” hypotheses, each of which has been shown to help explain some invasions. To the extent that biotic resistance depends upon local adaption by native species, altering selection pressures could reduce resistance and promote invasion (“local adaptation hypothesis”), and restoring natural regimes could reverse this effect.

Ecosystems and biodiversity around the globe face multiple threats, including climate change and invasive species. Non-native species are known for their resilience to disturbances and their ability to thrive more successfully than native species in urbanized or otherwise disturbed areas, and some of them can become invasive. It is a complex challenge to detect, manage, and control such species, which require coordinated efforts from society, government, and the academic community. In this study, the eMIAS (South American Invasive Mollusks Specialists) research group (27 experts from seven South American countries) aim to provide foundational knowledge for management of these species. We compiled and synthesized information on the mollusc species that are native to South America and that have been introduced to other regions of the world. A total of 29 species were detected, including 10 marine, 10 freshwater, and 9 terrestrial. For each species, the area of origin, date and place of introduction, and current distribution were determined. We could determine that (1) most of these introductions have occurred in connection with globalization processes, such as an increase in trade. (2) The potential source regions of those 29 species are also areas that received non-native species from elsewhere (e.g., Europe, Asia). (3) Regions where species introductions have taken place are subject to the impacts of climate change and/or urbanization.

Paramysis lacustris is a Ponto-Caspian mysid crustacean species. It inhabits coasts, estuaries and lower parts of rivers in the Black, Azov and Caspian seas and shows high levels of genetic structuring and cryptic diversity. The species has been introduced into the Baltic Sea basin and is considered to be a high risk invader. We developed ten microsatellite loci and tested their polymorphism in 70 individuals from four wild populations. The number of alleles per locus ranged from 4 to 23; none of the loci showed consistent deviations from Hardy–Weinberg equilibrium. These microsatellite markers will be useful to trace potential invasions and understand dynamics of native P. lacustris populations.

Although an increasing number of investigations have been made into the evolution of alien species once introduced, few studies have identified the invasion routes of these introduced species. Because multiple introductions are common in invasive species, failing to take into account the introduced lineages can be misleading when studying evolutionary change in alien species after they begin to extend their ranges. In Japan, diverse lineages of ryegrasses (Lolium spp.) were introduced as forage crops and contaminants in trading grain and have expanded to sandy coasts. We studied the expansion route of populations established along the coasts of three geographic regions within Japan by comparing variations in morphology and nuclear microsatellite and chloroplast DNA in the two habitats where ryegrasses were first introduced: croplands and international seaports. Chloroplast DNA haplotypes did not differ significantly among habitats and regions, but the coastal and seaport populations displayed similar microsatellite genetic compositions and morphological characteristics. Our results revealed that coastal populations originated from seaport populations derived from contaminants. Selective forces from the past, including domestication and naturalization, may have assisted the introduced lineages in colonizing new habitats. Nomenclature: Italian ryegrass, Lolium multiflorum L.; rigid ryegrass, Lolium rigidum Gaudin.

Biological invasions frequently bring about negative impacts on natural ecosystems, including changing their structure and function and causing loss of biodiversity. A large percentage of invasive species are introduced intentionally as horticulture plants by the green industry. Repeated introductions of non-native plant species have accelerated the invasion processes considerably despite the fact that only a small percentage of intentional introductions actually become invasive. Currently, there is a lack of specific information on non-native and invasive plants in the state of Kentucky, especially concerning species origin, taxonomic affinity, and the pathway of species introduction. This study is designed to gather information about plant species found in nurseries across the state of Kentucky to test the hypothesis that species belonging to certain families and coming from particular geographical regions may have a higher possibility to be introduced into new locations as horticulture plants. By identifying and recording 462 species in 101 families and 258 genera from twenty-two nurseries statewide, we discovered that the possibility for a species to be introduced as horticulture plant significantly relates to its native origin and family membership; non-native plant species, especially those with eastern Asian origins, are carried most by nurseries in general. Our results suggest that native origin and family membership of plant species could be used as an effective indicator in identifying the pool of potentially invasive species in the future. Our findings confirm that nurseries have been a major pathway of non-native plants introductions. Most importantly, our study points out the critical needs for having informed and educated personnel in the green industry, so that invasive exotic species will not be introduced in the first place.

There are good theoretical and educational reasons to place matters of implicit and explicit learning high on the agenda for SLA research. As for theoretical motivations, perhaps the most central issue in SLA theory construction in need of explanation is the differential success in one's first language (L1) and in one's second language (L2). Although acquisition of an L1 results in full mastery of the language (provided that children are exposed to sufficient quantities of input and do not suffer from mental disabilities), learners of an L2—even after many years of L2 exposure—differ widely in level of attainment. How can we explain universal success in the case of L1 acquisition and differential success in the case of L2 acquisition? Among the many explanations that have been proposed, including brain maturation and brain adaptation processes (critical period), access to Universal Grammar, L1 interference, and sociopsychological factors (see Hyltenstam & Abrahamsson, 2003, for a review), one finds explanations that involve the notions of implicit and explicit learning. Scholars working in different disciplines, in different theoretical schools, and sometimes using different terminology have argued that L1 acquisition (or at least the acquisition of L1 grammar) relies principally on processes of what we might now call implicit learning, whereas the acquisition of an L2 often relies on both implicit and explicit learning (Bley-Vroman, 1991; DeKeyser, 2003; N. Ellis, this issue; R. Ellis, 2004; Krashen, 1981; Reber & Allen, 2000).I am grateful to Rod Ellis for his thoughtful comments on previous versions of this text.

Identification of latent or unarticulated customer and other stakeholder needs has been a significant barrier to improving the efficiency and effectiveness of the front-end phase of new product development processes. In-depth determination of stakeholder needs entails analysis of their intentions; the overall aim of the work reported in this article is to establish a framework of intentional analysis, and its associated methods and techniques for improving traceability of design practice during the early phases of the design process. The specific aim of this article is to present a conceptual framework for design rationale systems. The framework built upon the cross-fertilization of approaches and methods drawn from systems engineering and philosophy, focussing on the notions of antecedence and consequence. It was developed in the course of tackling design problems originating in industrial contexts. The methods developed were thus evaluated, updated, and refined in real applications. Two application cases are described that have been drawn from the aerospace and power sectors, respectively. The applications showed that the framework's central antecedent/consequent scheme provides a cell from which to develop either a history of actual successive changes, or a tree of alternative possible projected designs.