A new invasive species in South America: Pinus oocarpa Schiede ex Schltdl.

Conifers have a long history of introductions into many parts of the world and are among the most notorious plant invaders. At least 20 species of the genus Pinus are now considered to be invasive in at least one region of the southern hemisphere. Here, we present a quantitative report of invasion by Pinus oocarpa in a relatively undisturbed vegetation of the Cerrado region of Brazil. The invasion front of P. oocarpa was 458 m distant from the area of introduction, which represents a mean rate of spread of 12.72 m year-1. The average density of invasive plants was 561 ind ha-1, with a maximum density of 1,212 ind ha-1. It is currently unknown if the studied invasive population has produced negative impacts on the invaded ecosystem. However, it would be safe to assume that with the observed densities and rate of spread, P. oocarpa could affect the native community that it invaded. An early response targeting the eradication of the invasive population could prevent these ecological costs

Invasions across secondary forest successional stages: effects of local plant community, soil, litter, and herbivory on Hovenia dulcis seed germination and seedling establishment

Species abilities for seed germination and seedling survival under different situations are good predictors of their capacity to colonize a broad range of habitats. Biotic conditions related to understory cover, and abiotic factors such as litter thickness and soil moisture can be determinants of plant establishment. We evaluated seed germination, seedling survival, and growth of the invasive tree Hovenia dulcis under experimental field conditions in three successional stages (open, semi-open, and closed vegetation) of a fragmented seasonal deciduous forest in southern Brazil. Our hypotheses were that H. dulcis seed germination, seedling survival, and seedling growth decrease along the successional gradient, that these factors are positively affected by soil moisture and percentage of bare soil, and negatively affected by understory cover and litter thickness. We also tested the hypothesis that herbivory on H. dulcis would decrease along the successional gradient. Our main finding was that H. dulcis can germinate and establish along all forest successional stages because it is shadetolerant. Abiotic factors were more important than biotic factors for seed germination. Soil moisture positively affected seed germination while litter thickness negatively influenced seed germination. Percentage of bare soil negatively influenced seedling survival. Germination rates were higher in closed vegetation, whereas seedling survival was higher in semi-open vegetation, and growth rates were higher in open vegetation. There was no difference in herbivory among successional stages. The results of our study show that intermediate forest succession stages congregate the most favorable conditions for H. dulcis establishment, likely making them more susceptible to invasion.Fil: Dechoum, Michele. Universidade Federal de Santa Catarina; BrasilFil: Zenni, Rafael D.. Universidade do Brasília; BrasilFil: Castellani, Tania. Universidade Federal de Santa Catarina; BrasilFil: Zalba, Sergio Martín. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rejmánek, M.. University of California at Davis; Estados Unido

Evolutionary dynamics of tree invasions: complementing the unified framework for biological invasions

Evolutionary processes greatly impact the outcomes of biological invasions. An extensive body of research suggests that invasive populations often undergo phenotypic and ecological divergence from their native sources. Evolution also operates at different and distinct stages during the invasion process. Thus, it is important to incorporate evolutionary change into frameworks of biological invasions because it allows us to conceptualize how these processes may facilitate or hinder invasion success. Here, we review such processes, with an emphasis on tree invasions, and place them in the context of the unified framework for biological invasions. The processes and mechanisms described are pre-introduction evolutionary history, sampling effect, founder effect, genotype-by-environment interactions, admixture, hybridization, polyploidization, rapid evolution, epigenetics and second-genomes. For the last, we propose that co-evolved symbionts, both beneficial and harmful, which are closely physiologically associated with invasive species, contain critical genetic traits that affect the evolutionary dynamics of biological invasions. By understanding the mechanisms underlying invasion success, researchers will be better equipped to predict, understand and manage biological invasions

Drivers of future alien species impacts: an expert‐based assessment

Understanding the likely future impacts of biological invasions is crucial yet highly challenging given the multiple relevant environmental, socio‐economic and societal contexts and drivers. In the absence of quantitative models, methods based on expert knowledge are the best option for assessing future invasion trajectories. Here, we present an expert assessment of the drivers of potential alien species impacts under contrasting scenarios and socioecological contexts through the mid‐21st century. Based on responses from 36 experts in biological invasions, moderate (20%–30%) increases in invasions, compared to the current conditions, are expected to cause major impacts on biodiversity in most socioecological contexts. Three main drivers of biological invasions—transport, climate change and socio‐economic change—were predicted to significantly affect future impacts of alien species on biodiversity even under a best‐case scenario. Other drivers (e.g. human demography and migration in tropical and subtropical regions) were also of high importance in specific global contexts (e.g. for individual taxonomic groups or biomes). We show that some best‐case scenarios can substantially reduce potential future impacts of biological invasions. However, rapid and comprehensive actions are necessary to use this potential and achieve the goals of the Post‐2020 Framework of the Convention on Biological Diversity

IPBES Invasive Alien Species Assessment: Chapter 1. Introducing biological invasions and the IPBES thematic assessment of invasive alien species and their control

Chapter 1: Introducing biological invasions and the IPBES thematic assessment of invasive alien species and their control of the Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services

Tapping into non-English-language science for the conservation of global biodiversity.

The widely held assumption that any important scientific information would be available in English underlies the underuse of non-English-language science across disciplines. However, non-English-language science is expected to bring unique and valuable scientific information, especially in disciplines where the evidence is patchy, and for emergent issues where synthesising available evidence is an urgent challenge. Yet such contribution of non-English-language science to scientific communities and the application of science is rarely quantified. Here, we show that non-English-language studies provide crucial evidence for informing global biodiversity conservation. By screening 419,679 peer-reviewed papers in 16 languages, we identified 1,234 non-English-language studies providing evidence on the effectiveness of biodiversity conservation interventions, compared to 4,412 English-language studies identified with the same criteria. Relevant non-English-language studies are being published at an increasing rate in 6 out of the 12 languages where there were a sufficient number of relevant studies. Incorporating non-English-language studies can expand the geographical coverage (i.e., the number of 2° × 2° grid cells with relevant studies) of English-language evidence by 12% to 25%, especially in biodiverse regions, and taxonomic coverage (i.e., the number of species covered by the relevant studies) by 5% to 32%, although they do tend to be based on less robust study designs. Our results show that synthesising non-English-language studies is key to overcoming the widespread lack of local, context-dependent evidence and facilitating evidence-based conservation globally. We urge wider disciplines to rigorously reassess the untapped potential of non-English-language science in informing decisions to address other global challenges. Please see the Supporting information files for Alternative Language Abstracts

Data from: Loci under selection during multiple range expansions of an invasive plant are mostly population-specific, but patterns are associated with climate

Identifying the genes underlying rapid evolutionary changes, describing their function and ascertaining the environmental pressures that determine fitness are the central elements needed for understanding of evolutionary processes and phenotypic changes that improve the fitness of populations. It has been hypothesized that rapid adaptive changes in new environments may contribute to the rapid spread and success of invasive plants and animals. As yet, studies of adaptation during invasion are scarce, as is knowledge of the genes underlying adaptation, especially in multiple replicated invasions. Here, we quantified how genotype frequencies change during invasions, resulting in rapid evolution of naturalized populations. We used six fully replicated common garden experiments in Brazil where Pinus taeda (loblolly pine) was introduced at the same time, in the same numbers, from the same seed sources, and has formed naturalized populations expanding outward from the plantations. We used a combination of nonparametric, population genetics and multivariate statistics to detect changes in genotype frequencies along each of the six naturalization gradients and their association with climate as well as shifts in allele frequencies compared to the source populations. Results show 25 genes with significant shifts in genotype frequencies. Six genes had shifts in more than one population. Climate explained 25% of the variation in the groups of genes under selection across all locations, but specific genes under strong selection during invasions did not show climate-related convergence. In conclusion, we detected rapid evolutionary changes during invasive range expansions, but the particular gene-level patterns of evolution may be population specific

The elephant in the room: The role of failed invasions in understanding invasion biology.

Most species introductions are not expected to result in invasion, and species that are invasive in one area are frequently not invasive in others. However, cases of introduced organisms that failed to invade are reported in many instances as anecdotes or are simply ignored. In this analysis, we aimed to find common characteristics between non-invasive populations of known invasive species and evaluated how the study of failed invasions can contribute to research on biological invasions. We found intraspecific variation in invasion success and several recurring explanations for why non-native species fail to invade; these included low propagule pressure, abiotic resistance, biotic resistance, genetic constraints and mutualist release. Furthermore, we identified key research topics where ignoring failed invasions could produce misleading results; these include studies on historical factors associated with invasions, distribution models of invasive species, the effect of species traits on invasiveness, genetic effects, biotic resistance and habitat invasibility. In conclusion, we found failed invasions can provide fundamental information on the relative importance of factors determining invasions and might be a key component of several research topics. Therefore, our analysis suggests that more specific and detailed studies on invasion failures are necessary.Fil: Zenni, Rafael D.. University of Tennessee; Estados UnidosFil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. University of Tennessee; Estados Unido