Identifying potentially invasive species and preventing their introduction and establishment are of critical importance in invasion ecology and land management. Although an extensive body of research ...has been dedicated to identifying traits that confer invasiveness, our current knowledge is still often inconclusive due to limitations in geographic extent and/or scope of traits analyzed. Here, using a comprehensive set of 45 traits, we performed a case study of invasive traits displayed by exotic woody plants in the United States (U.S.) by comparing 63 invasive and 794 non-invasive exotic woody plant species naturalized across the country. We found that invasive woody species often bear the following two key traits: vegetative reproduction and long-distance seed dispersal (via water, birds or mammals). Boosted classification tree models based on these traits accurately predicted species invasiveness (86% accuracy on average). Presented findings provide a generalized understanding of the relative importance of functional traits in identifying potentially invasive woody species in the U.S. The knowledge generated in this study can be used to improve current classification systems of non-native woody plants used by various U.S. governmental agencies and land managers.
Habitat invasibility is a central focus of invasion biology, with implications for basic ecological patterns and processes and for effective invasion management. "Invasibility" is, however, one of ...the most elusive metrics and misused terms in ecology. Empirical studies and meta-analyses of invasibility have produced inconsistent and even conflicting results. This lack of consistency, and subsequent difficulty in making broad cross-habitat comparisons, stem in part from (1) the indiscriminant use of a closely related, but fundamentally different concept, that of degree of invasion (DI) or level of invasion; and (2) the lack of common invasibility metrics, as illustrated by our review of all invasibility-related papers published in 2013. To facilitate both cross-habitat comparison and more robust ecological generalizations, we clarify the definitions of invasibility and DI, and for the first time propose a common metric for quantifying invasibility based on a habitat's resource availability as inferred from relative resident species richness and biomass. We demonstrate the feasibility of our metric using empirical data collected from 2475 plots from three forest ecosystems in the eastern United States. We also propose a similar metric for DI. Our unified, resource-based metrics are scaled from 0 to 1, facilitating cross-habitat comparisons. Our proposed metrics clearly distinguish invasibility and DI from each other, which will help to (1) advance invasion ecology by allowing more robust testing of generalizations and (2) facilitate more effective invasive species control and management.
The main aim of the study was to propose a useful methodological approach to define easily understandable indicators to use in communication campaigns organized to improve the efficacy of municipal ...solid waste collection. For this purpose, six economic-environmental indicators were defined, combining life cycle thinking and environmental communication. The indicators make it possible to obtain several combinations that can follow a variety of communication channels. Three indicators (quantity of recyclable materials recoverable from unsorted residual waste; total potential economic saving; number of jobs for young people as communicators) are expressed in absolute value and therefore refer to the whole community even if they are also good for single-targeted messages. The other three indicators (potential economic saving for each citizen; per capita saving of carbon dioxide equivalent; per capita saving of Disability Adjusted Life Years) are normalized with respect to the number of inhabitants and therefore refer to the individual citizen, but can also be used for global messages. As a case example, the methodology was applied to the collection of paper and cardboard in twelve Southern Italy cities obtaining very promising results. For example, the maximum quantity of paper and cardboard recoverable from unsorted waste would allow Naples and Palermo to recover more than €15 million. The maximum potential economic saving for each citizen was 25 €/capita. The economic saving obtained for Naples and Palermo could be translated in more than one thousand positions as young environmental communicators. Catania was the city with both the highest per capita potential saving of carbon dioxide (>60 kg CO2eq./capita) and maximum hypothetical per capita ‘life-time recovery’ (almost an hour). The innovative communication method used (‘Greenopoli’) assumed that school is the starting point to obtain a change of mindset because speaking with students (all potential communicators) means indirectly communicating with all other targets.
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•The study proposes a methodological approach with an example case.•Life cycle thinking and environmental communication have been combined.•The communicative approach is based on six easily understandable indicators.•Indicators allow obtaining many combinations to use in communication campaigns.•Communication campaigns should follow a pyramid approach with schools at the base.
Summary
The exponential growth of scientific literature – which we call the ‘big literature’ phenomenon – has created great challenges in literature comprehension and synthesis. The traditional ...manual literature synthesis processes are often unable to take advantage of big literature due to human limitations in time and cognition, creating the need for new literature synthesis methods to address this challenge.
In this paper, we discuss a highly useful literature synthesis approach, automated content analysis (ACA), which has not yet been widely adopted in the fields of ecology and evolutionary biology. ACA is a suite of machine learning tools for the qualitative and quantitative synthesis of big literature commonly used in the social sciences and in medical research.
Our goal is to introduce ecologists and evolutionary biologists to ACA and illustrate its capacity to synthesize overwhelming volumes of literature. First, we provide a brief history of the ACA method and summarize the fundamental process of ACA. Next, we present two ACA studies to illustrate the utility and versatility of ACA in synthesizing ecological and evolutionary literature. Finally, we discuss how to maximize the utility and contributions of ACA, as well as potential research directions that may help to advance the use of ACA in future ecological and evolutionary research.
Unlike manual methods of literature synthesis, ACA is able to process high volumes of literature at substantially shorter time spans, while helping to mitigate human biases. The overall efficiency and versatility of this method allow for a broad range of applications for literature review and synthesis, including both exploratory reviews and systematic reviews aiming to address more targeted research questions. By allowing for more extensive and comprehensive reviews of big literature, ACA has the potential to fill an important methodological gap and therefore contribute to the advancement of ecological and evolutionary research.
Aim: Much is known about the elevational diversity patterns of native species and about the mechanisms that drive these patterns. A similar level of understanding is needed for non-native species. ...Using published data, we examine elevational diversity patterns of non-native plants and compare the resulting patterns with those observed for native plants. Location: Global. Methods: We compiled data from 65 case studies on elevational diversity patterns of non-native plants around the world (including 32 cases in which both non-native and native plants were sampled). We compared the elevational distributions (upper and lower limits, and extents) and diversity patterns of non-native and native species. Results: Compared to native plant species, the elevational diversity patterns of non-native plant species were more negative (47% vs. 13%) and less unimodal (44% vs. 84%). That is, non-native species richness tended to be highest at lower elevations, whereas native species richness peaked at mid-elevations. In cases where species richness for both non-native and native species on the same mountains showed unimodal patterns in relation to elevation, maximum values in species richness occurred at lower elevations for non-native species. Main conclusions: At present levels of invasion, non-native and native species show different patterns in both distribution and diversity along elevational gradients worldwide. However, our observations constitute a snapshot of ongoing, long-term invasion processes. As non-native species typically show strong associations with human activities, future changes in human population (e.g. growth and migration), land use and climate change may promote upward spread of non-native species and may thus increase risks of impact on native species and communities.
Abstract
Objectives
We aimed to investigate and compare the efficacy and safety of two dolutegravir-based two-drug regimens: dolutegravir + lamivudine versus dolutegravir + rilpivirine.
Methods
We ...analysed a cohort of people living with HIV (PLWHIV) switching to dolutegravir + lamivudine or dolutegravir + rilpivirine. We excluded from the analysis PLWHIV with no available pre-switch genotypic test or with a known resistance mutation to one of the study drugs. We evaluated incidence of virological failure (VF) and treatment discontinuation (TD), as well as changes in immunological and metabolic parameters.
Results
We enrolled 592 PLWHIV: 306 in the lamivudine group and 286 in the rilpivirine group. We observed nine VFs in the lamivudine group 1.4 VF per 100 patient-years of follow-up (PYFU) and four VFs in the rilpivirine group (0.6 VF per 100 PYFU). Subsequent genotypic analysis showed no acquired resistance-associated mutations in those experiencing VF. Estimated probability of maintaining virological suppression at 144 and 240 weeks were 96.6% and 92.7%, respectively, in the lamivudine group and 98.7% and 98.7%, respectively, in the rilpivirine group (log-rank P = 0.172). The estimated probability of maintaining study regimen at Week 240 was 82.3% in the lamivudine group and 85.9% in the rilpivirine group (log-rank P = 0.018). We observed a significant improvement in CD4+ cell count at Week 240 in the lamivudine group (P = 0.012); in the rilpivirine group we registered a significant increase in CD4/CD8 ratio (P = 0.014).
Conclusions
Both analysed strategies are effective and safe as switch strategies in clinical practice, with a low incidence of VF and a favourable immunological recovery, even in the long term.
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•Urban stormwater ponds used to manage runoff could facilitate plant invasion.•We identified over 76,000 stormwater ponds across Florida, US.•Ponds in Gainesville, FL harbor high ...richness and cover of invasive plants.•Invasion severity is highest in temporary ponds with little to no management.•Results highlight the commonality and disservices of these designed ecosystems.
Designed ecosystems are built as part of ongoing urban expansion, providing a suite of valued ecosystem services. However, these new ecosystems could also promote disservices by facilitating the colonization and spread of invasive species. We conduct the first assessment of the quantity and invasion of an overlooked designed ecosystem: stormwater ponds. These ponds are commonly recommended for managing urban hydrology, but little is known about their ecology or extent of proliferation. Using a broad-scale survey of pond coverage in Florida, USA, we found that over 76,000 stormwater ponds have been built just in this state, forming 2.7% of total urban land cover. This extensive pondscape of manufactured habitats could facilitate species spread throughout urban areas and into nearby natural waterbodies. We also conducted a survey of the severity of plant invasion in 30 ponds in Gainesville, FL, US across two pond types (dry vs. wet), and a gradient of management intensities (low, medium, high) and pond ages. We unexpectedly found a high number of invasive plant species (28 in just 30 ponds). Ninety-six percent of surveyed ponds contained from one to ten of these species, with ponds exhibiting high turnover in invader composition (i.e., high beta diversity). The bank sections of dry unmanaged ponds exhibited the highest mean invasive species richness (5.8 ± 1.3) and the inundated centers of wet medium managed ponds exhibited the highest mean invasive species cover (34 ± 12%). Invasive plant richness and cover also tended to be greater in dry ponds with higher soil nutrient levels, and in older wet ponds. Therefore, we found that highly maintained and younger wet ponds were the least invaded. Nevertheless, common management practices that limit plant invasions may also limit native species establishment and invasion may increase in the decades following pond construction.
CONTEXT: Not accounting for spatial heterogeneity in ecological analyses can cause modeled relationships to vary across spatial scales, specifically different levels of spatial resolution. These ...varying results hinder both the utility of data collected at one spatial scale for analyses at others and the determination of underlying processes. OBJECTIVES: To briefly review existing methods for analyzing data collected at multiple scales, highlight the effects of spatial heterogeneity on the utility of these methods, and to illustrate a practical statistical method to account for the sources of spatial heterogeneity when they are unknown. METHODS: Using simulated examples, we show how not accounting for the drivers of spatial heterogeneity in statistical models can cause contradictory findings regarding relationship direction across spatial scales. We then show how mixed effects models can remedy this multiscaling issue. RESULTS: Ignoring sources of spatial heterogeneity in statistical models with coarse spatial scales produced contradictory results to the true underlying relationship. Treating drivers of spatial heterogeneity as random effects in a mixed effects model, however, allowed us to uncover this true relationship. CONCLUSIONS: Mixed effects models is advantageous as it is not always necessary to know the influential explanatory variables that cause spatial heterogeneity and no additional data are required. Furthermore, this approach is well documented, can be applied to data having various distribution types, and is easily executable using multiple statistical packages.
AIM: Stronger inferences about biological invasions may be obtained when accounting for multiple invasion measures and the spatial heterogeneity occurring across large geographic areas. We pursued ...this enquiry by utilizing a multimeasure, multiregional framework to investigate forest plant invasions at a subcontinental scale. LOCATION: United States of America (USA). METHODS: Using empirical data from a national survey of USA forests, we compiled and mapped invasion richness (number of invasive species) and invasion prevalence (percentage of plots invaded) for 2524 counties. We then modelled each of these invasion measures as functions of 22 factors reflective of propagule pressure and/or habitat invasibility for eastern and western forests separately using simultaneous autoregressive spatial error models. RESULTS: Eastern forests had higher mean invasion richness (6.1) and prevalence (48%) than western forests (3.2 and 10%, respectively). Spatial patterns of invasion richness and prevalence differed, especially in the West. Propagule pressure factors were always positively associated with both invasion measures. Factors associated with human legacy were nearly six times more strongly associated with western than eastern invasions. Unlike propagule pressure factors, habitat invasibility factors shared inconsistent associations with invasion measures. MAIN CONCLUSIONS: The weaker associations between human legacy and invasions in the heavily invaded East, compared to the less‐invaded West, suggest a declining effect of propagule pressure over time with increasing invasion intensity. The importance of propagule pressure in less‐invaded western forests suggests that spatial variability in propagule inputs, coupled with lags between establishment and commonness, drives the spatial differences between invasion richness and prevalence during early invasion stages. Meanwhile, declining spatial disagreement between invasion measures and the relative unimportance of propagule pressure, in heavily invaded eastern forests, suggest that species‐specific variation in response to habitat invasibility drives spatial differences between invasion measures during later invasion stages. These insights further illustrate the importance of spatial heterogeneity in invasive plant management and policy at macroscales.
Invader traits (including plant growth form) may play an important, and perhaps overlooked, role in determining macroscale patterns of biological invasions and therefore warrant greater consideration ...in future investigations aimed at understanding these patterns. To assess this need, we used empirical data from a national-level survey of forest in the contiguous 48 states of the USA to identify geographic hotspots of forest plant invasion for three distinct invasion characteristics: invasive species richness, trait richness (defined as the number of the five following plant growth forms represented by the invasive plants present at a given location: forbs, grasses, shrubs, trees, and vines), and species richness within each growth form. Three key findings emerged. 1) The hotspots identified encompassed from 9 to 23% of the total area of our study region, thereby revealing many forests to be not only invaded, but highly invaded. 2) Substantial spatial disagreement among hotspots of invasive species richness, invasive trait richness, and species richness of invasive plants within each growth form revealed many locations to be hotspots for invader traits, or for particular growth forms of invasive plants, rather than for invasive plants in general. 3) Despite eastern forests exhibiting higher levels of plant invasion than western forests, species richness for invasive forbs and grasses in the west were respectively greater than and equivalent to levels found in the east. Contrasting patterns between eastern and western forests in the number of invasive species detected for each growth form combined with the spatial disagreement found among hotspot types suggests trait-based variability in invasion drivers. Our findings reveal invader traits to be an important contributor to macroscale invasion patterns.
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