Alien birds are widely distributed across the globe, but information on their environmental impacts is available for less than a quarter of the regions in which they are located. We test a series of ...hypotheses better to understand why impact data are available for some regions but not others. Information on factors hypothesised to influence spatial variation in the availability of impact data were collated for 60 regions with actual, recorded alien bird impacts, and 187 regions without. These data were analysed using mixed effects models. The characteristics of alien bird invasions most strongly influence the availability of impact data, which are more likely to be available for regions with higher alien bird species richness and longer alien bird residence times. There are many regions of the world that lack impact data but are characterised by high alien bird species richness and long alien bird residence times: it is likely that the impacts of alien birds are going unnoticed within them. To a lesser extent, impact data are also more likely to be available for regions characterised by higher economic development. Improving the capacity for research amongst less developed regions may therefore be a key strategy to improve our understanding of the impacts of alien birds. Impact data availability was not found to be associated with impact severity, and therefore we cannot conclude that regions lacking impact data do so because the impacts sustained within them are less severe.
We identified emerging scientific, technological, and sociopolitical issues likely to affect how biological invasions are studied and managed over the next two decades. Issues were ranked according ...to their probability of emergence, pervasiveness, potential impact, and novelty. Top-ranked issues include the application of genomic modification tools to control invasions, effects of Arctic globalization on invasion risk in the Northern Hemisphere, commercial use of microbes to facilitate crop production, the emergence of invasive microbial pathogens, and the fate of intercontinental trade agreements. These diverse issues suggest an expanding interdisciplinary role for invasion science in biosecurity and ecosystem management, burgeoning applications of biotechnology in alien species detection and control, and new frontiers in the microbial ecology of invasions.
Expanding transportation networks, technological advances, global environmental change, and geopolitical forces are transforming risks of invasion worldwide.
Genomic modification tools offer novel risks and potential solutions to managing invasions.
Rapid warming and intensified human activities in the Arctic will alter invasion patterns and risks across the Northern Hemisphere.
Anthropogenic stressors promote rapid evolutionary shifts that cause native and alien populations to become invasive.
Microbial ecology is becoming increasingly relevant to understanding and managing invasions.
While the regional distribution of non-native species is increasingly well documented for some taxa, global analyses of non-native species in local assemblages are still missing. Here, we use a ...worldwide collection of assemblages from five taxa - ants, birds, mammals, spiders and vascular plants - to assess whether the incidence, frequency and proportions of naturalised non-native species depend on type and intensity of land use. In plants, assemblages of primary vegetation are least invaded. In the other taxa, primary vegetation is among the least invaded land-use types, but one or several other types have equally low levels of occurrence, frequency and proportions of non-native species. High land use intensity is associated with higher non-native incidence and frequency in primary vegetation, while intensity effects are inconsistent for other land-use types. These findings highlight the potential dual role of unused primary vegetation in preserving native biodiversity and in conferring resistance against biological invasions.
Aim To apply the recently published EICAT protocol to an assessment of the magnitude of environmental impacts of alien bird species established world-wide. Location Global. Methods A review of ...published literature and online resources was undertaken to collate information on the reported environmental impacts of 415 bird species with self-sustaining alien populations world-wide. The resulting data were then categorized following the EICAT guidelines and analysed using R. Results Environmental impact data were found for approximately 30% of species with alien populations. Most alien birds had low impacts, categorized as either minimal concern (MC) or minor (MN). However, 37 bird species had moderate (MO) impacts or above, including five with massive (MV) impacts. Almost half of all impacts identified related to competition between alien birds and native species. Impact magnitudes were non-randomly distributed: impacts due to predation tended to be more severe than for other impact mechanisms, and impacts on oceanic islands tended to be more severe than for other regions, but impacts associated with Psittaciform species tended to be less severe than for other alien bird orders. Approximately 35% of assessments were allocated a 'low' confidence rating. Main conclusions The EICAT protocol can be effectively applied to categorize and quantify the impacts of all alien species within an entire taxonomic class. The results demonstrate significant variation in both the type and severity of impacts generated by alien birds. However, we found no data regarding the environmental impacts of the great majority of alien bird species, and where impact data were available, our assessments were frequently allocated a 'low' confidence rating. Our work therefore identifies major data gaps that will help influence the direction of future invasive alien species impact research.
Much of the recent discussion concerning the form and underlying mechanistic basis of metabolic rate–temperature and development rate–temperature relationships has been precipitated by the ...development of the metabolic theory of ecology (MTE). Empirical tests of the theory’s fundamental equation are an essential component of establishing its validity. Here, we test the temperature component of the fundamental equation of the MTE as it applies to metabolic rate and development rate, using insects as model organisms. Specifically, we test (i) whether mean activation energies,E, approximate the 0.65 eV value proposed by the proponents of the MTE and whether the range of values is tightly constrained between 0.6 and 0.7 eV, as they have argued; (ii) whether phylogenetic signal is apparent in the rate‐temperature relationships; (iii) whether the slopes of the rate‐temperature relationships show consistent, directional variation associated with environmental variables; and (iv) whether intra‐ and interspecific rate‐temperature relationships differ significantly. Because the majority of activation energy values fell outside the predicted range and rate‐temperature relationships showed consistent directional variation correlated with large‐scale climatic variation, we conclude that data from insects provide only limited support for the MTE. In consequence, we consider alternative explanations for variation in rate‐temperature relationships.
Statistical approaches for inferring the spatial distribution of taxa (Species Distribution Models, SDMs) commonly rely on available occurrence data, which is often clumped and geographically ...restricted. Although available SDM methods address some of these factors, they could be more directly and accurately modelled using a spatially-explicit approach. Software to fit models with spatial autocorrelation parameters in SDMs are now widely available, but whether such approaches for inferring SDMs aid predictions compared to other methodologies is unknown. Here, within a simulated environment using 1000 generated species' ranges, we compared the performance of two commonly used non-spatial SDM methods (Maximum Entropy Modelling, MAXENT and boosted regression trees, BRT), to a spatial Bayesian SDM method (fitted using R-INLA), when the underlying data exhibit varying combinations of clumping and geographic restriction. Finally, we tested how any recommended methodological settings designed to account for spatially non-random patterns in the data impact inference. Spatial Bayesian SDM method was the most consistently accurate method, being in the top 2 most accurate methods in 7 out of 8 data sampling scenarios. Within high-coverage sample datasets, all methods performed fairly similarly. When sampling points were randomly spread, BRT had a 1-3% greater accuracy over the other methods and when samples were clumped, the spatial Bayesian SDM method had a 4%-8% better AUC score. Alternatively, when sampling points were restricted to a small section of the true range all methods were on average 10-12% less accurate, with greater variation among the methods. Model inference under the recommended settings to account for autocorrelation was not impacted by clumping or restriction of data, except for the complexity of the spatial regression term in the spatial Bayesian model. Methods, such as those made available by R-INLA, can be successfully used to account for spatial autocorrelation in an SDM context and, by taking account of random effects, produce outputs that can better elucidate the role of covariates in predicting species occurrence. Given that it is often unclear what the drivers are behind data clumping in an empirical occurrence dataset, or indeed how geographically restricted these data are, spatially-explicit Bayesian SDMs may be the better choice when modelling the spatial distribution of target species.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Extinctions have altered island ecosystems throughout the late Quaternary. Here, we review the main historic drivers of extinctions on islands, patterns in extinction chronologies between islands, ...and the potential for restoring ecosystems through reintroducing extirpated species. While some extinctions have been caused by climatic and environmental change, most have been caused by anthropogenic impacts. We propose a general model to describe patterns in these anthropogenic island extinctions. Hunting, habitat loss and the introduction of invasive predators accompanied prehistoric settlement and caused declines of endemic island species. Later settlement by European colonists brought further land development, a different suite of predators and new drivers, leading to more extinctions. Extinctions alter ecological networks, causing ripple effects for islands through the loss of ecosystem processes, functions and interactions between species. Reintroduction of extirpated species can help restore ecosystem function and processes, and can be guided by palaeoecology. However, reintroduction projects must also consider the cultural, social and economic needs of humans now inhabiting the islands and ensure resilience against future environmental and climate change.
The role of human tolerance is increasingly being proposed as a key driver of invasion success by alien species. Human‐habitat associations may facilitate both transport – making a species more ...available for introduction – and establishment – by creating environmental matching between human‐altered habitats at the sites of origin and introduction. Nevertheless, the assumption that alien species exhibit associations with human habitats in their native ranges has been largely overlooked.
We conduct the first global assessment of the relative importance of human‐habitat associations in shaping the native distributions of species introduced world‐wide, in relation to other key important drivers, that is climate and land‐use. For this, we applied deviance partitioning analysis and species distribution models (SDM) to 776 introduced alien bird species from five continents.
While an independent effect of climate, and a joint effect of climate and non‐urban land uses, appear as major factors governing alien species distribution in their native ranges, significant independent contributions of anthropogenic variables were found for most species. The effect of anthropogenic variables was mostly positive, or concave with highest responses at intermediate values. Notably, human‐habitat associations in the native distributions of alien birds were significantly higher than expected, relative to a pool of available species from the same bird families (N = 3,565). Thus, introduced alien birds are a non‐random sample with respect to their association with human‐altered habitats. However, an increase in introduction rates of species showing no response, or a negative response, to human influence has occurred over recent decades.
Synthesis and applications. To prevent invasions, understanding which species are most likely to become successful aliens outside their native range is essential. Our results support the hypothesis that association with humans may be an important driver of alien bird species distribution in their native ranges, and thus increase the likelihood that these species will end up being introduced and established elsewhere. To provide policymakers with robust predictions of invasion risk, we recommend including human‐habitat associations in invasion risk assessments, and accounting for them in species distribution models.
To prevent invasions, understanding which species are most likely to become successful aliens outside their native range is essential. Our results support the hypothesis that association with humans may be an important driver of alien bird species distribution in their native ranges, and thus increase the likelihood that these species will end up being introduced and established elsewhere. To provide policymakers with robust predictions of invasion risk, we recommend including human‐habitat associations in invasion risk assessments, and accounting for them in species distribution models.
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