Moussab/ORKG-training-evaluation-set huggingface dataset:
Research field: Ecology and Evolutionary Biology
Title: Functional group diversity, resource preemption and the genesis of invasion resistance in a community of marine algae
Abstract: Although many studies have investigated how community characteristics such as diversity and disturbance relate to invasibility, the mechanisms underlying biotic resistance to introduced species are not well understood. I manipulated the functional group composition of native algal communities and invaded them with the introduced, Japanese seaweed Sargassum muticum to understand how individual functional groups contributed to overall invasion resistance. The results suggested that space preemption by crustose and turfy algae inhibited S. muticum recruitment and that light preemption by canopy and understory algae reduced S. muticum survivorship. However, other mechanisms I did not investigate could have contributed to these two results. In this marine community the sequential preemption of key resources by different functional groups in different stages of the invasion generated resistance to invasion by S. muticum. Rather than acting collectively on a single resource the functional groups in this system were important for preempting either space or light, but not both resources. My experiment has important implications for diversity-invasibility studies, which typically look for an effect of diversity on individual resources. Overall invasion resistance will be due to the additive effects of individual functional groups (or species) summed over an invader's life cycle. Therefore, the cumulative effect of multiple functional groups (or species) acting on multiple resources is an alternative mechanism that could generate negative relationships between diversity and invasibility in a variety of biological systems.
Extracted statement — Investigated species: Algae
Research field: Ecology and Evolutionary Biology
Title: Introduction pathway and climate trump ecology and life history as predictors of establishment success in alien frogs and toads
Abstract: A major goal for ecology and evolution is to understand how abiotic and biotic factors shape patterns of biological diversity. Here, we show that variation in establishment success of nonnative frogs and toads is primarily explained by variation in introduction pathways and climatic similarity between the native range and introduction locality, with minor contributions from phylogeny, species ecology, and life history. This finding contrasts with recent evidence that particular species characteristics promote evolutionary range expansion and reduce the probability of extinction in native populations of amphibians, emphasizing how different mechanisms may shape species distributions on different temporal and spatial scales. We suggest that contemporary changes in the distribution of amphibians will be primarily determined by human-mediated extinctions and movement of species within climatic envelopes, and less by species-typical traits.
Extracted statement — Investigated species: Amphibians
Research field: Ecology and Evolutionary Biology
Title: Invasive Microstegium populations consistently outperform native range populations across diverse environments
Abstract: Plant species introduced into novel ranges may become invasive due to evolutionary change, phenotypic plasticity, or other biotic or abiotic mechanisms. Evolution of introduced populations could be the result of founder effects, drift, hybridization, or adaptation to local conditions, which could enhance the invasiveness of introduced species. However, understanding whether the success of invading populations is due to genetic differences between native and introduced populations may be obscured by origin x environment interactions. That is, studies conducted under a limited set of environmental conditions may show inconsistent results if native or introduced populations are differentially adapted to specific conditions. We tested for genetic differences between native and introduced populations, and for origin x environment interactions, between native (China) and introduced (U.S.) populations of the invasive annual grass Microstegium vimineum (stiltgrass) across 22 common gardens spanning a wide range of habitats and environmental conditions. On average, introduced populations produced 46% greater biomass and had 7.4% greater survival, and outperformed native range populations in every common garden. However, we found no evidence that introduced Microstegium exhibited greater phenotypic plasticity than native populations. Biomass of Microstegium was positively correlated with light and resident community richness and biomass across the common gardens. However, these relationships were equivalent for native and introduced populations, suggesting that the greater mean performance of introduced populations is not due to unequal responses to specific environmental parameters. Our data on performance of invasive and native populations suggest that post-introduction evolutionary changes may have enhanced the invasive potential of this species. Further, the ability of Microstegium to survive and grow across the wide variety of environmental conditions demonstrates that few habitats are immune to invasion.
Extracted statement —  Phenotypic plasticity form: Biomass
Research field: Ecology and Evolutionary Biology
Title: COMPETITION BETWEEN NATIVE PERENNIAL AND EXOTIC ANNUAL GRASSES: IMPLICATIONS FOR AN HISTORICAL INVASION
Abstract: Though established populations of invasive species can exert substantial competitive effects on native populations, exotic propagules may require disturbances that decrease competitive interference by resident species in order to become established. We compared the relative competitiveness of native perennial and exotic annual grasses in a California coastal prairie grassland to test whether the introduction of exotic propagules to coastal grasslands in the 19th century was likely to have been sufficient to shift community composition from native perennial to exotic annual grasses. Under experimental field con- ditions, we compared the aboveground productivity of native species alone to native species competing with exotics, and exotic species alone to exotic species competing with natives. Over the course of the four-year experiment, native grasses became increasingly dominant in the mixed-assemblage plots containing natives and exotics. Although the competitive interactions in the first growing season favored the exotics, over time the native grasses significantly reduced the productivity of exotic grasses. The number of exotic seedlings emerging and the biomass of dicot seedlings removed during weeding were also significantly lower in plots containing natives as compared to plots that did not contain natives. We found evidence that the ability of established native perennial species to limit space available for exotic annual seeds to germinate and to limit the light available to exotic seedlings reduced exotic productivity and shifted competitive interactions in favor of the natives. If interactions between native perennial and exotic annual grasses follow a similar pattern in other coastal grassland habitats, then the introduction of exotic grass propagules alone without changes in land use or climate, or both, was likely insufficient to convert the region's grasslands.
Extracted statement — Measure of invasion success: Biomass
Research field: Ecology and Evolutionary Biology
Title: Propagule pressure and resource availability determine plant community invasibility in a temperate forest understorey
Abstract: Few field experiments have examined the effects of both resource availability and propagule pressure on plant community invasibility. Two non-native forest species, a herb and a shrub (Hesperis matronalis and Rhamnus cathartica, respectively), were sown into 60 1-m 2 sub-plots distributed across three plots. These contained reconstructed native plant communities in a replaced surface soil layer in a North American forest interior. Resource availability and propagule pressure were manipulated as follows: understorey light level (shaded/unshaded), nutrient availability (control/fertilized), and seed pressures of the two non-native species (control/low/high). Hesperis and Rhamnus cover and the above-ground biomass of Hesperis were significantly higher in shaded sub-plots and at greater propagule pressures. Similarly, the above-ground biomass of Rhamnus was significantly increased with propagule pressure, although this was a function of density. In contrast, of species that seeded into plots from the surrounding forest during the growing season, the non-native species had significantly greater cover in unshaded sub-plots. Plants in these unshaded sub-plots were significantly taller than plants in shaded sub-plots, suggesting a greater fitness. Total and non-native species richness varied significantly among plots indicating the importance of fine-scale dispersal patterns. None of the experimental treatments influenced native species. Since the forest seed bank in our study was colonized primarily by non-native ruderal species that dominated understorey vegetation, the management of invasions by non-native species in forest understoreys will have to address factors that influence light levels and dispersal pathways.
Extracted statement — Measure of invasion success: Biomass
Research field: Ecology and Evolutionary Biology
Title: Phenotypic plasticity, precipitation, and invasiveness in the fire-promoting grass Pennisetum setaceum (poaceae)
Abstract: Invasiveness may result from genetic variation and adaptation or phenotypic plasticity, and genetic variation in fitness traits may be especially critical. Pennisetum setaceum (fountain grass, Poaceae) is highly invasive in Hawaii (HI), moderately invasive in Arizona (AZ), and less invasive in southern California (CA). In common garden experiments, we examined the relative importance of quantitative trait variation, precipitation, and phenotypic plasticity in invasiveness. In two very different environments, plants showed no differences by state of origin (HI, CA, AZ) in aboveground biomass, seeds/flower, and total seed number. Plants from different states were also similar within watering treatment. Plants with supplemental watering, relative to unwatered plants, had greater biomass, specific leaf area (SLA), and total seed number, but did not differ in seeds/flower. Progeny grown from seeds produced under different watering treatments showed no maternal effects in seed mass, germination, biomass or SLA. High phenotypic plasticity, rather than local adaptation is likely responsible for variation in invasiveness. Global change models indicate that temperature and precipitation patterns over the next several decades will change, although the direction of change is uncertain. Drier summers in southern California may retard further invasion, while wetter summers may favor the spread of fountain grass.
Extracted statement — Specific traits: Biomass
Research field: Ecology and Evolutionary Biology
Title: Patterns of bird invasion are consistent with environmental filtering
Abstract: Predicting invasion potential has global significance for managing ecosystems as well as important theoretical implications for understanding community assembly. Phylogenetic relationships of introduced species to the extant community may be predictive of establishment success because of the opposing forces of competition/shared enemies (which should limit invasions by close relatives) versus environmental filtering (which should allow invasions by close relatives). We examine here the association between establishment success of introduced birds and their phylogenetic relatedness to the extant avifauna within three highly invaded regions (Florida, New Zealand, and Hawaii). Published information on both successful and failed introductions, as well as native species, was compiled for all three regions. We created a phylogeny for each avifauna including all native and introduced bird species. From the estimated branch lengths on these phylogenies, we calculated multiple measurements of relatedness between each introduced species and the extant avifauna. We used generalized linear models to test for an association between relatedness and establishment success. We found that close relatedness to the extant avifauna was significantly associated with increased establishment success for exotic birds both at the regional (Florida, Hawaii, New Zealand) and sub-regional (islands within Hawaii) levels. Our results suggest that habitat filtering may be more important than interspecific competition in avian communities assembled under high rates of anthropogenic species introductions. This work also supports the utility of community phylogenetic methods in the study of vertebrate invasions.
Extracted statement — Investigated species: Birds
Research field: Ecology and Evolutionary Biology
Title: Global patterns of introduction effort and establishment success in birds
Abstract: Theory suggests that introduction effort (propagule size or number) should be a key determinant of establishment success for exotic species. Unfortunately, however, propagule pressure is not recorded for most introductions. Studies must therefore either use proxies whose efficacy must be largely assumed, or ignore effort altogether. The results of such studies will be flawed if effort is not distributed at random with respect to other characteristics that are predicted to influence success. We use global data for more than 600 introduction events for birds to show that introduction effort is both the strongest correlate of introduction success, and correlated with a large number of variables previously thought to influence success. Apart from effort, only habitat generalism relates to establishment success in birds.
Extracted statement — Investigated species: Birds
Research field: Ecology and Evolutionary Biology
Title: The role of competition and introduction effort in the success of passeriform birds introduced to New Zealand
Abstract: The finding that passeriform birds introduced to the islands of Hawaii and Saint Helena were more likely to successfully invade when fewer other introduced species were present has been interpreted as strong support for the hypothesis that interspecific competition influences invasion success. I tested whether invasions were more likely to succeed when fewer species were present using the records of passeriform birds introduced to four acclimatization districts in New Zealand. I also tested whether introduction effort, measured as the number of introductions and the total number of birds released, could predict invasion outcomes, a result previously established for all birds introduced to New Zealand. I found patterns consistent with both competition and introduction effort as explanations for invasion success. However, data supporting the two explanations were confounded such that the greater success of invaders arriving when fewer other species were present could have been due to a causal relationship between invasion success and introduction effort. Hence, without data on introduction effort, previous studies may have overestimated the degree to which the number of potential competitors could independently explain invasion outcomes and may therefore have overstated the importance of competition in structuring introduced avian assemblages. Furthermore, I suggest that a second pattern in avian invasion success previously attributed to competition, the morphological overdispersion of successful invaders, could also arise as an artifact of variation in introduction effort.
Extracted statement — Investigated species: Birds
Research field: Ecology and Evolutionary Biology
Title: High predictability in introduction outcomes and the geographical range size of introduced Australian birds: a role for climate
Abstract: Summary 1 We investigated factors hypothesized to influence introduction success and subsequent geographical range size in 52 species of bird that have been introduced to mainland Australia. 2 The 19 successful species had been introduced more times, at more sites and in greater overall numbers. Relative to failed species, successfully introduced species also had a greater area of climatically suitable habitat available in Australia, a larger overseas range size and were more likely to have been introduced successfully outside Australia. After controlling for phylogeny these relationships held, except that with overseas range size and, in addition, larger-bodied species had a higher probability of introduction success. There was also a marked taxonomic bias: gamebirds had a much lower probability of success than other species. A model including five of these variables explained perfectly the patterns in introduction success across-species. 3 Of the successful species, those with larger geographical ranges in Australia had a greater area of climatically suitable habitat, traits associated with a faster population growth rate (small body size, short incubation period and more broods per season) and a larger overseas range size. The relationships between range size in Australia, the extent of climatically suitable habitat and overseas range size held after controlling for phylogeny. 4 We discuss the probable causes underlying these relationships and why, in retrospect, the outcome of bird introductions to Australia are highly predictable.
Extracted statement — Investigated species: Birds
Research field: Ecology and Evolutionary Biology
Title: The Influence of Numbers Released on the Outcome of Attempts to Introduce Exotic Bird Species to New Zealand
Abstract: 1. Information on the approximate number of individuals released is available for 47 of the 133 exotic bird species introduced to New Zealand in the late 19th and early 20th centuries. Of these, 21 species had populations surviving in the wild in 1969-79. The long interval between introduction and assessment of outcome provides a rare opportunity to examine the factors correlated with successful establishment without the uncertainty of long-term population persistence associated with studies of short duration. 2. The probability of successful establishment was strongly influenced by the number of individuals released during the main period of introductions. Eight-three per cent of species that had more than 100 individuals released within a 10-year period became established, compared with 21% of species that had less than 100 birds released. The relationship between the probability of establishment and number of birds released was similar to that found in a previous study of introductions of exotic birds to Australia. 3. It was possible to look for a within-family influence on the success of introduction of the number of birds released in nine bird families. A positive influence was found within seven families and no effect in two families. This preponderance of families with a positive effect was statistically significant. 4. A significant effect of body weight on the probability of successful establishment was found, and negative effects of clutch size and latitude of origin. However, the statistical significance of these effects varied according to whether comparison was or was not restricted to within-family variation. After applying the Bonferroni adjustment to significance levels, to allow for the large number of variables and factors being considered, only the effect of the number of birds released was statistically significant. 5. No significant effects on the probability of successful establishment were apparent for the mean date of release, the minimum number of years in which birds were released, the hemisphere of origin (northern or southern) and the size and diversity of latitudinal distribution of the natural geographical range.
Extracted statement — Investigated species: Birds
Research field: Ecology and Evolutionary Biology
Title: Behavioural flexibility predicts invasion success in birds introduced to New Zealand
Abstract: A fundamental question in ecology is whether there are evolutionary characteristics of species that make some better than others at invading new communities. In birds, nesting habits, sexually selected traits, migration, clutch size and body mass have been suggested as important variables, but behavioural flexibility is another obvious trait that has received little attention. Behavioural flexibility allows animals to respond more rapidly to environmental changes and can therefore be advantageous when invading novel habitats. Behavioural flexibility is linked to relative brain size and, for foraging, has been operationalised as the number of innovations per taxon reported in the short note sections of ornithology journals. Here, we use data on avian species introduced to New Zealand and test the link between forebrain size, feeding innovation frequency and invasion success. Relative brain size was, as expected, a significant predictor of introduction success, after removing the effect of introduction effort. Species with relatively larger brains tended to be better invaders than species with smaller ones. Introduction effort, migratory strategy and mode of juvenile development were also significant in the models. Pair-wise comparisons of closely related species indicate that successful invaders also showed a higher frequency of foraging innovations in their region of origin. This study provides the first evidence in vertebrates of a general set of traits, behavioural flexibility, that can potentially favour invasion success.
Extracted statement — Investigated species: Birds
Research field: Ecology and Evolutionary Biology
Title: Correlates of Introduction Success in Exotic New Zealand Birds
Abstract: Whether or not a bird species will establish a new population after invasion of uncolonized habitat depends, from theory, on its life-history attributes and initial population size. Data about initial population sizes are often unobtainable for natural and deliberate avian invasions. In New Zealand, however, contemporary documentation of introduction efforts allowed us to systematically compare unsuccessful and successful invaders without bias. We obtained data for 79 species involved in 496 introduction events and used the present-day status of each species as the dependent variable in fitting multiple logistic regression models. We found that introduction efforts for species that migrated within their endemic ranges were significantly less likely to be successful than those for nonmigratory species with similar introduction efforts. Initial population size, measured as number of releases and as the minimum number of propagules liberated in New Zealand, significantly increased the probability of translocation success. A null model showed that species released more times had a higher probability per release of successful establishment. Among 36 species for which data were available, successful invaders had significantly higher natality/mortality ratios. Successful invaders were also liberated at significantly more sites. Invasion of New Zealand by exotic birds was therefore primarily related to management, an outcome that has implications for conservation biology.
Extracted statement — Investigated species: Birds