Moussab/ORKG-training-evaluation-set huggingface dataset:
Research field: Ecology and Evolutionary Biology
Title: Widespread association of the invasive ant Solenopsis invicta with an invasive mealybug
Abstract: Factors such as aggressiveness and adaptation to disturbed environments have been suggested as important characteristics of invasive ant species, but diet has rarely been considered. However, because invasive ants reach extraordinary densities at introduced locations, increased feeding efficiency or increased exploitation of new foods should be important in their success. Earlier studies suggest that honeydew produced by Homoptera (e.g., aphids, mealybugs, scale insects) may be important in the diet of the invasive ant species Solenopsis invicta. To determine if this is the case, we studied associations of S. invicta and Homoptera in east Texas and conducted a regional survey for such associations throughout the species' range in the southeast United States. In east Texas, we found that S. invicta tended Ho- moptera extensively and actively constructed shelters around them. The shelters housed a variety of Homoptera whose frequency differed according to either site location or season, presumably because of differences in host plant availability and temperature. Overall, we estimate that the honeydew produced in Homoptera shelters at study sites in east Texas could supply nearly one-half of the daily energetic requirements of an S. invicta colony. Of that, 70% may come from a single species of invasive Homoptera, the mealybugAntonina graminis. Homoptera shelters were also common at regional survey sites and A. graminis occurred in shelters at nine of 11 survey sites. A comparison of shelter densities at survey sites and in east Texas suggests that our results from east Texas could apply throughout the range of S. invicta in the southeast United States. Antonina graminis may be an ex- ceptionally important nutritional resource for S. invicta in the southeast United States. While it remains largely unstudied, the tending of introduced or invasive Homoptera also appears important to other, and perhaps all, invasive ant species. Exploitative or mutually beneficial associations that occur between these insects may be an important, previously unrecognized factor promoting their success.
Extracted statement — Outcome of interaction: Resource
Research field: Ecology and Evolutionary Biology
Title: Ecology of brushtail possums in New Zealand dryland ecosystem
Abstract: The introduced brushtail possum (Trichosurus vulpecula) is a major environmental and agricultural pest in New Zealand but little information is available on the ecology of possums in drylands, which cover c. 19% of the country. Here, we describe a temporal snapshot of the diet and feeding preferences of possums in a dryland habitat in New Zealand's South Island, as well as movement patterns and survival rates. We also briefly explore spatial patterns in capture rates. We trapped 279 possums at an average capture rate of 9 possums per 100 trap nights. Capture rates on individual trap lines varied from 0 to 38%, decreased with altitude, and were highest in the eastern (drier) parts of the study area. Stomach contents were dominated by forbs and sweet briar (Rosa rubiginosa); both items were consumed preferentially relative to availability. Possums also strongly preferred crack willow (Salix fragilis), which was uncommon in the study area and consumed only occasionally, but in large amounts. Estimated activity areas of 29 possums radio-tracked for up to 12 months varied from 0.2 to 19.5 ha (mean 5.1 ha). Nine possums (4 male, 5 female) undertook dispersal movements (≥1000 m), the longest of which was 4940 m. The most common dens of radio-collared possums were sweet briar shrubs, followed by rock outcrops. Estimated annual survival was 85% for adults and 54% for subadults. Differences between the diets, activity areas and den use of possums in this study and those in forest or farmland most likely reflect differences in availability and distribution of resources. Our results suggest that invasive willow and sweet briar may facilitate the existence of possums by providing abundant food and shelter. In turn, possums may facilitate the spread of weeds by acting as a seed vector. This basic ecological information will be useful in modelling and managing the impacts of possum populations in drylands.
Extracted statement — Outcome of interaction: Resource
Research field: Ecology and Evolutionary Biology
Title: Cane toads on cowpats: commercial livestock production facilitates toad invasion in tropical Australia
Abstract: Habitat disturbance and the spread of invasive organisms are major threats to biodiversity, but the interactions between these two factors remain poorly understood in many systems. Grazing activities may facilitate the spread of invasive cane toads (Rhinella marina) through tropical Australia by providing year-round access to otherwise-seasonal resources. We quantified the cane toad’s use of cowpats (feces piles) in the field, and conducted experimental trials to assess the potential role of cowpats as sources of prey, water, and warmth for toads. Our field surveys show that cane toads are found on or near cowpats more often than expected by chance. Field-enclosure experiments show that cowpats facilitate toad feeding by providing access to dung beetles. Cowpats also offer moist surfaces that can reduce dehydration rates of toads and are warmer than other nearby substrates. Livestock grazing is the primary form of land use over vast areas of Australia, and pastoral activities may have contributed substantially to the cane toad’s successful invasion of that continent.
Extracted statement — Outcome of interaction: Resource
Research field: Ecology and Evolutionary Biology
Title: Invasive alien plants infiltrate bird-mediated shrub nucleation processes in arid savanna
Abstract: 1 The cultivation and dissemination of alien ornamental plants increases their potential to invade. More specifically, species with bird‐dispersed seeds can potentially infiltrate natural nucleation processes in savannas. 2 To test (i) whether invasion depends on facilitation by host trees, (ii) whether propagule pressure determines invasion probability, and (iii) whether alien host plants are better facilitators of alien fleshy‐fruited species than indigenous species, we mapped the distribution of alien fleshy‐fruited species planted inside a military base, and compared this with the distribution of alien and native fleshy‐fruited species established in the surrounding natural vegetation. 3 Abundance and diversity of fleshy‐fruited plant species was much greater beneath tree canopies than in open grassland and, although some native fleshy‐fruited plants were found both beneath host trees and in the open, alien fleshy‐fruited plants were found only beneath trees. 4 Abundance of fleshy‐fruited alien species in the natural savanna was positively correlated with the number of individuals of those species planted in the grounds of the military base, while the species richness of alien fleshy‐fruited taxa decreased with distance from the military base, supporting the notion that propagule pressure is a fundamental driver of invasions. 5 There were more fleshy‐fruited species beneath native Acacia tortilis than beneath alien Prosopis sp. trees of the equivalent size. Although there were significant differences in native plant assemblages beneath these hosts, the proportion of alien to native fleshy‐fruited species did not differ with host. 6 Synthesis. Birds facilitate invasion of a semi‐arid African savanna by alien fleshy‐fruited plants, and this process does not require disturbance. Instead, propagule pressure and a few simple biological observations define the probability that a plant will invade, with alien species planted in gardens being a major source of propagules. Some invading species have the potential to transform this savanna by overtopping native trees, leading to ecosystem‐level impacts. Likewise, the invasion of the open savanna by alien host trees (such as Prosopis sp.) may change the diversity, abundance and species composition of the fleshy‐fruited understorey. These results illustrate the complex interplay between propagule pressure, facilitation, and a range of other factors in biological invasions.
Extracted statement — Outcome of interaction: Richness
Research field: Ecology and Evolutionary Biology
Title: Rapid evolution in response to introduced predators I: rates and patterns of morphological and life-history trait divergence
Abstract: Abstract Background Introduced species can have profound effects on native species, communities, and ecosystems, and have caused extinctions or declines in native species globally. We examined the evolutionary response of native zooplankton populations to the introduction of non-native salmonids in alpine lakes in the Sierra Nevada of California, USA. We compared morphological and life-history traits in populations of Daphnia with a known history of introduced salmonids and populations that have no history of salmonid introductions. Results Our results show that Daphnia populations co-existing with fish have undergone rapid adaptive reductions in body size and in the timing of reproduction. Size-related traits decreased by up to 13 percent in response to introduced fish. Rates of evolutionary change are as high as 4,238 darwins (0.036 haldanes). Conclusion Species introductions into aquatic habitats can dramatically alter the selective environment of native species leading to a rapid evolutionary response. Knowledge of the rates and limits of adaptation is an important component of understanding the long-term effects of alterations in the species composition of communities. We discuss the evolutionary consequences of species introductions and compare the rate of evolution observed in the Sierra Nevada Daphnia to published estimates of evolutionary change in ecological timescales.
Extracted statement — Species name: Salmonids
Research field: Ecology and Evolutionary Biology
Title: Quantifying the impact of an extreme climate event on species diversity in fragmented temperate forests: the effect of the October 1987 storm on British broadleaved woodlands
Abstract: We report the impact of an extreme weather event, the October 1987 severe storm, on fragmented woodlands in southern Britain. We analysed ecological changes between 1971 and 2002 in 143 200‐m2 plots in 10 woodland sites exposed to the storm with an ecologically equivalent sample of 150 plots in 16 non‐exposed sites. Comparing both years, understorey plant species‐richness, species composition, soil pH and woody basal area of the tree and shrub canopy were measured. We tested the hypothesis that the storm had deflected sites from the wider national trajectory of an increase in woody basal area and reduced understorey species‐richness associated with ageing canopies and declining woodland management. We also expected storm disturbance to amplify the background trend of increasing soil pH, a UK‐wide response to reduced atmospheric sulphur deposition. Path analysis was used to quantify indirect effects of storm exposure on understorey species richness via changes in woody basal area and soil pH. By 2002, storm exposure was estimated to have increased mean species richness per 200 m2 by 32%. Woody basal area changes were highly variable and did not significantly differ with storm exposure. Increasing soil pH was associated with a 7% increase in richness. There was no evidence that soil pH increased more as a function of storm exposure. Changes in species richness and basal area were negatively correlated: a 3.4% decrease in richness occurred for every 0.1‐m2 increase in woody basal area per plot. Despite all sites substantially exceeding the empirical critical load for nitrogen deposition, there was no evidence that in the 15 years since the storm, disturbance had triggered a eutrophication effect associated with dominance of gaps by nitrophilous species. Synthesis. Although the impacts of the 1987 storm were spatially variable in terms of impacts on woody basal area, the storm had a positive effect on understorey species richness. There was no evidence that disturbance had increased dominance of gaps by invasive species. This could change if recovery from acidification results in a soil pH regime associated with greater macronutrient availability.
Extracted statement — Type of disturbance: Storm
Research field: Ecology and Evolutionary Biology
Title: Non-native habitat as home for non-native species: comparison of communities associated with invasive tubeworm and native oyster reefs
Abstract: Introduction vectors for marine non-native species, such as oyster culture and boat foul- ing, often select for organisms dependent on hard substrates during some or all life stages. In soft- sediment estuaries, hard substrate is a limited resource, which can increase with the introduction of hard habitat-creating non-native species. Positive interactions between non-native, habitat-creating species and non-native species utilizing such habitats could be a mechanism for enhanced invasion success. Most previous studies on aquatic invasive habitat-creating species have demonstrated posi- tive responses in associated communities, but few have directly addressed responses of other non- native species. We explored the association of native and non-native species with invasive habitat- creating species by comparing communities associated with non-native, reef-building tubeworms Ficopomatus enigmaticus and native oysters Ostrea conchaphila in Elkhorn Slough, a central Califor- nia estuary. Non-native habitat supported greater densities of associated organisms—primarily highly abundant non-native amphipods (e.g. Monocorophium insidiosum, Melita nitida), tanaid (Sinelebus sp.), and tube-dwelling polychaetes (Polydora spp.). Detritivores were the most common trophic group, making up disproportionately more of the community associated with F. enigmaticus than was the case in the O. conchaphila community. Analysis of similarity (ANOSIM) showed that native species' community structure varied significantly among sites, but not between biogenic habi- tats. In contrast, non-natives varied with biogenic habitat type, but not with site. Thus, reefs of the invasive tubeworm F. enigmaticus interact positively with other non-native species.
Extracted statement — Investigated species: Tubeworm
Research field: Ecology and Evolutionary Biology
Title: A comparison of the urban flora of different phytoclimatic regions in Italy
Abstract: This study is a comparison of the spontaneous vascular flora of five Italian cities: Milan, Ancona, Rome, Cagliari and Palermo. The aims of the study are to test the hypothesis that urbanization results in uniformity of urban floras, and to evaluate the role of alien species in the flora of settlements located in different phytoclimatic regions. To obtain comparable data, ten plots of 1 ha, each representing typical urban habitats, were analysed in each city. The results indicate a low floristic similarity between the cities, while the strongest similarity appears within each city and between each city and the seminatural vegetation of the surrounding region. In the Mediterranean settlements, even the most urbanized plots reflect the characters of the surrounding landscape and are rich in native species, while aliens are relatively few. These results differ from the reported uniformity and the high proportion of aliens which generally characterize urban floras elsewhere. To explain this trend the importance of apophytes (indigenous plants expanding into man-made habitats) is highlighted; several Mediterranean species adapted to disturbance (i.e. grazing, trampling, and human activities) are pre-adapted to the urban environment. In addition, consideration is given to the minor role played by the ‘urban heat island’ in the Mediterranean basin, and to the structure and history of several Italian settlements, where ancient walls, ruins and archaeological sites in the periphery as well as in the historical centres act as conservative habitats and provide connection with seed-sources on the outskirts.
Extracted statement — Type of disturbance: Urbanization
Research field: Ecology and Evolutionary Biology
Title: Exotic invasive species in urban wetlands: environmental correlates and implications for wetland management
Abstract: Summary 1. Wetlands in urban regions are subjected to a wide variety of anthropogenic disturbances, many of which may promote invasions of exotic plant species. In order to devise management strategies, the influence of different aspects of the urban and natural environments on invasion and community structure must be understood. 2. The roles of soil variables, anthropogenic effects adjacent to and within the wetlands, and vegetation structure on exotic species occurrence within 21 forested wetlands in north-eastern New Jersey, USA, were compared. The hypotheses were tested that different vegetation strata and different invasive species respond similarly to environmental factors, and that invasion increases with increasing direct human impact, hydrologic disturbance, adjacent residential land use and decreasing wetland area. Canonical correspondence analyses, correlation and logistic regression analyses were used to examine invasion by individual species and overall site invasion, as measured by the absolute and relative number of exotic species in the site flora. 3. Within each stratum, different sets of environmental factors separated exotic and native species. Nutrients, soil clay content and pH, adjacent land use and canopy composition were the most frequently identified factors affecting species, but individual species showed highly individualistic responses to the sets of environmental variables, often responding in opposite ways to the same factor. 4. Overall invasion increased with decreasing area but only when sites > 100 ha were included. Unexpectedly, invasion decreased with increasing proportions of industrial/commercial adjacent land use. 5. The hypotheses were only partially supported; invasion does not increase in a simple way with increasing human presence and disturbance. 6. Synthesis and applications . The results suggest that a suite of environmental conditions can be identified that are associated with invasion into urban wetlands, which can be widely used for assessment and management. However, a comprehensive ecosystem approach is needed that places the remediation of physical alterations from urbanization within a landscape context. Specifically, sediment, inputs and hydrologic changes need to be related to adjoining urban land use and to the overlapping requirements of individual native and exotic species.
Extracted statement — Type of disturbance: Urbanization
Research field: Ecology and Evolutionary Biology
Title: Alien and native plant establishment in grassland communities is more strongly affected by disturbance than above- and below-ground enemies
Abstract: Understanding the factors that drive commonness and rarity of plant species and whether these factors differ for alien and native species are key questions in ecology. If a species is to become common in a community, incoming propagules must first be able to establish. The latter could be determined by competition with resident plants, the impacts of herbivores and soil biota, or a combination of these factors. We aimed to tease apart the roles that these factors play in determining establishment success in grassland communities of 10 alien and 10 native plant species that are either common or rare in Germany, and from four families. In a two‐year multisite field experiment, we assessed the establishment success of seeds and seedlings separately, under all factorial combinations of low vs. high disturbance (mowing vs mowing and tilling of the upper soil layer), suppression or not of pathogens (biocide application) and, for seedlings only, reduction or not of herbivores (net‐cages). Native species showed greater establishment success than alien species across all treatments, regardless of their commonness. Moreover, establishment success of all species was positively affected by disturbance. Aliens showed lower establishment success in undisturbed sites with biocide application. Release of the undisturbed resident community from pathogens by biocide application might explain this lower establishment success of aliens. These findings were consistent for establishment from either seeds or seedlings, although less significantly so for seedlings, suggesting a more important role of pathogens in very early stages of establishment after germination. Herbivore exclusion did play a limited role in seedling establishment success. Synthesis: In conclusion, we found that less disturbed grassland communities exhibited strong biotic resistance to establishment success of species, whether alien or native. However, we also found evidence that alien species may benefit weakly from soilborne enemy release, but that this advantage over native species is lost when the latter are also released by biocide application. Thus, disturbance was the major driver for plant species establishment success and effects of pathogens on alien plant establishment may only play a minor role.
Extracted statement — Research Method: Experiment
Research field: Ecology and Evolutionary Biology
Title: Determinants of vertebrate invasion success in Europe and North America
Abstract: Species that are frequently introduced to an exotic range have a high potential of becoming invasive. Besides propagule pressure, however, no other generally strong determinant of invasion success is known. Although evidence has accumulated that human affiliates (domesticates, pets, human commensals) also have high invasion success, existing studies do not distinguish whether this success can be completely explained by or is partly independent of propagule pressure. Here, we analyze both factors independently, propagule pressure and human affiliation. We also consider a third factor directly related to humans, hunting, and 17 traits on each species' population size and extent, diet, body size, and life history. Our dataset includes all 2362 freshwater fish, mammals, and birds native to Europe or North America. In contrast to most previous studies, we look at the complete invasion process consisting of (1) introduction, (2) establishment, and (3) spread. In this way, we not only consider which of the introduced species became invasive but also which species were introduced. Of the 20 factors tested, propagule pressure and human affiliation were the two strongest determinants of invasion success across all taxa and steps. This was true for multivariate analyses that account for intercorrelations among variables as well as univariate analyses, suggesting that human affiliation influenced invasion success independently of propagule pressure. Some factors affected the different steps of the invasion process antagonistically. For example, game species were much more likely to be introduced to an exotic continent than nonhunted species but tended to be less likely to establish themselves and spread. Such antagonistic effects show the importance of considering the complete invasion process.
Extracted statement — Measure of invasion success: Spread