Moussab/ORKG-training-evaluation-set huggingface dataset:
Research field: Ecology and Evolutionary Biology
Title: Variation in morphological characters of two invasive leafminers, Liriomyza huidobrensis and L. sativae, across a tropical elevation gradient
Abstract: Abstract Changes in morphological traits along elevation and latitudinal gradients in ectotherms are often interpreted in terms of the temperature-size rule, which states that the body size of organisms increases under low temperatures, and is therefore expected to increase with elevation and latitude. However other factors like host plant might contribute to spatial patterns in size as well, particularly for polyphagous insects. Here elevation patterns for trait size and shape in two leafminer species are examined, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) and L. sativae Blanchard, along a tropical elevation gradient in Java, Indonesia. Adult leafminers were trapped from different locations in the mountainous area of Dieng in the province of Central Java. To separate environmental versus genetic effects, L. huidobrensis originating from 1378 m and 2129 m ASL were reared in the laboratory for five generations. Size variation along the elevation gradient was only found in L. huidobrensis and this followed expectations based on the temperature-size rule. There were also complex changes in wing shape along the gradient. Morphological differences were influenced by genetic and environmental effects. Findings are discussed within the context of adaptation to different elevations in the two species.
Extracted statement — type of experiment: Lab
Research field: Ecology and Evolutionary Biology
Title: Growth, water relations, and stomatal development of Caragana korshinskii Kom. and Zygophyllum xanthoxylum (Bunge) Maxim. seedlings in response to water deficits
Abstract: Abstract The selection and introduction of drought tolerant species is a common method of restoring degraded grasslands in arid environments. This study investigated the effects of water stress on growth, water relations, Na+ and K+ accumulation, and stomatal development in the native plant species Zygophyllum xanthoxylum (Bunge) Maxim., and an introduced species, Caragana korshinskii Kom., under three watering regimes. Moderate drought significantly reduced pre‐dawn water potential, leaf relative water content, total biomass, total leaf area, above‐ground biomass, total number of leaves and specific leaf area, but it increased the root/total weight ratio (0.23 versus 0.33) in C. korshinskii. Only severe drought significantly affected water status and growth in Z. xanthoxylum. In any given watering regime, a significantly higher total biomass was observed in Z. xanthoxylum (1.14 g) compared to C. korshinskii (0.19 g). Moderate drought significantly increased Na+ accumulation in all parts of Z. xanthoxylum, e.g., moderate drought increased leaf Na+ concentration from 1.14 to 2.03 g/100 g DW, however, there was no change in Na+ (0.11 versus 0.12) in the leaf of C. korshinskii when subjected to moderate drought. Stomatal density increased as water availability was reduced in both C. korshinskii and Z. xanthoxylum, but there was no difference in stomatal index of either species. Stomatal length and width, and pore width were significantly reduced by moderate water stress in Z. xanthoxylum, but severe drought was required to produce a significant effect in C. korshinskii. These results indicated that C. korshinskii is more responsive to water stress and exhibits strong phenotypic plasticity especially in above‐ground/below‐ground biomass allocation. In contrast, Z. xanthoxylum was more tolerant to water deficit, with a lower specific leaf area and a strong ability to maintain water status through osmotic adjustment and stomatal closure, thereby providing an effective strategy to cope with local extreme arid environments.
Extracted statement — type of experiment: Lab
Research field: Ecology and Evolutionary Biology
Title: Phenotypic plasticity of an invasive acacia versus two native Mediterranean species
Abstract: <jats:p>

The phenotypic plasticity and the competitive ability of the invasive Acacia longifolia v. the indigenous Mediterranean dune species Halimium halimifolium and Pinus pinea were evaluated. In particular, we explored the hypothesis that phenotypic plasticity in response to biotic and abiotic factors explains the observed differences in competitiveness between invasive and native species. The seedlings’ ability to exploit different resource availabilities was examined in a two factorial experimental design of light and nutrient treatments by analysing 20 physiological and morphological traits. Competitiveness was tested using an additive experimental design in combination with 15N-labelling experiments. Light and nutrient availability had only minor effects on most physiological traits and differences between species were not significant. Plasticity in response to changes in resource availability occurred in morphological and allocation traits, revealing A. longifolia to be a species of intermediate responsiveness. The major competitive advantage of A. longifolia was its constitutively high shoot elongation rate at most resource treatments and its effective nutrient acquisition. Further, A. longifolia was found to be highly tolerant against competition from native species. In contrast to common expectations, the competition experiment indicated that A. longifolia expressed a constant allocation pattern and a phenotypic plasticity similar to that of the native species.
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Extracted statement — type of experiment: Lab
Research field: Ecology and Evolutionary Biology
Title: Predator-induced phenotypic plasticity in the exotic cladoceran Daphnia lumholtzi
Abstract: Summary 1. The exotic cladoceran Daphnia lumholtzi has recently invaded freshwater systems throughout the United States. Daphnia lumholtzi possesses extravagant head spines that are longer than those found on any other North American Daphnia. These spines are effective at reducing predation from many of the predators that are native to newly invaded habitats; however, they are plastic both in nature and in laboratory cultures. The purpose of this experiment was to better understand what environmental cues induce and maintain these effective predator-deterrent spines. We conducted life-table experiments on individual D. lumholtzi grown in water conditioned with an invertebrate insect predator, Chaoborus punctipennis, and water conditioned with a vertebrate fish predator, Lepomis macrochirus. 2. Daphnia lumholtzi exhibited morphological plasticity in response to kairomones released by both predators. However, direct exposure to predator kairomones during postembryonic development did not induce long spines in D. lumholtzi. In contrast, neonates produced from individuals exposed to Lepomis kairomones had significantly longer head and tail spines than neonates produced from control and Chaoborus individuals. These results suggest that there may be a maternal, or pre-embryonic, effect of kairomone exposure on spine development in D. lumholtzi. 3. Independent of these morphological shifts, D. lumholtzi also exhibited plasticity in life history characteristics in response to predator kairomones. For example, D. lumholtzi exhibited delayed reproduction in response to Chaoborus kairomones, and significantly more individuals produced resting eggs, or ephippia, in the presence of Lepomis kairomones.
Extracted statement — type of experiment: Lab
Research field: Ecology and Evolutionary Biology
Title: Behavioural plasticity associated with propagule size, resources, and the invasion success of the Argentine ant Linepithema humile
Abstract: Summary 1. The number of individuals involved in an invasion event, or ‘propagule size’, has a strong theoretical basis for influencing invasion success. However, rarely has propagule size been experimentally manipulated to examine changes in invader behaviour, and propagule longevity and success. 2. We manipulated propagule size of the invasive Argentine ant Linepithema humile in laboratory and field studies. Laboratory experiments involved L. humile propagules containing two queens and 10, 100, 200 or 1000 workers. Propagules were introduced into arenas containing colonies of queens and 200 workers of the competing native ant Monomorium antarcticum . The effects of food availability were investigated via treatments of only one central resource, or 10 separated resources. Field studies used similar colony sizes of L. humile , which were introduced into novel environments near an invasion front. 3. In laboratory studies, small propagules of L. humile were quickly annihilated. Only the larger propagule size survived and killed the native ant colony in some replicates. Aggression was largely independent of food availability, but the behaviour of L. humile changed substantially with propagule size. In larger propagules, aggressive behaviour was significantly more frequent, while L. humile were much more likely to avoid conflict in smaller propagules. 4. In field studies, however, propagule size did not influence colony persistence. Linepithema humile colonies persisted for up to 2 months, even in small propagules of 10 workers. Factors such as temperature or competitor abundance had no effect, although some colonies were decimated by M. antarcticum . 5. Synthesis and applications. Although propagule size has been correlated with invasion success in a wide variety of taxa, our results indicate that it will have limited predictive power with species displaying behavioural plasticity. We recommend that aspects of animal behaviour be given much more consideration in attempts to model invasion success. Secondly, areas of high biodiversity are thought to offer biotic resistance to invasion via the abundance of predators and competitors. Invasive pests such as L. humile appear to modify their behaviour according to local conditions, and establishment was not related to resource availability. We cannot necessarily rely on high levels of native biodiversity to repel invasions.
Extracted statement — type of experiment: Lab
Research field: Ecology and Evolutionary Biology
Title: Na emergent multiple predator effect may enhance biotic resistance in a stream fish assemblage
Abstract: While two cyprinid fishes introduced from nearby drainages have become widespread and abundant in the Eel River of northwestern California, a third nonindigenous cyprinid has remained largely confined to ≤25 km of one major tributary (the Van Duzen River) for at least 15 years. The downstream limit of this species, speckled dace, does not appear to correspond with any thresholds or steep gradients in abiotic conditions, but it lies near the upstream limits of three other fishes: coastrange sculpin, prickly sculpin, and nonindigenous Sacramento pikeminnow. We conducted a laboratory stream experiment to explore the potential for emergent multiple predator effects to influence biotic resistance in this situation. Sculpins in combination with Sacramento pikeminnow caused greater mortality of speckled dace than predicted based on their separate effects. In contrast to speckled dace, 99% of sculpin survived trials with Sacramento pikeminnow, in part because sculpin usually occupied benthic cover units while Sacramento pikeminnow occupied the water column. A 10-fold difference in benthic cover availability did not detectably influence biotic interactions in the experiment. The distribution of speckled dace in the Eel River drainage may be limited by two predator taxa with very different patterns of habitat use and a shortage of alternative habitats.
Extracted statement — type of experiment: Lab
Research field: Ecology and Evolutionary Biology
Title: Invasive fruits, novel foods, and choice: na investigation of european starling and american robin frugivory
Abstract: Abstract We compared the feeding choices of an invasive frugivore, the European Starling (Sturnus vulgaris), with those of a native, the American Robin (Turdus migratorius). Using captive birds, we tested whether these species differ in their preferences when offered a choice between a native and an invasive fruit, and between a novel and a familiar food. We examined willingness to eat fruits of selected invasive plants and to select a novel food by measuring the time elapsed before feeding began. Both species demonstrated significant preferences for invasive fruits over similar native fruits in two of three choice tests. Both starlings and robins ate autumn olive (Elaeagnus umbellata) fruits significantly more willingly than Asiatic bittersweet (Celastrus orbiculatus). Starlings, but not robins when choosing between a novel and a familiar food, strongly preferred the familiar food. We found no differences in willingness of birds to eat a novel food when it was the only food available. These results suggest that some fleshy-fruited invasive plants may receive more dispersal services than native plants with similar fruits, and that different frugivores may be seed dispersers for different invasive plants.
Extracted statement — type of experiment: Lab
Research field: Ecology and Evolutionary Biology
Title: Phenotypic variation of an alien species in a new environment: the body size and diet of American mink over time and at local and continental scales
Abstract: Introduced species must adapt their ecology, behaviour, and morphological traits to new conditions. The successful introduction and invasive potential of a species are related to its levels of phenotypic plasticity and genetic polymorphism. We analysed changes in the body mass and length of American mink (Neovison vison) since its introduction into the Warta Mouth National Park, western Poland, in relation to diet composition and colonization progress from 1996 to 2004. Mink body mass decreased significantly during the period of population establishment within the study area, with an average decrease of 13% from 1.36 to 1.18 kg in males and of 16% from 0.83 to 0.70 kg in females. Diet composition varied seasonally and between consecutive years. The main prey items were mammals and fish in the cold season and birds and fish in the warm season. During the study period the proportion of mammals preyed upon increased in the cold season and decreased in the warm season. The proportion of birds preyed upon decreased over the study period, whereas the proportion of fish increased. Following introduction, the strictly aquatic portion of mink diet (fish and frogs) increased over time, whereas the proportion of large prey (large birds, muskrats, and water voles) decreased. The average yearly proportion of large prey and average-sized prey in the mink diet was significantly correlated with the mean body masses of males and females. Biogeographical variation in the body mass and length of mink was best explained by the percentage of large prey in the mink diet in both sexes, and by latitude for females. Together these results demonstrate that American mink rapidly changed their body mass in relation to local conditions. This phenotypic variability may be underpinned by phenotypic plasticity and/or by adaptation of quantitative genetic variation. The potential to rapidly change phenotypic variation in this manner is an important factor determining the negative ecological impacts of invasive species. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 681–693.
Extracted statement — Investigated species: Mammals
Research field: Ecology and Evolutionary Biology
Title: Do biodiversity and human impact influence the introduction or establishment of alien mammals?
Abstract: What determines the number of alien species in a given region? ‘Native biodiversity’ and ‘human impact’ are typical answers to this question. Indeed, studies comparing different regions have frequently found positive relationships between number of alien species and measures of both native biodiversity (e.g. the number of native species) and human impact (e.g. human population). These relationships are typically explained by biotic acceptance or resistance, i.e. by influence of native biodiversity and human impact on the second step of the invasion process, establishment. The first step of the invasion process, introduction, has often been ignored. Here we investigate whether relationships between number of alien mammals and native biodiversity or human impact in 43 European countries are mainly shaped by differences in number of introduced mammals or establishment success. Our results suggest that correlation between number of native and established mammals is spurious, as it is simply explainable by the fact that both quantities are linked to country area. We also demonstrate that countries with higher human impact host more alien mammals than other countries because they received more introductions than other countries. Differences in number of alien mammals cannot be explained by differences in establishment success. Our findings highlight importance of human activities and question, at least for mammals in Europe, importance of biotic acceptance and resistance.
Extracted statement — Investigated species: Mammals
Research field: Ecology and Evolutionary Biology
Title: The short-term responses of small mammals to wildfire in semiarid mallee shrubland, Australia
Abstract: Context. Wildfire is a major driver of the structure and function of mallee eucalypt- and spinifex-dominated landscapes. Understanding how fire influences the distribution of biota in these fire-prone environments is essential for effective ecological and conservation-based management. Aims. We aimed to (1) determine the effects of an extensive wildfire (118 000 ha) on a small mammal community in the mallee shrublands of semiarid Australia and (2) assess the hypothesis that the fire-response patterns of small mammals can be predicted by their life-history characteristics. Methods. Small-mammal surveys were undertaken concurrently at 26 sites: once before the fire and on four occasions following the fire (including 14 sites that remained unburnt). We documented changes in small-mammal occurrence before and after the fire, and compared burnt and unburnt sites. In addition, key components of vegetation structure were assessed at each site. Key results. Wildfire had a strong influence on vegetation structure and on the occurrence of small mammals. The mallee ningaui, Ningaui yvonneae, a dasyurid marsupial, showed a marked decline in the immediate post-fire environment, corresponding with a reduction in hummock-grass cover in recently burnt vegetation. Species richness of native small mammals was positively associated with unburnt vegetation, although some species showed no clear response to wildfire. Conclusions. Our results are consistent with the contention that mammal responses to fire are associated with their known life-history traits. The species most strongly affected by wildfire, N. yvonneae, has the most specific habitat requirements and restricted life history of the small mammals in the study area. The only species positively associated with recently burnt vegetation, the introduced house mouse, Mus domesticus, has a flexible life history and non-specialised resource requirements. Implications. Maintaining sources for recolonisation after large-scale wildfires will be vital to the conservation of native small mammals in mallee ecosystems.
Extracted statement — Investigated species: Mammals
Research field: Ecology and Evolutionary Biology
Title: Mammals of the northern Philippines: tolerance for habitat disturbance and resistance to invasive species in an endemic insular fauna
Abstract: Aim Island faunas, particularly those with high levels of endemism, usually are considered especially susceptible to disruption from habitat disturbance and invasive alien species. We tested this general hypothesis by examining the distribution of small mammals along gradients of anthropogenic habitat disturbance in northern Luzon Island, an area with a very high level of mammalian endemism.
Extracted statement — Investigated species: Mammals
Research field: Ecology and Evolutionary Biology
Title: Treatment-based Markov chain models clarify mechanisms of invasion in na invaded grassland community
Abstract: What are the relative roles of mechanisms underlying plant responses in grassland communities invaded by both plants and mammals? What type of community can we expect in the future given current or novel conditions? We address these questions by comparing Markov chain community models among treatments from a field experiment on invasive species on Robinson Crusoe Island, Chile. Because of seed dispersal, grazing and disturbance, we predicted that the exotic European rabbit (Oryctolagus cuniculus) facilitates epizoochorous exotic plants (plants with seeds that stick to the skin an animal) at the expense of native plants. To test our hypothesis, we crossed rabbit exclosure treatments with disturbance treatments, and sampled the plant community in permanent plots over 3 years. We then estimated Markov chain model transition probabilities and found significant differences among treatments. As hypothesized, this modelling revealed that exotic plants survive better in disturbed areas, while natives prefer no rabbits or disturbance. Surprisingly, rabbits negatively affect epizoochorous plants. Markov chain dynamics indicate that an overall replacement of native plants by exotic plants is underway. Using a treatment-based approach to multi-species Markov chain models allowed us to examine the changes in the importance of mechanisms in response to experimental impacts on communities.
Extracted statement — Investigated species: Mammals
Research field: Ecology and Evolutionary Biology
Title: Linking the pattern to the mechanism: how na introduced mammal facilitates plant invasions
Abstract: Non-native mammals that are disturbance agents can promote non-native plant invasions, but to date there is scant evidence on the mechanisms behind this pattern. We used wild boar (Sus scrofa) as a model species to evaluate the role of non-native mammals in promoting plant invasion by identifying the degree to which soil disturbance and endozoochorous seed dispersal drive plant invasions. To test if soil disturbance promotes plant invasion, we conducted an exclosure experiment in which we recorded emergence, establishment and biomass of seedlings of seven non-native plant species planted in no-rooting, boar-rooting and artificial rooting patches in Patagonia, Argentina. To examine the role of boar in dispersing seeds we germinated viable seeds from 181 boar droppings and compared this collection to the soil seed bank by collecting a soil sample adjacent to each dropping. We found that both establishment and biomass of non-native seedlings in boar-rooting patches were double those in no-rooting patches. Values in artificial rooting patches were intermediate between those in boar-rooting and no-rooting treatments. By contrast, we found that the proportion of non-native seedlings in the soil samples was double that in the droppings, and over 80% of the germinated seeds were native species in both samples. Lastly, an effect size test showed that soil disturbance by wild boar rather than endozoochorous dispersal facilitates plant invasions. These results have implications for both the native and introduced ranges of wild boar, where rooting disturbance may facilitate community composition shifts.
Extracted statement — Investigated species: Mammals