Moussab/ORKG-training-evaluation-set huggingface dataset:
Research field: Ecology and Evolutionary Biology
Title: VARIATION IN PHENOTYPIC PLASTICITY AMONG NATIVE AND INVASIVE POPULATIONS OF ALLIARIA PETIOLATA
Abstract: Alliaria petiolata is a Eurasian biennial herb that is invasive in North America and for which phenotypic plasticity has been noted as a potentially important invasive trait. Using four European and four North American populations, we explored variation among populations in the response of a suite of antioxidant, antiherbivore, and morphological traits to the availability of water and nutrients and to jasmonic acid treatment. Multivariate analyses revealed substantial variation among populations in mean levels of these traits and in the response of this suite of traits to environmental variation, especially water availability. Univariate analyses revealed variation in plasticity among populations in the expression of all of the traits measured to at least one of these environmental factors, with the exception of leaf length. There was no evidence for continentally distinct plasticity patterns, but there was ample evidence for variation in phenotypic plasticity among the populations within continents. This implies that A. petiolata has the potential to evolve distinct phenotypic plasticity patterns within populations but that invasive populations are no more plastic than native populations.
Extracted statement — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Functional differences in response to drought in the invasive Taraxacum officinale from native and introduced alpine habitat ranges
Abstract: Background: Phenotypic plasticity and ecotypic differentiation have been suggested as the main mechanisms by which widely distributed species can colonise broad geographic areas with variable and stressful conditions. Some invasive plant species are among the most widely distributed plants worldwide. Plasticity and local adaptation could be the mechanisms for colonising new areas. Aims: We addressed if Taraxacum officinale from native (Alps) and introduced (Andes) stock responded similarly to drought treatment, in terms of photosynthesis, foliar angle, and flowering time. We also evaluated if ontogeny affected fitness and physiological responses to drought. Methods: We carried out two common garden experiments with both seedlings and adults (F2) of T. officinale from its native and introduced ranges in order to evaluate their plasticity and ecotypic differentiation under a drought treatment. Results: Our data suggest that the functional response of T. officinale individuals from the introduced range to drought is the result of local adaptation rather than plasticity. In addition, the individuals from the native distribution range were more sensitive to drought than those from the introduced distribution ranges at both seedling and adult stages. Conclusions: These results suggest that local adaptation may be a possible mechanism underlying the successful invasion of T. officinale in high mountain environments of the Andes.
Extracted statement — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Morphological differentiation of introduced pikeperch (Sander lucioperca L., 1758) populations in Tunisian freshwaters
Abstract: Summary In order to evaluate the phenotypic plasticity of introduced pikeperch populations in Tunisia, the intra- and interpopulation differentiation was analysed using a biometric approach. Thus, nine meristic counts and 23 morphological measurements were taken from 574 specimens collected from three dams and a hill lake. The univariate (anova) and multivariate analyses (PCA and DFA) showed a low meristic variability between the pikeperch samples and a segregated pikeperch group from the Sidi Salem dam which displayed a high distance between mouth and pectoral fin and a high antedorsal distance. In addition, the Korba hill lake population seemed to have more important values of total length, eye diameter, maximum body height and a higher distance between mouth and operculum than the other populations. However, the most accentuated segregation was found in the Lebna sample where the individuals were characterized by high snout length, body thickness, pectoral fin length, maximum body height and distance between mouth and operculum. This study shows the existence of morphological differentiations between populations derived from a single gene pool that have been isolated in separated sites for several decades although in relatively similar environments.
Extracted statement — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Elevational distribution limits of non-native species: combining observational and experimental evidence
Abstract: Background: In temperate mountains, most non-native plant species reach their distributional limit somewhere along the elevational gradient. However, it is unclear if growth limitations can explain upper range limits and whether phenotypic plasticity or genetic changes allow species to occupy a broad elevational gradient. Aims: We investigated how non-native plant individuals from different elevations responded to growing season temperatures, which represented conditions at the core and margin of the elevational distributions of the species. Methods: We recorded the occurrence of nine non-native species in the Swiss Alps and subsequently conducted a climate chamber experiment to assess growth rates of plants from different elevations under different temperature treatments. Results: The elevational limit observed in the field was not related to the species' temperature response in the climate chamber experiment. Almost all species showed a similar level of reduction in growth rates under lower temperatures independent of the upper elevational limit of the species' distribution. For two species we found indications for genetic differentiation among plants from different elevations. Conclusions: We conclude that factors other than growing season temperatures, such as extreme events or winter mortality, might shape the elevational limit of non-native species, and that ecological filtering might select for genotypes that are phenotypically plastic.
Extracted statement — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Invasion strategies in clonal aquatic plants: are phenotypic differences caused by phenotypic plasticity or local adaptation? 
Abstract: BACKGROUND AND AIMS The successful spread of invasive plants in new environments is often linked to multiple introductions and a diverse gene pool that facilitates local adaptation to variable environmental conditions. For clonal plants, however, phenotypic plasticity may be equally important. Here the primary adaptive strategy in three non-native, clonally reproducing macrophytes (Egeria densa, Elodea canadensis and Lagarosiphon major) in New Zealand freshwaters were examined and an attempt was made to link observed differences in plant morphology to local variation in habitat conditions. METHODS Field populations with a large phenotypic variety were sampled in a range of lakes and streams with different chemical and physical properties. The phenotypic plasticity of the species before and after cultivation was studied in a common garden growth experiment, and the genetic diversity of these same populations was also quantified. KEY RESULTS For all three species, greater variation in plant characteristics was found before they were grown in standardized conditions. Moreover, field populations displayed remarkably little genetic variation and there was little interaction between habitat conditions and plant morphological characteristics. CONCLUSIONS The results indicate that at the current stage of spread into New Zealand, the primary adaptive strategy of these three invasive macrophytes is phenotypic plasticity. However, while limited, the possibility that genetic diversity between populations may facilitate ecotypic differentiation in the future cannot be excluded. These results thus indicate that invasive clonal aquatic plants adapt to new introduced areas by phenotypic plasticity. Inorganic carbon, nitrogen and phosphorous were important in controlling plant size of E. canadensis and L. major, but no other relationships between plant characteristics and habitat conditions were apparent. This implies that within-species differences in plant size can be explained by local nutrient conditions. All together this strongly suggests that invasive clonal aquatic plants adapt to a wide range of habitats in introduced areas by phenotypic plasticity rather than local adaptation.
Extracted statement — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Phenotypic plasticity of thermal tolerance contributes to the invasion potential of Mediterranean fruit flies (Ceratitis capitata) 
Abstract: 1. The invasion success of Ceratitis capitata probably stems from physiological, morphological, and behavioural adaptations that enable them to survive in different habitats. However, it is generally poorly understood if variation in acute thermal tolerance and its phenotypic plasticity might be important in facilitating survival of C. capitata upon introduction to novel environments.
Extracted statement — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Evolution of dispersal traits along an invasion route in the wind-dispersed Senecio inaequidens (Asteraceae) 
Abstract: In introduced organisms, dispersal propensity is expected to increase during range expansion. This prediction is based on the assumption that phenotypic plasticity is low compared to genetic diversity, and an increase in dispersal can be counteracted by the Allee effect. Empirical evidence in support of these hypotheses is however lacking. The present study tested for evidence of differentiation in dispersal-related traits and the Allee effect in the wind-dispersed invasive Senecio inaequidens (Asteraceae). We collected capitula from individuals in ten field populations, along an invasion route including the original introduction site in southern France. In addition, we conducted a common garden experiment from field-collected seeds and obtained capitula from individuals representing the same ten field populations. We analysed phenotypic variation in dispersal traits between field and common garden environments as a function of the distance between populations and the introduction site. Our results revealed low levels of phenotypic differentiation among populations. However, significant clinal variation in dispersal traits was demonstrated in common garden plants representing the invasion route. In field populations, similar trends in dispersal-related traits and evidence of an Allee effect were not detected. In part, our results supported expectations of increased dispersal capacity with range expansion, and emphasized the contribution of phenotypic plasticity under natural conditions.
Extracted statement — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Understanding the consequences of seed dispersal in a heterogeneous environment 
Abstract: Plant distributions are in part determined by environmental heterogeneity on both large (landscape) and small (several meters) spatial scales. Plant populations can respond to environmental heterogeneity via genetic differentiation between large distinct patches, and via phenotypic plasticity in response to heterogeneity occurring at small scales relative to dispersal distance. As a result, the level of environmental heterogeneity experienced across generations, as determined by seed dispersal distance, may itself be under selection. Selection could act to increase or decrease seed dispersal distance, depending on patterns of heterogeneity in environmental quality with distance from a maternal home site. Serpentine soils, which impose harsh and variable abiotic stress on non-adapted plants, have been partially invaded by Erodium cicutarium in northern California, USA. Using nearby grassland sites characterized as either serpentine or non-serpentine, we collected seeds from dense patches of E. cicutarium on both soil types in spring 2004 and subsequently dispersed those seeds to one of four distances from their maternal home site (0, 0.5, 1, or 10 m). We examined distance-dependent patterns of variation in offspring lifetime fitness, conspecific density, soil availability, soil water content, and aboveground grass and forb biomass. ANOVA revealed a distinct fitness peak when seeds were dispersed 0.5 m from their maternal home site on serpentine patches. In non-serpentine patches, fitness was reduced only for seeds placed back into the maternal home site. Conspecific density was uniformly high within 1 m of a maternal home site on both soils, whereas soil water content and grass biomass were significantly heterogeneous among dispersal distances only on serpentine soils. Structural equation modeling and multigroup analysis revealed significantly stronger direct and indirect effects linking abiotic and biotic variation to offspring performance on serpentine soils than on non-serpentine soils, indicating the potential for soil-specific selection on seed dispersal distance in this invasive species.
Extracted statement — hypothesis: Phenotypic plasticity
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 — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Phenotypic variability in Holcus lanatus L. in southern Chile: a strategy that enhances plant survival and pasture stability
Abstract: <jats:p>

Holcus lanatus L. can colonise a wide range of sites within the naturalised grassland of the Humid Dominion of Chile. The objectives were to determine plant growth mechanisms and strategies that have allowed H. lanatus to colonise contrasting pastures and to determine the existence of ecotypes of H. lanatus in southern Chile. Plants of H. lanatus were collected from four geographic zones of southern Chile and established in a randomised complete block design with four replicates. Five newly emerging tillers were marked per plant and evaluated at the vegetative, pre-ear emergence, complete emerged inflorescence, end of flowering period, and mature seed stages. At each evaluation, one marked tiller was harvested per plant. The variables measured included lamina length and width, tiller height, length of the inflorescence, total number of leaves, and leaf, stem, and inflorescence mass. At each phenological stage, groups of accessions were statistically formed using cluster analysis. The grouping of accessions (cluster analysis) into statistically different groups (ANOVA and canonical variate analysis) indicated the existence of different ecotypes. The phenotypic variation within each group of the accessions suggested that each group has its own phenotypic plasticity. It is concluded that the successful colonisation by H. lanatus has resulted from diversity within the species.
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Extracted statement — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Differences in plasticity between invasive and native plants from a low resource environment
Abstract: 1 Phenotypic plasticity is often cited as an important mechanism of plant invasion. However, few studies have evaluated the plasticity of a diverse set of traits among invasive and native species, particularly in low resource habitats, and none have examined the functional significance of these traits. 2 I explored trait plasticity in response to variation in light and nutrient availability in five phylogenetically related pairs of native and invasive species occurring in a nutrient‐poor habitat. In addition to the magnitude of trait plasticity, I assessed the correlation between 16 leaf‐ and plant‐level traits and plant performance, as measured by total plant biomass. Because plasticity for morphological and physiological traits is thought to be limited in low resource environments (where native species usually display traits associated with resource conservation), I predicted that native and invasive species would display similar, low levels of trait plasticity. 3 Across treatments, invasive and native species within pairs differed with respect to many of the traits measured; however, invasive species as a group did not show consistent patterns in the direction of trait values. Relative to native species, invasive species displayed high plasticity in traits pertaining to biomass partitioning and leaf‐level nitrogen and light use, but only in response to nutrient availability. Invasive and native species showed similar levels of resource‐use efficiency and there was no relationship between species plasticity and resource‐use efficiency across species. 4 Traits associated with carbon fixation were strongly correlated with performance in invasive species while only a single resource conservation trait was strongly correlated with performance in multiple native species. Several highly plastic traits were not strongly correlated with performance which underscores the difficulty in assessing the functional significance of resource conservation traits over short timescales and calls into question the relevance of simple, quantitative assessments of trait plasticity. 5 Synthesis. My data support the idea that invasive species display high trait plasticity. The degree of plasticity observed here for species occurring in low resource systems corresponds with values observed in high resource systems, which contradicts the general paradigm that trait plasticity is constrained in low resource systems. Several traits were positively correlated with plant performance suggesting that trait plasticity will influence plant fitness.
Extracted statement — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Major morphological changes in a Lake Victoria cichlid fish within two decades
Abstract: During the upsurge of the introduced predatory Nile perch in Lake Victoria in the 1980s, the zooplanktivorous Haplochromis (Yssichromis) pyrrhocephalus nearly vanished. The species recovered coincident with the intense fishing of Nile perch in the 1990s, when water clarity and dissolved oxygen levels had decreased dramatically due to increased eutrophication. In response to the hypoxic conditions, total gill surface in resurgent H. pyrrhocephalus increased by 64%. Remarkably, head length, eye length, and head volume decreased in size, whereas cheek depth increased. Reductions in eye size and depth of the rostral part of the musculus sternohyoideus, and reallocation of space between the opercular and suspensorial compartments of the head may have permitted accommodation of larger gills in a smaller head. By contrast, the musculus levator posterior, located dorsal to the gills, increased in depth. This probably reflects an adaptive response to the larger and tougher prey types in the diet of resurgent H. pyrrhocephalus. These striking morphological changes over a time span of only two decades could be the combined result of phenotypic plasticity and genetic change and may have fostered recovery of this species.
Extracted statement — hypothesis: Phenotypic plasticity
Research field: Ecology and Evolutionary Biology
Title: Spreading of the invasive Carpobrotus aff. acinaciformis in Mediterranean ecosystems: The advantage of performing in different light environments
Abstract: ABSTRACT Question: Do specific environmental conditions affect the performance and growth dynamics of one of the most invasive taxa (Carpobrotus aff. acinaciformis) on Mediterranean islands? Location: Four populations located on Mallorca, Spain. Methods: We monitored growth rates of main and lateral shoots of this stoloniferous plant for over two years (2002–2003), comparing two habitats (rocky coast vs. coastal dune) and two different light conditions (sun vs. shade). In one population of each habitat type, we estimated electron transport rate and the level of plant stress (maximal photochemical efficiency Fv/Fm) by means of chlorophyll fluorescence. Results: Main shoots of Carpobrotus grew at similar rates at all sites, regardless habitat type. However, growth rate of lateral shoots was greater in shaded plants than in those exposed to sunlight. Its high phenotypic plasticity, expressed in different allocation patterns in sun and shade individuals, and its clonal growth which promotes the continuous sea...
Extracted statement — hypothesis: Phenotypic plasticity