Moussab/ORKG-training-evaluation-set huggingface dataset:
Research field: Ecology and Evolutionary Biology
Title: Differentiating successful and failed molluscan invaders in estuarine ecosystems
Abstract: ABSTRACT: Despite mounting evidence of invasive species’ impacts on the environment and society,our ability to predict invasion establishment, spread, and impact are inadequate. Efforts to explainand predict invasion outcomes have been limited primarily to terrestrial and freshwater ecosystems.Invasions are also common in coastal marine ecosystems, yet to date predictive marine invasion mod-els are absent. Here we present a model based on biological attributes associated with invasion suc-cess (establishment) of marine molluscs that compares successful and failed invasions from a groupof 93 species introduced to San Francisco Bay (SFB) in association with commercial oyster transfersfrom eastern North America (ca. 1869 to 1940). A multiple logistic regression model correctly classi-fied 83% of successful and 80% of failed invaders according to their source region abundance at thetime of oyster transfers, tolerance of low salinity, and developmental mode. We tested the generalityof the SFB invasion model by applying it to 3 coastal locations (2 in North America and 1 in Europe)that received oyster transfers from the same source and during the same time as SFB. The model cor-rectly predicted 100, 75, and 86% of successful invaders in these locations, indicating that abun-dance, environmental tolerance (ability to withstand low salinity), and developmental mode not onlyexplain patterns of invasion success in SFB, but more importantly, predict invasion success in geo-graphically disparate marine ecosystems. Finally, we demonstrate that the proportion of marine mol-luscs that succeeded in the latter stages of invasion (i.e. that establish self-sustaining populations,spread and become pests) is much greater than has been previously predicted or shown for otheranimals and plants.KEY WORDS: Invasion · Bivalve · Gastropod · Mollusc · Marine · Oyster · Vector · Risk assessment
Extracted statement — Investigated species: Molluscs
Research field: Ecology and Evolutionary Biology
Title: Invasiveness of Ammophila arenaria: Release from soil-borne pathogens?
Abstract: The Natural Enemies Hypothesis (i.e., introduced species experience release from their natural enemies) is a common explanation for why invasive species are so successful. We tested this hypothesis for Ammophila arenaria (Poaceae: European beachgrass), an aggressive plant invading the coastal dunes of California, USA, by comparing the demographic effects of belowground pathogens on A. arenaria in its introduced range to those reported in its native range. European research on A. arenaria in its native range has established that soil-borne pathogens, primarily nematodes and fungi, reduce A. arenaria's growth. In a greenhouse experiment designed to parallel European studies, seeds and 2-wk-old seedlings were planted in sterilized and nonsterilized soil collected from the A. arenaria root zone in its introduced range of California. We assessed the effects of pathogens via soil sterilization on three early performance traits: seed germination, seedling survival, and plant growth. We found that seed germinatio...
Extracted statement — Indicator for enemy release: Performance
Research field: Ecology and Evolutionary Biology
Title: Plant-soil biota interactions and spatial distribution of black cherry in its native and invasive ranges
Abstract: One explanation for the higher abundance of invasive species in their non-native than native ranges is the escape from natural enemies. But there are few experimental studies comparing the parallel impact of enemies (or competitors and mutualists) on a plant species in its native and invaded ranges, and release from soil pathogens has been rarely investigated. Here we present evidence showing that the invasion of black cherry (Prunus serotina) into north-western Europe is facilitated by the soil community. In the native range in the USA, the soil community that develops near black cherry inhibits the establishment of neighbouring conspecifics and reduces seedling performance in the greenhouse. In contrast, in the non-native range, black cherry readily establishes in close proximity to conspecifics, and the soil community enhances the growth of its seedlings. Understanding the effects of soil organisms on plant abundance will improve our ability to predict and counteract plant invasions.
Extracted statement — Indicator for enemy release: Performance
Research field: Ecology and Evolutionary Biology
Title: Herbivory, disease, recruitment limitation, and success of alien and native tree species
Abstract: The Enemies Hypothesis predicts that alien plants have a competitive ad- vantage over native plants because they are often introduced with few herbivores or diseases. To investigate this hypothesis, we transplanted seedlings of the invasive alien tree, Sapium sebiferum (Chinese tallow tree) and an ecologically similar native tree, Celtis laevigata (hackberry), into mesic forest, floodplain forest, and coastal prairie sites in east Texas and manipulated foliar fungal diseases and insect herbivores with fungicidal and insecticidal sprays. As predicted by the Enemies Hypothesis, insect herbivores caused significantly greater damage to untreated Celtis seedlings than to untreated Sapium seedlings. However, contrary to predictions, suppression of insect herbivores caused significantly greater in- creases in survivorship and growth of Sapium seedlings compared to Celtis seedlings. Regressions suggested that Sapium seedlings compensate for damage in the first year but that this greatly increases the risk of mortality in subsequent years. Fungal diseases had no effects on seedling survival or growth. The Recruitment Limitation Hypothesis predicts that the local abundance of a species will depend more on local seed input than on com- petitive ability at that location. To investigate this hypothesis, we added seeds of Celtis and Sapium on and off of artificial soil disturbances at all three sites. Adding seeds increased the density of Celtis seedlings and sometimes Sapium seedlings, with soil disturbance only affecting density of Celtis. Together the results of these experiments suggest that the success of Sapium may depend on high rates of seed input into these ecosystems and high growth potential, as well as performance advantages of seedlings caused by low rates of herbivory.
Extracted statement — Indicator for enemy release: Performance
Research field: Ecology and Evolutionary Biology
Title: The interaction between soil nutrients and leaf loss during early 14 establishment in plant invasion
Abstract: Nitrogen availability affects both plant growth and the preferences of herbivores. We hypothesized that an interaction between these two factors could affect the early establishment of native and exotic species differently, promoting invasion in natural systems. Taxonomically paired native and invasive species (Acer platanoides, Acer rubrum, Lonicera maackii, Diervilla lonicera, Celastrus orbiculata, Celastrus scandens, Elaeagnus umbellata, Ceanothus americanus, Ampelopsis brevipedunculata, and Vitis riparia) were grown in relatively high-resource (hardwood forests) and low-resource (pine barrens) communities on Long Island, New York, for a period of 3 months. Plants were grown in ambient and nitrogen-enhanced conditions in both communities. Nitrogen additions produced an average 12% initial increase in leaf number of all plants. By the end of the experiment, invasive species outperformed native species in nitrogen-enhanced plots in hardwood forests, where all plants experienced increased damage relative to control plots. Native species experienced higher overall amounts of damage in hardwood forests, losing, on average, 45% more leaves than exotic species, and only native species experienced a decline in growth rates (32% compared with controls). In contrast, in pine barrens, there were no differences in damage and no differences in performance between native and invasive plants. Our results suggest that unequal damage by natural enemies may play a role in determining community composition by shifting the competitive advantage to exotic species in nitrogen-enhanced environments. FOR. SCI. 53(6):701-709.
Extracted statement — Indicator for enemy release: Performance
Research field: Ecology and Evolutionary Biology
Title: Experimental field comparison of native and non-native maple seedlings: natural enemies, ecophysiology, growth and survival
Abstract: 1 Acer platanoides (Norway maple) is an important non‐native invasive canopy tree in North American deciduous forests, where native species diversity and abundance are greatly reduced under its canopy. We conducted a field experiment in North American forests to compare planted seedlings of A. platanoides and Acer saccharum (sugar maple), a widespread, common native that, like A. platanoides, is shade tolerant. Over two growing seasons in three forests we compared multiple components of seedling success: damage from natural enemies, ecophysiology, growth and survival. We reasoned that equal or superior performance by A. platanoides relative to A. saccharum indicates seedling characteristics that support invasiveness, while inferior performance indicates potential barriers to invasion. 2 Acer platanoides seedlings produced more leaves and allocated more biomass to roots, A. saccharum had greater water use efficiency, and the two species exhibited similar photosynthesis and first‐season mortality rates. Acer platanoides had greater winter survival and earlier spring leaf emergence, but second‐season mortality rates were similar. 3 The success of A. platanoides seedlings was not due to escape from natural enemies, contrary to the enemy release hypothesis. Foliar insect herbivory and disease symptoms were similarly high for both native and non‐native, and seedling biomass did not differ. Rather, A. platanoides compared well with A. saccharum because of its equivalent ability to photosynthesize in the low light herb layer, its higher leaf production and greater allocation to roots, and its lower winter mortality coupled with earlier spring emergence. Its only potential barrier to seedling establishment, relative to A. saccharum, was lower water use efficiency, which possibly could hinder its invasion into drier forests. 4 The spread of non‐native canopy trees poses an especially serious problem for native forest communities, because canopy trees strongly influence species in all forest layers. Success at reaching the canopy depends on a tree's ecology in previous life‐history stages, particularly as a vulnerable seedling, but little is known about seedling characteristics that promote non‐native tree invasion. Experimental field comparison with ecologically successful native trees provides insight into why non‐native trees succeed as seedlings, which is a necessary stage on their journey into the forest canopy.
Extracted statement — Indicator for enemy release: Performance
Research field: Ecology and Evolutionary Biology
Title: Testing hypotheses for exotic plant success: parallel experiments in the native and introduced ranges
Abstract: A central question in ecology concerns how some exotic plants that occur at low densities in their native range are able to attain much higher densities where they are introduced. This question has remained unresolved in part due to a lack of experiments that assess factors that affect the population growth or abundance of plants in both ranges. We tested two hypotheses for exotic plant success: escape from specialist insect herbivores and a greater response to disturbance in the introduced range. Within three introduced populations in Montana, USA, and three native populations in Germany, we experimentally manipulated insect herbivore pressure and created small-scale disturbances to determine how these factors affect the performance of houndstongue (Cynoglossum officinale), a widespread exotic in western North America. Herbivores reduced plant size and fecundity in the native range but had little effect on plant performance in the introduced range. Small-scale experimental disturbances enhanced seedling recruitment in both ranges, but subsequent seedling survival was more positively affected by disturbance in the introduced range. We combined these experimental results with demographic data from each population to parameterize integral projection population models to assess how enemy escape and disturbance might differentially influence C. officinale in each range. Model results suggest that escape from specialist insects would lead to only slight increases in the growth rate (lambda) of introduced populations. In contrast, the larger response to disturbance in the introduced vs. native range had much greater positive effects on lambda. These results together suggest that, at least in the regions where the experiments were performed, the differences in response to small disturbances by C. officinale contribute more to higher abundance in the introduced range compared to at home. Despite the challenges of conducting experiments on a wide biogeographic scale and the logistical constraints of adequately sampling populations within a range, this approach is a critical step forward to understanding the success of exotic plants.
Extracted statement — Indicator for enemy release: Performance
Research field: Ecology and Evolutionary Biology
Title: Remote analysis of biological invasion and the impact of enemy release
Abstract: Escape from natural enemies is a widely held generalization for the success of exotic plants. We conducted a large-scale experiment in Hawaii (USA) to quantify impacts of ungulate removal on plant growth and performance, and to test whether elimination of an exotic generalist herbivore facilitated exotic success. Assessment of impacted and control sites before and after ungulate exclusion using airborne imaging spectroscopy and LiDAR, time series satellite observations, and ground-based field studies over nine years indicated that removal of generalist herbivores facilitated exotic success, but the abundance of native species was unchanged. Vegetation cover <1 m in height increased in ungulate-free areas from 48.7% +/- 1.5% to 74.3% +/- 1.8% over 8.4 years, corresponding to an annualized growth rate of lambda = 1.05 +/- 0.01 yr(-1) (median +/- SD). Most of the change was attributable to exotic plant species, which increased from 24.4% +/- 1.4% to 49.1% +/- 2.0%, (lambda = 1.08 +/- 0.01 yr(-1)). Native plants experienced no significant change in cover (23.0% +/- 1.3% to 24.2% +/- 1.8%, lambda = 1.01 +/- 0.01 yr(-1)). Time series of satellite phenology were indistinguishable between the treatment and a 3.0-km2 control site for four years prior to ungulate removal, but they diverged immediately following exclusion of ungulates. Comparison of monthly EVI means before and after ungulate exclusion and between the managed and control areas indicates that EVI strongly increased in the managed area after ungulate exclusion. Field studies and airborne analyses show that the dominant invader was Senecio madagascariensis, an invasive annual forb that increased from < 0.01% to 14.7% fractional cover in ungulate-free areas (lambda = 1.89 +/- 0.34 yr(-1)), but which was nearly absent from the control site. A combination of canopy LAI, water, and fractional cover were expressed in satellite EVI time series and indicate that the invaded region maintained greenness during drought conditions. These findings demonstrate that enemy release from generalist herbivores can facilitate exotic success and suggest a plausible mechanism by which invasion occurred. They also show how novel remote-sensing technology can be integrated with conservation and management to help address exotic plant invasions.
Extracted statement — Indicator for enemy release: Performance
Research field: Ecology and Evolutionary Biology
Title: Little evidence for release from herbivores as a driver of plant invasiveness from a multi-species herbivore-removal experiment
Abstract: Enemy release is frequently posed as a main driver of invasiveness of alien species. However, an experimental multi-species test examining performance and herbivory of invasive alien, non-invasive alien and native plant species in the presence and absence of natural enemies is lacking. In a common garden experiment in Switzerland, we manipulated exposure of seven alien invasive, eight alien non-invasive and fourteen native species from six taxonomic groups to natural enemies (invertebrate herbivores), by applying a pesticide treatment under two different nutrient levels. We assessed biomass production, herbivore damage and the major herbivore taxa on plants. Across all species, plants gained significantly greater biomass under pesticide treatment. However, invasive, non-invasive and native species did not differ in their biomass response to pesticide treatment at either nutrient level. The proportion of leaves damaged on invasive species was significantly lower compared to native species, but not when compared to non-invasive species. However, the difference was lost when plant size was accounted for. There were no differences between invasive, non-invasive and native species in herbivore abundance. Our study offers little support for invertebrate herbivore release as a driver of plant invasiveness, but suggests that future enemy release studies should account for differences in plant size among species.
Extracted statement — Indicator for enemy release: Performance
Research field: Ecology and Evolutionary Biology
Title: Plant functional group identity and diversity determine biotic resistance to invasion by an exotic grass
Abstract: Biotic resistance, the ability of species in a community to limit invasion, is central to our understanding of how communities at risk of invasion assemble after disturbances, but it has yet to translate into guiding principles for the restoration of invasion‐resistant plant communities. We combined experimental, functional, and modelling approaches to investigate processes of community assembly contributing to biotic resistance to an introduced lineage of Phragmites australis, a model invasive species in North America. We hypothesized that (i) functional group identity would be a good predictor of biotic resistance to P. australis, while species identity effect would be redundant within functional group (ii) mixtures of species would be more invasion resistant than monocultures. We classified 36 resident wetland plants into four functional groups based on eight functional traits. We conducted two competition experiments based on the additive competition design with P. australis and monocultures or mixtures of wetland plants. As an indicator of biotic resistance, we calculated a relative competition index (RCIavg) based on the average performance of P. australis in competition treatment compared with control. To explain diversity effect further, we partitioned it into selection effect and complementarity effect and tested several diversity–interaction models. In monoculture treatments, RCIavg of wetland plants was significantly different among functional groups, but not within each functional group. We found the highest RCIavg for fast‐growing annuals, suggesting priority effect. RCIavg of wetland plants was significantly greater in mixture than in monoculture mainly due to complementarity–diversity effect among functional groups. In diversity–interaction models, species interaction patterns in mixtures were described best by interactions between functional groups when fitted to RCIavg or biomass, implying niche partitioning. Synthesis. Functional group identity and diversity of resident plant communities are good indicators of biotic resistance to invasion by introduced Phragmites australis, suggesting niche pre‐emption (priority effect) and niche partitioning (diversity effect) as underlying mechanisms. Guiding principles to understand and/or manage biological invasion could emerge from advances in community theory and the use of a functional framework. Targeting widely distributed invasive plants in different contexts and scaling up to field situations will facilitate generalization.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Plant functional group diversity as a mechanism for invasion resistance
Abstract: A commonly cited mechanism for invasion resistance is more complete resource use by diverse plant assemblages with maximum niche complementarity. We investigated the invasion resistance of several plant functional groups against the nonindigenous forb Spotted knapweed (Centaurea maculosa). The study consisted of a factorial combination of seven functional group removals (groups singularly or in combination) and two C. maculosa treatments (addition vs. no addition) applied in a randomized complete block design replicated four times at each of two sites. We quantified aboveground plant material nutrient concentration and uptake (concentration × biomass) by indigenous functional groups: grasses, shallow‐rooted forbs, deep‐rooted forbs, spikemoss, and the nonindigenous invader C. maculosa. In 2001, C. maculosa density depended upon which functional groups were removed. The highest C. maculosa densities occurred where all vegetation or all forbs were removed. Centaurea maculosa densities were the lowest in plots where nothing, shallow‐rooted forbs, deep‐rooted forbs, grasses, or spikemoss were removed. Functional group biomass was also collected and analyzed for nitrogen, phosphorus, potassium, and sulphur. Based on covariate analyses, postremoval indigenous plot biomass did not relate to invasion by C. maculosa. Analysis of variance indicated that C. maculosa tissue nutrient percentage and net nutrient uptake were most similar to indigenous forb functional groups. Our study suggests that establishing and maintaining a diversity of plant functional groups within the plant community enhances resistance to invasion. Indigenous plants of functionally similar groups as an invader may be particularly important in invasion resistance.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: The role of diversity and functional traits of species in community invasibility
Abstract: The invasion of exotic species into assemblages of native plants is a pervasive and widespread phenomenon. Many theoretical and observational studies suggest that diverse communities are more resistant to invasion by exotic species than less diverse ones. However, experimental results do not always support such a relationship. Therefore, the hypothesis of diversity-community invasibility is still a focus of controversy in the field of invasion ecology. In this study, we established and manipulated communities with different species diversity and different species functional groups (16 species belong to C3, C4, forbs and legumes, respectively) to test Elton's hypothesis and other relevant hypotheses by studying the process of invasion. Alligator weed (Alternanthera philoxeroides) was chosen as the invader. We found that the correlation between the decrement of extractable soil nitrogen and biomass of alligator weed was not significant, and that species diversity, independent of functional groups diversity, did not show a significant correlation with invasibility. However, the communities with higher functional groups diversity significantly reduced the biomass of alligator weed by decreasing its resource opportunity. Functional traits of species also influenced the success of the invasion. Alternanthera sessilis, in the same morphological and functional group as alligator weed, was significantly resistant to alligator weed invasion. Because community invasibility is influenced by many factors and interactions among them, the pattern and mechanisms of community invasibility are likely to be far subtler than we found in this study. More careful manipulated experiments coupled with theoretical modeling studies are essential steps to a more profound understanding of community invasibility.
Extracted statement — Investigated species: Plants