Moussab/ORKG-training-evaluation-set huggingface dataset:
Research field: Ecology and Evolutionary Biology
Title: Effects of fungal pathogens on seeds of native and exotic plants: a test using congeneric pairs 
Abstract: Summary 1 It has previously been hypothesized that low rates of attack by natural enemies may contribute to the invasiveness of exotic plants. 2 We tested this hypothesis by investigating the influence of pathogens on survival during a critical life-history stage: the seed bank. We used fungicide treatments to estimate the impacts of soil fungi on buried seeds of a taxonomically broad suite of congeneric natives and exotics, in both upland and wetland meadows. 3 Seeds of both natives and exotics were recovered at lower rates in wetlands than in uplands. Fungicide addition reduced this difference by improving recovery in wetlands, indicating that the lower recovery was largely attributable to a higher level of fungal mortality. This suggests that fungal pathogens may contribute to the exclusion of upland species from wetlands. 4 The effects of fungicide on the recovery of buried seeds did not differ between natives and exotics. Seeds of exotics were recovered at a higher rate than seeds of natives in uplands, but this effect was not attributable to fungal pathogens. 5 Fungal seed pathogens may offer poor prospects for the management of most exotic species. The lack of consistent differences in the responses of natives vs. exotics to fungicide suggests few aliens owe their success to low seed pathogen loads, while impacts of seed-pathogenic biocontrol agents on non-target species would be frequent.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Lack of pre-dispersal seed predators in introduced Asteraceae in New Zealand
Abstract: The idea that naturalised invading plants have fewer phytophagous insects associated with them in their new environment relative to their native range is often assumed, but quantitative data are few and mostly refer to pests on crop species. In this study, the incidence of seed-eating insect larvae in flowerheads of naturalised Asteraceae in New Zealand is compared with that in Britain where the species are native. Similar surveys were carried out in both countries by sampling 200 flowerheads of three populations of the same thirteen species. In the New Zealand populations only one seed-eating insect larva was found in 7800 flowerheads (0.013% infected flowerheads, all species combined) in contrast with the British populations which had 487 (6.24%) flowerheads infested. Possible reasons for the low colonization level of the introduced Asteraceae by native insects in New Zealand are 1) the relatively recent introduction of the plants (100-200 years), 2) their phylogenetic distance from the native flora, and 3) the specialised nature of the bud-infesting habit of the insects.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Impact of fire on leaf nutrients, arthropod fauna and herbivory of native and exotic eucalypts in Kings Park, Perth, Western Australia
Abstract: The vegetation of Kings Park, near the centre of Perth, Western Australia, once had an overstorey of Eucalyptus marginata (jarrah) or Eucalyptus gomphocephala (tuart), and many trees still remain in the bushland parts of the Park. Avenues and roadsides have been planted with eastern Australian species, including Eucalyptus cladocalyx (sugar gum) and Eucalyptus botryoides (southern mahogany), both of which have become invasive. The present study examined the effect of a recent burn on the level of herbivory on these native and exotic eucalypts. Leaf damage, shoot extension and number of new leaves were measured on tagged shoots of saplings of each tree species in unburnt and burnt areas over an 8-month period. Leaf macronutrient levels were quantified and the number of arthropods on saplings was measured at the end of the recording period by chemical knockdown. Leaf macronutrients were mostly higher in all four species in the burnt area, and this was associated with generally higher numbers of canopy arthropods and greater levels of leaf damage. It is suggested that the pulse of soil nutrients after the fire resulted in more nutrient-rich foliage, which in turn was more palatable to arthropods. The resulting high levels of herbivory possibly led to reduced shoot extension of E. gomphocephala, E. botryoides and, to a lesser extent, E. cladocalyx. This acts as a negative feedback mechanism that lessens the tendency for lush, post-fire regrowth to outcompete other species of plants. There was no consistent difference in the levels of the various types of leaf damage or of arthropods on the native and the exotic eucalypts, suggesting that freedom from herbivory is not contributing to the invasiveness of the two exotic species.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Herbivores and the success of exotic plants: a phylogenetically controlled experiment
Abstract: In a field experiment with 30 locally occurring old-field plant species grown in a common garden, we found that non-native plants suffer levels of attack (leaf herbivory) equal to or greater than levels suffered by congeneric native plants. This phylogenetically controlled analysis is in striking contrast to the recent findings from surveys of exotic organisms, and suggests that even if enemy release does accompany the invasion process, this may not be an important mechanism of invasion, particularly for plants with close relatives in the recipient flora.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Diversity and abundance patterns of phytophagous insect communities on alien and native host plants in the Brassicaceae
Abstract: The herbivore load (abundance and species richness of herbivores) on alien plants is supposed to be one of the keys to understand the invasiveness of species. We investigate the phytophagous insect communities on cabbage plants (Brassicaceae) in Europe. We compare the communities of endophagous and ectophagous insects as well as of Coleoptera and Lepidoptera on native and alien cabbage plant species. Contrary to many other reports, we found no differences in the herbivore load between native and alien hosts. The majority of insect species attacked alien as well as native hosts. Across insect species, there was no difference in the patterns of host range on native and on alien hosts. Likewise the similarity of insect communities across pairs of host species was not different between natives and aliens. We conclude that the general similarity in the community patterns between native and alien cabbage plant species are due to the chemical characteristics of this plant family. All cabbage plants share glucosinolates. This may facilitate host switches from natives to aliens. Hence the presence of native congeners may influence invasiveness of alien plants.
Extracted statement — Investigated species: Plants
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 — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Natural-enemy release facilitates habitat expansion of the invasive tropical shrub Clidemia hirta
Abstract: Nonnative, invasive plant species often increase in growth, abundance, or habitat distribution in their introduced ranges. The enemy-release hypothesis, proposed to account for these changes, posits that herbivores and pathogens (natural enemies) limit growth or survival of plants in native areas, that natural enemies have less impact in the introduced than in the native range, and that the release from natural-enemy regulation in areas of introduction accounts in part for observed changes in plant abundance. We tested experimentally the enemy-release hypothesis with the invasive neotropical shrub Clidemia hirta (L.) D. Don (Melastomataceae). Clidemia hirta does not occur in forest in its native range but is a vigorous invader of tropical forest in its introduced range. Therefore, we tested the specific prediction that release from natural enemies has contributed to its ex- panded habitat distribution. We planted C. hirta into understory and open habitats where it is native (Costa Rica) and where it has been introduced (Hawaii) and applied pesticides to examine the effects of fungal pathogen and insect herbivore exclusion. In understory sites in Costa Rica, C. hirta survival increased by 12% if sprayed with insecticide, 19% with fungicide, and 41% with both insecticide and fungicide compared to control plants sprayed only with water. Exclusion of natural enemies had no effect on survival in open sites in Costa Rica or in either habitat in Hawaii. Fungicide application promoted relative growth rates of plants that survived to the end of the experiment in both habitats of Costa Rica but not in Hawaii, suggesting that fungal pathogens only limit growth of C. hirta where it is native. Galls, stem borers, weevils, and leaf rollers were prevalent in Costa Rica but absent in Hawaii. In addition, the standing percentage of leaf area missing on plants in the control (water only) treatment was five times greater on plants in Costa Rica than in Hawaii and did not differ between habitats. The results from this study suggest that significant effects of herbivores and fungal pathogens may be limited to particular habitats. For Clidemia hirta, its absence from forest understory in its native range likely results in part from the strong pressures of natural enemies. Its invasion into Hawaiian forests is apparently aided by a release from these herbivores and pathogens.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Enemy release? An experiment with congeneric plant pairs and diverse above- and belowground enemies
Abstract: Several hypotheses proposed to explain the success of introduced species focus on altered interspecific interactions. One of the most prominent, the Enemy Release Hypothesis, posits that invading species benefit compared to their native counterparts if they lose their herbivores and pathogens during the invasion process. We previously reported on a common garden experiment (from 2002) in which we compared levels of herbivory between 30 taxonomically paired native and introduced old-field plants. In this phyloge- netically controlled comparison, herbivore damage tended to be higher on introduced than on native plants. This striking pattern, the opposite of current theory, prompted us to further investigate herbivory and several other interspecific interactions in a series of linked ex- periments with the same set of species. Here we show that, in these new experiments, introduced plants, on average, received less insect herbivory and were subject to half the negative soil microbial feedback compared to natives; attack by fungal and viral pathogens also tended to be reduced on introduced plants compared to natives. Although plant traits (foliar C:N, toughness, and water content) suggested that introduced species should be less resistant to generalist consumers, they were not consistently more heavily attacked. Finally, we used meta-analysis to combine data from this study with results from our previous work to show that escape generally was inconsistent among guilds of enemies: there were few instances in which escape from multiple guilds occurred for a taxonomic pair, and more cases in which the patterns of escape from different enemies canceled out. Our examination of multiple interspecific interactions demonstrates that escape from one guild of enemies does not necessarily imply escape from other guilds. Because the effects of each guild are likely to vary through space and time, the net effect of all enemies is also likely to be variable. The net effect of these interactions may create ''invasion opportunity windows'': times when introduced species make advances in native communities.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Invasive exotic plants suffer less herbivory than non-invasive exotic plants
Abstract: We surveyed naturally occurring leaf herbivory in nine invasive and nine non-invasive exotic plant species sampled in natural areas in Ontario, New York and Massachusetts, and found that invasive plants experienced, on average, 96% less leaf damage than non-invasive species. Invasive plants were also more taxonomically isolated than non-invasive plants, belonging to families with 75% fewer native North American genera. However, the relationship between taxonomic isolation at the family level and herbivory was weak. We suggest that invasive plants may possess novel phytochemicals with anti-herbivore properties in addition to allelopathic and anti-microbial characteristics. Herbivory could be employed as an easily measured predictor of the likelihood that recently introduced exotic plants may become invasive.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Herbivory, time since introduction and the invasiveness of exotic plants
Abstract: 1 We tested the enemy release hypothesis for invasiveness using field surveys of herbivory on 39 exotic and 30 native plant species growing in natural areas near Ottawa, Canada, and found that exotics suffered less herbivory than natives. 2 For the 39 introduced species, we also tested relationships between herbivory, invasiveness and time since introduction to North America. Highly invasive plants had significantly less herbivory than plants ranked as less invasive. Recently arrived plants also tended to be more invasive; however, there was no relationship between time since introduction and herbivory. 3 Release from herbivory may be key to the success of highly aggressive invaders. Low herbivory may also indicate that a plant possesses potent defensive chemicals that are novel to North America, which may confer resistance to pathogens or enable allelopathy in addition to deterring herbivorous insects.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Phytophagous insects of giant hogweed Heracleum mantegazzianum (Apiaceae) in invaded areas of Europe and in its native area of the Caucasus
Abstract: Giant hogweed, Heracleum mantegazzianum (Apiaceae), was introduced from the Caucasus into Western Europe more than 150 years ago and later became an invasive weed which created major problems for European authorities. Phytophagous insects were collected in the native range of the giant hogweed (Caucasus) and were compared to those found on plants in the invaded parts of Europe. The list of herbivores was compiled from surveys of 27 localities in nine countries during two seasons. In addition, litera- ture records for herbivores were analysed for a total of 16 Heracleum species. We recorded a total of 265 herbivorous insects on Heracleum species and we analysed them to describe the herbivore assemblages, locate vacant niches, and identify the most host- specific herbivores on H. mantegazzianum. When combining our investigations with similar studies of herbivores on other invasive weeds, all studies show a higher proportion of specialist herbivores in the native habitats compared to the invaded areas, supporting the "enemy release hypothesis" (ERH). When analysing the relative size of the niches (measured as plant organ biomass), we found less herbivore species per biomass on the stem and roots, and more on the leaves (Fig. 5). Most herbivores were polyphagous gener- alists, some were found to be oligophagous (feeding within the same family of host plants) and a few had only Heracleum species as host plants (monophagous). None were known to feed exclusively on H. mantegazzianum. The oligophagous herbivores were restricted to a few taxonomic groups, especially within the Hemiptera, and were particularly abundant on this weed.
Extracted statement — Investigated species: Plants
Research field: Ecology and Evolutionary Biology
Title: Insect herbivore faunal diversity among invasive, non-invasive and native Eugenia species: Implications for the enemy release hypothesis
Abstract: Abstract The enemy release hypothesis (ERH) frequently has been invoked to explain the naturalization and spread of introduced species. One ramification of the ERH is that invasive plants sustain less herbivore pressure than do native species. Empirical studies testing the ERH have mostly involved two-way comparisons between invasive introduced plants and their native counterparts in the invaded region. Testing the ERH would be more meaningful if such studies also included introduced non-invasive species because introduced plants, regardless of their abundance or impact, may support a reduced insect herbivore fauna and experience less damage. In this study, we employed a three-way comparison, in which we compared herbivore faunas among native, introduced invasive, and introduced non-invasive plants in the genus Eugenia (Myrtaceae) which all co-occur in South Florida. We observed a total of 25 insect species in 12 families and 6 orders feeding on the six species of Eugenia. Of these insect species, the majority were native (72%), polyphagous (64%), and ectophagous (68%). We found that invasive introduced Eugenia has a similar level of herbivore richness as both the native and the non-invasive introduced Eugenia. However, the numbers and percentages of oligophagous insect species were greatest on the native Eugenia, but they were not different between the invasive and non-invasive introduced Eugenia. One oligophagous endophagous insect has likely shifted from the native to the invasive, but none to the non-invasive Eugenia. In summary, the invasive Eugenia encountered equal, if not greater, herbivore pressure than the non-invasive Eugenia, including from oligophagous and endophagous herbivores. Our data only provided limited support to the ERH. We would not have been able to draw this conclusion without inclusion of the non-invasive Eugenia species in the study.
Extracted statement — Investigated species: Plants
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 — Investigated species: Plants