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Differences between fungal and bacterial decomposition trajectories can be related to differences in sensitivity to nutrient input and to plant secondary metabolites. The invasive plant Alliaria petiolata (Beib. Cavara and Grande; garlic mustard) produces unique secondary metabolites (glucosinolates) capable of altering the functioning of root-associated communities. However, few studies explore whether these compounds can alter litter decomposition— a route for ecosystem-level impacts of garlic mustard invasion. This preliminary study investigated the potential for aqueous garlic mustard leachate to alter mass loss from tea litterbags in artificially fungal-dominant compared to intact soils (fungal and bacterial components) in laboratory microcosm incubations. Garlic mustard and native Acer saccharum (Marsh.; sugar maple) leachates stimulated fungal decomposition indistinguishably. In intact soils, garlic mustard suppressed mass loss relative to a water control and native leachate, though this later effect was only marginally significant. These results suggest the energetic benefit of labile carbon in garlic mustard leachate may exceed any negative effect of glucosinolates for fungal decomposers, but that bacteria were more sensitive to leachate toxicity and the inhibitory effects of high nutrient input. Overall, our results imply the direction of garlic mustard’s effect on decomposition may depend on saprotrophic community composition and therefore the consequences for litter decay in garlic mustard invaded soils may be context-dependent. [ABSTRACT FROM AUTHOR]

Sisymbrium irio Linn belonging to family 'Cruciferae' is one of the well-known plant used in Unani Thearpy. Several studies done throughout the world on 'Sisymbrium irio L', also known as 'London Rocket' or 'Khakshi' has established that this annual herb is of tremendous medicinal benefits. This plant exhibits potential pharmacological activities such as antimicrobial, antioxidant, anti-inflammatory, analgesic, antipyretic, anticancer, detoxify spleen and liver, also used as febrifuge, expectorant, diuretic and used in the treatment of rheumatoid, voice disorders, boils, pimples, cough, and has bronchoprotective and hepatoprotective role. Various phytochemicals have been isolated scientifically from the different parts of the plants such as flavonoids, alkaloids, tannins, saponins, terpinoids, carbohydrates, phenolics compounds, fatty acids, steroids, amino acids and proteins which were found to be of 'Chemotherapeutic Interest'. This review paper summarizes the botanical description, ethnomedical, phytochemical and therapeutical role of the plant and highlighted the need of future research on this plant as a source of novel drug. [ABSTRACT FROM AUTHOR]

Sisymbrium irio (Family: Cruciferae) is used in Unani medicine. The qualitative and quantitative analysis showed the presence of different types of bioactive secondary metabolites for like phenols, flavonoids, saponins, terpenoids, except reducing sugar and cardiac glycosides. The antioxidant activity was checked by DPPH and ABTS free radical trapping methods by using standards such as ascorbic acid and trolox. The methanol extract of the Indian variety of the seeds of Sisymbrium irio showed a very high antioxidant activity. The major pharmacological bioactive chemical compounds identified in different solvent extracts of Sisymbrium irio were characterized as: 2, 4-Di-tert-butylphenol, n-Hexadecanoic acid, 3’, 5’-Dimethoxyacetophenone, γ-Tocopherol, Cholesterol, 1-Nonedecene, γ-Sitosterol, Ergot-5-en-ol, (3-Beta, 24R)-3-Methylcrotononitrile, 1, 2 - Cyclopentadi-one, 1, 3 - Cyclohexanedione, 4-Isothiocyanato-1-Butene, Isosorbide, Sinapic acid methyl ester, 1, E-8, Z-10-Pentadecatriene and 7-Tetradecenal, (Z) and GC-MS fatty acid composition of the cold pressed seeds oil of plant showed the presence of major fatty acids such as: Linolenic acid (36.29%), Linoleic acid (17.99%), Oleic acid (12.58%), cis-11-Eicosanoic acid (9.2%), Erucic acid (9.19%) and Palmitic acid (6.66%). The elemental analysis of the seeds showed the presence of magnesium, calcium, strontium, titanium, chromium, manganese, copper, zinc, boron, aluminium, silicon, barium, iron, phosphorus, sodium, potassium and lead. [ABSTRACT FROM AUTHOR]

1. Interactions between two trophic levels can be very intimate, often making species dependent on each other, something that increases with specialisation. Some specialised multivoltine herbivores may depend on multiple plant species for their survival over the course of a growing season, especially if their food plants are short‐lived and grow at different times. Later generations may exploit different plant species from those exploited by previous generations. 2. Multivoltine parasitoids as well as their natural enemies must also find their hosts on different food plants in different habitats across the season. Secondary hyperparasitoid communities have been studied on cocoons of the primary parasitoid, Cotesia glomerata (Hymenoptera: Braconidae), on black mustard (Brassica nigra) – a major food plant of its host, the large cabbage white (Pieris brassicae) – which grows in mid‐summer. 3. Here, hyperparasitoid communities on C. glomerata pupal clusters were studied on an early‐season host, garlic mustard, Alliaria petiolata, over 'time' (one season, April–July) in six closely located 'populations' (c. 2 km apart), and within two different 'areas' at greater separation (c. 100 km apart). At the plant level, spatial effects of pupal 'location' (canopy or bottom) on the plant were tested. 4. Although large‐scale separation (area) did not influence hyperparasitism, sampling time and small‐scale separation (population) affected hyperparasitism levels and composition of hyperparasitoid communities. Location on the plant strongly increased proportions of winged species in the canopy and proportions of wingless species in bottom‐located pupae. 5. These results show that hyperparasitism varies considerably at the local level, but that differences in hyperparasitoid communities do not increase with spatial distance. [ABSTRACT FROM AUTHOR]

Understanding the factors that determine invasion success for non‐native plants is crucial for maintaining global biodiversity and ecosystem functioning. One hypothesized mechanism by which many exotic plants can become invasive is through the disruption of key plant–mycorrhizal mutualisms, yet few studies have investigated how these disruptions can lead to invader success. We present an individual‐based model to examine how mutualism strengths between a native plant (Impatiens capensis) and mycorrhizal fungus can influence invasion success for a widespread plant invader, Alliaria petiolata (garlic mustard). Two questions were investigated as follows: (a) How does the strength of the mutualism between the native I. capensis and a mycorrhizal fungus affect resistance (i.e., native plant maintaining >60% of final equilibrium plant density) to garlic mustard invasion? (b) Is there a non‐linear relationship between initial garlic mustard density and invasiveness (i.e., garlic mustard representing >60% of final equilibrium plant density)? Our findings indicate that either low (i.e., facultative) or high (i.e., obligate) mutualism strengths between the native plant and mycorrhizal fungus were more likely to lead to garlic mustard invasiveness than intermediate levels, which resulted in higher resistance to garlic mustard invasion. Intermediate mutualism strengths allowed I. capensis to take advantage of increased fitness when the fungus was present but remained competitive enough to sustain high numbers without the fungus. Though strong mutualisms had the highest fitness without the invader, they proved most susceptible to invasion because the loss of the mycorrhizal fungus resulted in a reproductive output too low to compete with garlic mustard. Weak mutualisms were more competitive than strong mutualisms but still led to garlic mustard invasion. Furthermore, we found that under intermediate mutualism strengths, the initial density of garlic mustard (as a proxy for different levels of plant invasion) did not influence its invasion success, as high initial densities of garlic mustard did not lead to it becoming dominant. Our results indicate that plants that form weak or strong mutualisms with mycorrhizal fungi are most vulnerable to invasion, whereas intermediate mutualisms provide the highest resistance to an allelopathic invader. One hypothesized mechanism by which exotic plants can become invasive is through the disruption of key plant–mycorrhizal mutualisms, yet few studies have investigated how these disturbances can lead to invader success. We examined how the strength of the mutualism between a native plant and mycorrhizal fungus affects resistance to plant invasion. We show that the mutualisms of intermediate strengths are most resistant to plant invaders. [ABSTRACT FROM AUTHOR]

Abstract The invasive plant, garlic mustard (Alliaria petiolata), has the potential to affect soil microbial communities and ecosystem processes in temperate hardwood forests primarily through the release of allelopathic chemicals into the soil. These forest soils are also often affected (directly and indirectly) by the high abundance of white-tailed deer (Odocoileus virginianus), which can alter plant community composition and productivity. We examined the joint effects of deer and garlic mustard on soil microbial communities, soil nutrients and a native plant species' vital rates in a temperate forest 8 years after initiation of a paired plot deer exclusion/access study where garlic mustard was either removed from half of each plot or remained at ambient level in the other plot half. We examined soil microbial communities using DNA-based techniques and quantified nutrient availability and physicochemical properties. Deer exclusion affected the community structure of AM fungi, particularly when garlic mustard was present, but had no effect on soil chemistry. Garlic mustard removal plots showed no changes for soil fungi, but displayed higher soil carbon content. Interestingly, we found significant changes to native plant vital rates that mirrored soil responses; the presence of garlic mustard led to higher mortality of large, mature plants and reduced native plant cover and biomass. Our data suggest herbivore-plant-soil feedbacks and synergies can interact to negatively affect the soil ecology of forests. Management activities that reduce deer or invasive plant abundance may positively affect soil microbial communities and chemistry in temperate forests. Highlights • We quantified invasive plant and herbivore soil effects in a long-term experiment. • Microsite chemical conditions correlated with fungal communities' species composition. • Deer exclusion significantly affected arbuscular mycorrhizal communities in soil. • Effects of deer exclusion were strongest when invader, garlic mustard, was present. • Garlic mustard removal affected soil C:N but had no effects on fungal communities. [ABSTRACT FROM AUTHOR]

BACKGROUND: An oriental mustard population (P40) was identified as resistant to diflufenican by screening at the field rate. As diflufenican and picolinafen both target phytoene desaturase (PDS), cross‐resistance to picolinafen was suspected. The mechanism of resistance and its inheritance to diflufenican and picolinafen were investigated. RESULTS: At the lethal dose (LD50) level, population P40 was 237‐fold more resistant to diflufenican and seven‐fold more resistant to picolinafen compared to two susceptible populations. Population P40 also had a significantly higher resistance to diflufenican (237‐fold) than a previously described P3 population (143‐fold). In addition to the Leu‐498‐Val mutation in PDS identified in all individuals of the P3 and P40 populations, a Glu‐425‐Asp mutation was also found in P40. Neither mutation was detected in any individuals of the susceptible population. As the segregation of phenotype and genotype of the F2 individuals fitted the model for a single dominant allele, resistance to both diflufenican and picolinafen is likely encoded on the nuclear genome and is dominant. CONCLUSION: Resistance to diflufenican and picolinafen in the P40 population is likely conferred by Leu‐498‐Val and Glu‐425‐Asp mutations in the PDS gene. Inheritance of resistance to these herbicides is managed by a single dominant gene. © 2018 Society of Chemical Industry The evolution of herbicide resistance in oriental mustard has significantly increased in Australian cropping systems. This article presents the mechanism and inheritance of cross‐resistance to diflufenican and picolinafen in this weed species. [ABSTRACT FROM AUTHOR]

Abstract: The impact of global warming on seed dormancy loss and germination was investigated in Alliaria petiolata (garlic mustard), a common woodland/hedgerow plant in Eurasia, considered invasive in North America. Increased temperature may have serious implications, since seeds of this species germinate and emerge at low temperatures early in spring to establish and grow before canopy development of competing species. Dormancy was evaluated in seeds buried in field soils. Seedling emergence was also investigated in the field, and in a thermogradient tunnel under global warming scenarios representing predicted UK air temperatures through to 2080. Dormancy was simple, and its relief required the accumulation of low temperature chilling time. Under a global warming scenario, dormancy relief and seedling emergence declined and seed mortality increased as soil temperature increased along a thermal gradient. Seedling emergence advanced with soil temperature, peaking 8 days earlier under 2080 conditions. The results indicate that as mean temperature increases due to global warming, the chilling requirement for dormancy relief may not be fully satisfied, but seedling emergence will continue from low dormancy seeds in the population. Adaptation resulting from selection of this low dormancy proportion is likely to reduce the overall population chilling requirement. Seedling emergence is also likely to keep pace with the advancement of biological spring, enabling A. petiolata to maintain its strategy of establishment before the woodland canopy closes. However, this potential for adaptation may be countered by increased seed mortality in the seed bank as soils warm. [ABSTRACT FROM AUTHOR]

Introduction. Alliaria petiolata, an herbaceous plant, has invaded woodlands in North America. Its ecology has been thoroughly studied, but an overlooked aspect of its biology is seed dispersal distances and mechanisms. We measured seed dispersal distances in the field and tested if epizoochory is a potential mechanism for long- distance seed dispersal. Methods. Dispersal distances were measured by placing seed traps in a sector design around three seed point sources, which consisted of 15 second-year plants transplanted within a 0.25 m radius circle. Traps were placed at intervals ranging from 0.25- 3.25 m from the point source. Traps remained in the field until a majority of seeds were dispersed. Eight probability density functions were fitted to seed trap counts via maximum likelihood. Epizoochory was tested as a potential seed dispersal mechanism for A. petiolata through a combination of field and laboratory experiments. To test if small mammals transport A. petiolata seeds in their fur, experimental blocks were placed around dense A. petiolata patches. Each block contained a mammal inclusion treatment (MIT) and control. The MIT consisted of a wood-frame (31 ×61×31 cm) covered in wire mesh, except for the two 31 ×31 cm ends, placed over a germination tray filled with potting soil. A pan filled with bait was placed in the center of the tray. The control frame (11×31×61 cm) was placed over a germination tray and completely covered in wire mesh to exclude animal activity. Treatments were in the field for peak seed dispersal. In March, trays were moved to a greenhouse and A. petiolata seedlings were counted and then compared between treatments. To determine if A. petiolata seeds attach to raccoon (Procyon lotor) and white-tailed deer (Odocoileus virginianus) fur, wet and dry seeds were dropped onto wet and dry fur. Furs were rotated 180 degrees and the seeds that remained attached were counted. To measure seed retention, seeds were dropped on furs and rotated as before, then the furs were agitated for one hour. The seeds retained in the fur were counted. Results. For the seed dispersal experiment, the 2Dt function provided the best fit and was the most biologically meaningful. It predicted that seed density rapidly declined with distance from the point source. Mean dispersal distance was 0.52 m and 95% of seeds dispersed within 1.14 m. The epizoochory field experiment showed increased mammal activity and A. petiolata seedlings in germination trays of the MIT compared to control. Laboratory studies showed 3-26% of seeds were attached and retained by raccoon and deer fur. Retention significantly increased if either seed or fur were wet (57-98%). [ABSTRACT FROM AUTHOR]

Aim The ability to quantitatively measure the continuum of macroscale patterns of species invasion is a first step toward deeper understanding of their causal factors. We took advantage of two centuries worth of herbarium data, to evaluate a set of metrics to measure macroscale patterns, allowing cross-species comparisons of invasive expansion across large geographic areas. Methods We used herbarium specimens to reconstruct county-level invasion histories for two non-native plants (Alliaria petiolata and Lonicera japonica), with distinct spatiotemporal distribution patterns over the past two centuries. Using county centroids from species' initial occurrences, we quantified point pattern metrics from multiple disciplines (e.g. urban crime analysis, landscape ecology etc.) that are historically used at smaller spatial scales, to evaluate their ability to detect macroscale spatial diffusion and amount of directional expansion. Metrics were further assessed for their ease of use, data requirements, independence from other metrics and intuitiveness of interpretation. Important Findings We identified four suitable metrics for distinguishing differences in spatial patterns: (i) standard distance, (ii) number of patches, (iii) Euclidean nearest neighbor summary class statistic coefficient of variation and (iv) mean center that when applied to county-level presence data allowed us to determine the directions by which distributions expanded and if distributions increased via outward expansion, infilling and/or jump dispersal events. These metrics when compared during the same invasion phase are capable of quantifying macroscale variability among species in their distributional and dispersal patterns. Being able to quantify differences among species in these patterns is important in understanding the drivers of species dispersal patterns. These metrics therefore represent a simple yet thorough toolset for achieving this goal. [ABSTRACT FROM AUTHOR]

Commonly cultivated Brassicaceae mustards, namely garlic mustard (Alliaria petiolata), white mustard (Brassica alba), Ethiopian mustard (B. carinata), Asian mustard (B. juncea), oilseed rape (B. napus), black mustard (B. nigra), rapeseed (B. rapa), white ball mustard (Calepina irregularis), ball mustard (Neslia paniculata), treacle mustard (Erysimum repandum), hedge mustard (Sisymbrium officinale), Asian hedge mustard (S. orientale), smooth mustard (S. erysimoides) and canola are the major economically important oilseed crops in many countries. Mustards were naturalized to Australia and New Zealand and Australia is currently the second largest exporter of Brassicaceae oilseeds to meet the global demand for a healthy plant-derived oil, high in polyunsaturated fats. Apart from providing edible oil, various parts of these plants and many of their phytochemicals have been used traditionally for both agronomic as well as medicinal purposes, with evidence of their use by early Australian and New Zealand settlers and also the indigenous population. This review provides an overview of the current knowledge of traditional and agronomic uses of Brassicaceae oilseeds and mustards with a focus on their importance in Australia and New Zealand. [ABSTRACT FROM AUTHOR]

Garlic mustard [ Alliaria petiolate (M. Bieb.) Cava & Grande] is a problematic European invader of temperate Eastern North American forests. We studied its germination response at reduced oxygen (O2) concentrations. Seeds of garlic mustard were exposed to different O2 concentrations (20.9, 15, 10, 5, and 2.5 %) in two laboratory experiments. Germination rate increased, and it took fewer days to attain 50 % germination ( t50) at 15 % O2 than at 20.9 % O2. Germination declined at 5 % O2, and seedlings became stunted at 2.5 % O2. The ability of garlic mustard to thrive under low O2 concentrations may allow it to invade a wide variety of suboptimal habitats, such as shady understories where leaf litter cover the forest floors and on compressed and compact soils. Its ability to grow at low O2 levels may contribute to its invasiveness. [ABSTRACT FROM AUTHOR]

Given the difficulty that habitat managers face in controlling invasive species, assessing a project's feasibility before implementation can be a useful exercise. We describe efforts to eradicate a population of garlic mustard ( Alliaria petiolata) from an area of the Adirondack Park, United States. We applied a retrospective assessment of the feasibility of the project using 2 different decision support tools, the Invasive Plant Management Decision Analysis Tool ( IPMDAT) and WeedSearch. We modeled several scenarios in each tool by varying parameters related to the effectiveness of control in order to test the sensitivity of project success to particular assumptions. Except for a small decline between 2007 and 2009, the population increased during the control period. The number of surveyed transects with at least one garlic mustard individual increased, as did plant density within transects. IPMDAT and WeedSearch analysis confirmed that eradication of the garlic mustard population at this site was unlikely. IPMDAT discouraged proceeding with the goal of eradication, and only recommended containment if control of seed production could be effective and subpopulations (e.g. transects) could be eliminated. WeedSearch estimated that time required to achieve eradication would range from 11 years if control was 100% effective to more than 50 years if control was only 90% effective. The application of tools such as IPMDAT or WeedSearch can aid project planning by giving invasive species managers a more realistic picture of the commitment that may be required in order to achieve specific restoration goals. [ABSTRACT FROM AUTHOR]

Local differences in climate conditions may facilitate rapid evolutionary changes in introduced plants to optimize timing of germination or ability to survive in seed banks, which may constitute beneficial demographic adaptations during range expansions. Understanding differences in germination requirements and emergence patterns across a species' range is critical for demographic modelling and potential invasive species control efforts., We assessed germination responses of Alliaria petiolata using seeds collected from 10 populations spanning much of the North American distribution of the species. We compared germination responses under different stratification regimes in a growth chamber over 2·5 years, and evaluated seedling emergence in a common garden in Ithaca, New York over 13 years. We further evaluated how climate overlap between Ithaca and original collection sites influenced emergence patterns., In the laboratory, germination of all populations was similar and highest at 4 °C stratification. Seeds exposed to sub-zero temperatures delayed germination and population responses were variable. In the common garden, seedlings from most populations emerged over 13 years, and emergence patterns were strongly influenced by population. Annual emergence was positively correlated with spring temperature and inversely correlated with number of spring days with minimum temperature below freezing. Climate overlap between the common garden and original collection location enhanced germination, but common garden climate conditions over the course of the 13-year experiment and population identity had greater explanatory power., Synthesis. Laboratory germination tests did not reflect seedling emergence under field conditions. After 150 years of residence time in North America, Alliaria petiolata populations have developed striking differences in their responses to local climates and stratification requirements suggesting that a complex interplay of pre-adaptation, rapid evolutionary changes, and phenotypic plasticity result in locally adapted populations. [ABSTRACT FROM AUTHOR]

How variation in factors controlling species abundance and distribution between native and non-native ranges compares to that within ranges remains poorly understood. We used a globally distributed ruderal, Centaurea solstitialis ( Centaurea), to explore the possibility that the importance of those factors exhibits great variation between and within ranges. To test our hypothesis, we established seed addition experiments with soil disturbance (turnover and control) and biocide (fungicides, insecticide, and control) treatments in two regions within native (the Caucasus and south-western Turkey) and non-native (the western United States - US - and central Argentina) distributions. Also, we estimated the rate of vegetation recovery after disturbance (resilience) and related it to Centaurea density in experimental plots. Disturbance strongly increased Centaurea density in all regions. Density was similar between the native Caucasus and non-native Argentina and much greater in those regions than in the native Turkey and non-native US in biocide-free plots. Fungicides had positive effects on density in the US and negative ones in the Caucasus and Argentina, resulting in no differences between those three regions and greater density in the US than Turkey. Insecticide applications promoted Centaurea density in Turkey and Argentina, but inter-regional comparisons of density in treated plots were comparable to those in biocide-free plots. Overall, plants were smaller and less fecund in Turkey than the other regions, except the US. The greatest fungal attack was documented in Turkey, and herbivory was stronger there and in Argentina than in the Caucasus and US. The resilience of the local community explained a large proportion of variation in Centaurea density. These results support our hypothesis, and reveal that the speed at which competition is re-gained after disturbance may influence global variation in Centaurea abundance. Because many ruderals exhibit native and non-native distributions, our results are likely to be generalized to other systems. [ABSTRACT FROM AUTHOR]

Forecasting ecological responses to climate change, invasion, and their interaction must rely on understanding underlying mechanisms. However, such forecasts require extrapolation into new locations and environments. We linked demography and environment using experimental biogeography to forecast invasive and native species' potential ranges under present and future climate in New England, United States to overcome issues of extrapolation in novel environments. We studied two potentially nonequilibrium invasive plants' distributions, Alliaria petiolata (garlic mustard) and Berberis thunbergii (Japanese barberry), each paired with their native ecological analogs to better understand demographic drivers of invasions. Our models predict that climate change will considerably reduce establishment of a currently prolific invader (A. petiolata) throughout New England driven by poor demographic performance in warmer climates. In contrast, invasion of B. thunbergii will be facilitated because of higher growth and germination in warmer climates, with higher likelihood to establish farther north and in closed canopy habitats in the south. Invasion success is in high fecundity for both invasive species and demographic compensation for A. petiolata relative to native analogs. For A. petiolata, simulations suggest that eradication efforts would require unrealistic efficiency; hence, management should focus on inhibiting spread into colder, currently unoccupied areas, understanding source--sink dynamics, and understanding community dynamics should A. petiolata (which is allelopathic) decline. Our results--based on considerable differences with correlative occurrence models typically used for such biogeographic forecasts--suggest the urgency of incorporating mechanism into range forecasting and invasion management to understand how climate change may alter current invasion patterns. [ABSTRACT FROM AUTHOR]

Placing invasion in a more complete food web context expands our understanding of species invasions to reflect the inherent complexity of ecological networks. Garlic mustard ( Alliaria petiolata) has traditionally been predicted to dominate native communities through mechanisms embodied in popular hypotheses such as direct plant-plant interactions (allelopathy) and plant-herbivore interactions (enemy escape). However, garlic mustard also interacts directly with native predators by providing habitat for web-building spiders, which colonize the dry fruit structures (siliques) that garlic mustard leaves behind after it senesces. This interaction may lead to altered food web structure, resulting previously unexamined invasion consequences. This idea was tested in a field experiment including three treatments in which garlic mustard siliques were left intact (S+), removed (S−), or native species dominated and garlic mustard was absent (N). When siliques were intact, estimated insect abundance was locally reduced in invaded plots compared to native plots, but this relationship disappeared when siliques were removed. Phosphorus availability and the growth of one native plant species were both elevated in invaded plots where siliques were intact compared to plots where siliques were removed. Results indicate that garlic mustard's close association with web-building spiders initiates cascading invader impacts on the native community and ecosystem properties. This work supports recent theory suggesting that taking a broader food web perspective may help predict invasion impacts in different environmental contexts. [ABSTRACT FROM AUTHOR]

Ecological and evolutionary processes historically have been assumed to operate on significantly different time-scales. We know now from theory and work in experimental and model systems that these processes can feed back on each other on mutually relevant time-scales., Here, we present evidence of a soil-mediated eco-evolutionary feedback on the population dynamics of an invasive biennial plant, Alliaria petiolata., As populations age, natural selection drives down production of A. petiolata's important antimycorrhizal allelochemical, sinigrin. This occurs due to density-dependent selection on sinigrin, which is favoured under interspecific, but disfavoured under intraspecific, competition., We show that population stochastic growth rates (λS) and plant densities are positively related to sinigrin concentration measured in seedling roots. This interaction is mediated by sinigrin's positive effect on seedling and summer survival, which are important drivers of λS., Together, these illustrate how the evolution of a trait shaped by natural selection can influence the ecology of a species over a period of just years to decades, altering its trajectory of population growth and interactions with the species in the soil and plant communities it invades., Our findings confirm the predictions that eco-evolutionary feedbacks occur in natural populations. Furthermore, they improve our conceptual framework for projecting future population growth by linking the variation in plant demography to a critical competitive trait (sinigrin) whose selective advantages decrease as populations age. [ABSTRACT FROM AUTHOR]

Pieris rapae L., an invasive crop pest, may have recently begun using Alliaria petiolata Bieb. (Cavara & Grande), a European invasive biennial. We investigated how P. rapae uses forest habitats for nectar and oviposition and examined larval performance on A. petiolata in the field and laboratory. Being known primarily to occupy open habitats, we found that P. rapae regularly uses forest edge habitats, most surveyed A. petiolata plants had P. rapae damage, and P. rapae successfully used both stages of A. petiolata for larval development. [ABSTRACT FROM AUTHOR]

The article discusses the effects of the removal of invasive garlic mustard on the native flora and fauna, particularly the eastern red-backed salamander. Also cited are the considerations that should be considered when deciding the remediation and removal of non-native plants like its costs and benefits, as well as the Alliaria petiolata (garlic mustard) as an example of an invader of forests and woods in the U.S.

The article discusses a study published within the issue which showed post-establishment evolutionary change in invasive garlic mustard and reciprocal evolutionary change in a native species. The finding shows that evolutionary change leading to species coexistence could happen quickly. Also mentioned are the factor needed in understanding coevolution between competing native and invasive plant species and instances where coevolution between native and invasive competitors is not indicated.

Alliaria petiolata (garlic mustard, Brassicaceae) contains the glucosinolate sinigrin as well as alliarinoside, a γ-hydroxynitrile glucoside structurally related to cyanogenic glucosides. Sinigrin may defend this plant against a broad range of enemies, while alliarinoside confers resistance to specialized (glucosinolate-adapted) herbivores. Hydroxynitrile glucosides and glucosinolates are two classes of specialized metabolites, which generally do not occur in the same plant species. Administration of [UL-14C]-methionine to excised leaves of A. petiolata showed that both alliarinoside and sinigrin were biosynthesized from methionine. The biosynthesis of alliarinoside was shown not to bifurcate from sinigrin biosynthesis at the oxime level in contrast to the general scheme for hydroxynitrile glucoside biosynthesis. Instead, the aglucon of alliarinoside was formed from metabolism of sinigrin in experiments with crude extracts, suggesting a possible biosynthetic pathway in intact cells. Hence, the alliarinoside pathway may represent a route to hydroxynitrile glucoside biosynthesis resulting from convergent evolution. Metabolite profiling by LC-MS showed no evidence of the presence of cyanogenic glucosides in A. petiolata. However, we detected hydrogen cyanide (HCN) release from sinigrin and added thiocyanate ion and benzyl thiocyanate in A. petiolata indicating an enzymatic pathway from glucosinolates via allyl thiocyanate and indole glucosinolate derived thiocyanate ion to HCN. Alliarinoside biosynthesis and HCN release from glucosinolate-derived metabolites expand the range of glucosinolate-related defenses and can be viewed as a third line of defense, with glucosinolates and thiocyanate forming protein being the first and second lines, respectively. [ABSTRACT FROM AUTHOR]

While negative impacts of invasive species on native communities are well documented, less is known about how these communities respond to the removal of established populations of invasive species. With regard to invasive shrubs, studies examining native community response to removal at scales greater than experimental plots are lacking. We examined short-term effects of removing Lonicera maackii (Amur honeysuckle) and other non-native shrubs on native plant taxa in six mixed-hardwood forests. Each study site contained two 0.64 ha sample areas-an area where all non-native shrubs were removed and a reference area where no treatment was implemented. We sampled vegetation in the spring and summer before and after non-native shrubs were removed. Cover and diversity of native species, and densities of native woody seedlings, increased after shrub removal. However, we also observed significant increases in L. maackii seedling densities and Alliaria petiolata (garlic mustard) cover in removal areas. Changes in reference areas were less pronounced and mostly non-significant. Our results suggest that removing non-native shrubs allows short-term recovery of native communities across a range of invasion intensities. However, successful restoration will likely depend on renewed competition with invasive species that re-colonize treatment areas, the influence of herbivores, and subsequent control efforts. [ABSTRACT FROM AUTHOR]

Garlic mustard is a well-known invader of deciduous forests of North America, yet the influence of environmental factors on garlic mustard allelochemical production is not well understood. Three experiments were conducted to detect interactions between one garlic mustard allelochemical (glucosinolate) production and light availability. First, to detect patterns of glucosinolate production across a natural light gradient, leaves and roots of mature plants and first-year rosettes were sampled in patches ranging from 100 to 2 % of full sun within an Indiana forest. Second, to determine whether genetic variation drives observed correlations between glucosinolate content and light, seed collected across light gradients within six sites was grown in a common garden and glucosinolate production was measured. Finally, to understand whether local adaptation occurred in garlic mustard's response to light, seed collected from defined light environments across six sites was grown under four light treatments. Results of the field sampling showed that mature plants' root glucosinolate content was elevated in high compared to low light. In the common garden experiment, however, there was no correlation between light availability at seed origin and constitutive glucosinolate content. Additionally, in the common light treatments, there was no evidence for local adaptation to light environment. Overall, the results indicate that plasticity in response to light, not genetic variation among plants growing in different light environments, generates correlations between glucosinolate content and light in the field. Since mature garlic mustard populations in high light may exhibit increased glucosinolate content, it makes them potential targets for management. [ABSTRACT FROM AUTHOR]

Space and time are the two fundamental drivers of ecological dynamics. Studies exploring the Stress gradient hypothesis (SGH) - which predicts that the patterns of interspecific interactions shift from negative to positive with increasing environmental severity - conceptualize environmental severity predominantly from a spatial perspective. Here, from a temporal perspective and for intraspecific interactions, we asked: do the predictions of the SGH at the intraspecific level apply to seasonal change in environmental severity? We conducted a field experiment, which was complemented by a two-year field survey of natural populations of the non-native biennial forb Alliaria petiolata at the Koffler Scientific Reserve, Ontario, Canada. In both experiment and field survey studies we found statistically significant negative density-dependent survival in the productive summer period and positive density-dependent survival over the severe winter period. Effects were stronger in the field experiment than in the survey of natural populations. We suggest that the SGH at the intraspecific level may be applicable to seasonal variation in environmental severity, though our ability to detect its effect in natural communities may depend on other factors such as species dominance and environmental heterogeneity. [ABSTRACT FROM AUTHOR]

Specialized metabolites in plants influence their interactions with other species, including herbivorous insects, which may adapt to tolerate defensive phytochemicals. The chemical arsenal of Alliaria petiolata (garlic mustard, Brassicaceae) includes the glucosinolate sinigrin and alliarinoside, a hydroxynitrile glucoside with defensive properties to glucosinolate-adapted specialists. To further our understanding of the chemical ecology of A. petiolata, which is spreading invasively in North America, we investigated the metabolite profile and here report a novel natural product, petiolatamide, which is structurally related to sinigrin. In an extensive study of North American populations of A. petiolata, we demonstrate that genetic population differences as well as developmental regulation contribute to variation in the leaf content of petiolatamide, alliarinoside, sinigrin, and a related glycoside. We furthermore demonstrate widely different metabolic fates of these metabolites after ingestion in the glucosinolate-adapted herbivore Pieris rapae, ranging from simple passage over metabolic conversion to sequestration. The differences in metabolic fate were influenced by plant β-glucosidases, insect-mediated degradation, and the specificity of the larval gut transport system mediating sequestration. [ABSTRACT FROM AUTHOR]

The allelochemical alliarinoside present in garlic mustard (Alliaria petiolata), an invasive plant species in North America, was chemically synthesized using an efficient and practical synthetic strategy based on a simple reaction sequence. Commercially available 1,2,3,4,6-penta-O-acetyl-β- glucopyranose was converted into prop-2-enyl 2′,3′,4′,6′-tetra-O-acetyl-β-glucopyranoside and subjected to epoxidation. In a one-pot reaction, ring-opening of the epoxide using TMSCN under solvent free conditions followed by treatment of the formed trimethylsilyloxy nitrile with pyridine and phosphoryl chloride, afforded the acetylated β-unsaturated nitriles (Z)-4-(2′,3′,4′,6′-tetra-O-β-glucopyranosyloxy)but-2-enenitrile and its isomer (E)-4-(2′,3′,4′,6′-tetra-O-β-glucopyranosyloxy)but-2-enenitrile. Deacetylation of Z- and/or E-isomers afforded the target molecules alliarinoside and its isomer. [ABSTRACT FROM AUTHOR]

Ephemeral disturbances are common in many systems. Often, these brief events are assumed to be a nuisance with little long-term ecological impact. We quantified the impact of the ephemeral forest disturbance caused by gypsy moth canopy defoliation on exotic plant invasion in eight hardwood forests in the Delaware Water Gap National Recreation Area, USA. Six years following the gypsy moth disturbance, we were able to predict 59% of the increase in Alliaria petiolata abundance and 42% of the increase in Microstegium vimineum abundance with models incorporating an interaction between disturbance severity and propagule pressure. In addition, we found that the disturbance timing had substantial impacts on the invasion dynamics of Alliaria petiolata. Our results suggest that ephemeral disturbances can have important and long-lasting impacts on plant communities, and highlight the need to account for variations in disturbance characteristics and the role of propagule pressure in determining the disturbance-invasion relationship. [ABSTRACT FROM AUTHOR]

To understand what makes some species successful invaders, it is critical to quantify performance differences between native and introduced regions, and among populations occupying a broad range of environmental conditions within each region. However, these data are not available even for the world's most notorious invasive species. Here we introduce the Global Garlic Mustard Field Survey, a coordinated distributed field survey to collect performance data and germplasm from a single invasive species: garlic mustard (Alliaria petiolata) across its entire distribution using minimal resources. We chose this species for its ecological impacts, prominence in ecological studies of invasion success, simple life history, and several genetic and life history attributes that make it amenable to experimental study. We developed a standardised field survey protocol to estimate population size (area) and density, age structure, plant size and fecundity, as well as damage by herbivores and pathogens in each population, and to collect representative seed samples. Across four years and with contributions from 164 academic and non-academic participants from 16 countries in North America and Europe thus far, we have collected 45,788 measurements and counts of 137,811 plants from 383 populations and seeds from over 5,000 plants. All field data and seed resources will be curated for release to the scientific community. Our goal is to establish A. petiolata as a model species for plant invasion biology and to encourage large collaborative studies of other invasive species. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigates survival and reproduction of Pieris virginiensis Edwards (P. virginiensis), the West Virginia White butterfly in 2011-2012 in a habitat. It says that the study site is in Morrow County, Ohio and the scoring data were converted to presence or absence values. Results showed that only one egg found on more than 150 plants searched in two years at the location and Alliaria petiolata plant might contribute to the decline of P. virginiensis.

Facilitation among species may promote non-native plant invasions through alteration of environmental conditions, enemies or mutualists. However, the role of non-trophic indirect facilitation in invasions has rarely been examined., We used a long-term field experiment to test for indirect facilitation by invasions of Microstegium vimineum (stiltgrass) on a secondary invasion of Alliaria petiolata (garlic mustard) by introducing Alliaria seed into replicated plots previously invaded experimentally by Microstegium., Alliaria more readily colonized control plots without Microstegium but produced almost seven times more biomass and nearly four times as many siliques per plant in Microstegium-invaded plots. Improved performance of Alliaria in Microstegium-invaded plots compared to control plots overwhelmed differences in total number of plants such that, on average, invaded plots contained 327% greater total Alliaria biomass and 234% more total siliques compared to control plots., The facilitation of Alliaria in Microstegium-invaded plots was associated with an 85% reduction in the biomass of resident species at the peak of the growing season and significantly greater light availability in Microstegium-invaded than control plots early in the growing season., Synthesis. Our results demonstrate that an initial plant invasion associated with suppression of resident species and increased resource availability can facilitate a secondary plant invasion. Such positive interactions among species with similar habitat requirements, but offset phenologies, may exacerbate invasions and their impacts on native ecosystems. [ABSTRACT FROM AUTHOR]

The use and potential consequence of alien plant parts in the construction of open-cup leaf nests by Nearctic-breeding forest songbirds has not been investigated. We dissected 19 leaf nests constructed by Veeries (Catharus fuscescens) over two breeding seasons in a temperate broadleaf forest infested with alien plants. Our objectives were: (1) confirm the architectural approach used by Veeries to construct nests, (2) determine if Veeries used alien plant parts in nest construction, (3) determine if nest success was related to the use of alien material, (4) determine the use of alien plants relative to native plants, and (5) test for an association of alien plant mass with the progression of the nesting season. Our results showed that Veeries constructed three separate nest layers: (1) a platform for support, (2) an inner cup, and (3) nest lining. Veeries incorporated parts from six alien plant species in their nests representing 22% of the 27 species used. All nests contained alien plant parts but use differed among the three layers. In particular the use of stems of Alliaria petiolata and Rosa multiflora, two alien species, appeared to provide important structural support in the nest's outer layers. Although our sample size was small, we found no relationship between the use of alien plant parts and nest failure suggesting use of alien plant material does not have negative effects on productivity. We caution that sudden large-scale restoration efforts, which remove the alien forest plant species used in nest construction prior to the recovery of comparable native species, may result in the temporary reduction of materials available to birds for nest construction. [ABSTRACT FROM AUTHOR]

Invasive plant species can exhibit allelopathic effects on native plant species. The strength of this allelopathic effect ca n vary with invasive species, with target species and with type of plant tissue extract. The purpose of this study was to determine the direct effects of extracts from roots or leaves of three Midwestern US invasive plants (Alliariapetiolata, Lonicera maackii and Ranunculus ficaria) on the germination success of three native target species (Anemone virginiana, Blephilia hirsuta and Elymus hystrix) in a fully factorial experiment. Leaf extract treatments overall showed more germination inhibition compared to root extract treatments. As concentration increased, effects of extracts increased. Extracts of leaves of A. petiolata had the greatest inhibition of germination across all other treatments. Effects of root and leaf extracts of each invasive species varied with each target species. While E. hystrix showed little response to extracts of roots or leaves of L. maackii and R. ticaria, B. hirsuta and A. virginiana germination were reduced by leaf extracts of these two invasive species. This study confirms the strong direct allelopathic effects of A. petiolata, though the strength of the effect varies with target species and with type of tissue used to make extracts. This study is the first to directly compare the effects of these invasive species on a suite of native, ecologically-relevant target species. [ABSTRACT FROM AUTHOR]

The population effects of harvest depend on complex interactions between density dependence, seasonality, stage structure, and management timing. Here we present a periodic nonlinear matrix population model that incorporates seasonal density dependence with stage-selective and seasonally selective harvest. To this model, we apply newly developed perturbation analyses to determine how population densities respond to changes in harvest and demographic parameters. We use the model to examine the effects of popular control strategies and demographic perturbations on the invasive weed garlic mustard (Alliaria petiolata). We find that seasonality is a major factor in harvest outcomes, because population dynamics may depend significantly on both the season of management and the season of observation. Strategies that reduce densities in one season can drive increases in another, with strategies giving positive sensitivities of density in the target seasons leading to compensatory effects that invasive species managers should avoid. Conversely, demographic parameters to which density is very elastic (e.g., seeding survival, second-year rosette spring survival, and the flowering to fruiting adult transition for maximum summer densities) may indicate promising management targets. [ABSTRACT FROM AUTHOR]

Highlights: [•] Deer and the invasive plant Alliaria reduce the success of many native plants. [•] Field experiments can disentangle the effects of deer and Alliaria. [•] Deer and Alliaria often affect plant growth and survival independently. [•] Deer and Alliaria interact to reduce growth in red oak seedlings and two forbs. [•] Managers should control deer impacts first to protect palatable species. [Copyright &y& Elsevier]

The aim of the article is the syntaxonomic interpretation of hyperhalophilous woody or semi-woody vegetation withHalocnemumM. Bieb. along the coasts of the Mediterranean Basin. For this area, the two species ofHalocnemum, H. strobilaceum(Pall.) M. Bieb. andH. cruciatum(Forssk.) Tod. are identified; their morphological characteristics, synonymy and distribution are here described. The study carried out of particular aspects of the plant morphology and the micromorphological characteristics of the seeds collected from different places in the Mediterranean allows to better differentiate the two species. Vegetation studies already done in many communities of the Mediterranean by several authors threw into great confusion because onlyH. strobilacemhas been recognized as a dominant species. As regards the syntaxonomic analyses of the vegetation, the authors refer to the proposals already made by various scientists for the vegetation of inland salt basins of Eurasia and the Irano-Anatolian area, who suggested the classesKalidietea foliateandHalocnemetea strobilaceiirano-anatolica, respectively. Conversely, in the Mediterranean Basin, the vegetation study is present only in coastal areas where it is considerably impoverished in the number of species. Therefore, the authors propose to include hyperhalophilous, woody and fruticose vegetation in the classSarcocornietea fruticosae.However, the phytosociological and ecological diversity is highlighted proposing the orderHalocnemetalia cruciatiin which both the allianceHalocnemion strobilacei, for middle Eastern Europe, and the allianceHalocnemion cruciati, for North Africa with penetrations in the Western and Eastern Europe up to the Middle East coast, are included. This new interpretation has required the correction of the names of two associations (Frankenio corymbosae–Halocnemetum cruciatiandZygophylloalbi–Halocnemetumcruciati) and the proposal of two new associationsArthrocnemo machrostachyi–Halocnemetum cruciatiandHalocnemo cruciati–Sarcocornietum fruticosae.A further proposal concerns the addition of the allianceLimoniastrion monopetali, previously included in the orderLimonietalia, in the orderHalocnemetalia cruciati. [ABSTRACT FROM AUTHOR]

The effects of multiple invasive plants on soil fungal communities may impact native ecosystems differently than invasion by one species alone. Native plant communities are likely to have a differential above and below ground response to invaders, and therefore understanding fungal implications of invader interactions would be useful when considering restoration strategies. We examined how invasion by European species, Dog-strangling vine or DSV (Vincetoxicum rossicum) (also pale swallow-wort) and garlic mustard or GM (Alliaria petiolata), can alter root colonization by both the total and arbuscular mycorrhizal fungi. In two different sites in the Greater Toronto Area, we investigated fungal communities associated with each plant species in differing invasion scenarios using terminal restriction length polymorphism analysis. Fungal communities in DSV changed significantly in the presence of GM, with decreased colonization densities observed in both the total fungi (Student's t-test; t = 2.1, p = 0.02) and AMF communities (Student's t-test; t = 2.0, p = 0.03), as well as decreased overall phylotype richness of the total fungal communities associating with DSV growing in GM patches relative to those growing separately from GM in both sites (one-way ANOVA; F = 4.4, p = 0.02). The converse was not observed, suggesting that GM has the dominant effect on the invaded soil environment. These results suggest that multiple plant invaders influence the composition of soil fungi available to natives in a manner that is less predictable than invasion by a single species, possibly via increased carbon provision or antibiosis attributable to unique root exudates. [ABSTRACT FROM AUTHOR]

Alliaria petiolata (Garlic Mustard) decreases diversity of native plants and introduces novel litter inputs to forests, but whether Garlic Mustard's presence influences detritivores is unclear. Our goal was to determine if Garlic Mustard alters springtail (detritivore) densities during early invasion. We obtained epigeal (litter, humus, and soil) cores from invaded and uninvaded areas in a Pinus strobus (White Pine) forest and used high-gradient dynamic sampling to extract springtails. Invaded areas contained nearly three times more springtails than uninvaded areas, attributable to two springtail morphospecies from Collembola families Tomoceridae and Entomobryidae. Higher pH in invaded epigeal samples correlated with increased springtail abundance. pH alkalization also correlated with increased proportion ofjuvenile rosettes in mixed stands. Our results suggest a possible role for pH modulation of springtail abundance in response to Garlic Mustard invasion. [ABSTRACT FROM AUTHOR]

* Premise of the study: Invasive species are nonnative species that enter novel environments, establish sustained populations, and can negatively impact native species. Here we assess a potential weakness of invasive species (genetic load) and show how species might overcome genetic barriers. Colonization of novel habitats by invasive species typically involves few individuals, exposing populations to founder effects. We empirically tested a central Illinois population of an invasive biennial plant, Alliaria petiolata, for evidence of a founder effect by assessing the pattern of genetic load. * Methods: To estimate genetic load, we assayed offspring from three cross types (self-pollinated, outcrossed within- and between-populations) in a greenhouse. Vegetative and reproductive traits were measured on first-year plants grown with or without intraspecific competition. * Key results: We found substantial genetic load in this population of A. petiolata, which can mostly be attributed to genetic drift (founder effect) and not inbreeding depression. Between-population heterosis was expressed more than inbreeding depression under intraspecific competition. * Conclusions: Inbreeding may be adaptive for A. petiolata in its introduced range by providing reproductive assurance, with limited inbreeding load. Nevertheless, most of the genetic load in this population of A. petiolata is due to fixation of deleterious alleles. Drift load is expected, given that this population is near the edge of its continuous geographic range in highly fragmented habitats, and gene flow between isolated populations is likely highly limited. Preventing additional introduction and movement of propagules between isolated local populations should reduce heterosis and A. petiolata competitiveness. [ABSTRACT FROM AUTHOR]

Plant populations are often adapted to their local conditions, including abiotic factors as well as the biotic communities with which they interact. Soil communities, in particular, have strong effects on both the ecology and evolution of plant populations. Many invasive plant species alter the ecological relationships between native plants and soil communities; however, whether invaders also alter the evolutionary dynamics between native plants and soils is less well known. Here I show that populations of a native annual, Pilea pumila, shift from being maladapted to adapted to their local soil community with increasing history of invasion by Alliaria petiolala, an invader known to alter microbial communities. Additionally, native populations showed a signal of adaptation to soils of particular invasion stages, independent of local coevolutionary dynamics. These results suggest that invasive species affect not only the ecological, but also the evolutionary relationships of native species. [ABSTRACT FROM AUTHOR]

Alliaria petiolata (Garlic Mustard) is an invasive plant species which displaces native communities by lowering levels of mycorrhizal fungi essential to native plant nutrient acquisition. Consequently, the diets ofarthropods using these native plants as a primary food source may be altered. To assess the magnitude of this disruption, stable-isotope analyses of carbon, nitrogen, oxygen, and hydrogen were used to trophically differentiate the diets of arthropods in Garlic Mustard-invaded areas. In invaded areas, arthropods were depleted in δ13C and enriched in δ15N relative to arthropods in uninvaded areas, suggesting a change in trophic position among generalist predators. Slight trophic repositioning was observed in all 4 isotopes, indicating interactions of 3 primary predators throughout the study area. Most observable shifts are likely due to predators either altering prey source or traveling further to acquire nutrients. [ABSTRACT FROM AUTHOR]

Phenology affects the abiotic and biotic conditions that an organism encounters and, consequently, its fitness. For populations of high-latitude species, spring phenology often occurs earlier in warmer years and regions. Here we apply a novel approach, a comparison of slope of phenology on temperature over space versus over time, to identify the relative roles of plasticity and local adaptation in generating spatial phenological variation in three interacting species, a butterfly, Anthocharis cardamines, and its two host plants, Cardamine pratensis and Alliaria petiolata. All three species overlap in the time window over which mean temperatures best predict variation in phenology, and we find little evidence that a day length requirement causes the sensitive time window to be delayed as latitude increases. The focal species all show pronounced temperaturemediated phenological plasticity of similar magnitude. While we find no evidence for local adaptation in the flowering times of the plants, geographic variation in the phenology of the butterfly is consistent with countergradient local adaptation. The butterfly's phenology appears to be better predicted by temperature than it is by the flowering times of either host plant, and we find no evidence that coevolution has generated geographic variation in adaptive phenological plasticity. [ABSTRACT FROM AUTHOR]

Abstract: Prior studies report in various mammalian species that a neutral flavour can become strongly preferred after being associated with a positive consequence of its consumption. Two experiments were performed to study flavour preferences conditioned by a protein source in weaned pigs. In experiment 1, pigs were trained to drink (30min/day) one flavour (CS+) mixed into a 2% protein solution (Soybean Protein Concentrate; SPC or Porcine Digestible Peptides; PDP) and another flavour (CS−) mixed into water during 6 alternate sessions. The pigs in the SPC and PDP groups consumed more CS+ than CS− in the two-choice tests with both flavours presented in water (552 vs. 409mL, 571 vs. 414mL, respectively). In the last choice SPC and PDP animals preferred the CS+ over the CS− when both flavours were present in feed rather than water (650 vs. 536g and 678 vs. 513g, respectively). No differences were observed between the conditioning effects of the two proteins. In experiment 2, pigs were trained (30min/day) with a garlic flavour (CS) mixed with 4% PDP in sessions 1, 3, 5 and 7 unflavoured tap water in sessions 2, 4, 6 and 8 (Conditioned group) or with garlic flavour in water in sessions 1, 3, 5 and 7 and 4% PDP without added flavour in sessions 2, 4, 6 and 8 (control group). In subsequent choice tests conditioned pigs consumed more PDP+Garlic than PDP in Tests 1 (550mL vs. 372ml, P<0.05) and 3 (763mL vs. 503mL, P<0.05). In addition, pigs in the Conditioned group made significantly more first contacts (FC, number of piglets at a pan during the first 15s) with the PDP+Garlic solution than PDP solution in Tests 1 and 2 but not in Test 3. In contrast, the control group did not differ in their intakes of or first contacts to the two PDP solutions. The present results indicate that piglets can acquire preferences for a cue flavour added to protein products (PDP and SCP). The conditioned flavour preference also enhanced the attraction to the palatable protein (PDP) when the flavour and protein were combined. [Copyright &y& Elsevier]

Garlic mustard, Alliaria petiolata (M. Bieb.) Cavara & Grande, is an introduced biennial forb that has commonly been referred to as highly invasive and as having substantial negative effects on other plants in the eastern deciduous forests of North America. However, several recent studies have documented only modest effects on other plant species, raising questions as to the extent of the threat really posed by A. petiolata. Alliaria petiolata often exhibits an alternating two-year life-history cycle, with high rosette years alternating with high flowering stem years. It has been proposed that this cycle is partly driven by intraspecific competition between the stems and the rosettes. In a two-year study, we extensively sampled A. petiolata in a Minnesota woodland at two spatial scales, including 6.5 km of belt transects in a 6.8 ha study grid (20 x 20 m cells) and 90 small sampling quadrats (1.0 x 0.5 m) within the grid. At the large scale, we compared seed bank abundance and diversity of other herbaceous plants with A. petiolata abundance. Using the monitoring data we also investigated whether this population was exhibiting an alternating two-year life-history cycle, consistent with the intraspecific competition hypothesis for this phenomenon. At the small scale, we compared A. petiolata abundance with the abundance of other plants, including herbs, ferns, shrubs, and tree seedlings. We also conducted an ex-situ pot experiment in which we planted seeds of six tree species in soil collected from dense A. petiolata patches and soil collected where A. petiolata was absent and recorded emergence rates and seedling growth over an 8 wk period. Overall, we found little evidence that A. petiolata was negatively affecting other plant species. This is consistent with other recent studies and indicates that, despite earlier claims to the contrary, A. petiolata seems to be more a product than an agent of change in eastern North American deciduous forests. We also documented an alternating two-year life-history cycle, providing additional evidence to support the hypothesis that this cycle is at least partly being driven by intraspecific competition. [ABSTRACT FROM AUTHOR]

A combination of observational and experimental methods, in both the laboratory and field, were used to assess niche partitioning between Ceutorhynchus alliariae Brisout and C. roberti Gyllenhal (Coleoptera: Curculionidae), two coexisting shoot-boring weevils on garlic mustard, Alliaria petiolata (M. Bieb.) Cavara and Grande (Brassicaceae). We compared their morphology, oviposition behavior, larval development, distribution, abundance, and attack rates in their sympatric range, and of C. alliariae when found alone and in sympatry with C. roberti. Results indicate only very small differences in the fundamental niches of the two species. Comparison of C. alliariae in the range it occurs alone with the range where it co-occurs with C. roberti revealed some evidence for competition between the two species, i.e., attack levels of C. alliariae were reduced in areas where it co-occurred with C. roberti. However, the study showed no character displacement in regard to adult size or shoot choice of C. alliariae and we found no indication for superiority of either of the two species. Clearly, manipulative experiments would be necessary to unambiguously test for competition between the two species. Our results, based on a subset of niche dimensions known to be important in other systems, suggest that C. aUiariae and C. roberti may present one of the rare cases, in which niche differentiation is not the main mechanism underlying coexistence. [ABSTRACT FROM AUTHOR]

Abstract: Garlic mustard (Alliaria petiolata), an exotic biennial herb invasive to North American forests, has potential to affect resource availability in invaded soils. Garlic mustard produces a suite of toxic chemicals that impact diversity both above and belowground and thus likely alter ecosystem processes. To examine the effects of garlic mustard on soil biota and ecosystem processes, we sampled soil from invaded and uninvaded stands at a pine plantation on sandy soils in central Illinois. Several of the pine stands were also planted with the N2-fixing tree black locust (Robinia pseudoacacia). Results indicate that pine soils underlying garlic mustard have higher pH, and exhibit higher rates of N mineralization, relative nitrification and soil respiration compared to soils without garlic mustard. Nitrogen turnover on pine invaded stands is more similar to pine soils with the black locust trees present than to uninvaded pine stands without black locust. Garlic mustard cover was much greater in stands with black locust trees planted, suggesting that garlic mustard may be attracted to high N sites. Catabolic response profiles, which provide a measure of soil microbial function, indicated a shift in substrate use for one of the substrates tested in the presence of garlic mustard. While many of the soil characteristics measured did not differ between invaded and uninvaded stands, the differences with regard to N turnover were striking and will likely have long term effects on soil nutrient status, with potential to feedback to forest health. [Copyright &y& Elsevier]