Rhamnus Cathartica Research Articles

Invasive shrub removal may be more effective at reducing granivory than coating tree seeds with capsaicin

The utility of seed addition to promote tree regeneration can be greatly limited by animals that consume seeds. Moreover, given that restoration often occurs in forests where invasive shrubs are abundant, and evidence that invasive shrubs can increase granivory, it is important to explore whether methods for reducing granivory work equally well in invaded and uninvaded habitats. We used a multi-site field experiment spanning 160 days to explore whether coating seeds of Prunus serotina with capsaicin extract leads to reduced granivory in habitats with or without invasive shrubs (Rhamnus cathartica). Capsaicin-coated seeds were removed at a similar rate to uncoated seeds, but seeds in invaded plots had a 78.8% higher rate of removal compared to plots without invasive shrubs. Our findings suggest that managers seeking to encourage regeneration of native trees using direct seeding should consider invasive shrub removal as a top priority to limit the loss of seeds once sown.

Invasive Glossy Buckthorn (Frangula alnus) Has Weak Impact on Native Understory Plant and Saprophagous Macroarthropod Communities

Glossy buckthorn (Frangula alnus Miller) is an invasive alien plant species (IAPS) rapidly expanding in North America but is largely understudied compared to the common buckthorn (Rhamnus cathartica). Our study investigated the effects of a 27-year-old F. alnus invasion on native understory plant and saprophagous macroarthropod communities in a wet deciduous woodland in Southern Québec, Canada. We hypothesized a decreased taxonomic diversity and a change in community composition of both indicator taxa with increasing F. alnus density. The understory plant and saprophagous macroarthropod communities were characterized, respectively, through vegetation surveys and pitfall trapping across a density gradient of 43 plots invaded by F. alnus. Our results demonstrated that F. alnus did not exert a strong influence on species community composition, although the homogenization of understory plant communities was observed. Despite several decades of F. alnus invasion at our study site, the consequences on the selected indicator taxa were overall relatively small, suggesting that the magnitude of effects is variable. We suggest that further investigation at a larger scale should be performed to evaluate the effect of F. alnus on a broad diversity of indicators and understand any context dependency.

Woody invaders of a temperate forest have unique root-associated fungal communities

Non-native, invasive plants are increasingly common in Eastern North American forests, but their impact on soil fungi remains unclear. We used DNA metabarcoding to investigate the effects of nativity, plant mycorrhizal type and soil factors on root-associated fungal communities. We focused on understory woody plants in a deciduous forest tract in central New York state, and included three plant types, invasive arbuscular mycorrhizal (AM), native AM, and native ectomycorrhizal (EM), each represented by 3–5 species. We found lower fungal operational taxonomic unit (OTU) diversity in EM than AM plants, but no OTU diversity difference between native and invasive AM species. Pathogen OTU richness and relative abundance were not distinct between plant types. OTU composition was influenced by host mycorrhizal type and by AM plant nativity, with mycorrhizal fungi being important drivers in both cases. The relationships of soil characteristics (e.g., pH) with OTU composition were independent of plant nativity and mycorrhizal type. Specific root length of native AM species was lower than that of invasive AM plants, while EM plants were intermediate. Irrespective of plant type, OTU composition was distinct among plant species, particularly in fungal communities associated with the invader Rhamnus cathartica. These results suggest that invasive AM plants may shift fungal composition relative to native AM and EM plants, with potential long-term consequences for soil biodiversity.

Registration of CDL‐111 and CDL‐167 oat germplasm lines with pyramided adult plant crown rust resistance

AbstractOat (Avena sativa) production worldwide is constrained by crown rust (caused by Puccinia coronata f. sp. avenae), which can cause significant yield losses. The disease is often controlled by spraying fungicides or planting resistant cultivars. Developing host resistance, however, is a challenge due to the high genetic variability of the pathogen. Race‐specific resistance usually succumbs to new races in just a few years. As such, the USDA‐ARS Cereal Disease Laboratory developed mapping populations to identify adult plant resistance (APR) loci from Avena sativa donors. Resistant lines from the mapping populations were selected and crossed with buckthorn (Rhamnus cathartica L.) nursery selection lines BT1020‐1‐1 and BT1021‐1‐1, which possess a different gene for crown rust resistance derived from Avena strigosa. From the crosses, CDL‐111 (Reg. no. GP‐122, PI 702639) and CDL‐167 (Reg. no. GP‐123, PI 702640), both containing three APR quantitative trait loci, were selected as germplasm for resistance breeding. High‐throughput markers for selection were developed and implemented in pyramiding the APR loci.

Underutilized Canadian wild berries as potential sources of lipophilic bioactive compounds with antihypertensive properties.

Traditional berries are small fruits and are widely distributed in the Canadian prairies. The current study investigates the lipophilic bioactive compounds such as fatty acids, phytosterols, and terpenes, and their bioactivities, such as lipid peroxidation, as well as the antihypertensive activities of fourteen underutilized Canadian wild berries. These berries include Saskatoon berries (Amelanchier alnifolia), gooseberries (Ribes hirtellum), wild grapes (Vitis riparia), blackcurrants (Ribes nigrum), redcurrants (Ribes rubrum), haskap berries (Lonicera caerulea), wild raspberries (Rubus idaeus), wild blueberries (Vaccinium angustifolium), chokeberries (Aronia melanocarpa), buckthorn (Rhamnus cathartica), highbush cranberries (Viburnum trilobum), chokecherries (Prunus virginiana), nannyberries (Viburnum lentago) and snowberries (Symphoricarpos albus). The fatty acids, phytosterols, and terpenes were identified using Gas Chromatography-Mass Spectrometry (GC-MS). Lipid peroxidation and the antihypertensive activity assessed by measuring the berries' angiotensin converting enzyme 1 (ACE1) inhibitory activity were determined using in vitro methods. Notably, wild grapes exhibited the highest (p < 0.05) total fat content (7659 ± 312 μg per g DW), followed by haskap berries (4650 ± 184 μg per g DW). Polyunsaturated fatty acids (PUFAs) were highest (p < 0.05) in wild grapes (74%). Predominant phytosterols and terpenes identified in Canadian wild berries included β-sitosterol, isofucosterol, phytol, and α-amyrin. Saskatoon berries and gooseberries showed a distinct phytosterol and terpene profile compared to the other wild berries. Snowberries demonstrated the highest (p < 0.05) lipid peroxidation and the lowest (p < 0.05) angiotensin converting enzyme (ACE1) activity. This research provides valuable insights into the lipophilic bioactive compounds and their potential activities in vitro of the Canadian wild berries, offering a foundation for further exploration and potential applications in the context of nutraceuticals and functional foods.

Using stomatal conductance capacity during water stress as a tool for tree species selection for urban stormwater control systems

Improving our understanding of how different tree species function in urban stormwater management systems is important, as tree pits may provide a temporary reservoir for stormwater and as trees have the potential to actively reduce stormwater runoff by transpiration. While urban tree planting pits are increasingly used for short-term water storage during stormwater runoff events, this storage can have negative effects on both tree vitality and water removal capacity, since stress from waterlogging result in stomatal closure. However, sensitivity to water stress varies by species. It is therefore important to determine which tree species can maintain long-term vitality and continued transpiration even under water stress, and thus are suitable for such locations. Here, we studied how nine different tree species, varying in expected tolerance to water stress, were affected by short-term and seasonal waterlogging, in a greenhouse experiment. The seedlings (Magnolia x loebneri, Tilia tomentosa, and Sorbus torminalis – low water logging tolerance; Cercidiphyllum japonicum, Rhamnus cathartica, and Fraxinus ornus – medium water logging tolerance; Quercus palustris, Acer saccharinum, and Fraxinus pennsylvanica – high water logging tolerance) were exposed to two days, five days and seasonal waterlogging. The treatments reflected best practice (optimal), suboptimal and total lack of tree pit drainage, using Swedish standards. Stomatal conductance and leaf water potential were determined regularly over a period of 71 days, and morphological adjustments were registered. Four of the species were affected already after two days of waterlogging, with reduced stomatal conductance either during the waterlogging or immediately after, and only the most waterlogging tolerant species were unaffected by the five-day treatment. However, all plants survived waterlogging for almost 30 days before the estimated permanent wilting was reached in some plants. We suggest that tree species selection for stormwater management systems should consider the species’ capacity to maintain high stomatal conductance during waterlogging, as there were clear differences between species. The effectiveness of the selected species could have an important impact on the stormwater management capacity of cities, as well as on other aspects of ecosystem service delivery from urban trees.

Сomparative analysis of the species abundance and structure of plant communities involving &lt;i&gt;Rhamnus cathartica&lt;/i&gt; in Belarus and in the midwestern regions of the USA

The history of intentional introduction of Rhamnus cathartica L. into the Midwestern regions of the USA is briefly described. The species abundance and structure of plant communities, in which Rhamnus cathartica, a native species for Belarus and invasive in the USA grows, has been studied. We compared the studied parameters (floristic description of the monitoring plots, field enumeration of Rhamnus cathartica individuals, average height, projective coverage of the accompanying herb species) at two permanent sample plots in Belarus and three permanent sample plots in the Midwestern regions of the USA. The data confirmed the hypothesis of increased competitiveness of non-native species in the secondary range (EICA). In American populations, compared to Belarusian populations, Rhamnus cathartica has larger sizes, higher seed production, higher number of juvenile individuals, and higher total number of individuals in the population up to the formation of single-species thickets. Invading Rhamnus cathartica into natural plant communities in the USA reduces the number of herbaceous species 8 times! As control measures, the Minnesota Arboretum has begun balding the areas invaded by Rhamnus cathartica, removing juvenile plants (one to five years old) and replanting native tree species.

Monitoring the Spread of Grapevine Viruses in Vineyards of Contrasting Agronomic Practices: A Metagenomic Investigation.

This study investigated the transmission of grapevine viruses, specifically grapevine red blotch virus (GRBV) and grapevine Pinot gris virus (GPGV), in vineyards in Niagara Region, Ontario, Canada. Forty sentinel vines that were confirmed free of GRBV and GPGV by both high-throughput sequencing (HTS) and endpoint polymerase chain reaction (PCR) were introduced to two vineyards (one organic and one conventional) that were heavily infected with both GRBV and GPGV. Four months post-introduction, the sentinel vines were relocated to a phytotron. The HTS results from 15 months post-introduction revealed a widespread infection of GPGV among the sentinel vines but did not detect any GRBV. The GPGV infection rate of sentinel vines in the organic vineyard (13/18) was higher than in the conventional vineyard (1/19). The possibility of an alternative viral reservoir was assessed by testing the most abundant plants in between rows (Medicago sativa, Trifolium repens, Cirsium arvense and Taraxacum officinale), perennial plants in border areas (Fraxinus americana, Ulmus americana, Rhamnus cathartica) and wild grape (unknown Vitis sp.). The HTS result showed that cover crops and perennial plants did not harbor any grapevine viruses, while 4/5 wild grapes tested positive for GPGV but not GRBV. A pairwise sequence identity analysis revealed high similarities between the GPGV isolates found in the established vines on the vineyard and the newly contracted GPGV isolates in the sentinel vines, implicating a recent transmission event. This work provides novel insights into the spread of grapevine viruses in Niagara Region and is also the first direct proof of the spread of GPGV in natural vineyard conditions in North America.

Ecological and biological features and nectariferous value of elm trees

Bee pasturages and natural-climatic conditions in the forest fund of the steppe Pridonye are characterized by great variability. Plantations of European white elm, Scotch elm and English elm occupy 2.2% of the area of the steppe Pridonye. The purpose of this study was to identify honey-bearing species by the forest phytocenosis components in ravine elms and floodplain forests and to determine the honey productivity of plant formations. Accepted methods of scientific research in beekeeping were utilized. The silvicultural and taxational characteristics of the forest stand were obtained, the species composition of the honey-bearing flora was specified and the honey productivity by forest types was determined. Honey productivity of the plant formation of ravine elms is 106.4–203.3 kg/ha. European white elm (Ulmus laevis) provides honey productivity of 32.9 kg/ha in the forest phytocenosis on the shady banks of the ravine oak forests. Field maple (Acer campestre) contributes to this significant index (203.3 kg/ha) in the stand composition on high and steep gully slopes. On the light banks honey production is characterized by honey-bearing undergrowth species, which are found mainly in forest glades and woodsides, as well as the carpet plants representatives. In elm-herbage-nettle-blackberry floodplain forests, the main honey yield (35.3 kg/ha) is given by European white elm and white willow (Salix alba), while in the undergrowth it is given by common buckthorn (Rhamnus cathartica), alder (R. alnus), and European cranberry bush (Viburnum opulus). Skillful use of the honey-bearing potential of forest plants not only makes it possible to successfully develop beekeeping, but also to ensure a significant increase in the forest fund of the southern regions of the European part of the Russian Federation.

Assessment of the ecological state of green spaces of Almaty city on the example of Bostandyk district

The article provides an assessment of the ecological state of green spaces on the example of the Bostandyk district of Almaty. The total area of boulevards, squares and green areas of the Bostandyk district of Almaty today is 147.4 hectares. Bostandyk district of Almaty is one of the three greenest districts of Almaty after Medeu and Turksib districts. As our studies have shown, 95 % of green plantations of tree species in the Bostandyk district of Almaty are represented by introducers and a small part of local species — natives. The landscaping of the territory of the city of Almaty is represented by plantings of different types. These include groves, alleys, gardens, parks, boulevards, squares, green areas, intra-district gardening, street gardening. At the same time, a wide variety of species is observed in gardens, parks, boulevards, groves and a very small use of three or four species in landscaping streets. Among the tree plantations, 35 species are massive, which grow along all the streets, boulevards, squares of the Bostandyk district. From hardwoods: Populus nigra, Populus italica, Populus alba, Fraxinus excelsior and others. From the local natural flora grow — Armeniaca vulgaris, Prunus sogdiana, Fraxinus sogdiana, Rhamnus cathartica, Picea schrenkiana.

No evidence of a long-lived seedbank in common buckthorn, Rhamnus cathartica L., within Minnesota deciduous forests

No evidence of a long-lived seedbank in common buckthorn, Rhamnus cathartica L., within Minnesota deciduous forests

Ethnobotanical survey of wild plants used in Gümüşhane province (Turkey)

This study aimed to document the traditional uses of plants in Gümüşhane province. Ethnobotanical data on 74 taxa from 135 informants were collected between March 2018 and September 2019. Data were analyzed using quantitative indices of use-value (UV), information consent factor (ICF), and fidelity level (FL). The plants were used for different purposes, mainly for medicinal, food, and equipment. Malva neglecta, was the most used taxa for medicinal purposes. Polygonum aviculare was the most used taxon for food. Quercus petraea subsp. iberica and Pinus sylvestris were the most preferred species for equipment. Salvia verticillata, Rhamnus cathartica, Bilacunaria microcarpa, Taraxacum bessarabicum, Silene vulgaris, Carduus nutans, Helichrysum plicatum, Euphorbia esula subsp. tommasiniana, Thymus pubescens, and Phlomis herba-venti subsp. pungensare reported for the first time in the present study for various purposes.

Common Buckthorn Engineered Biochar (Rhamnus Cathartica), Calcined Quagga Mussel Shells (Dreissena Rostriformis), Pickled Steel, and Steel Slag as Filter Media for the Sorption of Phosphorus from Agricultural Runoff

The reuse of waste residuals as reactive media is a sustainable solution to remove phosphorus (P) from wastewater and reduce eutrophication. Large reactive waste media filters incorporated in edge-of-field treatment systems could reduce P loading from agricultural fields. We measured the treatment potential of regionally available waste residuals (i.e., calcined quagga mussel shells (CSHELL), magnesium activated biochar (MGBC), pickled steel (PSTEEL), and steel slag (SLAG)) for dissolved P removal. CSHELL and MGBC had elevated sorption capacities (64,419 and 50,642 mg kg−1, respectively) in comparison to SLAG and PSTEEL (14,541 mg kg−1 and 736 mg kg−1, respectively). However, CSHELL requires long reaction times for removal (22% removal after 1.5 h) and P sorbed to MGBC is removed with DI, reducing treatment potential. SLAG and PSTEEL were the only media with significant reductions of agricultural runoff and had the greatest overall treatment potential. SLAG is recommended for removal and replacement systems while PSTEEL is suitable for larger systems designed for regeneration on site.

ІСТОРИЧНА ГЕРБАРНА КОЛЕКЦІЯ В. М. ЧЕРНЯЄВА В ГЕРБАРІЇ УМАНСЬКОГО НАЦІОНАЛЬНОГО УНІВЕРСИТЕТУ САДІВНИЦТВА (UM)

The article describes the contribution of the famous Ukrainian scientist Vasyl Matviyovych Chernyaev to the science of botany and the development of herbarium. Biographical data are given.&#x0D; Among the funds of Herbarium (UM) of the students of Uman School of Agriculture and Horticulture (the successor is Uman National University of Horticulture) is a valuable historical collection of exicates Herbarium Florae Rossicae (1897–1907). It was established that the collection of exicates includes 1920 herbarium specimens (h. s.), the students of the school were included in the serial issues and they presented the flora of Uman region (Kyiv prov.). There is also a collection of excerpts the famous German florist, collector lichenologist, mycologist and bryologist L. G. Rabenhosta (181 h. s., dated 1801, 1803) and V. M. Chernyaev (29 h. s., 1860, 1864). The processed collections of dendroflora from V. M Chernyaev are represented by ten families of the Angiosperms division: Anacardiaceae, Betulaceae, Cornaceae, Fagaceae, Moraceae, Rhamnaceae, Rosaceae, Salicaceae, Sapindaceae. Among them are species Morus alba L., Quercus robur L., Rhamnus cathartica L., which belong to plants with medicinal properties (Hb. medic. Hipp. Cerniaew).&#x0D; According to the archival materials of the University Museum and rare old prints of the library, it has been established that the preserved historical collection was а part of "The Main Herbarium of Uman School of Agriculture and Horticulture" and served as material in training of gardeners to study Botany and Ornamental Gardening.&#x0D; The historical milestones of the scientific life of the famous scientist, who created botanical courses during the period of his work, was the head of the botanical garden of Kharkiv University and improved the herbarium, were studied. His herbarium collections, which is now stored in herbarium institutions (CWU, KW, MSUD), were purchased to the educational institutions or, probably, they were a gift from a naturalist.&#x0D; In the herbarium collections of V. M. Chernyaev, according to the processed labels, the place of plant growth is not indicated, but only the years, taxa and the name of the collector. Therefore, it should be assumed that the collection is focused on study of the flora of Kharkiv region (1860, 1864) during the period of retirement.&#x0D; The taxonomic affiliation of herbarium collections is arranged in alphabetical order of taxa and checked according to the modern botanical nomenclature "World Flora Online", as some names are synonymous or absent, and currently have no official recognition. The primary database was created, the inventory number was assigned, the sheets were certified with a stamp with the title (Scientific Herbarium of Uman National University of Horticulture (UM), registered in 2016 in the international database Index Herbariorum (New York).&#x0D; Therefore, the scientific herbarium of Uman National University of Horticulture (UM) with its historical collections deserves the attention and can rightfully take a place among the leading herbariums of Ukraine.

Apparent Hybridization of Nonnative Rhamnus Populations in Central New York and Connecticut, U.S.A.

The Eurasian Rhamnus cathartica is widespread, common, and naturalized in parts of the northeastern United States. Other nonnative buckthorn species are also present but underreported because intraspecific leaf polymorphisms, hybridization, and imprecise literature descriptions confuse identifications. A study of Rhamnus populations in Tompkins and Onondaga counties in New York and Hartford County in Connecticut provided an opportunity to revisit the literature and to propose identification aids based on infrequently reported fruit stone number and mature fruit pulp color. These characters facilitate inferences of ancestry of apparent hybrids involving R. cathartica, R. davurica, and R. utilis.

Age and phenology control photosynthesis and leaf traits in the understory woody species, Rhamnus cathartica and Prunus serotina.

Understory plants are often inadequately represented or neglected within analyses of forest ecosystem productivity. Further, the potential impacts of the biological factors of age class and growth form on carbon cycling physiology, and how it may vary across the growing season and amongst species of different native/non-native status, have not been thoroughly considered. Our study examines photosynthesis and associated physical leaf traits in two understory woody species, Rhamnus cathartica, introduced and invasive in North America, and Prunus serotina, a common subcanopy species native to North America. We estimated leaf-level photosynthesis as measured through light and carbon dioxide response curves, dark-adapted chlorophyll fluorescence and leaf traits (leaf mass per area and stomatal density) for each combination of species and age class at plots in the understory of a temperate deciduous research forest in the US Upper Midwest at two time points during the growing season, late spring (late May) and mid-summer (mid-July). Carbon assimilation rates from light response curves (A sat, A 400) and fluorescence capacity estimate F v/F m all increased between the two measurement points in both species and age class. Estimates of carbon reaction capacity (V cmax and J max) exhibited a different directional response to seasonal development, declining in seedlings of both species and P. serotina trees (~8-37 % reduction in V cmax, ~9-34 % reduction in J max), though increased in trees of R. cathartica (+24 % in V cmax, +9 % in J max). Divergent responses in photosynthetic parameters amongst these factors may be explained by species differences in leaf mass per area and stomatal density, which together are likely influenced by both growth form, canopy position and ontogeny. Overall, we believe our findings suggest complex, varied influences on photosynthesis that indicate environmental and biological plasticity which may contribute to the historic and continued expansion of R. cathartica in the US Upper Midwest region.

Cytotoxicity and Anti-Plasmodium berghei Activity of Emodin Loaded Nanoemulsion.

Malaria parasites cause a tremendous burden of disease in both the tropics and subtropics areas. Growing of drugs resistance in parasites is one of the most threats to malaria control. The aim of study was to investigate the anti-malarial activity of nano-emodin isolated from Rhamnus cathartica on Plasmodium berghei in mice to evaluate parasites inhibition rate using in-vivo test. The study was conducted in the School of Public Health, Tehran University of Medical Sciences, during 2020. Nano-emodin particles were prepared from Rhamnus cathartica, and confirmed by Zeta Potential Analyzer, DLS and electron microscopy techniques. Mice were infected with P. berghei and treated by emodin nano-particles. Parasitemia was evaluated in each group in comparison with control group. Toxicity test was done using twice the highest concentration of emodin extract on a separate group of mice and ED50 was calculated. Emodin extract was significantly effective in all concentrations on D4 (P<0.05). The most effective on parasitemia was observed in 400 mg/kg of Liquid Nano-emodin and solid (non-Nano) emodin. ED50 for emodin extract was determined 220 mg/kg. Toxicity test showed no toxic effect on the subjects. The emodin extract is safe, lack of side effects. So, it can be used for more and longer period of time and in higher doses. Emodin extract, either in form of liquid and nanoparticle or in a solid form, has the same therapeutic effect on P. berghei in infected Balb/c mice.

Using plants to control buckthorn (Rhamnus cathartica): Improved biotic resistance of forests through revegetation

Woody invaders of temperate forest understories reduce native diversity worldwide. Common buckthorn Rhamnus cathartica, is among the most widespread of such invaders in North America. Invaded communities often have seedbanks largely comprised of the dominant invader - with few native species remaining - and therefore lack the capacity to build biotic resistance against re-invasion following invader removal. Consequently, invaders, including buckthorn, often quickly re-establish in the absence of continued management. We investigated the capacity of native plant revegetation to inhibit buckthorn re-establishment from seedbanks in the understories of three forests of Minnesota, USA. Specifically, we established experimental plots subjected to seeding of 35 native species, planting of Pennsylvania sedge (Carex pensylvanica) plugs, or bare-root plantings of either mixed shrubs (Sambucus canadensis, Sambucus racemosa, Corylus americana, and Cornus racemosa) or mixed trees (Abies balsamea and Acer saccharum). We then measured buckthorn germinant establishment, growth, and survival for the following four growing seasons. We observed consistent impacts of revegetation on ground-level light availability and associated buckthorn performance. Compared to unplanted understory controls beneath the mature tree canopy, shrub plantings were the most impactful. Shrubs reduced light availability to buckthorn seedlings by 67% relative to unplanted controls (to <2% total light by the third year) and led to 51% lower year-over-year survival of buckthorn by the end of the experiment. Revegetation also suppressed buckthorn seedling growth. After four years, shrub plantings resulted in buckthorn that were 53% shorter and had 38% fewer leaves than buckthorn grown in unplanted controls. Considering the combined impacts on survival and growth, planted shrubs, trees, and sedges reduced buckthorn invasion by 89%, 81%, and 66%, respectively; and seeding alone reduced invasion by 51%. Our findings indicate that revegetating forests, particularly with shrubs and trees, can greatly reduce invasion by buckthorn and potentially other species. Greater adoption of revegetation by land managers may therefore increase native biodiversity, reduce herbicide applications, and improve the overall health and value of forests.

EDNA Analysis of Goat‐Grazed Rhamnus cathartica Soil Microbial Communities

Biological invasions of exotic species pose a significant threat to local biodiversity and ecosystem services. Redistribution of plant species in particular disrupts key structure‐function relationships in the soil by altering the composition of microbial taxa. This study combines environmental DNA analysis with a goat‐grazing intervention to investigate the taxonomic structure of soil microbiomes interacting with the invasive plant, Rhamnus cathartica (common Buckthorn). 16S (515F/806R) metabarcodes were amplified from soil DNA harvested before and after a goat‐grazing regimen on buckthorn‐invaded and control plots. Samples were sequenced on an Illumina iSeq, then analyzed using the DNA Subway Purple Line (QIIME 2.0) to process sequencing reads and calculate diversity indices. PCoA visualizations of Jaccard Beta diversity patterns revealed differences in community composition between buckthorn and control soils, but no effects from goat grazing. Five dominant taxa were identified in no‐buckthorn control soils, accounting for 35 +/‐ 9.6 SD% of the average relative abundance of total sequences. Genus DA101 notably demonstrated the largest decrease in average relative abundance in the buckthorn and goat‐grazed soils (% decrease = 6.4 +/‐ 2 SD), whereas the evenness of other taxa increased. Overall, buckthorn soil showed significant increases in Pielou’s taxonomical evenness (Kruskal‐Wallis H(2, N=29) = 10.9; p=0.004), but goat grazing had no impact on this score (p&gt;0.01). Faith’s phylogenetic diversity scores showed no significant differences between buckthorn, goat‐grazed, and control soils (Kruskal‐Wallis H(2, N=31) = 2.2; p=0.32). Taken together, these preliminary results illustrate that buckthorn increases taxonomical evenness but has no effect on overall phylogenetic diversity of soil communities. Moreover, buckthorn goat‐grazing had little impact on soil community structure. Future studies will investigate the role of DA101 on buckthorn suppression as a possible mitigation strategy for this invasive species.

HEPATOCELLULAR TOXICITY OF THE METABOLITE EMODIN PRODUCED BY THE COMMON BUCKTHORN (RHAMNUS CATHARTICA) IN GREEN FROG (LITHOBATES CLAMITANS) TADPOLES.

The secondary metabolite emodin, produced by the widely distributed invasive shrub known as the common buckthorn (Rhamnus cathartica), has been shown to produce deformities and mortality in invertebrates, fish, and amphibian larvae. Here, we describe the effects on the liver of green frog (Lithobates clamitans) tadpoles after 21 d of exposure to high concentrations of emodin in a controlled environment. Histopathologic analysis showed fibrosis, bile duct proliferation, hepatocellular swelling, and accumulations of flocculent material consistent with emodin within the gall bladder and bile ducts of exposed individuals. The extensive fibrosis produced probably impeded the blood flow within the portal triads, limiting the detoxification function of the liver and resulting in hepatocellular necrosis and premature death for the individuals exposed. Exposure to emodin in the environment could represent a significant threat to developing amphibian larvae and contribute to local declines of populations.