Search

Simple Summary: Invasive plants pose a significant threat to native ecosystems, and understanding their interactions with local arthropod communities is crucial for effective management strategies. This study aimed to identify arthropod species associated with glossy buckthorn (Frangula alnus), an invasive plant originating from Europe and colonizing North America. Over two years, arthropod samples were systematically collected from 16 different plots on five collection dates. The collected arthropods were identified, and their abundance, richness, and diversity were measured. Additionally, the study documented the arthropods emerging from F. alnus fruits and volatiles emitted by F. alnus. The results revealed that the dominant insect orders were true bugs (Hemiptera, 39.8%) and flies (Diptera, 22.3%). The dominant species was Psylla carpinicola (Hemiptera: Psyllidae), followed by Drosophila suzukii (Diptera: Drosophilidae); D. suzukii utilized F. alnus fruits for reproduction. Furthermore, the study noted that the abundance, richness, and diversity of arthropod orders were influenced by the phenology of F. alnus. This pioneering research provides valuable insights into the arthropod communities associated with F. alnus in North America, offering a foundation for the development of effective management strategies to control this invasive plant species. The invasive shrub glossy buckthorn (Frangula alnus) has been progressively colonizing the Northeastern United States and Southeastern Canada for more than a century. To determine the dominant arthropod orders and species associated with F. alnus, field surveys were conducted for two years across 16 plots within the Allegheny National Forest, Pennsylvania, USA. Statistical analyses were employed to assess the impact of seasonal variation on insect order richness and diversity. The comprehensive arthropod collection yielded 2845 insects and arachnids, with hemipterans comprising the majority (39.8%), followed by dipterans (22.3%) and arachnids (15.5%). Notably, 16.2% of the hemipterans collected were in the immature stages, indicating F. alnus as a host for development. The two dominant insect species of F. alnus were Psylla carpinicola (Hemiptera: Psyllidae) and Drosophila suzukii (Diptera: Drosophilidae); D. suzukii utilized F. alnus fruits for reproduction. Species richness and diversity exhibited significant variations depending on the phenology of F. alnus. The profiles of volatile compounds emitted from the leaves and flowers of F. alnus were analyzed to identify factors that potentially contribute to the attraction of herbivores and pollinators. The results of our study will advance the development of novel F. alnus management strategies leveraging the insects associated with this invasive species. [ABSTRACT FROM AUTHOR]

Simple Summary: Glossy buckthorn (Frangula alnus) (Rosales: Rhamnaceae) is an invasive shrub from Europe, threatening native vegetation in open and disturbed habitats. To determine the spatial distribution patterns of glossy buckthorn, the density and presence of F. alnus were recorded in 1412 transect sample points located on four sites in the Allegheny National Forest, Pennsylvania, USA. Geostatistical analyses were used to determine spatial autocorrelation among individual F. alnus samples and to measure their spatial dependency. Spatial patterns were examined using spatial analyses by distance indices (SADIE), and buffer analyses were conducted to determine the relationships between proximity to unpaved forest roads and both F. alnus density and presence. The results of this study showed that the density and presence of F. alnus decreased as the distance from the forest road increased. We also found a significant spatial aggregation of F. alnus in all four study sites. These findings imply that spatially targeted management of F. alnus would be possible by locating the patches of F. alnus and applying control measures only where needed. Glossy buckthorn (Frangula alnus) (Rosales: Rhamnaceae) is an invasive shrub from Europe that has been invading North America for over a century and threatening native vegetation in open and disturbed habitats. The treatment of F. alnus is currently restricted to the roadside, suggesting any individual F. alnus residing within the forest would be left unmanaged and would continue to spread in the area. This research was conducted to determine the spatial patterns and relationship of F. alnus with forest roads. The presence and density of F. alnus at 1412 sample points were recorded on four sites in the Allegheny National Forest, Pennsylvania, USA. Buffer analyses were conducted along roads to determine the relationship between F. alnus density and proximity to forest roads. Geostatistics and spatial analysis by distance indices (SADIE) were used to characterize the spatial pattern of F. alnus. Results of this study showed that F. alnus was spatially aggregated and resided beyond forest roads. Both the density and presence of F. alnus decreased as the distance from the forest road increased. These results imply the potential for precision management of F. alnus by locating and managing only where F. alnus presents. [ABSTRACT FROM AUTHOR]

Rhamnus cathartica and Frangula alnus are economically valuable medicinal plants from the Rhamnaceae family. However, their chloroplast genome structure, phylogenetic position, relationships, and evolution remain poorly understood. Herein, the complete chloroplast genome resources of R. cathartica and F. alnus have been added. The first comparative analysis of the Rhamnus and Frangula species based on complete chloroplast genomes was provided. The chloroplast genomes of R. cathartica and F. alnus exhibited a quadripartite structure, with total lengths of 161,149 bp and 161,255 bp, respectively. The lack of the infA and psbL genes does not negatively impact the normal functioning of Rhamnus and Frangula species. The rpl20 and rpl33 genes are undergoing rapid evolution. Rhamnus and Frangula species prefer amino acids with A/U-terminal codons. There were between 100 and 126 simple sequence repeats and between 38 and 100 long repeats. Several highly divergent intergenic regions (trnK-UUU–trnQ-UUG, atpH–atpI, trnY-GUA–trnE-UUC, trnG-GCC–trnfM-CAU, trnT-UGU–trnF-GAA, rpl20–rps12, and rpl22–rps19) and highly divergent genes (ycf3, ndhA, rpl32, and ycf1) were identified, which could serve as potential phylogenetic markers due to their variability. We reconstructed the phylogenetic relationships among Rhamnus species and F. alnus using complete chloroplast genomes. There is no significant correlation between the medicinal value of the species analyzed and their phylogenetic relationships. These results provide valuable insights for understanding the phylogenetic relationship and evolution of Rhamnus and Frangula species. These findings could serve as a foundation for future studies on the Rhamnaceae. [ABSTRACT FROM AUTHOR]

• SFC was used for the analysis of anthraquinones in Frangula alnus for the first time. • Seven derivatives could be resolved in less than six minutes on a DIOL phase. • The method permits the separation of glycosides and aglyca at the same time. • The assay was validated and is well applicable for real sample analysis. Anthraquinones are the major bioactive compounds in alder buckthorn , a plant with a long history of use for the treatment of obstipation in European and Asian traditional medicine. As these metabolites are also associated with toxic side effects, reliable analytical techniques for their determination are essential. Previously described methods mainly utilized Liquid Chromatography for this purpose, as the photometric assay described in the current edition of the European Pharmacopoeia lacks selectivity. In this study, the development and application of an alternative approach, Ultra-High Performance Supercritical Fluid Chromatography, is presented, facilitating the qualitative and quantitative determination of seven anthraquinone derivatives in under six minutes. This was possible by using a Torus™ DIOL column and a modifier comprising methanol with 10 % acetonitrile and 2.5 mM oxalic acid; applying a flow rate of 1.6 mL/min and an elevated temperature of 55 °C enabled optimal resolution. Regarding selectivity, linearity (R2 ≥ 0.9995), precision and accuracy (recovery rates between 96.6 and 103.3 %), all results were in line with the respective ICH requirements. Practical applicability of the assay was confirmed by analyzing different samples, including commercially available plant material, phytopharmaceuticals containing Frangula bark and wild collected samples. Except of the latter, glucofrangulin A always was the dominating compound; however, the overall anthraquinone content showed to be very variable ranging from 2.18 to 51.32 mg. [ABSTRACT FROM AUTHOR]

The invasive shrub glossy buckthorn (Frangula alnus) has been progressively colonizing the Northeastern United States and Southeastern Canada for more than a century. To determine the dominant arthropod orders and species associated with F. alnus, field surveys were conducted for two years across 16 plots within the Allegheny National Forest, Pennsylvania, USA. Statistical analyses were employed to assess the impact of seasonal variation on insect order richness and diversity. The comprehensive arthropod collection yielded 2845 insects and arachnids, with hemipterans comprising the majority (39.8%), followed by dipterans (22.3%) and arachnids (15.5%). Notably, 16.2% of the hemipterans collected were in the immature stages, indicating F. alnus as a host for development. The two dominant insect species of F. alnus were Psylla carpinicola (Hemiptera: Psyllidae) and Drosophila suzukii (Diptera: Drosophilidae); D. suzukii utilized F. alnus fruits for reproduction. Species richness and diversity exhibited significant variations depending on the phenology of F. alnus. The profiles of volatile compounds emitted from the leaves and flowers of F. alnus were analyzed to identify factors that potentially contribute to the attraction of herbivores and pollinators. The results of our study will advance the development of novel F. alnus management strategies leveraging the insects associated with this invasive species.

Glossy buckthorn (Frangula alnus) (Rosales: Rhamnaceae) is an invasive shrub from Europe that has been invading North America for over a century and threatening native vegetation in open and disturbed habitats. The treatment of F. alnus is currently restricted to the roadside, suggesting any individual F. alnus residing within the forest would be left unmanaged and would continue to spread in the area. This research was conducted to determine the spatial patterns and relationship of F. alnus with forest roads. The presence and density of F. alnus at 1412 sample points were recorded on four sites in the Allegheny National Forest, Pennsylvania, USA. Buffer analyses were conducted along roads to determine the relationship between F. alnus density and proximity to forest roads. Geostatistics and spatial analysis by distance indices (SADIE) were used to characterize the spatial pattern of F. alnus. Results of this study showed that F. alnus was spatially aggregated and resided beyond forest roads. Both the density and presence of F. alnus decreased as the distance from the forest road increased. These results imply the potential for precision management of F. alnus by locating and managing only where F. alnus presents.

The quality of leaves as food for insects is affected both by plant species and the light conditions present during growth. Little information exists concerning the impact of these factors on the diversity of insects that live in the forest understory. We studied arthropod fauna on six understory plant species commonly occurring in Europe. Different groups of herbivorous insects were identified, as well as predatory insects and arachnids. We analysed the influence of both plant species and light conditions during growth (low light; high light) on the species spectrum, and the number of insect specimens present. The resulting data were investigated in relation to the susceptibility of plant leaves to feeding by folivorous insects, as determined in earlier studies. We compared the similarity in species diversity, based on the Sørensen's coefficient, and discussed the potential causes of observed differences in leaf damages. We found a total of 153 arthropod taxa on studied plants, under both light conditions. Corylus avellana and Prunus serotina, species characterized by greater leaf damage, have a wider diversity of arthropod species, and a greater number of herbivorous insects. Generally, light conditions had a greater effect on arthropod abundance than on species diversity. For two plant species, C. avellana and P. serotina, light conditions strongly, but reversely, influenced the total number of insects and, thus, the extent of leaf damage. The number and abundance of zoophagous species, and ratio to folivores (except C. avellana) are associated more with plant species than with light conditions. [ABSTRACT FROM AUTHOR]

Frangula alnus and Peganum harmala populations growing in Saudi Arabia might be rich sources of natural compounds with important biological activities. A high performance liquid chromatography diode array revealed several polyphenols in the leaf extracts for the first time, including p-coumaric acid, rosmarinic acid, chlorogenic acid, ferulic acid, quercitrin, rutoside, quercetin and trifolin in F. alnus; and hydrocaffeic acid, protocatechuic acid, rosmarinic acid, caffeic acid and cynaroside in P. harmala. F. alnus and P. harmala showed strong antioxidant effects attributed to the polyphenolic composition of leaves and reduction of reactive oxygen species (ROS) accumulation. F. alnus and P. harmala leaf extracts showed cytotoxic effects against Jurkat, MCF-7, HeLa, and HT-29 cancer cells using MTT and flow cytometry assays. These activities were attributed to the polyphenolic composition of leaves including quercitrin, trifolin and cymaroside, as well as the activation of caspase family enzymes 2, 6, 8 and 9 in treated cancer cells compared to control. The current findings of this study include a novel comprehensive investigation on the polyphenol composition and anticancer effects of leaf extracts of F. alnus and P. harmala from natural populations in Saudi Arabia.

Copyright of Forestry Chronicle is the property of Canadian Institute of Forestry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Measuring and predicting invasive plant abundance is critical for understanding impacts on ecosystems and economies. Although spatial abundance datasets remain rare, occurrence datasets are increasingly available across broad regional scales. We asked whether the frequency of these point occurrences can be used as a proxy for abundance of invasive plants. We compiled both occurrence and abundance data for 13 regionally important invasive plants in the northeast United States from herbarium records and several contributed distribution datasets. We integrated all available abundance information based on infested area, stem count, percent cover, or qualitative descriptions into abundance rankings ranging from 0 (absent) to 4 (highly abundant). Within equal-area grid cells of 800 m, we counted numbers of occurrence points and used ordinal regression to test whether higher densities of occurrence points increased the odds of a higher abundance ranking. We compiled a total of 86,854 occurrence points in 34,596 grid cells, of which 26,114 points (30%) within 11,976 cells (35%) had some form of abundance information. Eleven of the 13 species had a slight but significantly positive odds ratio; that is, more occurrence points of a species increased the odds that the species was abundant within the grid cell. However, the predictive ability of the models was poor (κ < 0.2) for the majority of species. Additionally, most grid cells contained only one or two occurrence points, making it impossible to infer abundance in all but a few locations. These results suggest that currently available occurrence datasets do not effectively represent abundance, which could explain why many distribution models based on occurrence data are poor predictors of abundance. Increased efforts to consistently collect and report invasive species abundance, ideally estimating both infested area and average cover, are strongly needed for regional-scale assessments of potential abundance and associated impact. [ABSTRACT FROM AUTHOR]

Invasive glossy buckthorn could reduce restoration potential for understory native forest herbs by compromising their growth and biodiversity. Few studies of glossy buckthorn's effects on forest herbs exist, and none were done in early-successional, partially open hardwood forests. This study was conducted in a mature hybrid poplar plantation invaded by buckthorn, located in southeastern Québec.We tested the effect of buckthorn removal on the growth of three forest herb species, whether this effect varied among species, and if canopy type (two poplar clones) influenced this effect. Forest herbs were planted in herbicide (buckthorn removed) and control treatments in the plantation understory, an environment similar to that of early-successional hardwood forests. Over the first two growing seasons, species showed specific reactions to buckthorn cover. Mean relative growth rate (RGR) for Asarum canadense and Polygonatum pubescens was increased in the herbicide treatment (48% and 33%, respectively) and decreased in the control treatment (--35% and --33%, respectively). Sanguinaria canadensis growth was the highest among species, with no difference between treatments. No effects of canopy type were detected. Results suggest that planting forest herbs for restoration purposes may be unsuccessful if buckthorn is present. Important changes in understory flora biodiversity are likely to occur over the long term in forests invaded by buckthorn. [ABSTRACT FROM AUTHOR]

The use of medicinal plants is becoming increasingly appreciated in suppressing cancer growth and cancer prevention. In this study the antiproliferative effects of the water extracts of previously obtained ethanolic dry extracts of three different medicinal plants (Camellia sinensis, Frangula alnus from two different places and Rosmarinus officinalis) using cell lines derived from human cervix adenocarcinoma (Hela cells) were investigated. The extract of Camellia sinensis exhibited significant cytotoxic effect against Hela cells (IC50 40.88 μg/ml). Screening in Hela cells revealed a moderate cytotoxic effect (IC50 80.26μg/ml) of the extract of Rosmarinus officinalis, a mild cytotoxic effect (IC50 148.05 μg/ml) of the extract of Frangula alnus (originating in Bosnia), and the extract of Frangula alnus (originating in Serbia) did not show active cytotoxicity (IC50 > 200 μg/ml). The best antiproliferative properties are those of Camellia sinensis, followed by Rosmarinus officinalis, and the least effective was Frangula alnus. As regards geographic origin, the Frangula alnus from Bosnia possessed better antiproliferative effects than Frangula alnus from Serbia. [Projekat Ministarstva nauke Republike Srbije, br. 34021 i br. 175011]

Background and aims: Invasive plants have been associated with alterations to soil properties, functions, and organisms, with the potential to impact ecosystem processes. An observational study was conducted to determine how the invasive plant Frangula alnus affects soil microbial communities and biogeochemical processes in Wisconsin forests. Methods: Paired invaded/non-invaded sites ( n = 10), including high ( n = 5) and low ( n = 5) density invasions, were sampled in spring, summer, and fall. Soil was analyzed for extractable and total nitrogen (N), N mineralization rate, total carbon, microbial biomass carbon and N, and microbial community structure using terminal restriction fragment length polymorphisms. Results: Linear regression analysis with robust variance estimation revealed higher N mineralization rates in invaded sites than non-invaded sites in summer, and in high density invaded sites than non-invaded sites overall ( p < 0.05). There was not a corresponding increase in extractable N. No differences between invaded and non-invaded sites were observed for other variables. Conclusions: Nitrogen-rich F. alnus leaf litter (3.2 % of dry mass) may contribute to elevated N mineralization at these sites, though pre-existing conditions may be responsible. Results suggest that F. alnus alters N cycling but has little impact on soil carbon pools and microbial communities. [ABSTRACT FROM AUTHOR]

Native tree seedlings (nursery produced) were planted under control and herbicide treatments in the understory of a mature hybrid poplar plantation, naturally invaded by glossy buckthorn, a major invasive exotic shrub of Eastern North America. The objectives were to (1) test the negative effect of the invasive buckthorn on seedling growth, (2) determine if this effect differed for two tree species with different shade tolerances and edaphic requirements (sugar maple, red oak), and (3) determine if the type of canopy influenced this effect (5 clones). Confounding factors were reduced in this design (canopy composition and structure, age/size of seedlings), and several factors were controlled (transplantation date, deer exclusion). Several factors were measured (canopy openness, soil nutrients, canopy biomass, understory vegetation biomass, buckthorn density and biomass). After two growing seasons, seedlings of both species had reduced diameter and height increments under buckthorn. This difference was statistically significant for diameter increment. Canopy type did not have any effect on environmental variables or seedling growth. Buckthorn reduced light availability, but had no effect on soil moisture or soil nutrient availability. Consistent with sugar maple's ecological requirements, its diameter growth was explained (multiple regression) firstly by edaphic variables (positive effect: soil humidity and K), and secondly by buckthorn biomass (negative effect). Red oak growth was explained firstly by buckthorn biomass, and secondly by understory vegetation biomass, both negative effects. Seedlings of species with higher light requirements (red oak) may have large growth reductions under buckthorn cover and have difficulty overtopping it. These results indicate that under-planting (plantations, forests) or afforestation should occur rapidly after buckthorn removal, otherwise this introduced invasive shrub may greatly reduce survival and growth of planted trees. Restoration of red oak to areas of former abundance will likely be more difficult because of the competition from glossy buckthorn. [ABSTRACT FROM AUTHOR]

Many invasive plant species are able to establish within a wide range of community types. This establishment success depends on high propagule pressure and successful recruitment of seedlings following propagule dispersal into receptive environments. This study aimed to investigate interactions between propagule pressure and environmental resistance to seedling recruitment of the invasive shrub, glossy buckthorn ( Frangula alnus Mill.), over a range of wetland habitat types. We measured propagule deposition using seed traps and recruitment success using sown plots, while characterizing vegetation and abiotic environmental conditions in five adjacent wetland habitat types. Drier habitats, which included Cedar Swamp, Shrub Carr, and String, had lower resistance to buckthorn establishment than the wetter Flark and Cattail Marsh. The drier habitats supported more woody species and provided more raised hummock surfaces essential for successful buckthorn recruitment and establishment. Propagule pressure was also higher in dry habitats that supported higher densities of adult glossy buckthorn, while long-distance dispersal into areas with low adult density was uncommon. Natural recruitment was highest in sites with intense propagule pressure, but experimental sowing of seeds demonstrated that buckthorn establishes in wet sites with higher resistance if propagule pressure is increased and seeds are deposited on hummocks. This study demonstrates the affinity of glossy buckthorn for drier wetland sites, and provides empirical evidence that environmental resistance can be overcome by higher propagule pressure. [ABSTRACT FROM AUTHOR]

The buckthorns Rhamnus cathartica and Frangula alnus are nonnative invasive species in North America whose seeds are primarily dispersed by birds. This paper presents the first major compilation of the bird species that eat R. cathartica and F. alnus in eastern North America, where these buckthorns are most invasive and have few common congeners. Using fecal samples, observations, and an extensive literature search, I document 46 bird species that consume R. cathartica and F. alnus, and discuss which are the most competent dispersers of the seeds. I also correct a frequently repeated belief that 'blackbirds' are efficient dispersers of R. cathartica and F. alnus. [ABSTRACT FROM AUTHOR]

The exotic shrub glossy buckthorn (Frangula alnus) is a great concern among forest managers because it invades both open and shaded environments. To evaluate if buckthorn grows similarly across light environments, and if adopting different shapes contributes to an efficient use of light, we compared buckthorns growing in an open field and in the understory of a mature hybrid poplar plantation. For a given age, the relationships describing aboveground biomass of buckthorns in the open field and in the plantation were not significantly different. However, we observed a significant difference between the diameter-height relationships in the two environments. These results suggest a change in buckthorn's architecture, depending on the light environment in which it grows. Buckthorn adopts either an arborescent shape under a tree canopy, or a shrubby shape in an open field, to optimally capture the light available. This architectural plasticity helps explain a similar invasion success for glossy buckthorn growing in both open and shaded environments, at least up to the canopy closure level of the plantation used for this study. [ABSTRACT FROM AUTHOR]

The aroma profiles of thirteen different honey samples from four botanical origins: heather ( Calluna vulgaris ), raspberry ( Rubus idaeus ), rape ( Brassica napus ), alder buckthorn ( Frangula alnus ) and the blossoms of the four corresponding flowers were investigated to find odour-active compounds exclusively representing specific honeys based on odour-active compounds from the blossoms. Gas-chromatography–mass spectrometry (GC–MS) and gas-chromatography–olfactometry were used to determine and identify the odour-active compounds. Data was analysed using agglomerative hierarchical clustering and correspondence analysis. Honeys from the same botanical origin clustered together; however, none of the identified compounds were exclusive to a particular honey/blossom combination. Heather honey had the flavour profile most different to the others. Isophorone and 2-methylbutyric acid were found only in heather honeys. Heather honey was characterised by having more “sweet” and “candy-like” notes, raspberry honeys had more “green” notes, while alder buckthorn had more “honey” and “floral” notes. [ABSTRACT FROM AUTHOR]

The spatial distribution of non-native, invasive plants on the landscape is strongly influenced by human action. People introduce non-native species to new landscapes and regions (propagule pressure) as well as increase ecosystem invasibility through disturbance of native ecosystems. However, the relative importance of different landscape drivers of invasion may vary with landscape context (i.e., the types and amounts of surrounding land cover and land use). If so, data collected in one context may not be appropriate for predicting invasion risk across a broader landscape. To test whether independent occurrence datasets suggest similar landscape drivers of invasion, we compared landscape models based on data compiled by the Invasive Plant Atlas of New England (IPANE), which are contributed opportunistically by trained citizen scientists, to models based on Forest Stewardship plans (FSPs), which are located in privately owned and relatively undisturbed forests. We evaluated 16 landscape variables related to propagule pressure and/or disturbance for significant predictors of invasive plant presence based on presence/absence and count regression models. Presence and richness of invasive plants within FSPs was most influenced by proportion of open land and proximity to residential areas, which are both sources of propagules in forest interiors. In contrast, IPANE invasive plant presence and richness for the same area was influenced by distance to roads and streams. These results suggest that landscape drivers of invasion vary considerably depending on landscape context, and the choice of occurrence dataset will strongly influence model results. [ABSTRACT FROM AUTHOR]

Effects of invasive plants on soil properties and microbial communities have been observed, but the mechanisms driving change are less obvious. The objective of this study was to determine the short-term impacts of litter from the invasive shrub Frangula alnus on soil properties and soil microorganims. In situ soil rings (6-cm diameter by 7-cm deep) received the following aqueous treatments: deionized water, dextrose, cellulose, Quercus alba leaf extract, and F. alnus leaf extract ( n = 7) and were sampled 1, 2, and 4 weeks after additions were made. Microbial biomass carbon did not respond differently to treatments containing carbon (C) sources at any sampling period, suggesting that C quality had little impact on microbial abundance at this site. However, in weeks 1 and 2, soil treated with F. alnus had significantly higher total extractable nitrogen (N) than the control, dextrose, cellulose, and Q. alba extract (all comparisons for both weeks p < 0.001). We suspect that the increase in extractable N in the F. alnus-treated soil was due to enhanced N mineralization. In addition, changes to the microbial biomass C-to-N ratio in the F. alnus-treated soil indicated that microbial function had been altered. Overall, results from this study suggest that F. alnus leaf litter has the capacity to alter soil properties and microbial function by stimulating N mineralization. [ABSTRACT FROM AUTHOR]

To investigate the hypothesis that Frangula alnus, glossy buckthorn, is causing a decrease in native plant diversity in forested plant communities of southwest New Hampshire, thirty nine 20-m x 20-m plots were established in five different forest types, and all buckthorn saplings and seedlings were removed from 15 of the plots. A nested plot design was used to sample shrubs and herbs. Treatment plots were kept free of buckthorn for five years. There was a positive relationship between pre-treat-ment buckthorn density and percent openness of the forest canopy, and with basal area of white pine (Pinus strobus), but not with soil wetness indicators. No significant changes in overall plant diversity or stem density were detected after buckthorn was removed, although stem density of woody plants, and seedlings of Acer rubrum did show significant increases in the treatment plots when compared to controls, but these effects were only seen in areas with the highest densities of buckthorn. No effects of buckthorn were observed below an average of 8.25 stems per m2. Compared to other areas of the northeastern United States, the densities of buckthorn were very low. Buckthorn seedling densities showed small increases in the control and monitoring plots, perhaps indicating a slow build-up to a "threshold" density, beyond which greater impacts on native species may be seen. [ABSTRACT FROM AUTHOR]

Although the hazel dormouse Muscardinus avellanarius is considered both a highly specialized and a threatened mammal species in Europe, it is relatively common and widespread in Lithuania, situated on the northern periphery of its distributional range. We studied dormouse diet over the entire activity season using microscopic analysis of feces to gain a better understanding of its ecology. Our results confirm that the hazel dormouse is indeed a selective feeder, always showing a preference for the reproductive parts of plants. However, the plant species used by dormice in Lithuania are different from those used in other parts of the dormouse range (e.g., England). In Lithuania, the main dormouse food sources are the inflorescence of willow, oak, and spruce in spring; the berries of honeysuckle, raspberry, and glossy buckthorn in summer; and the berries of glossy buckthorn, oak acorns, and hazelnuts in autumn. Only in early summer, the proportion of food of animal origin is high. The berries of glossy buckthorn are very important to dormouse for feeding and accumulation of fat reserves in autumn. The adaptability of dormice to feed on local plants, as well as the sufficient diversity of food plants in their habitats, allows these animals to be relatively common and widespread on the northern periphery of their range. [ABSTRACT FROM AUTHOR]

Landsat TM and ETM+ satellite images from 2001 to 2011 were used to map the extent and change of the invasive shrubs common and glossy buckthorn ( Frangula alnus and Rhamnus cathartica) at Irwin Prairie State Nature Preserve (IPSNP), and throughout Oak Openings, a 1,500 km region, located in NW Ohio, USA and SE Michigan near Lake Erie. In the Oak Openings, buckthorn directly threatens native biodiversity and habitat health of this globally rare ecosystem. Buckthorn that forms as dense shrub thicket in the understory is often obscured from satellite view by other canopy and is not spectrally dissimilar enough to be characterized using multispectral images. To address this, time series tasseled cap greenness images of land surface areas dominated by buckthorn thicket (which exhibit early leaf-out, late senescence) was used to identify areas covered by thicket with a heterogeneous background. A time series of vegetation index values was calculated from 49 Landsat images and combined with in-situ observations to define the land surface phenology of buckthorn thicket and other vegetation types. The phenological differences among land surfaces dominated by distinct vegetation types in the Oak Openings Region were used to map the extent of buckthorn thicket using a supervised classification method. Buckthorn thicket was identified in 0.43 % of the classified pixels (940 ha) in the 2007-2011 imagery and in 0.31 % (690 ha) of the 2001-2006 images. A Kappa test of the 2007-2011 classification yielded a value of 0.73 with 88 % overall accuracy of presence or absence of thicket based on 60 samples throughout the Oak Openings. The areal extent of buckthorn thicket increased by 39 % (255 ha) in the study area over the time period from 2001 to 2011. [ABSTRACT FROM AUTHOR]

Abstract: Frangula rupestris and Frangula alnus are deciduous shrubs distributed in Balkan Peninsula. While the bark of F. alnus is medicinally widely used, little is known about chemical and biological properties of F. rupestris. In the present study, F. rupestris and F. alnus bark were evaluated for their reducing power, DPPH radical scavenging and chelating activity, as well as antioxidant activity in β-carotene-linoleic acid assay. In addition, phenolic content, anthraquinone profile and antimicrobial activity of F. rupestris and F. alnus bark were determined. The most represented anthraquinone derivatives in F. rupestris and F. alnus bark were physcion (0.11mg/g) and emodin (2.03mg/g), respectively. Both species demonstrated excellent antioxidant and antimicrobial activities with MIC values equal or lower than 2.5mg/mL. The presented research indicates that both species may have health benefits as natural antioxidants and antimicrobial agents for use in functional foods or medicine. [Copyright &y& Elsevier]

Abstract: The extent to which forests can be invaded by exotic plants and the role of tree harvest in facilitating such invasions are important issues in invasion biology. Our objective was to determine: (a) whether a widespread exotic shrub, glossy buckthorn (Frangula alnus), can invade a common northeastern US forest type, (b) the extent to which logging facilitates buckthorn invasion, (c) whether buckthorn invades gaps through pre-disturbance (‘advance’) regeneration, (d) whether or not it forms uneven-aged populations in invaded stands. We selected nine eastern white pine – hardwoods stands in Durham, NH. Three were undisturbed, three were clear-cut, and three were partially cut. Cutting occurred ⩾6years prior to sampling. Glossy buckthorn (⩾0.5m tall) was present in all stands at the time of sampling and most buckthorn populations were all-aged, suggesting that recruitment by seed continued after initial establishment and that long-term persistence in these stands is possible. Buckthorn was present in four of six cut stands prior to cutting, indicating some advance regeneration. The results support the view that forests are not inherently resistant to invasion by exotic plants. Compared to uncut stands, however, buckthorn had higher densities in clear-cut and partially cut stands. In partially cut stands, buckthorn density was greater in canopy gaps than in adjacent uncut areas. Thus, logging facilitated buckthorn invasion. Given this result and the known negative effects of buckthorn on tree regeneration, control measures should be considered when logging stands where buckthorn invasion is likely. [Copyright &y& Elsevier]

Prairie fens are unique in their high plant and animal diversity; however, many are currently threatened by the invasion of exotic glossy buckthorn (Fran gula alnus). Land managers and conservationists have observed a variety of qualitative changes in prairie fen after F alnus invasion, but these observations have not been previously quantified. Here, we contrast abiotic and plant community parameters in areas of a Michigan prairie fen invaded by buckthorn with that of uninvaded references sites within the same fen. Our results document a variety of significant differences including: lower soil pH, fewer vegetative hummocks, less light availability, lower plant coefficient of conservatism, less total plant cover, and lower graminoid relative abundance in invaded versus uninvaded areas. We also investigated the buckthorn invasion process by examining abiotic and plant community differences within partially invaded plots. In such plots, F alnus-invaded areas had significantly greater percent soil organic matter, fewer vegetative hummocks/rn2, and lower mean coefficient of plant conservatism. We propose that F alnus may be facilitating its own invasion of fen habitats and that resulting hummock degradation may pose a long-lasting detriment to fen biodiversity. We anticipate that wetland managers will be able to use this study to provide a baseline against which fen restoration success can be gauged. [ABSTRACT FROM AUTHOR]

The primary objective of this study was to determine whether the exotic, invasive shrub, glossy buckthorn ( Frangula alnus), is more abundant in canopy gaps created by logging than in uncut forests. Secondary objectives were to determine whether buckthorn abundance in gaps is related to gap size, and whether or not buckthorn exhibits advanced regeneration. The abundance of glossy buckthorn was estimated in five patch cuts and three single-tree cuts in a 90 year old eastern hemlock–eastern white pine–sweet birch forest at the Woodman Horticultural Farm in Durham, NH, USA. Glossy buckthorn was 96 times more abundant in logged areas than in uncut control plots. The three largest but youngest gaps (>0.08 ha; 5 years old) had the greatest proportion of tall (>2 m), reproductively mature glossy buckthorn individuals, with 18.4% fruiting. The older, medium-sized gaps (ca. 0.03 ha; 10 years old) contained the highest overall densities of glossy buckthorn, but few stems were flowering (~2%) and none were fruiting at the time of sampling. Small gaps (<0.01 ha; 10 years old) appeared to be sinks for glossy buckthorn, as all individuals were <0.5 m tall and none were >4 years old. As age and size of gaps were correlated, it was difficult to determine which factor played a larger role in the establishment and persistence of glossy buckthorn. However, the greater proportion of individuals >2 m tall and greater reproductive vigor of glossy buckthorn in large gaps relative to small gaps—despite fewer years available for growth—suggest that larger disturbances lead to more resources available for buckthorn growth, survival, and reproduction. Individuals <0.5 m tall were observed in uncut control plots at low density (<30 stems/ha) and 5% of stems in large gaps were older than the gaps themselves, suggesting that gap formation released previously established glossy buckthorn individuals (i.e., advanced regeneration). [ABSTRACT FROM AUTHOR]