Rubus Fruticosus Agg Research Articles

Horizontal viewsheds of large herbivores as a function of woodland structure.

There is great potential for the use of terrestrial laser scanning (TLS) to quantify aspects of habitat structure in the study of animal ecology and behaviour. Viewsheds-the area visible from a given position-influence an animal's perception of risk and ability to respond to potential danger. The management and conservation of large herbivores and their habitats can benefit greatly from understanding how vegetation structure shapes viewsheds and influences animal activity patterns and foraging behaviour. This study aimed to identify how woodland understory structure influenced horizontal viewsheds at deer eye height. Mobile TLS was used in August 2020 to quantify horizontal visibility-in the form of Viewshed Coefficients (VC)-and understory leaf area index (LAI) of 71 circular sample plots (15-m radius) across 10 woodland sites in North Wales (UK) where fallow deer (Dama dama) are present. The plots were also surveyed in summer for woody plant size structure, stem density and bramble (Rubus fruticosus agg.). Eight plots were re-scanned twice in winter to compare seasonal VC values and assess scan consistency. Sample plots with higher densities of small stems had significantly reduced VC 1 m from the ground. Other stem size classes, mean percentage bramble cover and understory LAI did not significantly affect VC. There was no difference in VC between summer and winter scans, or between repeated winter scans. The density of small stems influenced viewsheds at deer eye height and may alter behavioural responses to perceived risk. This study demonstrates how TLS technology can be applied to address questions in large herbivore ecology and conservation.

Food for flower‐visiting insects: Appreciating common native wild flowering plants

Abstract Native wild flowering plants provide important season‐round nectar and pollen resources for flower‐visiting insects, but many are unappreciated or even disliked by members of the public; for example ivy (Hedera spp.), dandelion (Taraxacum officinale agg.) and bramble (Rubus fruticosus agg.). This antipathy has received little research attention despite a pressing need for a societal shift towards greater awareness of such plants and recognition of their ecological value. Engendering greater awareness and appreciation of common wild‐growing plants could greatly improve floral resource availability for flower‐visiting insects, enhance biodiversity and simultaneously benefit human physical and mental well‐being. However, there are multiple challenges to changing public attitudes. Knowledge of common wild flowering plants among members of the public is limited and this phenomenon is symptomatic of a diminishing human connection to nature. While many species of wild flowering plants may be overlooked due to a lack of awareness or knowledge, it is evident that some ‘weeds’ are actively unpopular. Reframing societal perceptions towards ecological value could be achieved in several ways including through formal education, messaging by the media, businesses and environmental organisations, and by encouraging public participation in urban land management. Read the free Plain Language Summary for this article on the Journal blog.

Marvellous moths! pollen deposition rate of bramble (Rubus futicosus L. agg.) is greater at night than day.

Widespread concerns about declines of wild pollinating insects has attracted considerable research interest, largely directed towards identifying key nectar sources and assessing the contribution of pollinators towards ecosystem services. However, previous work has almost exclusively focussed on bees and other diurnal invertebrate taxa. This study aimed to assess the relative contribution of diurnal and nocturnal insects to the pollination of bramble (Rubus fruticosus agg.), a common and widespread species aggregate across Europe, which has been identified as a key source of pollen and nectar for diurnal pollinators. Bramble flower visitation rates by diurnal and nocturnal insects were quantified by analysing over 380,000 interval photographs taken over a 3-day period across 10 sites. A pollinator exclusion experiment was also undertaken to assess the importance of diurnal and nocturnal insects for pollination by analysing pollen deposition on 480 bramble stigmas of nocturnally exposed, diurnally exposed and unvisited control flowers across all sites. Flower visitation was significantly higher during the day, comprising 83% of all visits made by a range of taxa. Nocturnal visitation was almost exclusively by moths. Crucially, pollen deposition rates of bramble were significantly higher during the night compared with the day. No relationship was detected between pollen counts and flower visitation rates, suggesting that moths are more efficient pollinators of bramble compared with diurnal insects. Overall, this work provides further evidence of the value of bramble as a resource for pollinators and demonstrates that moths likely play an important role in bramble pollination.

Pesticide mixtures detected in crop and non-target wild plant pollen and nectar

Cultivation of mass flowering entomophilous crops benefits from the presence of managed and wild pollinators, who visit flowers to forage on pollen and nectar. However, management of these crops typically includes application of pesticides, the presence of which may pose a hazard for pollinators foraging in an agricultural environment. To determine the levels of potential exposure to pesticides, their presence and concentration in pollen and nectar need assessing, both within and beyond the target crop plants. We selected ten pesticide compounds and one metabolite and analysed their occurrence in a crop (Brassica napus) and a wild plant (Rubus fruticosus agg.), which was flowering in field edges. Nectar and pollen from both plants were collected from five spring and five winter sown B. napus fields in Ireland, and were tested for pesticide residues, using QuEChERS and Liquid Chromatography tandem mass spectrometry (LC-MS/MS). Pesticide residues were detected in plant pollen and nectar of both plants. Most detections were from fields with no recorded application of the respective compounds in that year, but higher concentrations were observed in recently treated fields. Overall, more residues were detected in B. napus pollen and nectar than in the wild plant, and B. napus pollen had the highest mean concentration of residues. All matrices were contaminated with at least three compounds, and the most frequently detected compounds were fungicides. The most common compound mixture was comprised of the fungicides azoxystrobin, boscalid, and the neonicotinoid insecticide clothianidin, which was not recently applied on the fields. Our results indicate that persistent compounds like the neonicotinoids, should be continuously monitored for their presence and fate in the field environment. The toxicological evaluation of the compound mixtures identified in the present study should be performed, to determine their impacts on foraging insects that may be exposed to them.

Fruit Qualities of Interspecific Hybrid and First Backcross Generations between Red Raspberry and Rubus parvifolius

Interspecific hybridization is useful in raspberry (Rubus idaeus L. ssp. idaeus) breeding to introgression of traits such as heat or cold tolerance, and excellent fruit qualities. Rubus L. wild species in Asia, including Rubus parvifolius L., have been attracting a great deal of attention as sources of new traits in breeding raspberry and blackberry (Rubus fruticosus Agg.). We previously developed and selected IPI-1 and IPI-3 first backcross (BC1) hybrids, [‘Indian Summer’ (R. idaeus ssp. idaeus) × R. parvifolius] × ‘Indian Summer’, as raspberry cultivars adapted to the warm climate in parts of Japan. In this study, we investigated the growth, morphological traits, and fruit qualities, such as sugar, organic acid, anthocyanins, and carotenoids, of each of these IPI lines over a 2-year period to discern their potential as commercial raspberry cultivars. IPI lines had the characteristic of primocane fruit with overflowing from side buds while the parent, IP-1 (‘Indian Summer’ × R. parvifolius), did not. IPI lines showed significantly lower values in anthocyanin content than red raspberry ‘Skeena’, while showing higher carotenoid contents. This study is the first research about fruit qualities such as anthocyanin and carotenoid content of BC1 hybrids using Japanese wild Rubus species.

Displacing and translocating hazel dormice (Muscardinus avellanarius) as road development mitigation measures

Road development can remove valuable wildlife habitat and reduce habitat connectivity. Where such works impact on European Protected Species in the UK, such as hazel dormice (Muscardinus avellanarius), mitigation is required to satisfy the relevant Statutory Nature Conservation Organisation licensing process. The study described here concerns the removal of dense road verge landscape planting occupied by hazel dormice prior to the construction of a new road junction and slip roads on a dual carriageway in Wales. Pre-construction monitoring started in May 2007, followed by vegetation clearance between August and September. Dormice were displaced into retained habitat through maximum daily vegetation clearance of 30 m lengths (varying widths), in parallel with translocation. This process resulted in the discovery of 48 natural (i.e. not within a nest box) dormouse nests, and the capture of 29 dormice for translocation; 90% were successfully released. Whilst within soft-release cages prior to release, dormice preferred a diet of blackberries (Rubus fruticosus agg.) and freshly picked hazel (Corylus avellana) nuts, prompting a recommendation for early Autumn (mid-August – September) as the ideal translocation season. Other recommendations for displacing and translocating dormice are provided, albeit limited in the absence of comprehensive pre-construction, and post-translocation monitoring.

Vegetation changes in the Hasbruch forest nature reserve (NW Germany) depend on management and habitat type

AimsWe carried out vegetation studies in the ancient Hasbruch forest, which provided the unique conditions of unmanaged (UM) and managed (M) stands in two vegetation types Stellario-Carpinetum loniceretosum (POOR) and stachyetosum (RICH) stands in one closed forest allowing us to study (1) the changes in species composition and richness over 20 years considering the entire forest as well as (2) group-specific changes. LocationHasbruch forest in the lowlands of Lower Saxony, Germany. MethodsIn 2016 we resurveyed the vascular plant species composition of 79 semi-permanent plots analysed in 1996. General and group-specific trends as well as drivers of changes were analysed using DCA, PCA, LM, t-test, U test, ANOVA. ResultsTree and shrub layer coverage increased significantly in the entire forest. Herb layer species richness decreased significantly only in group RICH_UM. While the pH-value increased significantly in group POOR, it decreased significantly in group B. EIV F increased significantly in group POOR_M and decreased significantly in group RICH_UM. EIV L increased significantly in both of the managed groups, while it decreased significantly in group RICH_UM. An increase was found for EIV N in group POOR_M, whereas a decrease was found in group RICH_M. Strongly increasing species were Ilex aquifolium, Rubus fruticosus agg. and Hedera helix; strongly decreasing species Geum urbanum and Primula elatior. The change in species richness was positively affected by ΔpH and negatively affected by ΔT1cov in the entire forest. ConclusionsThe main drivers for changes in species richness and composition in the Hasbruch forest were light and water availability. The effects of the drivers strongly depended on the vegetation type. Changes in species composition were more pronounced in nutrient-rich forests than on nutrient-poor sites. In nutrient-rich forests, decreased groundwater influence led to decreased soil pH which especially affected typical woodland plants in a negative way. Management positively affected light-demanding species as well as some N-demanding species. Thus, unmanaged, nutrient-rich stands displayed the highest losses in species diversity. In the nutrient-poor stands, changes in species composition were not significantly related to changes in soil and management. However, increasing pH as well as increased Ellenberg L, F, and N values suggest a tendency towards eutrophication. This is possibly a consequence of N deposition and recovery from soil acidification.

Are badgers Meles meles effective dispersal agents for bramble Rubus fruticosus agg. in Ireland?

We studied four aspects of the dispersal of bramble by badgers: plant distribution, occurrence of fruits in diet, lack of damage to seed during ingestion, and beneficial effects on seed germination. The distribution of bramble plants was concentrated around a main sett and associated latrines. Examination of fresh badger dung samples in October 1992 showed that plants represented the main food items, with bramble seeds being by far the most common seeds present. Scanning electron microscopy of seeds before and after passage through the gut of badgers revealed little damage but for a reduced extent of the surface reticulations. Egested seeds exhibited a faster rate of germination than seeds in intact fruits or those washed clear of pericarp tissue. These results suggest that badgers are effective dispersers of brambles in Ireland.

Generalisation and specialisation in hoverfly (Syrphidae) grassland pollen transport networks revealed by DNA metabarcoding.

Pollination by insects is a key ecosystem service and important to wider ecosystem function. Most species‐level pollination networks studied have a generalised structure, with plants having several potential pollinators, and pollinators in turn visiting a number of different plant species. This is in apparent contrast to a plant's need for efficient conspecific pollen transfer.The aim of this study was to investigate the structure of pollen transport networks at three levels of biological hierarchy: community, species and individual. We did this using hoverflies in the genus Eristalis, a key group of non‐Hymenopteran pollinators.We constructed pollen transport networks using DNA metabarcoding to identify pollen. We captured hoverflies in conservation grasslands in west Wales, UK, removed external pollen loads, sequenced the pollen DNA on the Illumina MiSeq platform using the standard plant barcode rbcL, and matched sequences using a pre‐existing plant DNA barcode reference library.We found that Eristalis hoverflies transport pollen from 65 plant taxa, more than previously appreciated. Networks were generalised at the site and species level, suggesting some degree of functional redundancy, and were more generalised in late summer compared to early summer. In contrast, pollen transport at the individual level showed some degree of specialisation. Hoverflies defined as “single‐plant visitors” varied from 40% of those captured in early summer to 24% in late summer. Individual hoverflies became more generalised in late summer, possibly in response to an increase in floral resources. Rubus fruticosus agg. and Succisa pratensis were key plant species for hoverflies at our sitesOur results contribute to resolving the apparent paradox of how generalised pollinator networks can provide efficient pollination to plant species. Generalised hoverfly pollen transport networks may result from a varied range of short‐term specialised feeding bouts by individual insects. The generalisation and functional redundancy of Eristalis pollen transport networks may increase the stability of the pollination service they deliver.

Ungulates increase forest plant species richness to the benefit of non-forest specialists.

Large wild ungulates are a major biotic factor shaping plant communities. They influence species abundance and occurrence directly by herbivory and plant dispersal, or indirectly by modifying plant-plant interactions and through soil disturbance. In forest ecosystems, researchers' attention has been mainly focused on deer overabundance. Far less is known about the effects on understory plant dynamics and diversity of wild ungulates where their abundance is maintained at lower levels to mitigate impacts on tree regeneration. We used vegetation data collected over 10years on 82 pairs of exclosure (excluding ungulates) and control plots located in a nation-wide forest monitoring network (Renecofor). We report the effects of ungulate exclusion on (i) plant species richness and ecological characteristics, (ii) and cover percentage of herbaceous and shrub layers. We also analyzed the response of these variables along gradients of ungulate abundance, based on hunting statistics, for wild boar (Sus scrofa), red deer (Cervus elaphus) and roe deer (Capreolus capreolus). Outside the exclosures, forest ungulates maintained higher species richness in the herbaceous layer (+15%), while the shrub layer was 17% less rich, and the plant communities became more light-demanding. Inside the exclosures, shrub cover increased, often to the benefit of bramble (Rubus fruticosus agg.). Ungulates tend to favour ruderal, hemerobic, epizoochorous and non-forest species. Among plots, the magnitude of vegetation changes was proportional to deer abundance. We conclude that ungulates, through the control of the shrub layer, indirectly increase herbaceous plant species richness by increasing light reaching the ground. However, this increase is detrimental to the peculiarity of forest plant communities and contributes to a landscape-level biotic homogenization. Even at population density levels considered to be harmless for overall plantspecies richness, ungulates remain a conservation issue for plant community composition.

Plant remains and amphorae from the Roman harbour under Flacius Street in Pula (Istria, Croatia)

The aim of this archaeobotanical and archaeological research is to expand knowledge about Roman diet and plant cultivation in Istria and to compare it with similar localities on the Eastern Adriatic coast. We have also tried to find some new information about maritime trade routes in the Mediterranean area in ancient times. Out of 27 samples collected from an excavated Roman port in Flacius Street in Pula, in total, 9809 plant macrofossils were recovered, identified and analysed. The results of the analysis show that most of the plant remains belong to the group of fruit trees and nuts. The most abundant are the remains of Ficus carica, Pinus pinea, Vitis vinifera subsp. vinifera, Rubus fruticosus agg. and Olea europaea subsp. europaea. These are all species that are widespread in the Mediterranean area and have likely always been consumed by the local population. The number of ruderal and weed species found is relatively high (31) in comparison with other plant categories (fruit trees and nuts; fruit collected from the wild; cereals; condiments; oil crops; vegetables and tubers; plants of fresh water environments; elements of maquis), but as they came to the site accidentally and not by targeted human activity, there are far fewer macrofossils of such plants than those of cultivated species. There were a few elements of evergreen forest vegetation and plants of aquatic habitats at the site (2 + 1), which suggests the existence of this type of vegetation in the area of the site in Roman times. Archaeobotanical comparisons of the site in Flacius Street with similar coastal Roman sites—Verige Bay on Veli Brijuni (first-fifth century ad), the port of Zaton near Nin (first-third century ad) and Caska Bay on the island of Pag (first and second century ad)—reveal considerable similarities, confirming the uniformity in nutrition and plant growth in the wider coastal area. Together with the two Roman ships, during the archaeological excavations of the Roman harbour and its layers, we collected over 2000 different archaeological artefacts out of which a large number was almost perfectly preserved. Some of the mentioned artefacts include ceramic amphorae, ceramic table- and kitchenware, ceramic lamps, different usable objects made of glass, wooden use objects, parts of ship’s equipment and other wooden tools, architecture elements from the nearby port as well as residential structures and remains of stone monuments. Because of the large amount of artefacts found at the site, the analysis of the artefacts and data processing are still in progress. As a contribution for recognizing organic remains, we isolated the amphorae whose purpose was the storage and maritime transportation of different food products and ingredients.

The gas exchange performance of the European blackberry (Rubus fruticosus agg.) and ecological traits for interpreting colonization in forest canopy gaps

Blackberry is a considerable weed in both antropogenous habitats and semi-natural vegetation, and this results in robust colonization in open sites. Our research investigated the carbon gain and water exchange performance of this species under ecologically contrasted forest gap conditions in temperate deciduous forests. We used a Kruskal–Wallis test to assess this species ecophysiological behaviour in response to the functional relevance of light environment, seasons and forest gap character. Our research also confirmed significant relationships between abundance, gap characteristics and light response measures. Light environment plays an essential role in the development of assimilation and water use efficiency. Seasonal variation affects transpiration, and forest type influences stomatal conductance. The amount of precipitation and canopy gap size is linked to the relative abundance of the species. These characteristics integrate with a nitrogen biomass trade-off across forest types. Measures of stomatal conductance and assimilation turned out to be the most significant functional variables including a gas exchange indicator for species abundance. Extended functional leaf phenology can promote successful colonization under adequate abiotic conditions. Our results conclude that environmental-related canopy gap size can be recommended for ecologically contrasted forest types, thus modulating the biomass production of the blackberry.

Responses of an ancient woodland field layer to soil translocation: methods and timing

AbstractQuestionsDo woodland field layer communities reassemble effectively after being translocated from a donor to a receptor site? Does the method of soil handling (turfing or loose‐tipping) or the season of transfer determine the outcome?LocationA deciduous ancient coppice woodland in Kent, southeast England.MethodsTwo methods of soil translocation were compared: loose‐tipping, involving stripping a layer of topsoil and re‐spreading it at a receptor site; and soil placement, in which soil turves were cut and laid intact. The operation also provided an opportunity to observe the effects of seasonal translocation, respectively, in autumn and spring. Soil compaction, texture and chemistry were assessed after translocation, while vegetation cover changes were followed over a 10‐yr period.ResultsImmediately after soil transfer, the vegetation community reverted to an earlier successional stage, with bare ground rapidly colonized by annuals and biennials, many germinating from the soil seed bank. By the third year after translocation, a perennial vegetation cover had developed comprising grasses and woodland‐edge opportunists as well as most of the original woodland species. After 10 yr, bramble (Rubus fruticosus agg.) dominated the receptor sites, along with the woodland geophyte bluebell (Hyacinthoides non‐scripta), while some woodland species became less abundant. Localized soil compaction radically altered species composition. Autumn translocation promoted better immediate recovery of forest species than spring translocation, while soil placement caused less initial damage than loose‐tipping. Convergence in vegetation composition in all soil handling treatments was observed towards canopy closure.ConclusionsResults illustrate the importance of conducting translocation operations in the autumn when the vegetation is dormant and soil moisture is low, and point to the need for sensitive soil handling. After 10 yr the field layer at the receptor site still resembled that of the donor, but with differences in abundance of some individual species.

Long-term effects of gap creation and liming on understory vegetation with a focus on tree regeneration in a European beech (Fagus sylvatica L.) forest

The long-term effects of gap creation and liming on tree regeneration and understory competition were examined in a mature European beech (Fagus sylvatica) stand on a nutrient-poor site. In 1989, trees were felled to create four 30 m wide circular gaps, and 3 t ha-1 fine dolomite was applied to two of these gaps and the surrounding area, whereas the remaining two gaps and most parts of the stand remained untreated. In 2010, the stand density was 153 trees x ha-1 and the basal area was 29.51 m2 x ha-1. Testing a factorial combination of two levels of canopy cover (gap and stand) and two levels of lime application (limed and unlimed), the results of the case study partly support our initial hypothesis that the combined or single effects of liming and canopy removal on understory plant communities last for more than 20 years. Some effects disappeared slowly over time, while others did not. Understory vegetation of the unlimed gaps and the limed and unlimed stands was rapidly dominated by beech regeneration, whereas limed gaps were dominated by fireweed (Epilobium angustifolium), bramble (Rubus fruticosus agg.) and raspberry (Rubus ideaus) for around 14 years. There, the density of the beech regeneration was reduced by competitive ground vegetation species. Plant species richness (n/100 m²) was still significantly different after 23 years, with an average 10 species per 100 m² in the limed stand area, 5 species in the unlimed stand area, 25 species in the limed gaps, and only 5 species in the unlimed gaps. Only the combination of liming and canopy removal enhanced the species richness in the long run. On our study site, this combination of liming and canopy opening had a long lasting influence on the ground vegetation in terms of retarding the beech regeneration and enhancing species’ richness.

Surviving on the edge: a conservation-oriented habitat analysis and forest edge manipulation for the hazel dormouse in the Netherlands

We studied the effect of a forest edge management quasi-experiment on hazel dormouse (Muscardinus avellanarius) nest numbers in the reproductive season in the Netherlands. We found that the number of nests increased significantly from 2009 to 2013 in managed edges after clearing 75–100 % of mature trees, with a peak in the second year, whereas those in unmanaged edges decreased. In addition, we studied habitat characteristics in forest edges and hedgerows, and found a positive effect of a high upper shrub layer and a high abundance of blackberry (Rubus fruticosus agg. and Rubus spp.), rowan (Sorbus aucuparia) and common hawthorn (Crataegus monogyna) on nest densities. Based on these results, we propose a potential dormouse management strategy that extends conventionally advocated coppice management for regions with well-developed forest edges by (i) postulating a blackberry-oriented landscape restoration approach and (ii) using clearing of mature trees as a tool to boost local dormouse populations in forest edges that have become unsuitable as dormouse habitat due to vegetational succession.

Acute toxicity, brine shrimp cytotoxicity, anthelmintic and relaxant potentials of fruits of Rubus fruticosus Agg

BackgroundRubus fruticosus is used in tribal medicine as anthelmintic and an antispasmodic. In the current work, we investigated the anthelmintic and antispasmodic activities of crude methanol extract of fruits of R. fruticosus on scientific grounds. Acute toxicity and brine shrimp cytotoxicity activity of the extract were also performed.MethodsAcute toxicity study of crude methanol extract of R. fruticosus was performed on mice. In vitro Brine shrimp cytotoxicity assay was performed on shrimps of Artemia salina. In vitro Anthelmintic activity was tested against Raillietina spiralis and Ascaridia galli. Relaxant activities were tested on spontaneous rabbits’ jejunal preparations. Calcium chloride curves were constructed to elucidate possible mode of action of the extract.ResultsLD 50 of the extract for acute toxicity studies was 887.75 ± 9.22 mg/ml. While CC 50 of the extract for Brine shrimps cytotoxicity assay was 13.28 ± 2.47 μg/ml. Test samples of crude methanolic extract of R. fruticosus (Rf.Cr) at concentration 20 mg/ml showed excellent anthelmintic activity against Raillietina spiralis. Anthelmintic activity was 1.37 times of albendazole against the Raillietina spiralis at concentration 40 mg/ml. At higher concentration (40 mg/ml), Rf.Cr has 89. 83% parasiticidal activity. The mean EC50 relaxation activity for spontaneous and KCl-induced contractions was 7.96 ± 0.1 and 6.45 ± 0.29 mg/ml, respectively. EC 50 (Log[Ca++]M) for control calcium chloride curves was −1.75 ± 0.01 vs. EC 50 −1.78 ± 0.06 in the presence of 3.0 mg/ml of Rf.Cr. Similarly, EC 50(Log[Ca++]M) in the absence and presence of verapamil (0.1 μM) were −2.46 ± 0.01 and −1.72 ± 0.02, respectively.ConclusionsThe anthelmintic and relaxant activities explained traditional uses of R. fruticosus on scientific grounds. Relaxant activity follows the inhibition of voltage gated channels. Although the plant extract has cytotoxic effects, yet it is evident from acute toxicity study that it is safe in concentration 100 mg/kg. Further work is required to isolate pharmacologically active compounds.

Origins and distribution of invasive Rubus fruticosus L. agg. (Rosaceae) clones in the Western United States

In facultatively asexual invasive species, an understanding of the origins and diversity of clones can reveal introduction and invasion pathways and inform management efforts. In this study, we use microsatellite and chloroplast DNA markers to infer clonal diversity of the Rubus fruticosus agg. invasion in the Western United States, determine the relationship of these clones to clones found in other exotic ranges, and determine the geographic and genetic origins of the invasive clones. We found two invasive clones in the Western United States, where the invasion had previously been thought to consist of a single asexual lineage. The most common clone was genetically identical to the microspecies R. armeniacus from the native range of Germany, while the second clone was identical to the microspecies R. anglocandicans in the invaded range of Australia and closely related to samples from the native ranges of England and Serbia. A third distinct clone was identified in a collection from the exotic range of Chile. Our results demonstrate that cryptic genetic diversity may be present in asexual invasions that are thought to be homogeneous. However, the asexual relationships between R. fruticosus agg. clones in the native and multiple exotic ranges indicate that preadaptation has played an important role in invasion success in this species aggregate.

Long-term deer exclusion in yew-wood and oakwood habitats in southwest Ireland: Changes in ground flora and species diversity

Changes in ground flora were monitored over a 32-year period in deer exclosures in a yew-wood and a neighbouring oakwood in Killarney National Park, southwest Ireland; both woods are Annex I habitats under the European Habitats Directive. Comparison was made with unfenced plots adjacent to each of the exclosures. During the period of the study, both woods were heavily grazed by introduced sika deer ( Cervus nippon). In the yew-wood exclosures, total ground flora cover increased markedly during the period of deer exclusion, the main species to increase in abundance being Rubus fruticosus agg. and Hedera helix. Herbaceous species increased initially in frequency but subsequently declined; herbaceous species had higher total cover in unfenced plots than in fenced plots at the end of the study. In the oakwood, Luzula sylvatica and Vaccinium myrtillus expanded their cover in one exclosure with cover in ferns declining, but in other exclosures where dense holly thickets developed, it was instead R. fruticosus and H. helix that became more abundant within the fences than outside. Overall, long-term fencing has caused a shift from vegetation characterised by woodland specialist to woodland generalist species and there are indications of a long-term decline in diversity. We conclude that chronic heavy grazing in these woodlands has strongly influenced the overall abundance and composition of the ground flora, but that complete exclusion of grazing is also undesirable due to potential declines in diversity of woodland specialists.

Use of a trap garden to find additional genetically distinct isolates of the rust fungus Phragmidium violaceum to enhance biological control of European blackberry in Australia

Biological control agents can be more effective if their populations are genetically diverse, particularly when the target invasive plant comprises a range of genotypes with different susceptibilities and occurs across various microclimates. We report on the use of an efficient approach to find, in the native range, diverse isolates of a rust fungus for biological control. An outdoor trap garden containing various clones of invasive European blackberry (Rubus fruticosus agg.) collected in Australia, each with a different DNA phenotype, was established in France. Within 4 weeks of establishment, the leaf-rust fungus Phragmidium violaceum was recovered from all clones in the garden. Molecular analyses of eight recovered and purified isolates of the fungus from the garden revealed that they were genetically distinct from each other and from isolates already present in Australia. These garden isolates also represented a subset of the population existing in Europe, when compared to isolates collected about 30 years ago. Two pathogenicity phenotypes were observed among the garden isolates in bioassays consisting of representative blackberry clones from Australia, and together the isolates were capable of infecting all clones. Results from host-specificity tests on key non-target plant species closely related to European blackberry concurred with previous findings that the leaf-rust fungus does not pose a threat to commercial blackberry cultivars and Rubus species native to Australia. The release and establishment of the garden isolates in Australia has potential to increase the genetic diversity and evolutionary potential of the leaf-rust fungus for more effective biological control.

Genetic differentiation between hosts and locations in populations of latent Botrytis cinerea in southern England

This study tested the hypothesis that aggressive, localized infections and asymptomatic systemic infections were caused by distinct specialized groups of Botrytis cinerea, using microsatellite genotypes at nine loci of 243 isolates of B. cinerea obtained from four hosts (strawberry (Fragaria×ananassa), blackberry (Rubus fruticosus agg.), dandelion, (Taraxacum officinale agg.) and primrose (Primula vulgaris)) in three regions in southern England (in the vicinities of Brighton, Reading and Bath). The populations were extremely variable, with up to 20 alleles per locus and high genic diversity. Each host in each region had a population of B. cinerea with distinctive genetic features, and there were also consistent host and regional distinctions. The B. cinerea population from strawberry was distinguished from that on other hosts, including blackberry, most notably by a common 154‐bp amplicon at locus 5 (present in 35 of 77 samples) that was rare in isolates from other hosts (9/166), and by the rarity (3/77) of a 112‐bp allele at locus 7 that was common (58/166) in isolates from other hosts. There was significant linkage disequilibrium overall within the B. cinerea populations on blackberry and strawberry, but with quite different patterns of association among isolates from the two hosts. No evidence was found for differentiation between populations of B. cinerea from systemically infected hosts and those from locally infected fruits.