A survey of allozyme variation was conducted in populations of the newly arisen allopolyploid species Senecio cambrensis and its two parental species S. vulgaris and S. squalidus sampled from the three locations in Britain where S. cambrensis is known to occur, i.e. at Wrexham and Mochdre in Wales, and Edinburgh in Scotland. Electrophoretic variation at the Acp-1 and aEst-1 loci provided strong evidence of separate origins of S. cambrensis in Wales and Edinburgh. The possibility of two additional independent origins of the species in Wales was indicated by the variadon pattern at the Aat-3 locus, although this variation could be explained as a result of segregation from a fixed heterozygote (representative of a single origin) following pairing between homoeologous chromosomes, as could the pattern of variation recorded at the j3Est-3 locus. For no enzyme system were additional allozymes found in S. cambrensis which were not present in one of the respective parents. The ability of S. cambrensis to originate at different locations and to generate genetic diversity following recombination between its parental genomes, might act in favour of its establishment and diversification in Britain.

A survey of allelic variation at the Aat-3 locus in Senecio squalidus and S. vulgaris revealed that the Aat-3c allele, which was present at high frequency in British populations of S. squalidus, was also common in British radiate groundsel (S. vulgaris var. hibernicus) but was rare among individuals of the non-radiate groundsel (S. vulgaris var. vulgaris) which co-occurred with var. hibernicus and was absent from British, Irish and mainland European populations monomorphic for var. vulgaris. This evidence is taken as confirmation of an introgressive origin of S. vulgaris var. hibernicus across a chromosome barrier following hybridization between S. vulgaris var. vulgaris (2n 40) and radiate S. squalidus (2n 20) and backcrossing to S. vulgaris var. vulgaris. Genetic analysis showed that the Aat-3 locus, which is duplicated in S. vulgaris is not linked to the ray floret locus controlling capitulum type. It is suggested that the close association between the Aat-3c allele and the radiate allele in populations of S. vulgaris polymorphic for capitulum type may be maintained by selection favouring a co-adapted complex of genes introgressed from S. squalidus, although alternative explanations are not ruled out. The introgression of the Aat-3c allele and associated genetic material from S. squalidus into £ vulgaris is likely to have enhanced the level of genetic variation present within S. vulgaris and may have been a factor that has favoured the spread of S. vulgaris var. hibernicus in Britain following its origin last century.

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Background: It has been reported that some plants of the self-compatible species Senecio vulgaris produce capitula containing long-styled florets which fail to set seed when left to self-pollinate, although readily set seed when self-pollinated by hand. Aims: To determine if production of long-styled florets is associated with higher outcrossing rate in S. vulgaris, and whether long-styles occur in non-pollinated florets, whereas short-styles are present in self-pollinated florets. Methods: The frequency of long-styled florets was compared in the radiate and non-radiate variants of S. vulgaris, known to exhibit higher and lower outcrossing rates, respectively. In addition, style length was compared in emasculated florets that were either self-pollinated or left non-pollinated. Results: Long-styled florets were more frequent in the higher outcrossing radiate variant. Following emasculation, long styles occurred in non-pollinated florets, while short styles were present in self-pollinated florets. The two variants did not differ in style length within the non-pollinated or within the self-pollinated floret categories. Conclusions: A high frequency of long-styled florets is associated with higher outcrossing rate in S. vulgaris and results from delayed self-pollination and pollen germination on stigmas. IntroductionUnderstanding the causes, effects and maintenance of variation in outcrossing rate between and within species is of importance in the study of plant evolution (Goodwillie et al. 2005(Goodwillie et al. , 2010Porcher et al. 2009). Most flowering plants are hermaphrodite (Richards 1986) and a large proportion of these are self-compatible and able to reproduce by a mixture of selfing and outcrossing. Although theory predicts that mating systems should evolve towards a stable system of either predominant selfing or outcrossing (but see Winn et al. 2011;Barrett 2014), it has been estimated that ca. 40% of plant species exhibit a mixed mating system where outcrossing rate ranges between 0.2 and 0.8 across species (Goodwillie et al. 2005). A review of the influence of floral display traits on plant-mating system variation (Goodwillie et al. 2010) showed that outcrossing rate was positively associated with the product of flower size and number. Outcrossing rate is also positively associated with pollenovule ratio across species (Cruden 1977), although not necessarily within populations of a species (Damgaard and Abbott 1995). Other floral traits that promote outcrossing in self-compatible plants include protandry (anther dehiscence preceding stigma receptivity within a flower), protogyny (stigma receptivity preceding anther dehiscence) and

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Grassland restoration has become a key tool in addressing the drastic losses of seminatural grassland since the mid-twentieth century. This study examined the restoration by green hay transfer of upland hay meadows, a particularly scarce and vulnerable habitat, over an 11-year chronosequence. The community composition of 18 restoration meadows was compared with that of donor reference sites in two study areas in the Pennine region of northern England. The study investigated: differences in community composition between donor and restoration meadows; transfer of upland hay meadow target species; and the effect of time and isolation from neighboring meadows on the community composition of the restoration meadows. Results showed that restoration meadows differed from donor meadows in that some target species were easily transferred whilst others were not found in the restoration meadows, or were at low levels of cover. Time had a significant effect on the community composition of the restoration meadows, but the similarity between restoration sites and donor sites did not increase with time, and the effect of isolation was not significant. The study showed that the green hay transfer method increases botanical diversity and is an important first step in meadow restoration. However, further restoration activity, such as seed addition, is likely to be required if restoration sites are to resemble closely the reference donor sites. Implications for Practice• Green hay transfer is a valuable technique for the first phase of the restoration of upland hay meadows where site conditions and management regimes are favorable. • A limited suite of target species can be successfully transferred using this method but, over time, the meadow community should be monitored to assess fluctuations in key species, and decisions should be taken on how and when to introduce missing target species, e.g. by further seed addition. • The isolation of the restoration site from other similar plant communities does not appear to be a barrier to initial establishment of target species following green hay transfer, although it should be considered in initial decision-making if long-term restoration is to rely on subsequent colonization from existing populations.

The demise of coppicing in UK ancient woodlands, combined with the planting of non-native, fast-growing conifers in the twentieth century, heightens the potential recharge value of ground flora seed banks. Soil cores from adjoining semi-natural and conifer-containing stands in four lowland ancient woods in central England were removed to establish seed bank species richness. During a fourteen-month germination trial soil from two depths yielded 6554 seedlings from 81 species, ten of which showed a strong affinity for ancient woodland conditions. Juncus effusus accounted for 80 of emergent seeds whilst 23 other species, including Lysimachia nummularia and Potentilla sterilis, were represented by only one individual. Species richness is described by a model that explains 40 of observed variance (P < 0.00001). The model has three significant variables: species richness increases as soil pH rises, and decreases with both depth and increasing time since the most recent planting/disturbance event. No difference was found in the density of seeds from species common to paired semi-natural and conifer-containing stands that were separated only by a woodland ride, suggesting prior management and environmental conditions have a greater influence on seed banks than current stand type. Sørensen similarity index values revealed poor congruence between above-ground vegetation and species in the seed bank. Taking pH measurements in conifer stands identified as younger in terms of planting/disturbance may help locate areas where greater numbers of species (including woodland specialists) are located. Caution is required, however, as these seed banks may also contain non-target, competitive species that may swamp the regeneration of woodland specialists. © 2010 Springer Science+Business Media B.V

The Blue Tit Cyanistes caeruleus prefer to use nest boxes to raise their young rather than nests in natural tree cavities. However, nest boxes provide a warm, humid microclimate that is favourable to the growth of rich bacterial communities. In this study we investigated how the bacterial community developed throughout the breeding season and whether it had any effect on egg or nestling mortality. Samples were collected across six sites and three breeding seasons at the completion of nest building, clutch completion and immediately post fledging. Bacterial counts were obtained for each sample, including a total bacterial count using non-selective media and bacterial counts on selective media for Staphylococcus spp. and Enterobacter spp, which may indicate pathogenicity to the birds. There were significantly more bacteria (total counts and counts for Staphylococcus spp. and Enterobacter spp. specifically) present within the nest box at the post fledging stage compared to the two earlier stages, likely due to increased activity by the adult birds (feeding of the nestlings and defecating) and less time by the adult birds for self-preening and nest sanitation. No positive relationship was found between bacterial counts and either egg mortality, nestling mortality or brood size; however, a negative relationship between egg mortality and total bacterial count was identified. Although somewhat unexpected, this negative relationship may indicate the presence of a greater number of symbiotic bacteria, which could offer a greater level of protection.Keywords Bacteria · Birds · Nest · Breeding · Success Zusammenfassung Wachsende Belastung durch Bakterien in Nistkästen von Blaumeisen während der Brutzeit und ihr möglicher Einfluss auf Schlüpfen und FlüggewerdenBlaumeisen (Cyanistes caeruleus) ziehen für die Aufzucht ihrer Jungen Nistkästen den natürlichen Baumhöhlen vor. Aber die Nistkästen bieten ein warmes und feuchtes Mikroklima, das die Entwicklung von Bakteriengemeinschaften fördert. In dieser Studie wurde untersucht, wie sich die Bakteriengemeinschaften während der Brutzeit entwickelten und ob sie einen Einfluss auf die Sterberate der Nestlinge oder das Absterben der Eier hatten. Über drei Brutzeiten und sechs Brutplätze hinweg wurden während des Nestbaus, der Vervollständigung des Geleges und unmittelbar nach Ausfliegen der Jungen Proben gesammelt und für jede Probe die darin enthaltenen Bakterien gezählt. Zum einen wurde mit unspezifischen Nährmedien die Gesamtzahl ermittelt, zum anderen anhand von spezifischen Medien die Anzahl von Staphylococcus spp. und von Enterobacter spp., die beide als Hinweis auf bakterielle Pathogenität für die Vögel genommen werden können. Nach dem Ausfliegen gab es in den Nistkästen signifikant mehr Bakterien (insgesamt, sowie auch Staphylococcus spp. und Enterobacter spp.), vermutlich wegen der erhöhten Aktivität für das Füttern der Jungen und Entfernen der Kotballen und der entsprechend weniger verfügbaren Zeit für das Putzen der Nester und der Adulten selbst. Ein positiver Zusa...