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Bioblitzes are a popular approach to engage people and collect biodiversity data. Despite this, few studies have actually evaluated the multiple outcomes of bioblitz activities. We used a systematic review, an analysis of data from more than 1000 bioblitzes, and a detailed analysis of one specific bioblitz to inform our inquiry. We evaluated five possible bioblitz outcomes, which were creating a species inventory, engaging people in biological recording, enhancing learning about nature, discovering a species new to an area, and promoting an organization. We conclude that bioblitzes are diverse but overall effective at their aims and have advantages over unstructured biodiversity recording. We demonstrate for the first time that bioblitzes increase the recording activity of the participants for several months after the event. In addition, we provide evidence that bioblitzes are effective at bringing people and organizations together to build communities of professionals and amateurs, critical for conserving and protecting biodiversity.

For centuries, naturalists from the Global North have traveled southwards to collect specimens of species from regions where there were many. The legacy of this is that the large natural history collections and the biodiverse regions of the world are often distant from one another. The unique and often disappearing species and ecosystems in these regions need conservation, yet much of the data on this biodiversity resides in collections and with the experts that work in them, rather than in the countries where it is needed. In this poster we zoom in on Grand Cayman, a small island in the Caribbean, facing severe threats to its endemic biodiversity - from habitat loss to introduced species. More specifically we focus on the endemic blue iguana (Cyclura lewisi) and the invasive green iguana (Iguana iguana). Specimens from the Cayman Islands are dispersed over American and European natural history collections and give data on the species present, their abundances and the interactions among those species (e.g. their food plants and parasites). Such data can be used in risk assessments and conservation planning, and the specimens themselves can inform research, such as population genetics. While the Cayman Islands are small they provide an excellent case study of the issues of conservation, society, climate and other environmental change in the tropics. Islands are highly sensitive to environmental change, but the lessons learned from them can be extended to other areas, including continents. On this poster, we describe the From Blue Iguanas to Blue Vervain project (Fig. 1), which aims to connect the biodiverse Caribbean UK Overseas Territories of Montserrat and the Cayman Islands with natural science collections around the world. We aim to learn ways to address issues of access and benefit-sharing, particularly how residents of these biodiverse places can benefit from the data and research linked to specimens originating in their islands.

Evolutionary understanding is central to biology. It is also an essential prerequisite to understanding and making informed decisions about societal issues such as climate change. Yet, evolution is generally poorly understood by civil society and many misconceptions exist. Citizen science, which has been increasing in popularity as a means to gather new data and promote scientific literacy, is one strategy through which people could learn about evolution. However, despite the potential for citizen science to promote evolution learning opportunities, very few projects implement them. In this paper, we make the case for incorporating evolution education into citizen science, define key learning goals, and suggest opportunities for designing and evaluating projects in order to promote scientific literacy in evolution., X.S.-P. is funded through FCT – Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of 19 July. A.M. benefited from funding by the laboratory ‘Evolution et Diversité Biologique’ as part of the ‘Laboratoires d’Excellence’ LABEX TULIP (ANR -10-LABX-41) and LABEX CEBA (ANR-10-LABX-25-01).This article is based upon work from COST Actions ‘CA17127 EuroScitizen’ ‘CA17122 Alien CSI’, ‘CA15212 Citizen Science’, supported by COST (European Cooperation in Science and Technology; www.cost.eu).

In support of researchers considering using the bioblitz method we collateda number of recommendationsthat may help get maximum benefit from the bioblitz.This list is a supplement toa reviewofbioblitzes.

The BiCIKL Project is born from a vision that biodiversity data are most useful if they are viewed as a network of data that can be integrated and viewed from different starting points. BiCIKL’s goal is to realize that vision by linking biodiversity data infrastructures, particularly for literature, molecular sequences, specimens, nomenclature and analytics. BiCIKL is an Open Science project creating Open FAIR data and services for the whole research community. BiCIKL intends to inspire novel, innovative, research and build services that can produce new and valuable knowledge, necessary for the protection of biodiversity and of our environment. BiCIKL will develop methods and workflows to harvest, link and access data extracted from literature. Yet, as the project gets underway, we need to better understand the existing infrastructures, their limitations, the nature of the data they hold, the services they provide and particularly how they can interoperate. To do this we organised a week-long hackathon where small teams worked on a number of pilot projects (Table 1) that were chosen to test the existing linkages between infrastructures and to extract novel ones. We will present our experience of running a hackathon and our evaluation of how successfully it achieved its aims. We will also give examples of the projects we conducted and how successful they were. Finally we will give our preliminary evaluation of what we learned about the interoperability of infrastructures and what recommendations we can give to improve their interoperability, whether that is improvements to the data standards used, the means to access the data and analyse them, or even the physical bandwidth and computational restrictions that limit the potential for research.

A report on the results and outcome of the Green Pioneers (NL: Groene Pioniers) project (2019-2020), a citizen science project by Meise Botanic Garden, to increase awareness on invasive species and to increase quality and quantity of invasive species data. This project was financed by the Flemish government, Department of Economy, Science and Innovation (EWI)., Green Pioneers is a citizen project of Meise Botanic Garden financed by the Flemish government, Department of Economy, Science and Innovation (EWI).

Many species have been introduced beyond their native ranges and many have become global weeds. Human mediated dispersal has removed the geographic isolation of these species, reversing millions of years of independent evolution. Examples are the Oxalis species in section Corniculatae where several species have become invasive. Here we characterize and formally describe a hybrid between O. dillenii and O. corniculata, which occurs spontaneously in Belgium and Japan. Oxalis corniculata is probably native to Japan, but both species are alien to Belgium and O. dillenii is native to North America. We formally name this hybrid as Oxalis × vanaelstii. Although this hybrid is sterile, it is nevertheless vigorous and perennial. Both parent species grow as weeds in gardens; therefore, it is likely to be more common than currently appreciated in countries where these species co-occur.

Emerging in the 1990s, bioblitzes have become flagship events for biodiversity assessments. Although the format varies, a bioblitz is generally an intensive, short-term survey in a specific area. Bioblitzes collect biodiversity data and can therefore play a role in research, discovery of new species at a site and monitoring. They may also promote public engagement, community building, and education and outreach. However, the question remains, how effective are bioblitzes at achieving these goals? To evaluate the value of bioblitzes for these multiple goals, we conducted two meta-analyses, one on sixty published bioblitzes and the other on 1860 bioblitzes conducted using iNaturalist. Furthermore, we made an in-depth analysis of the data collected during a bioblitz we organized ourselves. From these analyses we found bioblitzes are effective at gathering data—collecting on average more than 300 species records—despite limitations of bias, which many types of biodiversity surveys suffer from, such as preferences for charismatic taxa, and uneven sampling effort in time and space. However, because the survey intensity, duration and extent are more controlled, a bioblitz is more repeatable than some other forms of survey. We also found that bioblitzes were highly effective at engaging people in sustained activity after they participated in a bioblitz. A bioblitz may therefore act as a trigger for participation in biological recording, which is supported by the use of technology, particularly smartphone apps. Another important aspect is the involvement of both citizen scientists and professional biologists, creating learning opportunities in both directions. Indeed, it was clear that many bioblitzes acted as brokerage events between individuals and organizations, and between professionals who work in biodiversity research and conservation. Such community building is important for communication and building trust between organizations and citizens to the benefit of biodiversity research and conservation. From the impartial perspective of hypothesis-driven science, bioblitzes may seem like a lot of work with limited scientific gain. However, this largely overlooks how important people, communities and their organizations are in gathering data, and in conserving biodiversity.

Hybridization is a creative evolutionary force, increasing genomic diversity and facilitating adaptation and even speciation. Hybrids often face significant challenges to establishment, including reduced fertility that arises from genomic incompatibilities between their parents. Whole-genome duplication in hybrids (allopolyploidy) can restore fertility, cause immediate phenotypic changes, and generate reproductive isolation. Yet the survival of polyploid lineages is uncertain, and few studies have compared the performance of recently formed allopolyploids and their parents under field conditions. Here, we use natural and synthetically produced hybrid and polyploid monkeyflowers (Mimulus spp.) to study how polyploidy contributes to the fertility, reproductive isolation, phenotype, and performance of hybrids in the field. We find that polyploidization restores fertility and that allopolyploids are reproductively isolated from their parents. The phenotype of allopolyploids displays the classic gigas effect of whole-genome duplication, in which plants have larger organs and are slower to flower. Field experiments indicate that survival of synthetic hybrids before and after polyploidization is intermediate between that of the parents, whereas natural hybrids have higher survival than all other taxa. We conclude that hybridization and polyploidy can act as sources of genomic novelty, but adaptive evolution is key in mediating the establishment of young allopolyploid lineages., Hybridization and whole-genome duplication can be creative evolutionary forces and can fuel adaptation and speciation. This study uses natural and synthetically produced hybrid and polyploid monkeyflowers (Mimulus spp.) to study how polyploidy contributes to the fertility, reproductive isolation, phenotype, and performance of hybrids in the field.

Invasieve planten vormen een ernstige en aanhoudende bedreiging voor de inheemse biodiversiteit. Ze kunnen de plek innemen van minder competitieve planten, ecologische netwerken verstoren, middelen voor de ene soort verminderen en voor de andere doen toenemen. De meeste planten die geïntroduceerd worden in nieuwe regio’s doen dat met behulp van de mens, zeer vaak vanuit tuinen. Eens invasieve planten in opmars zijn, is het zeer moeilijk tot bijna onmogelijk hen terug te dringen. Daarom is het belangrijk in de eerste plaats te voorkomen dat ze zich verspreiden. Om het bewustzijn met betrekking tot dit probleem in België te verhogen, hebben we een informatieve zoekkaart ontworpen om mensen te helpen invasieve planten te herkennen en om uit te leggen wat men precies kan doen om de situatie te verbeteren.

Les plantes exotiques envahissantes représentent un risque réel et grandissant pour la biodiversité autochtone. Elles peuvent remplacer les plantes endémiques moins compétitives et perturber les réseaux écologiques, diminuant ainsi les ressources de certaines espèces tout en les augmentant pour d’autres. L’introduction dans de nouvelles zones de la plupart de ces plantes invasives résulte de l’activité humaine et souvent via les jardineries. Les plantes invasives sont vigoureuses et leur control difficile, souvent impossible. Réduire le taux de propagation de ces espèces est donc important. Afin de sensibiliser à ce problème en Belgique, nous avons créé une infographie pour aider les citoyens à reconnaitre certaines des plantes invasives les plus communes tout en donnant des conseils à celles et ceux qui voudraient améliorer la situation.

Invasive plants are a real and growing risk to native biodiversity. They can displace less competitive plants, disturb ecological networks, reducing resources for some species and increasing them for others. Most plants are introduced to new areas by human activity, often from gardens. Invasive plants are vigorous and their control is difficult, often impossible, so reducing the rate at which they are spread is important. To raise awareness of the issue in Belgium we have created an infographic to help people recognise some invasive plants and to explain what people can do to ameliorate the situation.

The reduction in genetic diversity in polyploid lineages, formed from whole-genome duplication of a few individuals, can affect their long-term evolutionary potential. Because most polyploids originate multiple times, secondary contact and gene exchange among independently formed polyploids can create novel genetic combinations and reduce the severity of genetic bottlenecks. However, independently originated polyploids may be reproductively isolated from each other due to genetic and chromosomal differences predating the polyploidisation event, or evolving subsequently in the dynamic genomes of young polyploid populations. Here we conducted experimental crosses to investigate the phenotype and interfertility between two independently originated populations of the allopolyploid Mimulus peregrinus (Phrymaceae). We found that individuals from the two populations are phenotypically distinct, but that inter- and intrapopulation crosses are not statistically different. Interpopulation crosses produce viable and fertile offspring, although our results suggest the existence of partial reproductive barriers in the form of reduced pollen viability. We found no difference in pollen viability between F1 and F2 generations. In contrast, we detected a reduction in floral and vegetative size, and in the proportion of plants that flowered, between F1 and F2 generations for both intra- and interpopulation crosses. Together, our results indicate that populations of independent origin can partially exchange genes, producing variable offspring, and that the phenotype of M. peregrinus may be unstable in the early generations. Natural selection on genetically-based variation may be required for the evolution of more stable and fertile individuals of this nascent allopolyploid.

Forests exhibit leaf- and ecosystem-level responses to environmental changes. Specifically, rising carbon dioxide (CO2 ) levels over the past century are expected to have increased the intrinsic water-use efficiency (iWUE) of tropical trees while the ecosystem is gradually pushed into progressive nutrient limitation. Due to the long-term character of these changes, however, observational datasets to validate both paradigms are limited in space and time. In this study, we used a unique herbarium record to go back nearly a century and show that despite the rise in CO2 concentrations, iWUE has decreased in central African tropical trees in the Congo Basin. Although we find evidence that points to leaf-level adaptation to increasing CO2 -that is, increasing photosynthesis-related nutrients and decreasing maximum stomatal conductance, a decrease in leaf δ13 C clearly indicates a decreasing iWUE over time. Additionally, the stoichiometric carbon to nitrogen and nitrogen to phosphorus ratios in the leaves show no sign of progressive nutrient limitation as they have remained constant since 1938, which suggests that nutrients have not increasingly limited productivity in this biome. Altogether, the data suggest that other environmental factors, such as increasing temperature, might have negatively affected net photosynthesis and consequently downregulated the iWUE. Results from this study reveal that the second largest tropical forest on Earth has responded differently to recent environmental changes than expected, highlighting the need for further on-ground monitoring in the Congo Basin.

Plant functional traits have shown to be relevant predictors of forest functional responses to climate change. However, the trait-based approach to study plant performances and ecological strategies has mostly been focused on trait comparisons at the interspecific and intraspecific levels. In this study, we analyzed traits variation and association at the individual level. We measured wood and leaf traits at different height locations within the crown of five individuals of Pericopsis elata (Harms) Meeuwen (Fabaceae) from the northern tropical forest of the Democratic Republic of the Congo. All traits varied between and within individuals. The between-individual variation was more important for leaf traits (23%&ndash, 48%) than for wood traits (~10%) where the within-individual variation showed to be more important (33%&ndash, 39%). The sample location height within the crown was found to be the driving factor of this within-individual variation. In a gradient from the base to the top of the crown, theoretical specific hydraulic conductivity and specific leaf area decreased while the stomatal density increased. We found significant relationships among traits and between wood and leaf traits. However, these relationships varied with the position within the crown. The relationship between vessel size and vessel density was negative at the bottom part of the crown but positive upward. Also, the negative relationship between stomatal density and stomatal size became stronger with increasing height within the crown. Finally, the positive relationship between specific leaf area and theoretical specific hydraulic conductivity became stronger in higher parts of the crown, suggesting that P. elata constantly adapts its water use with respect to its water supply, more strongly at the top of the crown where the environment is more extreme and less buffered against environmental fluctuations.

One of the most important issues for controlling the spread of invasive species is public awareness (Dehnen-Schmutz et al. 2018). Passively, the public are responsible for the spread of invasive species, for example by moving dirty boats from one water body to another. But they also actively spread invasive species by releasing them in the wild. The spread of some invasive species could be slowed or even halted if the general public were more aware of the risks. Furthermore, this is a global issue, not restricted to one country or language, and hence needs to be tackled at an international level. The Convention on Biological Diversity has a specific target to identify pathways of introduction and manage invasive species (Convention on Biological Diversity 2014). As part of this awareness-raising, the public needs information on how to identify invasive species, as well as how to know their regulatory status, distribution and transmission. They also need to be aware of how invasive species impact biodiversity, ecosystem services and health. This information needs to be up-to-date, reliable and unbiased, but also supported by evidence. Many information platforms exist on invasive species and new information is being generated all the time on this dynamic issue. However, pre-eminent among information sources on the internet is Wikipedia. Consistently ranked in the top ten of most visited websites, with more than 15 billion page views a month across 300 language editions, it is the go-to website on many subjects (Wikimedia 2019). Invasive species such as the zebra mussel and water hyacinth receive over 500 daily page views, just on the English edition alone. Wikipedia is arguably one of the largest citizen science projects, containing information on every area of science and connecting, through its citations, scientific literature with the general public. Wikipedia has been criticized about many aspects of its content and editorship, including its quality and neutrality (Kumar et al. 2016, Wagner et al. 2016, Hargittai and Shaw 2014). Nevertheless, its dominance in the provision of information cannot be ignored and addressing Wikipedia's problems by direct engagement might be more productive than ignoring it. Increasingly, different disciplines are engaging with Wikipedia for communication, recognizing that it can be a productive communication channel (Murray 2018). Invasive species are a global problem and tackling them is a global issue. We have been investigating the current status of invasive species information on Wikipedia, whether it contains relevant information on impacts and control, and whether the information is consistent across different language versions. We will present what we have found and make recommendations on what to improve and how we can engage with Wikipedia.

When researchers and managers are asked to rank the issues that prevent adequate control of invasive species, lack of public awareness is at the top of the list (Dehnen‐Schmutz et al. 2018). It is therefore imperative to raise the general public's awareness of the potential risks of introducing alien species into the wild. Green Pioneers, a citizen science project funded by the Flemish Government, (Fig. 1) aims to address this issue in Belgium, across age groups. The project aims to Create awareness on invasive species, highlighting how invasions can be avoided and how to mitigate their impact. Improve communication between citizens and scientists on conservation and invasive plant species. Augment the quality and quantity of data on invasive species. Create awareness on invasive species, highlighting how invasions can be avoided and how to mitigate their impact. Improve communication between citizens and scientists on conservation and invasive plant species. Augment the quality and quantity of data on invasive species. The project is developing three kinds of activity, specifically to attract a broad demographic: - 'Young Pioneers', by developing tools for teachers in science, technology, engineering and mathemathics for school children from 12-15 years old. - 'Online Pioneers', through our online citizen science platform DoeDat.be, by helping with the transcription of label information on herbarium specimens, - and 'Visiteers', by inviting companies and working age people to help us in the collection and to inform them about invasive species. Finally, we will be organizing a BioBlitz in spring 2020 at Meise Botanic Garden where we will celebrate plants and all our Green Pioneers, while also spreading the message of invasive plant awareness. During our 48 hour BioBlitz, scientists, volunteers and citizens are workig together to survey the biodiversity of our Botanic Garden. Ultimately, Green Pioneers aim to encourage recording of alien species by amateur botanists and create a generation of responsible gardeners who understand the consequences of releasing invasive alien plants into the wild.

The distylous genus Pulmonaria contains approximately 18 species that are widely distributed across Eurasia. Previous studies have shown that species delimitation in the genus is problematic, but have not yet explored the evolutionary history of the genus. Premating reproductive barriers between European species appear to be weak, as several species have strongly overlapping distribution areas, flower at the same time and share the same pollinators, suggesting that hybridization may have contributed to the evolutionary history of Pulmonaria. To test this hypothesis, phylogenetic analyses of nuclear ITS and plastid data (rps16, trnH-psbA, rpl16) from 48 allopatric and four sympatric populations were performed to (1) provide a molecular phylogeny for nine of the most common Pulmonaria species in Europe, (2) detect current and ancient hybridization events, and (3) assess the contribution of hybridization versus incomplete lineage sorting to the inferred phylogenetic patterns. Our results showed that gene trees displayed widespread, strongly supported incongruence associated with the conflicting position of hybrid samples rather than incomplete lineage sorting. Evidence was found of different degrees of hybridization, ranging from current interspecific gene flow at secondary contact zones to introgression at the population level and at least one event of hybrid speciation. Overall, these results suggest that hybridization and introgression were - and could still be - important processes affecting speciation in the genus Pulmonaria.

Plant leaf stomata are the gatekeepers of the atmosphere–plant interface and are essential building blocks of land surface models as they control transpiration and photosynthesis. Although more stomatal trait data are needed to significantly reduce the error in these model predictions, recording these traits is time‐consuming, and no standardized protocol is currently available. Some attempts were made to automate stomatal detection from photomicrographs; however, these approaches have the disadvantage of using classic image processing or targeting a narrow taxonomic entity which makes these technologies less robust and generalizable to other plant species. We propose an easy‐to‐use and adaptable workflow from leaf to label. A methodology for automatic stomata detection was developed using deep neural networks according to the state of the art and its applicability demonstrated across the phylogeny of the angiosperms.We used a patch‐based approach for training/tuning three different deep learning architectures. For training, we used 431 micrographs taken from leaf prints made according to the nail polish method from herbarium specimens of 19 species. The best‐performing architecture was tested on 595 images of 16 additional species spread across the angiosperm phylogeny.The nail polish method was successfully applied in 78% of the species sampled here. The VGG19 architecture slightly outperformed the basic shallow and deep architectures, with a confidence threshold equal to 0.7 resulting in an optimal trade‐off between precision and recall. Applying this threshold, the VGG19 architecture obtained an average F‐score of 0.87, 0.89, and 0.67 on the training, validation, and unseen test set, respectively. The average accuracy was very high (94%) for computed stomatal counts on unseen images of species used for training.The leaf‐to‐label pipeline is an easy‐to‐use workflow for researchers of different areas of expertise interested in detecting stomata more efficiently. The described methodology was based on multiple species and well‐established methods so that it can serve as a reference for future work., Our paper proposes a newly developed methodology for automatic stomata detection using deep neural networks according to the state of the art and demonstrates its applicability across the phylogeny of the angiosperms.

Although tropical rainforests play an important role in regulating the world’s climate, they are at the same time particularly vulnerable to changes in the climate. Intense and prolonged droughts, for instance, can lead to biomass loss which will further accelerate these changes. Especially for tree species it becomes problematic, due to their long lifespan, to quickly adapt to or evade unfavorable climatic conditions affecting the composition of the forest community as a whole and consequently the ecosystem services that the rainforests provide. A long-term drying trend currently threatens tropical regions worldwide but is especially strong in the central African rainforest, the second-largest rainforest on Earth. The impact of this decrease in precipitation on the vegetation is, however, still largely unknown due to the limited amount of historical eco-climatological data. Fortunately, these kind of data do exist albeit in a poorly accessible (analog) format in herbarium collections. To investigate if trees show changes in morphology and/or physiology invoked by climatic changes in the last century, the COBECORE team (Congo Basin Eco-Climatological Data Recovery and Valorization”) is exploring the usability of herbaria as potential sources of plant leaf functional trait data using established protocols adjusted to dried leaf material. Photosynthesis as well as gas exchange and transpiration are processes regulated by a plant’s leaves, and depend on the specific leaf area (SLA) and the number and size of the stomata. The less area the latter structures occupy on the leaf the less the plant will suffer from water losses which increases the resistance to drought of plants. We explored the recently digitized African Herbarium of the Botanic Garden Meise which contains over 1.2 million African specimens with a very good coverage of the Congo Basin, dating back to 1880. Currently, we obtained average SLA measurements for 833 herbarium specimens from 59 of the most common tree species of central African rainforests. Pictures for stomata counts and size measurements were taken from over one hundred specimens mainly focused on three Prioria species, giant tree species (up to 60 metres) currently suffering from overexploitation. The data generated in this project will be valuable to understand some lower-level vegetation responses such as plant water use needed to model and predict long-term climate change impacts on vegetation.

Summary This account presents information on all aspects of the biology of Pulmonaria officinalis L. (Common Lungwort) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characteristics, herbivores and disease, history and conservation. Pulmonaria officinalis is a distylous, perennial rosette hemicryptophyte that is naturalized in Britain. It occurs predominantly in the understory of broadleaved, mixed, open woods rich in hornbeam, beech and oak, but is has also been recorded from hedges, banks alongside streams, (sunken) roadsides, built-up areas, gardens, rubbish tips, yew woodland and, less frequently, coniferous woodland. Its native range stretches from southern Sweden, in the north, to northern Italy, in the south, and from western Germany to Poland and Lithuania. It is most common in central Europe. Pulmonaria officinalis reproduces both by sexual and vegetative means. The underground parts consist of a slowly creeping rhizome with adventitious roots. Despite the presence of an elaiosome that is attractive to ants that likely facilitates seed dispersal, populations often show a significant fine-scale spatial genetic structure and small neighbourhood sizes. The leaves and flowering stalks are covered in hairs of varied length and stiffness, and stems and inflorescences are sparsely covered with glandular hairs. Flowers of P. officinalis are heterostylous, with distinct pin and thrum morphs. The corolla varies from purple, violet or blue to shades of pink and red, or sometimes white. The flowers are mainly pollinated by solitary bees and bumblebees. Pulmonaria officinalis has significantly expanded its distribution in the British Isles since the 18th century, especially in southern England. P. officinalis is currently not regarded as threatened in Europe. Nonetheless, small, isolated populations of the species often show reduced reproductive success and lower genetic diversity, potentially affecting their long-term survival. Preservation of local habitat conditions by regular opening of the forest canopy and restoration of gene flow among populations are required to maintain viable populations of P. officinalis in the long term.

†Background and Aims In heterostylous plant species, skewed morph ratios are not uncommon and may arise from a range of factors. Despite the recognized importance of skewed morph ratios on overall reproductive success within populations, little is known about the impact of skewed morph ratios on population genetic diversity and differentiation in heterostylous species. This study specifically aimed to clarify the effect of population size and morph bias on population genetic diversity and differentiation in the temperate forest herb Pulmonaria officinalis. This species is characterized by a distylous breeding system and shows morph-specific differences in reproductive success. †Methods Genetic diversity was determined for 27 P. officinalis populations in northern Belgium by using eight recently developed microsatellite markers. Multiple regressions were used to assess the relationship between genetic diversity, morph bias and population size, and FST-values were calculated for short- and long-styled morphs separately to study genetic differentiation as a function of morph type. †Key Results For all genetic measures used, morph bias was more important in explaining patterns of genetic diversity than population size, and in all cases patterns of population genetic diversity followed a quadratic function, which showed a symmetrical decrease in genetic diversity with increasing morph bias. However, probably due to the reproductive advantage of L-morphs relative to S-morphs, maximum genetic diversity was found in populations showing an excess of L-morphs (60.7 % L-morph). On the other hand, no significant difference in pairwise genetic distances between populations was observed between L- (0.107) and S-morphs (0.106). †Conclusions Our results indicate that significant deviations from equal morph ratios not only affect plant reproductive success but also population genetic diversity of heterostylous plant species. Hence, when defining conservation measures for populations of heterostylous plant species, morph ratios should be considered as an important trait affecting their long-term population viability.

PREMISE OF THE STUDY Populations at the edge of a species' distribution area are often small and have low levels of gene flow resulting in lower genetic variation and higher differentiation compared to core populations. This study examined genetic variation among populations of the distylous temperate forest herb Pulmonaria officinalis located in the core, the edge, and outside the species' main distribution range. METHODS We compared patterns of genetic variation for eight microsatellite loci between disjunct (Belgium), edge (western Germany), and core (eastern Germany) populations of P. officinalis. KEY RESULTS Disjunct populations contained only a subset of alleles found in edge and core populations and had significantly lower within-population genetic variation. No significant differences, however, in within-population genetic variation were found between edge and core populations, except for allelic and genotypic richness. Genetic differentiation was highest among disjunct (F(ST) = 0.11) and lowest among core populations (F(ST) = 0.03). Significant (P < 0.01) isolation by distance was found for disjunct and edge populations (r(M) = 0.29 and 0.50, respectively), but not for core populations (r(M) = 0.18). CONCLUSIONS The results are best interpreted from a "dynamic range" point of view in which the observed low levels of genetic diversity and high genetic differentiation in disjunct populations are best explained through historical processes, most likely the introduction of the species in medieval times. Lower levels of gene flow caused by the pronounced fragmentation of forests in Belgium may further have contributed to the genetic structure of P. officinalis in these disjunct populations.

International audience; Surveys of the incompatibility status of island floras have shown a deficit in taxa possessing homomorphic or heteromorphic incompatibility. This observation provides strong evidence for Baker’s Rule (1967) in that self-incompatibility can impede these taxa of colonizing and establishing on islands. The woody liana Hugonia serrata Lam. (Linaceae) is an extremely rare plant species endemic to the Mascarene Islands of La Réunion and Mauritius in the southern Indian Ocean. Previous research has documented the existence of tristyly in this species, thereby raising the number of known tristylous families to six. However, data were based on a very small sampling size and currently no data on the self-incompatibility system of the species are available. In this study, we investigated in detail the breeding system of H. serrata. Calculation of reciprocity and precision indices based on measurements of reproductive organs in a much larger sample size confirmed tristyly in this species. This style–stamen polymorphism was accompanied by several ancillary polymorphisms in stigma size, stigma color, anther size and pollen size. The rigidity of the heteromorphic incompatibility system was tested using experimental hand-pollinations. Significantly fewer pollen tubes arrived at the ovary after self- and illegitimate pollination (7%) than after legitimate pollination (12%). Seed set after self-pollination (3.6%) was also much lower than after legitimate pollination (66.7%). Comparison of seed set after legitimate pollination with natural seed set showed evidence for outcross pollen limitation. Our results indicate that despite severe pollen limitation and limited mate availability the heteromorphic incompatibility system in H. serrata is still strict after colonization of La Réunion Island. Because H. serrata is extremely long-lived, these results suggest that establishment of heterostylous species on islands may have been favored by their long life span.

Background Geographical ranges of plants and their pollinators do not always entirely overlap and it has been suggested that the absence of specialized pollinators at range margins may induce changes in mating systems. Because a species’ mating system is known to have a considerable effect on within-population pollen movement, the extent of fine-scale spatial genetic structure (SGS) can be expected to differ between populations located at different parts of their geographical range. To test this prediction, we compared the fine-scale SGS between two core and two disjunct populations of the distylous forest herb Pulmonaria officinalis. Because in disjunct populations of this species the heteromorphic self-incompatibility system showed relaxation in the long-styled morph, but not in the short-styled morph, we also hypothesized that the extent of fine-scale SGS and clustering differed between morphs. Results Spatial autocorrelation analyses showed a significant decrease in genetic relatedness with spatial distance for both core and disjunct populations with the weakest SGS found in one of the core populations (Sp = 0.0014). No evidence of stronger SGS in the long-styled morph was found in the center of the range whereas one disjunct population showed a significantly (P = 0.029) higher SGS in the long-styled morph (SpL = 0.0070) than in the short-styled morph (SpS = 0.0044). Conclusions Consistent with previous analyses on distylous plant species, we found weak, but significant spatial genetic structure. However, the extent of SGS varied substantially between populations within regions, suggesting that population characteristics other than mating system (e.g. local pollinator assemblages, population history) may be as important in determining variation in SGS.