Spatial Isolation Research Articles

Seed productivity of alloplasmic lines of Beta patula and B. maritima with sterile cytoplasm under the conditions of apozygotic reproduction

Purpose. Revealing the effect of the cytoplasmic genome of replaced lines with the plasma of wild species Beta patula and B. maritima L., and apozygotic lines A4–A8 with the cytoplasm of S vulgaris Owen on the main factors of apozygotic reproduction, seed productivity, germination, monogermity and sterility as affected by the genetic origin of breeding material.
 Methods. The research was carried out in the Cytogenetics Laboratory (IBCSB), the Laboratory for Apomixis and Polyploidy of the Yaltushkiv EBS, and the Laboratory for Adaptive Breeding (Veselyi Podil EBS). Apozygotic seeds were obtained under a pollen-free regime according to the IBCSB’s Methods for Spatial Isolation and Parchment Insulators. Each seed bearer plant phenotype was determined during the flowering period by pollen sterility and partial flowering. Classification of plants was performed according to Owen (1945), with identifying plants of CMS-0, Type CMS-1, and CMS-2 types. The Monogermity of seed plants was assessed visually by the presence of separate fruits on the central shoots. In 2021, the roots of the replaced lines of the Veselyi Podil EBS were planted under the conditions of a pollen-free regime in the experimental field of the IBCSB. Seed production under apozygositic conditions was studied, taking into account the number of set fruits per 10-cm segment with 5 replications for each seed bearer. Germination was determined on the 10th day and germination vigour on the 5th day.
 Results. New sources of cytoplasmic male sterility (CMS) were obtained in the cytogenetics laboratory based on a genetic model of crossbreeding analysis, using differentiation and tools according to the marker-linked genes of hypocotyl color R+r-, and one / two-year development cycle B+b-. The analyzers for the nature of sugar beet sterility were sterility maintainers, dominant homozygotes for recessive genes of anthocyanin color, development cycle, partial fertility and sterility (NBeta vulgaris Sxxzz rr bb). Monogerm pollen-sterile lines with an apomictic way of seed reproduction (Yaltushkiv EBS) (A4–A8 Beta vulgaris Sxxzz rr), selected for the dominant color of the hypocotyl R+r-, stabilized for the trait of monogermity, 100% sterility and 2x gene ploidy, were characterized by low seed productivity. High rates of apozygotic seed development (80 to 96.4% of the number of set flowers) were observed against the background of the sterile cytoplasm of Beta maritima (Turkey). In the CMS BC4S patula line, the number of set apozygotic seeds ranges from 34 ± 0.3 to 39 ± 0.42, and the indicators of degenerated flowers under apozygotic regime varied from 31.2 to 54.3%. Isolated were seed plants with high self-reproduction, such as BC4S maritima Turkey, k.2/1, k.6/2, k.6/3 and k.3/4, k.9/4 on the background of new plasma of wild species of B. patula. The phenomenon of high self-reproduction of seeds (up to 98.5−96.4% of set flowers) was detected in line 21-011 CHS BC5S patula, which was comparable with hybrids and sterility maintainers (97.5−93.1%), which is determined by a special interaction of the beet nuclear genome of sugar beet and new plasma of wild species of the genus Beta L.
 Conclusions. The apomictic way of seed reproduction ensures the shortening of the breeding scheme for sugar beet due to high seed reproduction of mother parent in substituted lines with new plasma and differentiation by gametophytic reduction of parthenogenesis using morphological marker traits.

Ambient struggling: food, chronic disease, and spatial isolation among the urban poor.

This paper uses the survival strategies of food shelf clients to explore how food access, chronic disease, and spatial isolation shape the lives of low- and no- income urban citizens. The abundant availability of unhealthy food intersects with the presence of long-term health conditions to create a marginalized urbanspace where low quality commodity food is available, but exacerbates existing health conditions, is difficult to access, and does little to create food security. To survive, clients have normalized a sustenance strategy of going to multiple food serving sites, carrying food long-distances and using SNAP benefits to make ends meet. However, this nourishment strategy is time-consuming and unsafe, demanding that people put themselves in precarious positions and push their bodies farther physically than is healthy. These food procurement strategies exacerbate their marginalization. Qualitative data from food shelf users is used to develop a theory of ambient struggling wherein the struggle for food access is unhealthy and time-consuming, making it difficult to improve their standard of living.

Are populations less genetically diverse and more differentiated at the species range edges? Analysis of the quantitative trait and molecular variation in wild oat Avena sterilis

Abstract Although understanding factors determining the genetic makeup of natural populations has long been an important goal of evolutionary biology, the effect of population position within the species range (i.e., interior vs. edge) on species genetic variation is still unclear. According to the ‘abundant center’ hypothesis, the range edge populations are expected to exhibit lower genetic variation and higher differentiation than core populations because of their greater spatial isolation and smaller size. We tested these predictions by comparing the extent and structure of neutral (SSR) and quantitative trait genetic variation in 20 populations of an annual grass Avena sterilis hierarchically sampled at the species range core and two opposite edges. Within-population genetic diversity was reduced at the desert range edge compared to the range core as assessed by six SSR markers but not by eight quantitative traits; no reduction was detected at the mountain edge. Genetic differentiation among populations was higher at the desert range edge than the range core in both molecular markers and quantitative traits, but not at the mountain edge. Our results imply that the pattern of population genetic variation at the species range edges largely depends on the steepness of the environmental cline that has a major effect on species fitness. The more gradual the environmental cline from the species interior towards the edge, the higher the probability of detecting reduced genetic diversity and increased differentiation of peripheral populations as predicted by the ‘abundant center’ hypothesis.

Co-invading ectomycorrhizal fungal succession in pine-invaded mountain grasslands

Ectomycorrhizal (EM) fungal communities that associate with invading pines ( Pinus spp.) are expected to be poor in species diversity. However, long-term successional trajectories and the persistence of dispersal limitations of EM fungi in the exotic range are not well understood. We sampled the roots and surrounding soil of Pinus elliottii and P. taeda trees invading mountain grasslands of Argentina. We also sampled the EM fungal spore bank in grassland soil near (∼150 m) and far (∼850 m) from the original pine plantations. We found 86 different co-invasive EM fungal OTUs. Differential dispersal capacities among EM fungi were detected in the spore bank of grassland soil, but not under mature pines. After thirty years of invasion, the age, but not the degree of spatial isolation of pine individuals affected the EM fungal composition. We showed how EM fungal succession occurs during pine invasions, which may have clear consequences for ecosystem functioning of co-invaded sites. • Pines often rely on co-introduced ectomycorrhizal (EM) fungi to invade native ecosystems. • EM fungal succession and persistence of dispersal limitations are poorly understood. • We found that invading pines can host a highly diverse EM fungal community. • The age but not the spatial isolation of pines affected EM fungal composition. • Dispersal limitations of EM fungi are only relevant during early pine invasion.

A high-performance optical trace oxygen sensor based on the room-temperature phosphorescence from palladium (II) octaethylporphyrin

A high-performance oxygen sensor is developed based on room temperature phosphorescence. The optimized sensing probe is fabricated by Sol-gel matrix doped with Palladium (II) octaethylporphyrin (PdOEP), and a sensitivity of the PdOEP probe reached 29.23 kPa−1. Dual-channel structure is designed to eliminate fluctuation of excitation source. One channel is used to detect oxygen sensing phosphorescence from PdOEP probe, and the other is used for receiving reference fluorescence signal, which is induced by 7-Diethylamino-4-methylcoumarin (C1). The C1 is insensitive to oxygen and is placed side by side with PdOEP probe, the spatial isolation of PdOEP and C1 probes could avoid the interference of different emissions. Photomultiplier tube equipped photon counter is employed as the sampling unit to promote the signal-to-noise ratio. The detection limit and indication error of measurement system reached 0.1 Pa and ± 1.5 %, respectively. In addition, the 1.9 μm thickness of probe ensures the system response within 5 s.

New hulless oat variety ‘Azil’

The current paper has presented the study results of the new hulless oat variety ‘Azil’, which was developed by the method of individual-family selection from the hybrid population ‘Krestyansky local × ZALP’. The purpose of the current study was to identify economically valuable traits, physico-biochemical indicators of the grain of the new hulless oat variety ‘Azil’. According to the length of the vegetation period, ‘Azil’ is classified as a middle maturing variety. In the State Variety Testing, the realized productivity of the variety ‘Azil’ was 5.36 t/ha. During the study, there has been found that with intensive and high-intensity cultivation in compliance with the technological methods of protection against diseases, weeds and pests, the productivity of the variety ‘Azil’ improved in relation to the basic technology from 0.75 to 1.42 t/ha (or on 12 and 23 %, respectively). The estimation of groat properties has revealed a larger protein and oil percentage in grain of the new variety than that of the hulled and hulless standard varieties ‘Yakov’ and ‘Vyatsky’ (2.2 and 0.2 % of protein; 1.3 and 0.5 % of oil) . There has been identified high loose smut resistance of the variety ‘Azil’ (up to 6.4 % damage) on artificial and natural backgrounds. There has been established a fungi composition and mycotoxins’ content in grain of the standard oat varieties ‘Yakov’ and ‘Vyatsky’, as well as 13 hulless breeding lines of the Federal Research Center “Nemchinovka”. The variety ‘Azil’ has demonstrated an increased resistance to the accumulation of T-2 toxin. Using biochemical methods there has been found heterogeneity of the new variety, consisting of two biotypes. When conducting primary seed production, there has been recommended to use the method of individual-family selection with a double estimation of the progeny and maintaining spatial isolation with other hulless oats.

Research on the paths and strategies of the integrated development of culture and tourism industry in urban historical blocks.

COVID-19 has brought about great impact on the global economy. Various countries have adopted different levels of spatial isolation measures to curb the spread of the epidemic. These measures not only limit the spatial flow of people and property, but also cause global anxiety and public mental health problems. Corresponding to this process, cultural demands are growing stronger and the humanistic shift in today's urban economic development also puts forward higher requirements for local culture. Historic districts are an important symbolic historical and cultural landscape of a city, and many cities regard them as important starting points for the shaping of urban characteristics and competitiveness. Taking Qingming Bridge Historical and Cultural Block in Wuxi City as an example, combined with the public's mental health needs in the context of COVID-19 and the current background of the return of humanism in urban development, and construct a more sustainable framework for the renewal and development of urban historical blocks, focusing on the integration and development of the cultural landscape and tourism in the historical block. A comprehensive analysis shows that the development of Qingming Bridge Historical and Cultural Block must be based on the comprehensive investment of "four types of resources," such as culture, land, capital, and labor, and must rely on the cooperation of the "two sectors" of culture and tourism. By earnestly respecting the above, as well as the "triple bottom line" of regional ecology, economy, and society, sustainable development can be achieved.

Predictors of plant endemism in two west African forest hotspots

Centres of endemism have been much studied by biogeographers, ecologists, and evolutionary theorists, and are considered conservation priorities. It is therefore important to understand the ecological traits of restricted range taxa, and the landscape-scale drivers of high endemism. Here, we investigate correlates of floristic endemism within two of west Africa’s forest biodiversity hotspots at local scale. We assembled distribution data for 1,042 vascular plant taxa from 114 sample locations within forest reserves of south west Ghana, and for 1,735 vascular plant taxa from 454 sample locations within the Nimba Mountains (Liberia and Guinea). A quantitative index of global endemism called the Genetic Heat Index was modelled linearly. We tested the significance of modern climate, altitude and disturbance as factors predicting endemism rates in these two forest reserves. Annual rainfall was significantly and positively related to endemism rates in both south west Ghana and the Nimba Mountains. Altitude was a significant predictor of endemism rates in the Nimba Mountains, with a quadratic relationship highlighting particularly high endemism over 1,000 m. Local topography rather than altitude was a significant predictor or endemism in SW Ghana, where altitude varies less. Areas of high rainfall and high altitude are geographically restricted across the western African forests, acting as edaphic islands driving spatial isolation. Disturbed vegetation samples had lower endemism rates than undisturbed samples in both Nimba and SW Ghana, and overall pioneer species had wider areas of occupancy than shade-bearing species. Endemism rates increased slightly with each year following clearance. Disturbance thus creates and maintains vegetation types which support a lower proportion of globally rare species in the two biodiversity hotspots surveyed. From the point of view of the conservation of globally rare plants, it is important to keep additional disturbance in the south west Ghana hotspot, particularly Ankasa, to a minimum, as is the current practice, and in the Nimba mountains to establish community forests which may be left relatively undisturbed amid farming and mining activities.

Remodeling nanodroplets into hierarchical mesoporous silica nanoreactors with multiple chambers

Multi-chambered architectures have attracted much attention due to the ability to establish multifunctional partitions in different chambers, but manipulating the chamber numbers and coupling multi-functionality within the multi-chambered mesoporous nanoparticle remains a challenge. Herein, we propose a nanodroplet remodeling strategy for the synthesis of hierarchical multi-chambered mesoporous silica nanoparticles with tunable architectures. Typically, the dual-chambered nanoparticles with a high surface area of ~469 m2 g−1 present two interconnected cavities like a calabash. Furthermore, based on this nanodroplet remodeling strategy, multiple species (magnetic, catalytic, optic, etc.) can be separately anchored in different chamber without obvious mutual-crosstalk. We design a dual-chambered mesoporous nanoreactors with spatial isolation of Au and Pd active-sites for the cascade synthesis of 2-phenylindole from 1-nitro-2-(phenylethynyl)benzene. Due to the efficient mass transfer of reactants and intermediates in the dual-chambered structure, the selectivity of the target product reaches to ~76.5%, far exceeding that of single-chambered nanoreactors (~41.3%).

A supraparticle-based biomimetic cascade catalyst for continuous flow reaction

Robust millimeter-sized spherical particles with controlled compositions and microstructures hold promises of important practical applications especially in relation to continuous flow cascade catalysis. However, the efficient fabrication methods for producing such particles remain scare. Here, we demonstrate a liquid marble approach to fabricate robust mm-sized porous supraparticles (SPs) through the bottom-up assembly of silica nanoparticles in the presence of strength additive or surface interactions, without the need for the specific liquid-repellent surfaces used by the existing methods. As the proof of the concept, our method was exemplified by fabricating biomimetic cascade catalysts through assembly of two types of well-defined catalytically active nanoparticles. The obtained SP-based cascade catalysts work well in industrially preferred fixed-bed reactors, exhibiting excellent catalysis efficiency, controlled reaction kinetics, high enantioselectivity (99% ee) and outstanding stability (200~500 h) in the cascades of ketone hydrogenation-kinetic resolution and amine racemization-kinetic resolution. The excellent catalytic performances are attributed to the structural features, reconciling close proximity of different catalytic sites and their sufficient spatial isolation.

Spatial isolation impacts pollinator visitation and reproductive success of a threatened self-incompatible Mediterranean tree

Pollination service is crucial to achieve successful plant sexual reproduction and long-term population persistence. This pollination service can be affected by plant conspecific density and also by intrinsic features of individuals related to their flowering phenology and floral display. However, studies examining intrinsic and extrinsic traits on pollinator visitation and reproductive success of Mediterranean trees with limited reproduction are still scarce. We analyzed the effects of plant isolation, flowering phenology, flower weight and tree size on flower visitation probability, flowering patch visitation probability, fruit set and crop size. To this end, we intensively monitored pollinator visitation and fruit production of 67 (in 2019) and 73 (in 2020) Pyrus bourgaeana Decne trees within a threatened Mediterranean population. Our results revealed that isolated individuals received more pollinators than those on conspecific aggregations, suggesting intraspecific competition for pollinators in dense flowering neighborhoods. However, fruit set was higher in trees close to flowering conspecifics despite having fewer visits from pollinators, suggesting pollen limitation but not pollinator limitation in spatially isolated trees. Interestingly, we found increased crop sizes in spatially isolated trees which could be related to reduced intraspecific competition for resources in low-density neighborhoods (water, nutrients) and/or to higher reproductive investment (i.e. higher flower production). Overall, our results indicated pollen but not pollinator limitation in spatially isolated trees. Under this scenario of sexual reproduction mediated by pollinators, our findings stress the relevance of individuals' spatial distribution for self-incompatible trees exhibiting low individuals’ densities.

Isolation anchoring strategy for in situ synthesis of iron single-atom catalysts towards long-term rechargeable zinc-air battery

The reasonable design and construction of single-atom electrocatalysts with low-cost and excellent intrinsic activity for oxygen reduction reaction (ORR) is indispensable in metal-air batteries. Herein, a facile isolation anchoring strategy was reported for in situ formation of porous N-doped carbon catalysts (Fe1/NC) rich in Fe single atoms. The d-glucose, zinc gluconate and N-rich histidine were deployed as spatial isolation agents and anchoring agents to inhibit iron atom aggregation during the high-temperature pyrolysis. The as-synthesized Fe1/NC catalyst shows remarkable stability and superior ORR electrocatalytic activity under both alkaline and acidic conditions owing to highly dispersed Fe–N4 sites, especially with a half-wave potential up to 0.91 V in 0.1 M KOH, exceeding 60 mV compared with Pt/C. Notably, the Fe1/NC-based Zn-air battery exhibits maximal power density of 164 mW cm−2, large specific capacities of 769 mA h gZn−1, excellent cycle stability over 300 h, and great potential in renewable energy conversion electronics.

Isolation of Shared Resources for Mixed-Criticality AUTOSAR Applications

Temporal isolation without consideration of spatial isolation has been attained for mixed-criticality systems, while the need for spatial isolation is urgently required in the automotive industry. Moreover, tasks with different criticality levels sharing the same resources are a common requirement for safety-critical automotive applications. Such tasks are more challenging to spatially isolate due to context sharing to access the same resources. Nevertheless, safety certification cannot be issued without addressing spatial isolation. This paper argues that traditional real-time locking solutions are unsuitable for mixed-criticality applications within the automotive open system architecture (AUTOSAR). We adopted the server task named resource server for spatial isolation within AUTOSAR limitations. We formalized a software component model for reducing design space and proposed the mapping algorithms. Properties of resource servers within AUTOSAR were formally analyzed for blocking delays, task priority assignment, and utilization analysis. Case studies in a powertrain domain of an electric vehicle were carried out to assess the proposed solutions.

Site isolated Ru clusters and sulfoacids in a yolk-shell nanoreactor towards cellulose valorization to 1,2-propylene glycol

Direct conversion of cellulose to high yield 1,2-propylene glycol (1,2-PG) is amazing in the biomass valorization to diols, since this process is atom-economic, carbon neutral, and the produced 1,2-PG has a large market demand. However, it is very challenging to control cellulose hydrogenolysis owing to high reactivity of intermediates (like glucose) and metal-acid repelling, leading to decreased selectivity of metal-acid multi-functional catalysts. Aimed at this, we herein developed a highly selective metal-acid catalyst (Ru/NC@void@MC-SO3H) with site isolated Ru clusters (1.4 nm) on the core and sulfoacids on the shell in a yolk-shell nanoreactor by a layer-by-layer assembly before chemical transformation. The spatial isolation of metal and acid sites integrated in a mesoporous yolk-shell nanoreactor not only facilitates the metal-acid synergism in hydrolysis, isomerization/hydrogenolysis and hydrogenation cascade reactions, but also provides a designated diffusion pathway that is favorable for reaction species. As expected, the elaborately fabricated Ru/NC@void@MC-SO3H proves to be highly selective to 1,2- PG (38 % yield), delivering a productivity of 342.86 mol h−1 gRu–1 and an extremely high turnover number of 173264, outperforming the state-of-art metal-acid catalysts for cellulose hydrogenolysis to 1,2-PG. Our characterization and performance test suggest that sulfoacids are mainly responsible for cellulose hydrolysis, while N-stabilized Ru centers contribute to the glucose isomerization to fructose and its further hydrogenolysis to dihydroxyacetone, followed by hydrogenation to 1,2-PG on metallic Ru species. The acidity and basicity optimized for site isolated Ru/NC@void@MC-SO3H is beneficial to balance intermediate reactions, rendering a higher selectivity to target 1,2-PG. The concept illustrated in this study will provide a guide for the development of other site isolated multi- functional catalysts towards cellulosic biomass conversion and other cascade reactions.

Reimagining the Food Shelf: Conceptualizing the Food Shelf as a Community Food Security Project

ABSTRACT The Private Emergency Food Shelf (PEFS) system has been critiqued for its unhealthy food, stigmatizing environments, and relationships with corporate interests; however less has been said about how food shelves can transform their practices. This paper examines the PEFS system using the Community Food Security (CFS) framework. Drawing on qualitative research, we identify three ways food shelves can better respond to the lived realities of food insecure people: providing trauma-informed food support, healthy food access, and addressing spatial isolation. The discussion elaborates on how food shelves can offer food and serve as an entree to wider social support systems.

The Secret Children of the Border Area. Closed Institutions for Children with Disabilities in Blagoevgrad Region in the 1960-es

The article examines the activities of two closed institutions for children with disabilities in Southwestern Bulgaria in the 1960s, located in former border zones in the difficult-to-access mountain area. The living conditions, the qualifications of the staff, the work of adolescents in agriculture and the production of drawing pins, the communication barriers with parents and the outside world are presented. The documents of the two insitutions show that there were significant differences in the care of children between the single social homes for children with disabilities in Bulgaria. Located in the close conditions of spatial remoteness and the border zone, in unsuitable buildings of former border posts, the differences in the care of children in the two institutions are due to a very large extent to the different attitudes of staff and management towards children and work. But even in the best case, as it is in the home for children with severe disabilities from 3 to 10 years of age in the village of Debochitsa, the achievements of the staff were primarily reduced to improvements in the environment, care for hygiene and nutrition and educational activities with the most ‘promising’ children. In the preserved sources, children and adolescents had no names, no biographies, no faces (no photographs left), no voice. They were seen above all as bodies with physical needs, and grown adolescents as labor force. Scientific discourse in the 1950s and 1960s stressed the developmental deficits of these children and emphasized their difference' and not their abilities. This contributed to their spatial separation and isolation from other children and from the social life.

Ecological niche differences regulate the assembly of bacterial community in endophytic and rhizosphere of Eucalyptus

The relationship between microorganisms and plants has been a hot topic of research because of its direct link to plant health and productivity, and these interactions are not limited to the soil. The structural and ecological variation of bacterial communities due to spatial isolation in different parts of plants is still unclear. Whether intensive management of Eucalyptus plantations affects this variation should also be concerned. To investigate the mechanisms underlying bacterial changes in different ecological niches of Eucalyptus and the stability of bacterial communities after continuous high-intensity planting of Eucalyptus, we studied the effects of long-term plantation of Eucalyptus on the structure, assembly patterns, and interactions of the bacterial community. Woodlands that planted with Eucalyptus urophylla S.T. Blake × Eucalyptus grandis Hill ex Maiden (Eucalyptus urograndis, hereafter E. urograndis) in three generations (10 years after planting) were selected for study, and the woodlands were cleared and replanted with E. urograndis. Rhizosphere soil, roots, stems, branches, and leaves of E. urograndis differing in age (2, 4, and 6 years) after planting were sampled, and the rhizosphere soil bacteria and endophytic bacterial communities of different parts were determined using the 16S rRNA technique. We detected structural variation in the soil and endophytic bacterial communities as well as variation in community assembly. Stochastic processes made large contributions to the assembly of highly abundant soil bacterial communities, as well as low-abundant endophytic bacterial communities of the branches and leaves (especially leaves), and this pattern may be strongly related to the ecological niches of the bacteria. The bacterial correlation network demonstrated that the properties of Eucalyptus soil and their endophytic bacterial communities can vary 6 years after successive plantings. Thus, measures should be taken to ecologically restore Eucalyptus woodlands after 15 years of high-intensity planting to ensure the stability of microbial community structure, the maintenance of adequate ecological properties during Eucalyptus planting, and the sustainable production and management of Eucalyptus plantations.

The oceanographic isolation of the Ogasawara Islands and genetic divergence in a reef‐building coral

AbstractAimDue to their spatial isolation, oceanic islands are natural systems to study evolutionary divergence. The Ogasawara Islands belong to the most isolated archipelagos on Earth and are well‐known for their high terrestrial endemicity; however, less is known about the marine realm. Here, we analyse the degree of oceanographic isolation of the archipelago based on genetic data of a reef‐building coral and a biophysical dispersal model.LocationNorth‐Western Pacific (Ogasawara, Ryukyu, Daito Islands, Guam).TaxonGalaxea fascicularis L.MethodThree to 15 specimens were sampled at several sites in Ogasawara and its closest potential migration sources in southern Japan and the Mariana Islands (Guam) and RAD‐sequenced. 108 specimens from the common Pacific lineages ‘L’ (Ryukyu‐ and Daito Islands, Guam) and ‘Ogasawara’ (Ogasawara) were analysed with population genetics and demographic modelling. Oceanographic dispersal was investigated by inverse particle tracking using a Lagrangian particle advection simulation based on ROMS and applying biological dispersal parameters of G. fascicularis.ResultsThe G. fascicularis population in Ogasawara is genetically highly differentiated from the next closest reefs in the region and has diverged from the Ryukyu Islands under very little, asymmetric, eastward migration. Inverse particle tracking confirmed the oceanographic isolation of Ogasawara and showed that the islands are rarely but most likely reached by settlers from the Ryukyu Islands by long‐distance‐dispersal of exceptionally long‐lived larvae (>44 days), with no dispersal vice versa.Main conclusionsOgasawara is a dispersal sink location and the high degree of genetic differentiation in Galaxea has resulted from strong oceanographic isolation. This research highlights how oceanographic features impact species‐level genetic differentiation even in well‐dispersed taxa such as broadcast‐spawning corals, and they are likely even more pronounced in less vagile organisms. These findings suggest the Ogasawaran Archipelago should be considered an important priority for marine conservation, alongside its high importance for terrestrial conservation.

Plant species diversity and composition in limestone forests of the Vietnamese Cat Ba National Park

Plant species diversity and composition play crucial roles in many ecosystem services and are largely influenced by environmental conditions, as well as natural and/or anthropogenic disturbances. However, our knowledge of the drivers of plant species diversity and composition in the limestone forests of Vietnam, a hotspot of biodiversity, is limited. To fill this knowledge gap, we surveyed plant species in the Cat Ba National Park (CBNP), located on a limestone archipelago. We hypothesised that: (1) topography, accessibility and spatial isolation drive the diversity and composition of plant communities in the CBNP and that (2) isolated areas contribute to high floristic regional diversity by supporting unique species assemblages. We expected high tree species diversity within the tropical limestone forests of the CBNP, but also that: (3) the abundance of non-tree species negatively affects tree regeneration diversity and abundance. Data were obtained from 90 random sample plots (500 m2) and 450 sub-sample plots (25 m2) in three areas of the CBNP. We differentiated four different plant species communities and found a total of 302 species belonging to 112 families. Tree species contributed 50% to total species richness. The distribution of different plant communities in the CBNP was driven mainly by topography; that is, the percentage of rock surface and slope and concomitant differences in soil depth. Contrary to our expectations, isolated areas did not contribute greatly to the CBNP’s plant species diversity. It seems that isolated areas and, as in our case, rough topography, may act as natural barriers to seed dispersal, creating an environmental filter for tree species. Across the CBNP, there was no effect of non-tree species on tree species regeneration, but regeneration patterns differed between communities. In species-rich communities growing under favourable site conditions (e.g. low rock surface and slope), greater coverage by non-tree species had an increasingly negative effect on tree species richness and abundance in the regeneration layer. The opposite was observed in communities growing under harsh site conditions. We conclude that plant species diversity in the CBNP is high, particularly in easily accessible lowland areas where tree species contribute greatly to biodiversity. However, here, non-tree species can even restrict tree regeneration.

Stressful, isolated, yet diverse: Green roofs have rich microbiomes that are not dominated by oligotrophic taxa.

Green roofs are unique ecosystems combining two major community assembly filters, namely stress and spatial isolation. As such, they represent an interesting model ecosystem in community ecology. In this study, we characterized the microbiome structure on 19 green roofs and 5 urban parks as a benchmark comparison (i.e. non-isolated, non-stressful habitats). Green roofs were not species depauperate, showing similar α-diversity compared to surrounding parks. We also did not find an overrepresentation of bacterial phyla typically recognized as oligotrophs, which calls into question the notion of green roofs as highly stressful habitats for bacteria, and/or the conservatism of nutritional ecophysiology at the phylum level. The geographical position of a roof, or its degree of spatial isolation (assessed through its height and area) were not important predictors of microbiome diversity and structure, suggesting that dispersal limitations impose little constraints on green roof microbiome assembly. Finally, key microbial groups (e.g. archaeal nitrifiers, Actinobacteria) were much less frequent and/or abundant on green roofs, which may have important implications for nutrient cycling and urban biogeochemistry. More work will be required to phenotype the microorganisms overrepresented on green roofs and specifically measure key soil processes in these unique urban ecosystems.