High Taxonomic Diversity Research Articles

Combining bio-logging, stable isotopes and DNA metabarcoding to reveal the foraging ecology and diet of the Endangered Bermuda petrel Pterodroma cahow

The foraging range of central-place predators is limited by spatiotemporal and energetic constraints. Gadfly petrels Pterodroma spp. are seabirds well adapted to travel vast distances in oceans with sustained wind conditions, although our understanding of their foraging ecology in these heterogeneous and highly dynamic environments is still limited. We studied the foraging behaviour, habitat use, ecological niche and diet of the Endangered Bermuda petrel P. cahow, endemic to the western North Atlantic. We used GPS loggers to track foraging trips during incubation and early chick-rearing in 2019 and 2022, and employed DNA metabarcoding coupled with stable isotope analyses to reveal dietary habits. Our analyses showed that petrels travelled over a vast area of the western North Atlantic while foraging over deep, pelagic waters. Specifically, in the early chick-rearing phase, they reduced their foraging range and time spent at sea compared to incubation. Foraging locations were associated with varying sets of environmental variables between breeding phases, including mesoscale oceanographic features, distance to the colony and wind speed. Petrels also showed narrow isotopic niches, and the ranges of δ15N and δ13C values suggested consistency in trophic habits. Finally, we found high taxonomic diversity in the diet, including exclusively meso-bathypelagic fishes and cephalopods. Our results contribute critical new knowledge on Bermuda petrel foraging-behaviour plasticity, a feature that can help predict how a small population of an endangered species may respond to climate-related changes in wind regimes and oceanic processes expected in the North Atlantic Ocean.

Coleoptera associated with intermittent streams and their riparian zones in south coastal British Columbia

AbstractIntermittent streams that periodically cease surface flow have long been understudied in ecology and underrepresented in conservation policy. However, they currently account for 30–50% of the global river network, and that number is rising due to anthropogenic water extraction, land-use change, and climate change. We explored the Coleoptera biodiversity of the south Pacific coast region of British Columbia, Canada, using pitfall traps at perennial and naturally intermittent stream reaches, in shoreline, dry streambed, and riparian habitats, in both flowing (spring and early summer) and nonflowing (late summer) phases. We found that habitats around perennial reaches had significantly greater abundance of Coleoptera individuals than did those around intermittent reaches. However, neither habitat type nor flow regime was a significant predictor of taxon richness, and intermittent stream sites featured unique taxa that were not found near perennial streams. This aligns with recent results from other taxonomic groups; that is, finding that intermittent ecosystems can host high taxonomic diversity of Coleoptera, on par with or even greater than that of perennial streams. Because intermittent streams will likely become more prevalent within the global river network, a better understanding of how different species use these habitats is needed to inform appropriate biodiversity conservation efforts and flow management.

Indigenous diazotrophs and their effective properties for organic agriculture

Nitrogen-fixing microorganisms (diazotrophs) converting the atmospheric N2 into usable form NH4 are considered the key players in the nitrogen cycle, chiefly responsible for the enriching nitrogen content in the soils. Globally, biological fixation of N2 greatly contributes to plant growth, lessens the need for chemical fertilizers, and thus contributes to the mitigation of greenhouse gases NOx. In this study, diazotrophic bacterial strains were isolated from rhizosphere soils and root nodules of legume and non-legume plants in Vietnam. Quantitative analyzes by the acetylene reduction assay showed that the isolates have high nitrogen fixation activity compared with that of reference strain Azospirillum vinelandii KCTC 2426. In addition, other effective capabilities of the isolated strains toward supporting agriculture were investigated, i.e. synthesizing IAA and siderophore for promoting plant growth, or producing exopolysaccharides for maintaining soil moisture. Taxonomic positions of the isolated strains were identified based on the comparative analyses of sequences of the 16S rDNA and gene related to nitrogen fixation (nifH), revealing a high taxonomic diversity among free-living and symbiotic diazotrophic isolates. Direct support of the selected isolates to plant growth was proven in experiments with mung beans under laboratory conditions. Thus, the native diazotrophic strains obtained in this study would be good microbial sources for application in organic agriculture and soil amendment.

FLORA OF BARKOV MOUNTAIN (FLORA OF MOUNT BARKOV (SUBPOLAR URALS) AND ITS ROLE IN THE CONSERVATION OF RARE PLANTS

A list of vascular plants of the Barkova Mountain in Subpolar Urals (1320 m above sea level) made up of 237 species from 124 genera and 45 families is published. The high taxonomic diversity of the flora is predicated on a number of factors: mountainous relief and significant altitudinal range (670 m), the presence of several altitudinal vegetation belts and a vast mountain-top plateau, heterogeneous bedrocks, climatic conditions of subarctic highlands, and the general history of the flora formation during the Late Pleistocene. The flora of the Barkova Mountain occupies a transitional position, with both arctic montane and boreal features, and is classified as hypoarctic montane with regional characteristics. Two taxa (Sedum roseum and Castilleja arctica subsp. vorkutensis) are included in the Red Data Book of the Russian Federation, 27 taxa - in the Red Data Book of the Komi Republic, and 13 - in the Appendix to the regional Red Data Book. Many protected species are represented by marginal populations in the study area. Two species (Ranunculus kamchaticus and Draba pauciflora) have single records for the Komi Republic. Despite the recent significant human impact, the Barkova Mountain is important for the conservation of the floral diversity of the region, the Yugyd Va National Park and the Virgin Komi Forests UNESCO World Heritage Site.

Soil Actinomycetes of Vietnam Tropical Forests

Actinomycetes are an important group of bioactive hydrolytic bacteria in any ecosystem. However, the actinomycete biodiversity in tropical ecosystems, particularly in Vietnam, is still underexplored. The aim of this article is to analyze the abundance, taxonomic structure and ecophysiological features of actinomycete complexes of soils and litter in Vietnam’s protected areas. A total of 41 samples of soils, plant litter and suspended soils were collected from six of Vietnam’s national parks and nature reserves. The direct inoculation technique showed that the total abundance of actinomycetes varied from 2.0 × 104 to 1.0 × 108 CFU/g. According to the luminescent microscopy with acridine orange dye, the length of the actinomycete mycelium was as long as 1000 m/g in the litter of Xuan Son National Park. A total of 80 strains were isolated and tested for antagonistic activity against Bacillus subtilis, Aspergillus niger and Candida albicans. Inoculation on Getchinson’s medium showed high cellulolytic activity. The most active strains were isolated from alluvial brown soil, plant litter and suspended soil of the Pu Hoat Nature Reserve. In these samples, actinomycetes adapted to high temperatures and low pH were found to be predominant. High-throughput sequencing of the V3–V4 region of the 16S rRNA gene and bioinformatic analysis confirmed the high taxonomic diversity and high hydrolytic activity of actinomycete complexes of the Pu Hoat Nature Reserve samples.

Taxonomic, functional and phylogenetic diversity peaks do not coincide along a compositional gradient in forest‐grassland mosaics

Abstract Ecosystems with forest and grassland patches as alternative stable states usually contain various closed, semi‐open and open habitats, which may be aligned along a vegetation cover gradient. Taxonomic diversity usually peaks near the middle of the gradient, but our knowledge on functional and phylogenetic diversity trends along gradients is more limited. We investigated the eight main habitats of Hungarian forest‐grassland mosaics, representing various vegetation cover values, and compared their species composition as well as their taxonomic, functional and phylogenetic diversity. We found a compositional gradient ranging from large forest patches through smaller‐sized forest patches and edges to closed and open grasslands. Species richness peaked at the middle of the gradient (at edges). Shannon diversity was high near the middle and at the open end of the gradient. Functional diversity was high throughout woody habitats (in forests and at edges) and was significantly lower in grasslands. When considering all species, phylogenetic diversity tended to peak at north‐facing forest edges. When excluding non‐angiosperms, this peak disappeared. The high taxonomic diversity at the middle of the gradient is in line with the edge‐effect theory. Our results suggest that community assembly in grasslands may be dominated by environmental filtering, while competition may be decisive in woody habitats. The low phylogenetic diversity of grassland habitats can be explained by their young evolutionary age compared to forests. Synthesis. Functional and phylogenetic diversity do not necessarily coincide with taxonomic diversity along vegetation cover gradients. In ecosystems where forest and grassland patches represent alternative stable states, the trends of taxonomic diversity may be similar to those revealed here, but functional diversity patterns may be more system‐specific for some traits. Trends in phylogenetic diversity may vary according to the evolutionary age of the habitats.

Материалы к флоре печеночников Национального парка «Койгородский» (Республика Коми, Россия)

The Koigorodsky National Park (56.7 thousand hectares) was established on December 7, 2019. It is located on the border of the Komi Republic and the Kirov region. An annotated list of liverworts collected in the Koigorodsky National Park has been presented in the article for the first time. The list includes 38 species and one subspecies of 28 genera, 21 families, seven orders (Blasiales, Jungermanniales, Marchantiales, Metzgeriales, Pelliales, Porellales, Ptilidiales), and two classes (Marchantiopsida and Jungermanniopsida). For each species, the article provides data on structures associated with reproductuion, geographical locations, substrate and the species habitats. Three liverworts species listed in the Red Data Book of the Komi Republic such as Anastrophyllum michauxii, Lophozia ascendens, and Scapania apiculata have been found in the flora. Indicator species of old-growth forests such as Calypogeia suecica, Crossocalyx hellerianus, Riccardia latifrons, and Syzygiella autumnalis have been found. The rare epiphytic liverwort Frullania oakesiana has been discovered in the Komi Republic flora for the first time. 23 species that can potentially be found within the Koygorodsky National Park have been identified on the Tulashor site adjacent territory (the Nurgush Nature Reserve). At present, the taxonomic diversity of the studied flora is probably 62%. The floras of the Koigorodsky National Park and the Tulashor site are parts of a single flora covering a large old-growth spruce forests array and, accordingly, are similar in structure. Forest habitats and spruce forests are characterized by the highest taxonomic diversity: 33 or 87% and 27 or 71% species, respectively. Liverworts prefer to grow on rotting wood due to reduced competition from vascular plants. About 79 % of the identified species form reproductive structures. This indicates that growth conditions are favorable. The remote southwestern part of the national park is promising for further research.

Configurational landscape heterogeneity: Crop-fallow boundaries enhance the taxonomic diversity of carabid beetles and spiders

Arthropod biodiversity in agricultural landscapes is favoured by high levels of compositional and configurational heterogeneity. In terms of composition, the high value of non-crop habitats is firmly established. In contrast, the causes underlying positive effects of configurational heterogeneity, i.e. patch size and boundary length, are less well understood. We here test the hypothesis that boundaries comprise valuable habitats in its own right by enhancing the taxonomic diversity of carabid beetles and spiders. We used pitfall traps placed along transects running from the interior of wheat fields across the habitat boundary to the interior of unmanaged grassland fallows. Taxonomic diversity was highest around the boundaries due to (1) spillover effects but also (2) species showing a distinct preference for edge habitat. For carabids, habitat boundaries harboured distinct species assemblages. Grassland fallows had, especially in spiders, positive effects on the taxonomic diversity of crop fields close to the boundary, while no negative effects of crop fields on adjacent fallows could be found. Overall, taxonomic diversity was higher in grassland fallows than in crop fields, though differences were surprisingly small. The high taxonomic diversity found for boundaries suggest that these may comprise valuable habitats in its own rights, which in turn may causally underpin positive effects of configurational heterogeneity on arthropod diversity in agroecosystems. Thus, increasing configurational heterogeneity, e.g. by promoting small field sizes and high edge density, seems an important tool for preserving farmland biodiversity.

Filicinae Taxonomic Diversity in the Tourism Area of Tretes Waterfall Wonosalam Kabupaten Jombang

Filicinae is a fern with the most species members. The Filicinae includes approximately 170 genera and 7000 species. Filicinae grows in wet, humid, and shady environmental conditions, like waterfall areas with an altitude of 1100-1300 meters above sea level (m a s l). The study aimed to determine the taxonomic diversity of the Filicinae in the Tretes Wonosalam Waterfall Tourism area. Taxonomic diversity is very important in tourism areas because it prevents species extinction due to the destruction of the habitat, they live in. This was descriptive research with exploration and observation techniques used purposive sampling methods based on altitude. The results of the study were stated in the form of an inventory list of species and families of each station. Data gained of species diversity were analyzed using taxonomic diversity with the formula (∆) and dominance diversity with the formula (∆*). Exploration results found 37 species from 12 families composed of 10 species from 7 families at station 1; 12 species from 6 families at station 2; 14 species from 7 families at station 3; and 22 species from 12 families at station 4. The highest taxonomic diversity (∆) was station 4 with 106.8 while the lowest for station 1 was 25.63. Dominance diversity (∆*) at all stations in this study was in the medium category. The highest family found in the study was Tectariaceae with six species.

Beak morphology and limb proportions as adaptations of hadrosaurid foraging ecology

Hadrosauridae, consisting of two subfamilies (Hadrosaurinae and Lambeosaurinae), is a successful herbivorous dinosaur group that established a high taxonomic diversity and a cosmopolitan biogeographic distribution during the Late Cretaceous. While its success is often attributed to a highly specialized oral processing system, the foraging strategy of this group remains unclear. This study focuses on two critical factors in foraging strategy, food selectivity and locomotor ecology, in these hadrosaurid subfamilies. Three-dimensional beak shapes and limb segment proportions are used as the proxies for food selectivity and locomotor ecology, respectively. The beak shape analysis demonstrates trends of anteriorly acute beaks in hadrosaurines and anteriorly wide beaks in lambeosaurines. The limb segment proportion analysis shows short proximal limb segments in hadrosaurines and long proximal limb segments in lambeosaurines. These results suggest that hadrosaurines preferred selective consumption of high-quality food with energy-inefficient locomotor ecology, while lambeosaurines preferred mass consumption of low-quality food with energy-efficient locomotion and that differences in foraging strategy might have enhanced dietary niche partitioning in the subfamily level of hadrosaurids. In addition, this study tests a relationship between limb proportions and habitat environments in hadrosaurids. We demonstrate that hadrosaurids from the coastal environments have shorter forelimbs than those from the terrestrial environment. Since short forelimbs are better suited for temporal bipedalism than long forelimbs, the limb proportion difference may indicate adaptations to different feeding heights, possibly due to different regional vegetations.

The Anisian (Middle Triassic) brachiopods from the southern Qilian Mountains, north‐western China

AbstractThe Anisian (Middle Triassic) witnessed the diversification of brachiopods after the Permian–Triassic extinction. The Anisian brachiopod fauna from the southern Qilian Mountains in north‐western China has the highest taxonomic diversity at species level among coeval faunas worldwide. Nevertheless, many taxa from this remote region remain poorly defined, and therefore require emendation. Here we describe 23 species (including two uncertain species) in 15 brachiopod genera based on well‐preserved carbonate and silicified specimens collected from the Anisian Dajialian and Qieermagou formations in Tianjun, southern Qilian Mountains. Two new genera (Crenulatomargus, Tianjunospina) and six new species (Costirhynchopsis xui, Crenulatomargus terebratuliformis, Schwagerispira elegans, Lepismatina? inusitata, Tianjunospina junheensis, Qilianoconcha circularis) are erected. The diagnoses of Triasorhynchia, Yangkongia, Sinucostella, Aequspiriferina, Qilianoconcha and Parantiptychia are emended. Also, the genus Eoantiptychia and the family Triasorhynchiidae are regarded as junior synonyms of Qilianoconcha and Tetrarhynchiidae, respectively. After systematic description and taxonomic emendation, 56 species (including seven uncertain species) in 26 genera are confirmed in the southern Qilian brachiopod fauna. Network analysis of 14 brachiopod faunas worldwide shows that six groups were detected during the Anisian (Qingyan, southern Qilian – western Qinling, Himalaya – northern Siberia, central Qinghai, New Zealand, and Europe/western Tethys). Compared with those from the western Tethys, the eastern Tethyan faunas are less allied to each other. Except for the assemblage from the adjacent western Qinling area, other coeval faunas have much lower affinities with the Qilian fauna.

Karst Ecosystems of Middle Timan, Russia: Soils, Plant Communities, and Soil Oribatid Mites

Oribatid mites are distinguished by high taxonomic diversity and abundance in almost all natural zones; they are used as an indicator group of microarthropods in the study of natural landscapes and anthropogenically disturbed ecosystems. In the karst landscapes of the North, the oribatid mites are very poorly studied. The aim of this study was to investigate the diversity of soil types, plant communities, and oribatid mites in karst relief forms in the conditions of the northern taiga forests. The material was collected in July 2020 in the karst landscapes of Timan Ridge, found in the European northeast of Russia. The research sites were located in the profile of the karst crater and in the profile of the slope in the Ukhta River Valley. A sedge wetland community, and pine–bilberry–green-moss forest, located in the depression between glacial hills and uplands were also examined. A total of seven sites were examined. Geobotanical descriptions were made by standard methods, descriptions of the soil profile, and samples of the soil microfauna; 12 in each site were collected. A total of 51 oribatid mite species from 39 genera and 31 families were found. The highest taxonomic diversity of oribatids was noted in forest phytocenoses located in the upper part of the karst crater slope, the lower part of the karst crater slope, and on rock outcrops in the lower part of the slope in Ukhta river valley. Ordination of the oribatid mite community by NMDS method showed the association of sites S3, S4, and S5 located on the slope of the karst crater in one group, and sites S6 and S7 located on a slope in the Ukhta River Valley, as well as S2 (pine–bilberry–green-moss forest located in the depression between glacial hills and uplands), in another group. The swamp community was located separately from other communities. Species of oribatid mites, which created the specifics of each community, were noted. The specifics of the population of oribatid mites of karst landscapes were that along with the features of fauna, characteristic for zonal north-taiga forests (the predominance of polyzonal widespread species) were found the “conditionally southern” species, the main area of distribution of which is located in lower latitudes. The study provides the basis for future studies of poorly known oribatid mites of karst landscapes of Northern Europe.

High molecular diversity in the functional group of small bacterivorous non-scaled chrysomonad flagellates

“Spumella”-like flagellates describes similar or even indiscernible colourless non-scaled chrysophytes which are important bacterivores common in different aquatic ecosystems. Recently, phylogenetic analyses revealed a high taxonomic diversity of these flagellates leading to the description of several new genera and species. Our present work on the functional group of pelagic bacterivorous chrysomonads from different water bodies resulted in an extended taxonomic analysis among chrysophytes unveiling yet undescribed genera and species pointing to the high hidden diversity of bacterivores in the pelagial of freshwaters. On the basis of phylogenetic analyses, we describe four new genera Atacamaspumella, Chlorospumella, Pseudapoikia, and Vivaspumella and a new species of the recently described genus Poteriospumella. Beside this, we redescribe the species Ochromonas vasocystis Doflein, 1923 to Poteriospumella vasocystis comb. nov. substantiated on the high sequence similarity with Poteriospumella lacustris Boenigk et Findenig and Poteriospumella maldiviensis nov. sp.

Spatial patterns of macrobenthos taxonomic and functional diversity throughout the ecotones from river to lake: A case study in Northern China

Macrobenthos taxonomic and functional diversity are key indicators of ecosystem health. River–lake ecotones are key macrobenthos habitats. However, we don’t fully understand macrobenthos biodiversity patterns in these ecotones. We studied water environment, sediment heavy metal contents, and macrobenthos community, which we sampled simultaneously from 29 sampling sites along the Fu River–Baiyangdian Lake gradient in Northern China with five field surveys from 2018 to 2019. Six trait classes resolved into 25 categories were allocated to macrobenthos through a binary coding system. We used the RLQ framework (R, environmental variables; L, species of taxa; Q, traits) and fourth-corner analyses to evaluate the relationship between environmental variables and macrobenthos traits. Finally, we carried out variance partitioning to assess the contributions of environmental variables to variation of macrobenthos diversities. As the results, TN and TP contents in the river and lake mouths were lower than those in the adjacent river and lake, indicating that the river–lake ecotones played a role in purifying the water and buffering pollution. High taxonomic diversity of macrobenthos in the lake mouth and the presence of unique taxa in the two ecotones revealed edge effects, but the macrobenthos abundance and biomass were extremely low compared with those in the adjacent river and lake. We found no significant correlation between the taxonomic and functional diversity indices in the river and lake mouths. Water depth, water transparency, TN, and TP were the main water environmental drivers of macrobenthos taxonomic and functional diversity, explaining up to 45.5% and 56.2% of the variation, respectively. Sediment Cd, Cr, Cu, Pb, and Zn contents explained 15.1% and 32.8%, respectively, of macrobenthos taxonomic and functional diversity. Our results suggest that functional diversity approaches based on biological traits can complement taxonomic approaches in river–lake ecotones. Furthermore, improving water depth, transparency, eutrophication, and heavy metal pollution will improve macrobenthos diversity in these ecotones and maintain ecosystem health.

Community assessment of crustose calcifying red algae as coral recruitment substrates.

Successful recruitment of invertebrate larvae to reef substrates is essential to the health of tropical coral reef ecosystems and to their capacity to recover from disturbances. Crustose calcifying red algae (CCRA) are a species rich group of seaweeds that have been identified as important recruitment substrates for scleractinian corals. Most studies on the settlement preference of coral larvae on CCRA use morphological species identifications that can lead to unreliable species identification and do not allow for examining species-specific interactions between coral larvae and CCRA. Accurate identifications of CCRA species is important for coral reef restoration and management to assess CCRA community composition and to detect CCRA species that are favored as coral recruitment substrates. In this study, DNA sequence analysis, was used to identify CCRA species to (1) investigate the species richness and community composition of CCRA on experimental coral recruitment tiles and (2) assess if the coral Acropora surculosa preferred any of these CCRA species as recruitment substrates. The CCRA community assemblages on the coral recruitment tiles was species-rich, comprising 27 distinct CCRA species of the orders Corallinales and Peyssonneliales which constitute new species records for Guam. Lithophylloideae sp. 1 (Corallinales) was the CCRA species that was significantly favored by coral larvae as a recruitment substrate. Lithophylloideae sp. 1 showed to hold a valuable ecological role for coral larval recruitment preference. Lithophylloideae sp. 1 had the highest benthic cover on the recruitment tiles and contained most A. surculosa recruits. DNA barcoding revealed a high taxonomic diversity of CCRA species on a microhabitat scale and provided detailed insight into the species-specific ecological interactions between CCRA and corals. With a steady decline in coral cover, detailed information on species interactions that drive reef recovery is valuable for the planning of marine management actions and restoration efforts.

Soil Depth Significantly Shifted Microbial Community Structures and Functions in a Semiarid Prairie Agroecosystem.

The North American Great Plains cover a large area of the Nearctic ecozone, and an important part of this biome is semiarid. The sustainable intensification of agriculture that is necessary to produce food for an ever-increasing world population requires knowledge of the taxonomic and functional structure of the soil microbial community. In this study, we investigated the influence of soil depth on the composition and functions of the microbial communities hosted in agricultural soils of a semiarid agroecosystem, using metagenomic profiling, and compared them to changes in soil chemical and physical properties. Shotgun sequencing was used to determine the composition and functions of the soil microbial community of 45 soil samples from three soil depths (0–15 cm, 15–30 cm, and 30–60 cm) under different agricultural land use types (native prairie, seeded prairie, and cropland) in southwest Saskatchewan. Analysis of community composition revealed the declining abundance of phyla Verrucomicrobia, Bacteroidetes, Chlorophyta, Bacillariophyta, and Acidobacteria with soil depth, whereas the abundance of phyla Ascomycota, Nitrospirae, Planctomycetes, and Cyanobacteria increased with soil depth. Soil functional genes related to nucleosides and nucleotides, phosphorus (P) metabolism, cell division and cell cycle, amino acids and derivatives, membrane transport, and fatty acids were particularly abundant at 30–60 cm. In contrast, functional genes related to DNA and RNA metabolism, metabolism of nitrogen, sulfur and carbohydrates, and stress response were more abundant in the top soil depth. The RDA analysis of functional genes and soil physico-chemical properties revealed a positive correlation between phages and soil organic P concentrations. In the rooting zone of this semiarid agroecosystem, soil microbes express variable structural patterns of taxonomic and functional diversity at different soil depths. This study shows that the soil microbial community is structured by soil depth and physicochemical properties, with the middle soil depth being an intermediate transition zone with a higher taxonomic diversity. Our results suggest the co-existence of various microbial phyla adapted to upper and lower soil depths in an intermediate-depth transition zone.

Construction and Proactive Management Led to Tree Removals on an Urban College Campus

Urban trees in lawns and along streets are anthropogenically constructed systems, in that these tree communities are formed by human planting and removal actions. Tree mortality studies are essential to understanding the temporal dynamism of urban forests, and in particular, it is critical to incorporate institutional records and human decision-making regarding tree removals. In this study, we investigated tree removals on a highly urbanized college campus in Philadelphia, Pennsylvania (US) by analyzing field inventories and institutional records, and by considering firsthand accounts of the University Landscape Architect. The annual mortality rate was 4.3%, higher than typical for comparable studies, which we attribute to construction pressure and proactive management to promptly remove unhealthy trees and manage risk. Capital projects and other construction caused 48.5% of all removals, other human land use decisions caused 2.0%, and tree health decline and risk management collectively accounted for 48.7%. The number of removed trees exactly equaled the number of new trees, and the campus has high taxonomic diversity, reflecting the extensive oversight by university tree and landscape professionals regarding tree removal and planting decisions. This study demonstrates the value of mixed-methods and transdisciplinary research to understand how urban forests change over time.

Spatial organization of the soil macrofauna community in a floodplain forest

Soil fauna is an important functional component of terrestrial ecosystems. Several hierarchical levels of spatial organization of pedobionts communities can be distinguished: point level, ecosystem level and landscape level. Of particular importance is the ecosystem level of spatial organization where the results of interaction between soil animals and soil and plant environmental factors, as well as the results of the influence of factors of neutral nature are expressed to the greatest extent. The aim of the work is to test the hypothesis that the spatial patterns of soil macrofauna at the ecosystem level can be explained by ecomorphs. Soil animals were sampled in floodplain ecosystems in the Dnieper River valley. Animals were sampled according to a regular grid with recording of local coordinates of sampling points. At the same points, soil properties were measured and geobotanical descriptions of vegetation were made. Phytoindication assessment of environmental factors was carried out on the basis of vegetation descriptions. The soil animal community is represented by high taxonomic and ecological diversity. The spatial distribution of soil macrofauna is not random and is a consequence of environmental factors and causes of a neutral nature. The ratio of these factors varies depending on the scale level. The fine-scale level is represented by factors of neutral nature. Medium- and broad-scale components are determined by soil and vegetation factors. The main spatial patterns of variation in the soil animal community correlate with the ecomorphic features of the animals. The ecomorphic approach allows interpreting the information on the spatial organization of pedobionts communities.

Abundance and Diversity of Dimethylsulfoniopropionate Degradation Genes of Roseobacter Group in the Northern South China Sea

Bacterial degradation of dimethylsulfoniopropionate (DMSP) plays a significant role in ecosystem productivity and global climate. In this study, the abundance and diversity of Roseobacter group DMSP degradation genes were explored in spatial scale of the South China Sea (SCS). Quantitative PCR showed that a higher abundance of dmdA (DMSP demethylase) and dddP (DMSP lyase) genes was detected above 75 m than deep water, especially in surface water. A high ratio of dmdA/dddP existed in all sites and increased with water depth, indicating that demethylation was the main degradation pathway in the Roseobacter group. High-throughput sequencing analysis showed that distribution of dmdA gene had a significant layering structure in the northern SCS, and high taxonomic diversity of dmdA gene was observed in near-surface waters (25 and 50 m). DmdA gene in the Roseobacter group, such as Leisingera, Nioella, Roseobacter, Roseovarius, Donghicola, Phaeobacter, and Tateyamaria, had remarkable specificity due to the effect of different sites and water depths. Different ecological strategies of DMSP degradation may be used by members of the bacterial community harboring demethylation genes. In addition, many dmdA sequences were affiliated with unidentified bacteria, indicating that the SCS reserved high diversity of DMSP-degrading bacteria. Canonical correspondence analysis (CCA) suggested that temperature and depth were the most important factors to determine the taxonomic distribution of DMSP degradation genes in the Roseobacter group, as well as their abundance. This study highlighted the understanding of the role of Roseobacter group in DMSP degradation in the tropical ocean.

Cytobacts: Abundant and Diverse Vertically Seed-Transmitted Cultivation-Recalcitrant Intracellular Bacteria Ubiquitous to Vascular Plants

We have recently described ‘Cytobacts’ as abundant intracellular endophytic bacteria inhabiting live plant cells based on the observations with callus and cell suspension cultures of grapevine and other plant species with the origin ascribable to field explants. In this study, we investigated the prevalence of such cytoplasmic bacterial associations in field plants across different taxa, their cultivability, and the extent of taxonomic diversity and explored the possibility of their embryo-mediated vertical transmission. Over 100 genera of field plants were surveyed for ‘Cytobacts’ through bright-field live-cell imaging as per our previous experience using fresh tissue sections from surface-sterilized shoot-tissues with parallel cultivation-based assessments. This revealed widespread cellular bacterial associations visualized as copious motile micro-particles in the cytoplasm with no or sparse colony forming units (CFU) from the tissue-homogenates indicating their general non-cultivability. Based on the ease of detection and the abundance of ‘Cytobacts’ in fresh tissue sections, the surveyed plants were empirically classified into three groups: (i) motile bacteria detected instantly in most cells; (ii) motility not so widely observed, but seen in some cells; and (iii) only occasional motile units observed, but abundant non-motile bacterial cells present. Microscopy versus 16S-rRNA V3–V4 amplicon profiling on shoot-tip tissues of four representative plants—tomato, watermelon, periwinkle, and maize—showed high bacterial abundance and taxonomic diversity (11–15 phyla) with the dominance of Proteobacteria followed by Firmicutes/Actinobacteria, and several other phyla in minor shares. The low CFU/absence of bacterial CFU from the tissue homogenates on standard bacteriological media endorsed their cultivation-recalcitrance. Intracellular bacterial colonization implied that the associated organisms are able to transmit vertically to the next generation through the seed-embryos. Microscopy and 16S-rRNA V3–V4 amplicon/metagenome profiling of mature embryos excised from fresh watermelon seeds revealed heavy embryo colonization by diverse bacteria with sparse or no CFU. Observations with grapevine fresh fruit-derived seeds and seed-embryos endorsed the vertical transmission by diverse cultivation-recalcitrant endophytic bacteria (CREB). By and large, Proteobacteria formed the major phylum in fresh seed-embryos with varying shares of diverse phyla. Thus, we document ‘Cytobacts’ comprising diverse and vertically transmissible CREBs as a ubiquitous phenomenon in vascular plants.