Higher Taxa Richness Research Articles

Urban bryophyte floras of Spain: a meta-analysis

ABSTRACT Introduction Bryophytes constitute an important part of the unmanaged plant diversity of urban areas. They represent, directly and indirectly, an important food, shelter and microhabitat-engineering resource allowing the establishment of other organisms, thereby increasing the biodiversity of urban areas. However, their contribution to urban biodiversity is generally overlooked and poorly understood. Methods In this study, we compared pre-existing data from 23 Spanish urban bryophyte floras and used taxon accumulation curves and ordination analyses to reveal emergent patterns related to urban biodiversity in Spain. Key results The compilation of these 23 floras revealed 286 bryophytes represented in urban areas in peninsular Spain and the Balearic Islands, including 2.80% and 3.50% of taxa considered under some threat category at the European and Iberian scales, respectively. Taxon richness and diversity varied greatly across cities and were strongly affected by climatic characteristics and extension of the studied cities. Ordination analyses showed an alignment of the different floras with the geographical location of the cities. Eurosiberian (Atlantic) and eastern and southern cities showed a higher taxon richness compared with cities from central Spain, which showed taxon assemblies comprising the commonest and widespread taxa. We also found that taxon richness was influenced by methodological factors (i.e. sampling intensity and the time the study was done). Conclusions Our study results suggest a need for adequate sampling of habitat heterogeneity within the urban landscape and point to the contribution of bryological knowledge to our understanding of the biodiversity of urban areas.

Multi-decadal improvements in the ecological quality of European rivers are not consistently reflected in biodiversity metrics.

Humans impact terrestrial, marine and freshwater ecosystems, yet many broad-scale studies have found no systematic, negative biodiversity changes (for example, decreasing abundance or taxon richness). Here we show that mixed biodiversity responses may arise because community metrics show variable responses to anthropogenic impacts across broad spatial scales. We first quantified temporal trends in anthropogenic impacts for 1,365 riverine invertebrate communities from 23 European countries, based on similarity to least-impacted reference communities. Reference comparisons provide necessary, but often missing, baselines for evaluating whether communities are negatively impacted or have improved (less or more similar, respectively). We then determined whether changing impacts were consistently reflected in metrics of community abundance, taxon richness, evenness and composition. Invertebrate communities improved, that is, became more similar to reference conditions, from 1992 until the 2010s, after which improvements plateaued. Improvements were generally reflected by higher taxon richness, providing evidence that certain community metrics can broadly indicate anthropogenic impacts. However, richness responses were highly variable among sites, and we found no consistent responses in community abundance, evenness or composition. These findings suggest that, without sufficient data and careful metric selection, many common community metrics cannot reliably reflect anthropogenic impacts, helping explain the prevalence of mixed biodiversity trends.

Diversity, habitat endemicity and trophic ecology of the fauna of Loki’s Castle vent field on the Arctic Mid-Ocean Ridge

Loki’s Castle Vent Field (LCVF, 2300 m) was discovered in 2008 and represents the first black-smoker vent field discovered on the Arctic Mid-Ocean Ridge (AMOR). However, a comprehensive faunal inventory of the LCVF has not yet been published, hindering the inclusion of the Arctic in biogeographic analyses of vent fauna. There is an urgent need to understand the diversity, spatial distribution and ecosystem function of the biological communities along the AMOR, which will inform environmental impact assesments of future deep-sea mining activities in the region. Therefore, our aim with this paper is to provide a comprehensive inventory of the fauna at LCVF and present a first insight into the food web of the vent community. The fauna of LCVF has a high degree of novelty, with five new species previously described and another ten new species awaiting formal description. Most of the new species from LCVF are either hydrothermal vent specialists or have been reported from other chemosynthesis-based ecosystems. The highest taxon richness is found in the diffuse venting areas and may be promoted by the biogenic habitat generated by the foundation species Sclerolinum contortum. The isotopic signatures of the vent community of LCVF show a clear influence of chemosynthetic primary production on the foodweb. Considering the novel and specialised fauna documented in this paper, hydrothermal vents on the AMOR should be regarded as vulnerable marine ecosystems and protective measures must therefore be implemented, especially considering the potential threat from resource exploration and exploitation activities in the near future.

Comparison of Soil Arthropod Diversity and Community Structure in Various Types of Land Cover in Malang Region, East Java, Indonesia

Land cover heterogeneity can affect the structure of biodiversity in the supplied niche, so it is necessary to know the taxa community. This study aimed to understand the effect of land cover variation on the diversity and community structure of soil arthropods. The types of habitats used include urban areas, agroforestry, gardens, and natural forests which are determined in the Malang Region, East Java, Indonesia. Hand sorting and hay bait traps were applied in this study to obtain a variety of arthropod soils and the Berlese-Tullgren funnel was used to extract them. As a result, there are 25 families from 15 orders collected based on their ecological roles. The abundance of Philoscidae in sites S1 and S2 (urban green space), Talitridae in site S6 (agroforestry), and Isotomidae in sites S3, S4, and S5 (highland mixed forest) was highest and dominant. Site S7 has the highest diversity (H' = 2.56; 1-D = 0.90; J' = 0.76) even though its family richness is lower. The site S3 counter-site had relatively high taxa richness (TR = 13), but low diversity (H' = 1.02; 1-D = 0.39; J' = 0.16). Based on clustering analysis and NMDS ordination, 3 classifications of habitat types were obtained, namely I (S6 & S7), II (S3, S4 & S5), and III (S1 & S2). Mixed forest habitats contain a more complex diversity of soil arthropods, which can serve as a model for improving the fertility of disturbed ecosystems.

Crop wild relatives in Lebanon: mapping the distribution of Poaceae and Fabaceae priority taxa for conservation planning

Lebanon is a part of the Fertile Crescent recognized for its agrobiodiversity wealth in terms of both cultivated plants and crop wild relatives (CWR) diversity. Within the context of climate change and its adverse effect on agrobiodiversity, conservation of CWRs in Lebanon is essential to prevent the loss of potentially useful genetic diversity and to facilitate their use in crop breeding. To establish a comprehensive conservation plan for Lebanese CWR belonging to Poaceae and Fabaceae, in this study we prioritized 16 taxa based on their value for world security and local economy, gene pool (primary and secondary) and genome type (A, B and D for Triticum genera). Georeferenced occurrence data of populations belonging to the prioritized taxa list were retrieved from different sources and imported into QGIS to visualize by mapping their distribution in-situ and ex-situ on the Lebanese territory, highlighting sites with highest density per genus and sites characterised by the highest taxa richness. The analysis allowed to identify Lebanese areas that still need further surveying actions (mainly the south-west parts of the country) and showed that priority taxa had different distribution pattern independently from genus. Bekaa and Baalbak governorates were evaluated to include sites represented with highest taxa richness, which makes them preliminary contenders to be included within in-situ conservation actions. This study provided a foundation for further research into the conservation planning of crop wild relatives belonging to Poaceae and Fabaceae in Lebanon by identifying areas with highest taxa richness.

Seasonal Patterns of Phytoplankton Taxon Richness in Lakes: Effects of Temperature, Turnover and Abundance

Species richness is a key ecological characteristic that influences numerous ecosystem functions. Here we analyse the patterns and possible causes of phytoplankton taxon richness in seasonal datasets from twenty contrasting lakes in the English Lake District over six years and near-weekly datasets over 33years from Windermere. Taxon richness was lowest in winter and highest in summer or autumn in all of the lakes. Observed richness was very similar to richness estimated from coverage and sampling effort, implying that it closely reflected true seasonal patterns. Summer populations were dominated by Chlorophyta and functional groups X1, F, N and P (sensu Reynolds). In Windermere, weekly taxon richness was strongly positively correlated with surface water temperature, as was the number of functional groups and the number of taxa per functional group. Turnover in richness of taxa and functional groups were positively correlated and both were related to surface temperature. This suggests that high taxon richness in summer is linked to higher water temperature, promoting a turnover in richness of taxa and functional groups in these lakes. However, since the number of taxa per unit concentration of chlorophyll a decreased with increasing concentration of chlorophyll a, competition might occur when abundance is high.

Marginal lands and fungi - linking the type of soil contamination with fungal community composition.

SummaryFungi can be found in almost all ecosystems. Some of them can even survive in harsh, anthropogenically transformed environments, such as post‐industrial soils. In order to verify how the soil fungal diversity may be changed by pollution, two soil samples from each of the 28 post‐industrial sites were collected. Each soil sample was characterized in terms of concentration of heavy metals and petroleum derivatives. To identify soil fungal communities, fungal internal transcribed spacer 2 (ITS2) amplicon was sequenced for each sample using Illumina MiSeq platform. There were significant differences in the community structure and taxonomic diversity among the analysed samples. The highest taxon richness and evenness were observed in the non‐polluted sites, and lower numbers of taxa were identified in multi‐polluted soils. The presence of monocyclic aromatic hydrocarbons, gasoline and mineral oil was determined as the factors driving the differences in the mycobiome. Furthermore, in the culture‐based selection experiment, two main groups of fungi growing on polluted media were identified – generalists able to live in the presence of pollution, and specialists adapted to the usage of BTEX as a sole source of energy. Our selection experiment proved that it is long‐term soil contamination that shapes the community, rather than temporary addition of pollutant.

Microbial Dispersal, Including Bison Dung Vectored Dispersal, Increases Soil Microbial Diversity in a Grassland Ecosystem.

Microbial communities display biogeographical patterns that are driven by local environmental conditions and dispersal limitation, but the relative importance of underlying dispersal mechanisms and their consequences on community structure are not well described. High dispersal rates can cause soil microbial communities to become more homogenous across space and therefore it is important to identify factors that promote dispersal. This study experimentally manipulated microbial dispersal within different land management treatments at a native tallgrass prairie site, by changing the relative openness of soil to dispersal and by simulating vector dispersal via bison dung addition. We deployed experimental soil bags with mesh open or closed to dispersal, and placed bison dung over a subset of these bags, to areas with three different land managements: active bison grazing and annual fire, annual fire but no bison grazing, and no bison grazing with infrequent fire. We expected microbial dispersal to be highest in grazed and burned environments, and that the addition of dung would consistently increase overall microbial richness and lead to homogenization of communities over time. Results show that dispersal rates, as the accumulation of taxa over the course of the 3-month experiment, increase taxonomic richness similarly in all land management treatments. Additionally, bison dung seems to be serving as a dispersal and homogenization vector, based on the consistently higher taxon richness and increased community similarity across contrasting grazing and fire treatments when dung is added. This finding also points to microbial dispersal as an important function that herbivores perform in grassland ecosystems, and in turn, as a function that was lost at a continental scale following bison extermination across the Great Plains of North America in the nineteenth century. This study is the first to detect that dispersal and vector dispersal by grazing mammals promote grassland soil microbial diversity and affect microbial community composition.

Transitional and small aquatic cave habitats diversification based on protist assemblages in the Veternica cave (Medvednica Mt., Croatia)

Protists in caves are scarcely researched. Most cave studies address the diversity of protists, but very little is known about their habitats and spatio-temporal dynamics. The aim of this study was to investigate the diversity and abundance of protists in the Veternica cave in the Medvednica mountain in Croatia on hygropetric and sinter and clay pools during six months. During this study, 47 protists taxa were distinguished belonging to the groups of heterotrophic flagellates, ciliates, heliozoans, stramenopiles and testate and naked amoebae. The highest taxon richness was found at the sinter pool site richest in bats guano (36 taxa). Most diverse were testate amoebae and ciliates. The number of taxa and their abundance differed significantly between the sampling sites. The prospected habitats supported different protist assemblages, proved by ordination analysis. The most distinctive habitat was the hygropetric. Habitat heterogeneity could be attributed to the presence of inorganic and organic sediments at the sites and habitat microhydrology (lotic or lentic system). Kendall’s concordance coefficient showed a good synchronicity between the habitats in the Veternica cave, based on taxon richness and abundance of protists indicating similar seasonal trends. Seasonality in the studied habitats is attributed to the hydro-meteorological conditions in the Veternica cave drainage area. This study is one of the few studies of spatio-temporal diversity and abundance of protists in caves. Despite the similar appearance of small transitional and aquatic habitats in caves, an example of this study showed specific habitat diversification.

Wildland fire smoke alters the composition, diversity, and potential atmospheric function of microbial life in the aerobiome

The atmosphere contains a diverse reservoir of microbes but the sources and factors contributing to microbial aerosol variability are not well constrained. To advance understanding of microbial emissions in wildfire smoke, we used unmanned aircraft systems to analyze the aerosols above high-intensity forest fires in the western United States. Our results show that samples of the smoke contained ~four-fold higher concentrations of cells (1.02 ± 0.26 × 105 m−3) compared to background air, with 78% of microbes in smoke inferred to be viable. Fivefold higher taxon richness and ~threefold enrichment of ice nucleating particle concentrations in smoke implies that wildfires are an important source of diverse bacteria and fungi as well as meteorologically relevant aerosols. We estimate that such fires emit 3.71 × 1014 microbial cells ha−1 under typical wildfire conditions in western US forests and demonstrate that wildland biomass combustion has a large-scale influence on the local atmospheric microbial assemblages. Given the long-range transport of wildfire smoke emissions, these results expand the concept of a wildfire’s perimeter of biological impact and have implications to biogeography, gene flow, the dispersal of plant, animal, and human pathogens, and meteorology.

WOODY AND SEMI-WOODY PLANTS, WILD AND NATIVE TO DRY AND SEMI-HUMID FORESTS FROM THE ÁREA DE PROTECCIÓN DE FLORA Y FAUNA MESETA DE CACAXTLA, SINALOA, MÉXICO

<p><strong>Background. </strong>Plant catalogues are basic to propose and manage natural protected areas. Through those censuses plans and conservation strategies are developed, plus comparisons can be made over time. Updated floristic listings are urgent in tropical forests due to the threats to their biodiversity. <strong>Objective. </strong>Present a structured listing by family, genus and species, which quantifies the hierarchical relations of genera-species and family-genera while arranging life-forms and including species with endangered status recorded in national (NOM-059 SEMARNAT 2010) and international (Red list, UICN) legislation of woody and semi-woody plants from dry and semi-humid forest from the Área de Protección de Flora y Fauna Meseta de Cacaxtla, Sinaloa, México (APFFMC). <strong>Methodology. </strong>Published studies about the site were reviewed, selecting the indigenous species with secondary growth, excluding the invasive, naturalized, cultivated, ornamental ones, collating different online sites, specialized bibliography and consulting specialists. Regarding the nomenclature different sources and databases were employed. Through field trips, the presence of taxa was corroborated and new registers were included. The listing was sorted alphabetically. <strong>Results.</strong> 60 families, 223 genera and 389 species were recorded. Fabaceae was the family with the highest taxa richness, with 44 genera and 75 species, followed by Malvaceae (19/31), Euphorbiaceae (12/34), Asteraceae (10/17), Cactaceae (9/21) and Apocynaceae (8/10). A low number of 13 genera and 12 families gathered five or more species and genera respectively. On the other hand, a high quantity of 210 genera and 48 families presented four or less taxa. The most diverse genera were <em>Croton</em> (12 species), <em>Bursera</em> (8), <em>Solanum</em> (7), <em>Ficus</em> and <em>Randia</em> (6); <em>Opuntia</em>,<em> Merremia</em>, <em>Euphorbia</em>, <em>Lonchocarpus</em>, <em>Mimosa,</em> <em>Senna, Jatropha </em>and <em>Sideroxylon</em> (5). The tree category grouped 146 species, followed by shrub (114), sub-shrub (54), vine (51), succulent and semi-succulent (21) and parasitic (3). According to the NOM 059 SEMARNAT-2010 endangered species list, five species were included in the Amenazadas (A) category and two Sujetas a protección especial (Pr). The red list (UICN) comprehended 173 species for the Natural Protected Area (ANP). In the Least concern category (LC) 155 taxa were counted, Near threatened (NT) with four, Vulnerable (V) seven and Endangered (EN) again seven. <strong>Implications.</strong> A renewed listing of alien, native, woody and semi-woody species from dry and semi-humid forests of the APFFMC, is crucial for its contribution to a proper management and decision taking in the ANP. 94 taxa names were updated. At family level, the inclusion of Sterculiaceae into Malvaceae was the most significant change. <strong>Conclusions. </strong>The taxonomic richness concentrated inside the APFFMC, whose surface is inferior to 1% of the state, oscillates between 10.41 and 13.93% of the species; 19.95 and 22.80 % of the genera and 29.70 and 30% of the families reported in the state of Sinaloa, Mexico.</p>

Antarctic Hairgrass Rhizosphere Microbiomes: Microscale Effects Shape Diversity, Structure, and Function.

The rhizosphere microbiome of the native Antarctic hairgrass Deschampsia antarctica from the central maritime Antarctic was investigated using 16S RNA metagenomics and compared to those of the second native Antarctic plant Colobanthus quitensis and closely related temperate D. cespitosa. The rhizosphere microbial communities of D. antarctica and D. cespitosa had high taxon richness, while that of C. quitensis had markedly lower diversity. The majority of bacteria in the rhizosphere communities of the hairgrass were affiliated to Proteobacteria, Bacteroidetes, and Actinobacteria. The rhizosphere of C. quitensis was dominated by Actinobacteria. All microbial communities included high proportions of unique amplicon sequence variants (ASVs) and there was high heterogeneity between samples at the ASV level. The soil parameters examined did not explain this heterogeneity. Bacteria belonging to Actinobacteria, Bacteroidetes, and Proteobacteria were sensitive to fluctuations in the soil surface temperature. The values of the United Soil Surface Temperature Influence Index (UTII, Iti) showed that variations in most microbial communities from Galindez Island were associated with microscale variations in temperature. Metabolic predictions in silico using PICRUSt 2.0, based on the taxonomically affiliated part of the microbiomes, showed similarities with the rhizosphere community of D. antarctica in terms of the predicted functional repertoire. The results obtained indicate that these communities are involved in the primary processes of soil development (particularly the degradation of lignin and lignin-derived compounds) in the central maritime Antarctic and may be beneficial for the growth of Antarctic vascular plants. However, due to the limitations associated with interpreting PICRUSt 2.0 outputs, these predictions need to be verified experimentally.

The Gut Microbiota of Naturally Occurring and Laboratory Aquaculture Lytechinus variegatus Revealed Differences in the Community Composition, Taxonomic Co-Occurrence, and Predicted Functional Attributes

Sea urchins, in many instances, are collected from the wild, maintained in the laboratory aquaculture environment, and used as model animals for various scientific investigations. It has been increasingly evident that diet-driven dysbiosis of the gut microbiome could affect animal health and physiology, thereby impacting the outcome of the scientific studies. In this study, we compared the gut microbiome between naturally occurring (ENV) and formulated diet-fed laboratory aquaculture (LAB) sea urchin Lytechinus variegatus by amplicon sequencing of the V4 region of the 16S rRNA gene and bioinformatics tools. Overall, the ENV gut digesta had higher taxa richness with an abundance of Propionigenium, Photobacterium, Roseimarinus, and Flavobacteriales. In contrast, the LAB group revealed fewer taxa richness, but noticeable abundances of Arcobacter, Agarivorans, and Shewanella. However, Campylobacteraceae, primarily represented by Arcobacter spp., was commonly associated with the gut tissues of both ENV and LAB groups whereas the gut digesta had taxa from Gammaproteobacteria, particularly Vibrio spp. Similarly, the co-occurrence network displayed taxonomic organizations interconnected by Arcobacter and Vibrio as being the key taxa in gut tissues and gut digesta, respectively. Predicted functional analysis of the gut tissues microbiota of both ENV and LAB groups showed a higher trend in energy-related metabolisms, whereas amino acids, carbohydrate, and lipid metabolisms heightened in the gut digesta. This study provides an outlook of the laboratory-formulated diet-fed aquaculture L. variegatus gut microbiome and predicted metabolic profile as compared to the naturally occurring animals, which should be taken into consideration for consistency, reproducibility, and translatability of scientific studies.

Estimating aquatic invertebrate diversity in the southern Alps using data from Biodiversity Days

High biodiversity is a prerequisite for the integrity, stability, and functioning of global aquatic ecosystems, but it is currently subject to anthropogenic threats. Small freshwater bodies with high habitat diversity are essential to sustain regional biodiversity, but species inventory and biodiversity are largely overlooked, especially in mountainous regions. In the Italian Alps, obligate assessments of freshwater biota (e.g., for the European water framework directive, WFD) are usually done in larger rivers or lakes only, which is why many taxa from small freshwater habitats might have been overlooked so far. Here we summarize and discuss the efforts to record aquatic invertebrates within the framework of so-called "Biodiversity Days", organized since 2001 at 13 different sites located across the North Italian province of South Tyrol. These events with voluntary participation of scientists and naturalists from universities and environmental agencies led to the detection of 334 benthic invertebrate taxa in streams and lakes (mostly species or genus level), whereby higher taxa richness was found in streams. The overall hierarchy of species numbers within invertebrate orders or families corresponded to that of other Alpine regions (groups richest in taxa were Chironomidae and Trichoptera) and these Biodiversity Days contributed to biodiversity research of that region in detecting 167 additional taxa. Besides analyzing yearly gains in the regional taxa inventory, we predict that future surveys will lead to new discoveries of aquatic taxa for that province (i.e., current modeling estimates a regional inventory of more than 600 taxa). However, specific surveys in hitherto unconsidered habitats, such as morphologically modified or urban waters, might reveal even more taxa than currently estimated. Besides characterizing the invertebrate fauna of this region and providing a first reference list for future monitoring projects in the same region, this work demonstrates that such Biodiversity Days can contribute to biodiversity research.

Microhabitat distribution of aquatic oligochaete communities in the Western Balkans peat bog

AbstractPeat bog pools are rare and fragmented in the Western Balkans. Thus, aquatic macroinvertebrate diversity and the implications for microhabitat loss in these ecosystems are poorly known. Aquatic oligochaetes, widely used as indicators, were sampled using a benthos net in the largest and oldest Croatian bog, in four main water body types: a pond, a deep pool, a shallow pool and a ditch. As these microhabitats lack spatial replication both in the studied bog and in the region, we applied a nested study design with replicates sampled over time. We found a species‐rich aquatic oligochaete fauna, with 11 taxa recorded. Oligochaete communities were strongly affected by vegetation complexity and the morphology of bog water bodies, namely, their size and depth. As revealed by generalised linear mixed models (GLMMs), taxon richness and abundance were significantly higher in the ditch than in other water body types. This could be attributed to the vegetation complexity, supporting many different niches and providing allochthonous food supplies for oligochaetes. The various bog pools contribute to regional biodiversity and promote distinct patterns in the spatial distribution of oligochaetes. However, the predominance of ubiquitous oligochaetes, with high taxon richness, might indicate the degradation of the studied peat bog. This was further confirmed by the spread of vascular plants to the bog area and higher pH water values. All these warning signals suggest that hydro‐ecological conditions should be urgently improved in order to preserve communities in the bog studied.

Structure of aquatic macroinvertebrate communities in streams of a sub-basin in the Pampa Biome, Southern Brazil

The Piratinim River is located in the northwest of Rio Grande do Sul, and represents an important effluent from the Uruguay River, with streams located far from urbanized areas, in conditions similar to those of environmental integrity, but under the influence of agricultural activities. In this study, we aim at investigating the structure of the aquatic macroinvertebrate community in streams of the Piratinim river basin by observing both spatial and local scales. The sampling was carried out in six streams distributed in three regions (upper, middle and lower) of the basin, thus exploring its upstream, intermediate and downstream stretches, during spring and autumn. Macroinvertebrates were collected using aquatic dipnets and were identified at the family level; trophic-functional categories were established according to the classification adapted to the state of Paraná. The spatial and temporal variations of the groups and of the biotic attributes (density, richness, diversity and equitability) were subjected to Kruskal-Wallis non-parametric tests anda posterioriDunn’s tests. The abiotic variables were obtained to verify possible influence on the composition of the macroinvertebrate community, evaluated through a Canonical Correspondence Analysis. We sampled 11,564 macroinvertebrate individuals from 72 taxa, and found a predominance of the collector-filter trophic group. Abundance and richness were different between streams; the highest densities were found in the streams located in the upper region of the watershed (Chuní and Itú). The highest taxon richness was found in the lower region of the watershed (Guaracapa stream), and the lowest richness was found in the two streams for the intermediate region (Santana and Ximbocu). Diversity and equitability did not vary; temporal variations were not found. Canonical correspondence analysis explained 31.7% of the data variability. The main environmental variables that influenced macroinvertebrates distribution were temperature, electrical conductivity, dissolved oxygen, altitude and extension of the riparian forest. Seasonality and the longitudinal gradient along the basin represented determining factors for the structure and distribution of the macroinvertebrate community in the tributary streams of the Piratinim River.

Metabarcoding analysis of the bacterial succession during vermicomposting of municipal solid waste employing the earthworm Eisenia fetida

A culture-independent DNA metabarcoding analysis of the bacterial communities was carried out throughout a complete vermicomposting cycle of municipal solid waste material using the earthworm Eisenia fetida. 16S rRNA amplicons from the initial material (0 days), an intermediate (42 days), and a final stage (84 days) were sequenced in an Illumina NGS platform and compared. A steady increase in community diversity was observed corresponding to a 2.5-fold higher taxa richness and correspondingly risen values of the Shannon and Simpson ecological indexes and the evenness parameter. A total of 49,665 operational taxonomic units (OTUs) were counted. From the qualitative standpoint, a clear successional shift was observed with an initial community dominated by putatively plant-associated groups belonging to the Rhizobiales order within the Alphaproteobacteria class, regressively leaving the scores of relative abundance (RA) to the Firmicutes phylum and in particular to the Bacilli. Vermistabilization of municipal solid waste (MSW) increased (p < 0.001) the TKN and total P content in the final vermicompost, while pH, TOC, and C/N ratio declined (p < 0.001) in the process. Likewise, a progressive decrease was noticed in β-glucosidase, acid phosphatase, and urease activity while protease and dehydrogenase showed a slight increase, followed by a steep fall. A strong positive correlation was observed among the canonical functions of physico-chemical attributes and enzyme activities. The canonical correspondence analysis (CCA) revealed that significant families did not change on the temporal scale; however, their abundance was influenced by the abiotic environmental factors. In comparison to prior studies on vermicomposting that used different earthworm species (Eisenia andrei) and different substrates, results reflect a considerable degree of substrate specificity for the earthworm species used. The results offer clues to optimize the vermistabilization of MSW along with its potential use in agriculture, to foster improved levels of the circular economy.

Centers of endemism of freshwater protists deviate from pattern of taxon richness on a continental scale

Here, we analyzed patterns of taxon richness and endemism of freshwater protists in Europe. Even though the significance of physicochemical parameters but also of geographic constraints for protist distribution is documented, it remains unclear where regional areas of high protist diversity are located and whether areas of high taxon richness harbor a high proportion of endemics. Further, patterns may be universal for protists or deviate between taxonomic groups. Based on amplicon sequencing campaigns targeting the SSU and ITS region of the rDNA we address these patterns at two different levels of phylogenetic resolution. Our analyses demonstrate that protists have restricted geographical distribution areas. For many taxonomic groups the regions of high taxon richness deviate from those having a high proportion of putative endemics. In particular, the diversity of high mountain lakes as azonal habitats deviated from surrounding lowlands, i.e. many taxa were found exclusively in high mountain lakes and several putatively endemic taxa occurred in mountain regions like the Alps, the Pyrenees or the Massif Central. Beyond that, taxonomic groups showed a pronounced accumulation of putative endemics in distinct regions, e.g. Dinophyceae along the Baltic Sea coastline, and Chrysophyceae in Scandinavia. Many other groups did not have pronounced areas of increased endemism but geographically restricted taxa were found across Europe.

Culture Independent Diversity of Bacterial Communities Indigenous to Lower Altitude at Laohugou Glacial Environment

High-throughput sequencing approach of the 16S rRNA gene was employed to evaluate the bacterial diversity inhabit in melted water, snow, soil, and rocks samples at the lower altitudes of the Laohugou glacial environment. Bioinformatics tools were used to process millions of Illumina reads for alpha and beta diversities of bacterial communities. The diversity indices such as Chao, Shannon, and Simpson were different in the collected samples and solid samples (soil and rocks) showed higher taxon richness and evenness. Taxonomic diversity was unexpectedly higher and the major portion of sequences was assigned to Proteobacteria, Actinobacteria, and Acidobacteria. Higher variation in community structure was reported at the class level and Alphaproteobacteria was dominant. The solid niches were occupied by a higher number of phyla compared with liquid. The physicochemical variables acted as spatial gradients and associated with the bacterial structural communities of the glacial ecosystem. Findings showed that both Proteobacteria and Actinobacteria in solid samples influenced the bacterial community structure in downstream liquid samples. Interestingly, the metagenomic biomarkers were higher in liquid samples. This study provides precious datasets to understand the bacterial community in a better way under the influence of spatial, physical and environmental factors.

Benthic macroinvertebrate assemblages of a stream-lake network in the upper zone of the trans-Andean basin of the Valdivia River (Chile)

ABSTRACT Stream-lake networks include multiple transition zones between lake-like and river-like conditions. This study analysed environmental features, macroinvertebrate assemblages (MIB) and functional feeding groups in outlet, inlet and tributary streams (i.e. streams other than the main stem) of a stream-lake network in Chilean Andean lakes, to verify if lake outlets reflect an ecotone condition. Permutational analysis of variance and canonical analysis of principal coordinates based on environmental features and MIB revealed a significant difference between stream types. Higher taxa richness was found in tributaries, whereas population densities, equitability and diversity indices varied between stream types. Eighty-five taxa were identified, with 7% of taxa found exclusively in outlets, 5% in inlets, and 22% in tributaries. Collector-gatherers were dominant in all stream types and there was no statistical differences among feeding groups and stream types. The distance-based linear model identified water temperature, % rock, % sand, and % FPOM coverage as having significant influence on richness and density of MIB in summer, while water temperature and %FPOM coverage were significant in spring. Our results suggest that lake outlets house MIB different than lake inlets and tributaries, as well as environmental variables, supporting the idea that Andean lake outlets reflect an ecotone condition.