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Forest ground vegetation may serve as an early warning system for monitoring anthropogenic global-change impacts on temperate forests. Climate warming may induce a decline of cool-adapted species to the benefit of more thermophilous plants. Nitrogen deposition has been documented to potentially result in soil eutrophication or acidification, which can increase the proportion of species with higher nutrient requirements and species impoverishment caused by competitive exclusion. Abiotic forest disturbances are changing the light conditions in the forest understorey environment. In this resurvey study, we tested the magnitude and direction of change in alpha (species richness) and beta (within-site dissimilarity) diversity and composition of forest ground vegetation in forests of different types in Slovenia over fifteen years. Using plant-derived characteristics (Ellenberg-type indicator values) and by testing a priori predictions concerning expected effects of environmental drivers, we show that the magnitude and direction of forest ground vegetation diversity and floristic changes varies greatly between forest sites. Divergent responses at different sites resulted in low net change of alpha and beta diversity and a weak overall environmental signal. The largest decrease in species number was observed in lowland oak-hornbeam forests, which were also among the sites with the greatest compositional shifts. Changes in beta diversity did not show any consistent trend, and anticipated floristic convergence was not confirmed when all sites were considered. Thermophilization was mainly detected in montane beech sites and alpine spruce forests whereas eutrophication signal was most significant on nutrient-poor sites. Vegetation responses were strongly dependent on initial site conditions. Shrinkage of ecological gradients (process of ecological homogenization) suggests that sites positioned at the ends of the gradients are losing their original ecological character and are becoming more similar to mid-gradient sites that generally exhibit smaller changes. Our results point to the importance of local stand dynamics and overstorey disturbances in explaining the temporal trends in forest ground vegetation. Ground vegetation in Slovenian forests is changing in directions also dictated by multiple regional and global change drivers. [ABSTRACT FROM AUTHOR]

Ecological study on plant diversity and soil characteristics of two contrasting sites (Prosopis juliflora-invaded and non-invaded) in Hastinapur Wildlife Sanctuary was undertaken to understand the structure of vegetation and soils and implication of exotic dominance in a dry tropical region of India. Seasonal floristic composition was recorded for one year through monthly visits. Phytosociological study of the two sites in each of three seasons was carried out by sampling a total of 120 quadrats (each 1mx1m, n= 20×3×2). Plant species density and abundance was estimated for both sites in each season. Seasonal surface soil (0-10 cm) samples were analyzed for soil pH, moisture content, organic C, and total N. Species occurrences and their relative abundance data were used to estimate alpha and beta diversity. A total of 76 plant species from 29 families were recorded (Malvaceae, Fabaceae and Asteraceae being top dominants). Maximum flora was recorded in rainy season at both sites, higher at non-invaded sites in all seasons. Beta diversity followed similar trend, higher in rainy season and at non-invaded than invaded sites, highest being 13.2 at non-invaded site in rainy season. Dominants changed with site and season. Vegetation patches were distinct in drier seasons compared to rainy months. Soil organic carbon, total nitrogen and C : N ratios were high at invaded sites compared to non-invaded sites except in summer season. While higher diversity and higher similarity amongst different sites in rainy season indicated a homogenization impact in Indian dry tropical regions, higher diversity at non-invaded site suggested implication of diversity-reducing impact of tree invader Prosopis juliflora. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that bioclimatic conditions affect the species richness, abundance, and diversity of sand flies in neighboring physiographic regions with endemic transmission of cutaneous leishmaniasis. A sampling program was performed in southeastern Mexico in the High Plateau of Chiapas and the Eastern Mountains physiographic regions, between April 2009 and March 2011. CDC light traps were placed in five randomly selected houses, four CDC traps in four transects in the surrounding vegetation zones, and a modified Magoon trap baited with one protected person was installed at the periphery of the villages at each study site. A total of 12,349 sand flies were identified as species, of which 98.2% were collected in the Eastern Mountains and the rest in the High Plateau of Chiapas. The Eastern Mountains region recorded a significantly higher diversity (H' = 2.04), with a species richness of 27 sand flies species and a higher evenness index (J´ = 0.62) compared to the High Plateau of Chiapas region (H' = 1.02, S = 10, J´ = 0.31). Psychodopygus panamensis (Shannon) (Diptera: Psychodidae) and Pintomyia (Pifanomyia) ovallesi (Ortiz) were the most abundant species in the Eastern Mountains, whereas Lutzomyia (Tricholateralis) cruciata (Coquillett) was most abundant in the High Plateau of Chiapas. We conclude that the differences in species richness, diversity, and abundance of sand flies between these two physiographic regions are due to the bioclimatic effects that in the Eastern Mountains are favorable for the formation of microhabitats due to the warm-warm conditions and the humid-temperate conditions which act as limiting factors in the High Plateau of Chiapas region. In addition, changes in land use due to anthropogenic activities significantly affected the structure of sand fly communities in both regions. [ABSTRACT FROM AUTHOR]

Context: In residential landscapes, people acknowledge and manage larger, conventionally attractive plants differently than smaller, less conspicuous ones, possibly leading to a divergence in basic ecological patterns such as diversity-area relationships. Objectives: We tested for divergences between lawn and non-lawn plants, and compared perceived and actual species richness in residential yards. We hypothesized that: (1) homeowner perception of plant species richness is more related to the actual species richness of non-lawn plants than lawn plants, and (2) alpha diversity will increase more rapidly, and beta diversity will decrease less rapidly for non-lawn plants than lawn plants with increasing spatial scale. Methods: We recorded all plant species in four 5 × 5 m plots in the front and back yards of 30 residences within four neighborhoods of Gainesville, Florida, United States (N = 238 plots). We also surveyed residents regarding perceived plant species richness in their yards. Results: We detected 386 non-lawn and 140 lawn species. Perceived plant species richness was positively related to non-lawn species richness and negatively related to lawn species richness, suggesting perception of species richness largely reflected that of non-lawn plants. Alpha diversity increased more rapidly, while beta diversity decreased less rapidly, for non-lawn plants than lawn plants with increasing spatial scale, although lawns had more species within individual yards. Conclusions: Findings revealed a divergence in diversity-area relationships between different plant groups in residential landscapes. We should consider the ecological implications of unrecognized plant diversity, particularly in residential lawns, where management often strives to limit plant species richness. [ABSTRACT FROM AUTHOR]

Host-microbe dynamics are of increasing interest in marine research due to their role in host health and productivity. Changes in the shell microbiome of American lobsters have been associated with epizootic shell disease, a syndrome that is spreading northwards across the eastern U.S. and Canadian Atlantic coast. This study analyzed differences in alpha and beta diversity, as well as differentially abundant taxa, in the shell-associated bacterial community of apparently healthy lobsters from four lobster fishing areas (LFAs) in Atlantic Canada. Over 180 lobsters from New Brunswick, Nova Scotia and Prince Edward Island (PEI) were sampled during seven sampling events over four sampling months. The bacterial community was identified using novel PacBio long-read sequencing, while alpha and beta diversity parameters were analyzed using linear regression models and weighted UniFrac distances. The bacterial richness, diversity and evenness differed by sampling location, sampling month, and molt stage, but not by lobster sex or size, nor sampling depth. Similarly, based on LFA, sampling month, year and lobster molt stage, the shell microbiome differed in microbial community composition with up to 34 out of 162 taxa differing significantly in abundance between sampling groups. This large-scale microbial survey suggests that the shell microbial diversity of apparently healthy lobsters is influenced by spatial and temporal factors such as geographic location, as well as the length of time the carapace is exposed to the surrounding seawater. [ABSTRACT FROM AUTHOR]

Host-microbe dynamics are of increasing interest in marine research due to their role in host health and productivity. Changes in the shell microbiome of American lobsters have been associated with epizootic shell disease, a syndrome that is spreading northwards across the eastern U.S. and Canadian Atlantic coast. This study analyzed differences in alpha and beta diversity, as well as differentially abundant taxa, in the shell-associated bacterial community of apparently healthy lobsters from four lobster fishing areas (LFAs) in Atlantic Canada. Over 180 lobsters from New Brunswick, Nova Scotia and Prince Edward Island (PEI) were sampled during seven sampling events over four sampling months. The bacterial community was identified using novel PacBio long-read sequencing, while alpha and beta diversity parameters were analyzed using linear regression models and weighted UniFrac distances. The bacterial richness, diversity and evenness differed by sampling location, sampling month, and molt stage, but not by lobster sex or size, nor sampling depth. Similarly, based on LFA, sampling month, year and lobster molt stage, the shell microbiome differed in microbial community composition with up to 34 out of 162 taxa differing significantly in abundance between sampling groups. This large-scale microbial survey suggests that the shell microbial diversity of apparently healthy lobsters is influenced by spatial and temporal factors such as geographic location, as well as the length of time the carapace is exposed to the surrounding seawater.

The use of nanoparticles, such as titanium dioxide (TiO2-NPs), has increased substantially over the years. Some of them will end up in the soil, where their effect on plants and the soil bacterial community needs to be studied to determine their possible environmental risks. In this paper, beans (Phaseolus vulgaris L.) were cultivated in soil with 0, 150, or 300 mg TiO2-NPs kg−1. Plant development, nodule formation, chlorophyl content, and the bacterial community were monitored in uncultivated, non-rhizosphere, and rhizosphere soils. TiO2-NPs did not affect the beans' growth and their chlorophyl content, but they did increase bacterial diversity and had a significant effect on the bacterial community structure in the rhizosphere, but not in the bulk and non-rhizosphere soil. Although the relative abundance of most bacterial groups varied with the TiO2-NP application rate, the cultivation of the bean plants, or the exposure time, that of Acidobacteria decreased, while that of Planctomycetes increased in the TiO2-NP-amended soil. Many bacterial groups were affected by the cultivation of the bean plants, i.e., the relative abundance of Acidobacteria, Gemmatimonadetes, Deltaproteobacteria, and Firmicutes mostly decreased in the rhizosphere independent of the application of TiO2-NPs or the time of exposure, while most groups belonging to Actinobacteria, Bacteroidetes, Rhizobiaceae, Phyllobacteriaceae, and Sphingomonadaceae were enriched. [ABSTRACT FROM AUTHOR]

Introduction: The well-known eastern Asian (EA) and eastern North American (ENA) floristic disjunction provides a unique system for biogeographic and evolutionary studies. Despite considerable interest in the disjunction, few studies have investigated the patterns and their underlying drivers of allopatric divergence in sister species or lineages isolated in the two areas. Endophyte diversity and assembly in disjunct sister taxa, as an ecological trait, may have played an important role in the processes of allopatric evolution, but no studies have examined endophytes in these lineages. Here we compared foliar endophytic fungi and bacteria-archaea (FEF and FEB) in 17 EA-ENA disjunct species or clade pairs from genera representing conifers and 10 orders of five major groups of angiosperms and 23 species of Cornus from EA and North America. Methods: Metagenomic sequencing of fungal ITS and bacterial-archaeal 16S rDNA was used to capture the foliar endophytic communities. Alpha and beta diversity of fungi and bacteria were compared at multiple scales and dimensions to gain insights into the relative roles of historical geographic isolation, host identity, phylogeny, and environment from samples at different sites in shaping endophytic diversity patterns. Results: We found that beta diversity of endophytes varied greatly among plant individuals within species and between species among genera at the same sampling site, and among three sampling sites, but little variation between region-of-origin of all plant species (EA vs ENA) and between EA-ENA disjunct counterparts within genera. Various numbers of indicator fungal species differing in abundance were identified for each plant genus and Cornus species. An overall significant correlation between endophyte community dissimilarity and phylogenetic distance of plants was detected among the disjunct genera but not among species of Cornus. However, significant correlations between beta diversities at different taxonomic scales of endophytes and phylogenetic distances of Cornus species were observed. Discussion: Our results suggest important roles of host identity and environment (sampling sites), and a likely minor role of phylogenetic divergence and historical biogeographic isolation in shaping the pattern of foliar endophyte diversity and assembly in the EA-ENA disjunct genera and Cornus. The results lead to a hypothesis that the sister taxa in EA and ENA likely differ in FEF and FEB when growing in native habitats due to differences in local environments, which may potentially drive allopatric divergence of the functional features of species. [ABSTRACT FROM AUTHOR]

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ABSTRACT Temperature, pH, and hydrochemistry of terrestrial hot springs play a critical role in shaping thermal microbial communities. However, the interactions of biotic and abiotic factors at this terrestrial-aquatic interface are still not well understood on a global scale, and the question of how underground events influence microbial communities remains open. To answer this, 11 new samples obtained from the El Tatio geothermal field were analyzed by 16S rRNA amplicon sequencing (V4 region), along with 191 samples from previous publications obtained from the Taupo Volcanic Zone, the Yellowstone Plateau Volcanic Field, and the Eastern Tibetan Plateau, with their temperature, pH, and major ion concentration. Microbial alpha diversity was lower in acid-sulfate waters, and no significant correlations were found with temperature. However, moderate correlations were observed between chemical parameters such as pH (mostly constrained to temperatures below 70°C), SO4 2− and abundances of members of the phyla Armatimonadota, Deinococcota, Chloroflexota, Campilobacterota, and Thermoplasmatota. pH and SO4 2− gradients were explained by phase separation of sulfur-rich hydrothermal fluids and oxidation of reduced sulfur in the steam phase, which were identified as key processes shaping these communities. Ordination and permutational analysis of variance showed that temperature, pH, and major element hydrochemistry explain only 24% of the microbial community structure. Therefore, most of the variance remained unexplained, suggesting that other environmental or biotic factors are also involved and highlighting the environmental complexity of the ecosystem and its great potential to test niche theory ecological associated questions. IMPORTANCE This is the first approach to investigate whether geothermal processes could have an influence on the ecology of thermal microbial communities on a global scale. In addition to temperature and pH, microbial communities are structured by sulfate concentrations, which depends on the tectono-magmatic settings (such as the depth of magmatic chambers) and the local settings (such as the availability of a confining layer separating NaCl waters from steam after phase separation) and the possibility of mixing with more diluted fluids. Comparison of microbial communities from different geothermal areas by homogeneous sequence processing showed that no significant geographic distance decay was detected on the microbial communities according to Bray-Curtis, Jaccard, unweighted, and weighted Unifrac similarity/dissimilarity indices. Instead, an ancient potential divergence in the same taxonomic groups is suggested between globally distant thermal zones.

Background: The production of red fruits, such as blueberry, has been threatened by several stressors from severe periods of drought, nutrient scarcity, phytopathogens, and costs with fertilization programs with adverse consequences. Thus, there is an urgent need to increase this crop's resilience whilst promoting sustainable agriculture. Plant growth-promoting microorganisms (PGPMs) constitute not only a solution to tackle water and nutrient deficits in soils, but also as a control against phytopathogens and as green compounds for agricultural practices. Methods: In this study, a metagenomic approach of the local fungal and bacterial community of the rhizosphere of Vaccinium corymbosum plants was performed. At the same time, both epiphytic and endophytic microorganisms were isolated in order to disclose putative beneficial native organisms. Results: Results showed a high relative abundance of Archaeorhizomyces and Serendipita genera in the ITS sequencing, and Bradyrhizobium genus in the 16S sequencing. Diversity analysis disclosed that the fungal community presented a higher inter-sample variability than the bacterial community, and beta-diversity analysis further corroborated this result. Trichoderma spp., Bacillus spp., and Mucor moelleri were isolated from the V. corymbosum plants. Discussion: This work revealed a native microbial community capable of establishing mycorrhizal relationships, and with beneficial physiological traits for blueberry production. It was also possible to isolate several naturally-occurring microorganisms that are known to have plant growth-promoting activity and confer tolerance to hydric stress, a serious climate change threat. Future studies should be performed with these isolates to disclose their efficiency in conferring the needed resilience for this and several crops. [ABSTRACT FROM AUTHOR]

Purpose: Understanding the impact of neighbor tree diversity on soil biodiversity at the individual tree scale and clarifying which facets of neighbor tree diversity have a decisive impact on soil biodiversity. Methods: We collected and identified soil nematodes underneath 256 individual trees of 16 species at four species-richness levels (1, 2, 4, 8 species) in a large tree diversity experiment in southeast China. We analyzed how the taxonomic, phylogenetic, and functional diversity of the nematode community were influenced by neighbor tree diversity. Results: Our analyses showed that nematode alpha diversity at the individual tree scale decreased with increasing neighbor tree richness while beta diversity increased at taxonomic, phylogenetic, and functional levels. Nematode alpha diversity at the plot scale increased with increasing neighbor tree richness. Secondly, we found that reducing redundant species and increasing distinct species led to the differentiation of nematode communities under different individual trees in high-richness plots. Finally, our data revealed that the functional diversity of the neighbor tree community had the largest effects on the diversity of the local nematode community. Conclusion: Our study emphasizes that there is a significant influence from neighboring trees, mainly the functional traits of the trees, even though they are spaced at distances multitudes greater than the distance over which soil nematodes can move. Hence it is important to consider these broader spatial aspects when examining the plant and soil biotic interactions. [ABSTRACT FROM AUTHOR]

Understanding patterns and driving factors of freshwater fish biodiversity in metacommunities is essential for biological conservation but rarely studied in regions experiencing rapid land use changes. We examined changes of both alpha and beta fish diversities in taxonomic, functional, and phylogenetic facets during the 1980 s to 2010 s, and quantified contributions from natural and human drivers in lakes located in China's fastest economic development region. Results showed that almost all indices of alpha and beta diversity decreased through time. For alpha diversity, taxonomic and functional richness declined by 13 to 15%. Rheophilic and piscivorous fish species declined by 50 and 36%, respectively. For beta diversity, the decline of overall functional (-31%) diversity was greater than taxonomic (-17%) and phylogenetic (-19%) diversity. The decline of multiple facets of beta diversity indicated that fish communities in these lakes have homogenized through time. Land use (i.e., increased urban land and aquaculture ponds), hydrology (i.e., increased water level), climate (i.e., increased air temperature), and fishing (i.e., increased lake fishery catch) factors all made significant contributions to both alpha and beta fish diversity decline in multiple facets. The overall contribution from land use to the decline of multidimensional fish diversity was greater than those of other stressors. While attention should be given to both local human disturbance and regional climate factors, in regions experiencing rapid economic development and land use changes, local disturbances should be considered as a priority in biodiversity management plans.

Backgorund The production of red fruits, such as blueberry, has been threatened by several stressors from severe periods of drought, nutrient scarcity, phytopathogens, and costs with fertilization programs with adverse consequences. Thus, there is an urgent need to increase this crop’s resilience whilst promoting sustainable agriculture. Plant growth-promoting microorganisms (PGPMs) constitute not only a solution to tackle water and nutrient deficits in soils, but also as a control against phytopathogens and as green compounds for agricultural practices. Methods In this study, a metagenomic approach of the local fungal and bacterial community of the rhizosphere of Vaccinium corymbosum plants was performed. At the same time, both epiphytic and endophytic microorganisms were isolated in order to disclose putative beneficial native organisms. Results Results showed a high relative abundance of Archaeorhizomyces and Serendipita genera in the ITS sequencing, and Bradyrhizobium genus in the 16S sequencing. Diversity analysis disclosed that the fungal community presented a higher inter-sample variability than the bacterial community, and beta-diversity analysis further corroborated this result. Trichoderma spp., Bacillus spp., and Mucor moelleri were isolated from the V. corymbosum plants. Discussion This work revealed a native microbial community capable of establishing mycorrhizal relationships, and with beneficial physiological traits for blueberry production. It was also possible to isolate several naturally-occurring microorganisms that are known to have plant growth-promoting activity and confer tolerance to hydric stress, a serious climate change threat. Future studies should be performed with these isolates to disclose their efficiency in conferring the needed resilience for this and several crops.

Freshwaters are among the most vulnerable ecosystems to climate warming, with projected temperature increases over the coming decades leading to significant losses of aquatic biodiversity. Experimental studies that directly warm entire natural ecosystems in the tropics are needed, for understanding the disturbances on aquatic communities. Therefore, we conducted an experiment to test the impacts of predicted future warming on density, alpha diversity, and beta diversity of freshwater aquatic communities, inhabiting natural microecosystems—Neotropical tank bromeliads. Aquatic communities within the tanks bromeliads were experimentally exposed to warming, with temperatures ranging from 23.58 to 31.72°C. Linear regression analysis was used to test the impacts of warming. Next, distance‐based redundancy analysis was performed to assess how warming might alter total beta diversity and its components. This experiment was conducted across a gradient of habitat size (bromeliad water volume) and availability of detrital basal resources. A combination of the highest detritus biomass and higher experimental temperatures resulted in the greatest density of flagellates. However, the density of flagellates declined in bromeliads with higher water volume and lower detritus biomass. Moreover, the combination of the highest water volume and high temperature reduced density of copepods. Finally, warming changed microfauna species composition, mostly through species substitution (βrepl component of total beta‐diversity). These findings indicate that warming strongly structures freshwater communities by reducing or increasing densities of different aquatic communities groups. It also enhances beta‐diversity, and many of these effects are modulated by habitat size or detrital resources. [ABSTRACT FROM AUTHOR]

Understanding contributions of different environmental drivers to the structure and function of river biota is critical for biodiversity and environmental conservation. Yet, there is no consensus on which drivers have the greatest impact on fish diversity, especially in watersheds disturbed by multiple human activities. Fish taxonomic, phylogenetic, and functional diversity at both alpha and beta dimensions and their environmental drivers were studied in a total of 84 river sites from three watersheds, Huai River watershed (HRW), Sui River watershed (SRW), and Yishusi River watershed (YRW) in the Eastern Huai River Basin of China. Results showed that rivers in the three watersheds had no significant difference in both taxonomic and functional alpha diversity. Rivers in the HRW had significantly higher phylogenetic alpha diversity. For taxonomic and phylogenetic beta diversity, the overall beta diversity and turnover component were significant higher in the HRW. For functional beta diversity, the overall beta diversity was significantly lower in the HRW. Multiple linear regression (MLR) and redundancy analysis (RDA) showed that local (e.g., nutrients, dissolved oxygen, river width, transparency), regional (e.g., wetland), climate (e.g., temperature), and spatial variables structured alpha and beta fish diversity. Variation partitioning analysis indicated that the pure contributions of local and spatial variables were more important than that of climate and regional variables, which suggested that spatial effects and local environmental filtering were the main factors driving the beta diversity of fish assemblages in these rivers. The current study highlights the importance of considering multidimensional diversity and multiple environmental factors for conserving river fishes. [ABSTRACT FROM AUTHOR]

Microorganisms play as fundamental contributors to maintain hosts' fitness, which can be shaped by external environment. Moreover, symbiotic microbiome also varied within species (e.g., between sexes and developmental stages). However, we still need more studies to quantify whether the intraspecific variation patterns of symbiotic microbes can be modified with the change of environment. The Chinese giant salamander (CGS; Andrias davidianus) is a Critically Endangered species. Despite quantitative captive bred individuals were released to rebuild wild populations, the effectiveness is limited. More importantly, no studies have revealed the adaptation of released CGSs to the complex field conditions. In the present study, we explored whether reintroduction can reshape the intraspecific variations of symbiotic microbiota in captive bred CGSs using high-throughput amplicon sequencing of the16S rRNA gene. We found no significant difference of symbiotic microbiome in captive bred males and females, but released males and females differed significantly in skin microbiome. Juveniles had higher diversity of microbial symbiont than adults in hatchery, but lower diversity in field. Moreover, dominant bacterial taxa differed between juveniles and adults in both hatchery and field. Importantly, this symbiotic microbiome variations within species can be modified (alpha and beta diversity, and community composition) when captive bred individuals were released to the field. Overall, we observed a lower alpha diversity and higher relative abundance of Chryseobacterium, Plesiomonas, and Acinetobacter in the bacterial community of captive bred individuals. Instead, higher alpha diversity of symbiotic microbiota and higher relative abundance of S24-7 and Lactobacillus was detected in released individuals. These modifications may associate with the change of living environment, as well as the specific behavior within CGSs (e.g., movement patterns and foraging activities). Future studies can incorporate other approaches (e.g., blood physiology) to better evaluate the growth and health of reintroduced CGSs. [ABSTRACT FROM AUTHOR]

Beetles of the subfamily Scarabaeinae are commonly used as ecological indicators in studies about the effects of environmental changes. We analyzed the influence of the type of habitat, vegetation, mammals (as food resource), and temperature on dung beetle metacommunities in subtropical native forests and Pinus monocultures to evaluate the factors driving these assemblages. In the summer of 2018/2019, we sampled 12 areas in Southern Brazil, six Pinus monocultures and six native forests. We performed a dispersal test, applying a marking-recapture method. Some recaptures occurred in different habitats, showing low dispersal between habitats. We recorded behavioral activities confirming the use of both native forest and Pinus areas. The metrics did not reflect the difference in the environmental quality of the areas regarding species richness and diversity in different habitats. This shows that these metrics are not the best when using dung beetle assemblages as ecological indicators of biodiversity loss resulting from land-use changes, requiring complementing the analysis with composition analysis methods. When we partitioned beta diversity between habitats, we observed a dissimilarity between Pinus monocultures and native forest assemblages due to species substitution, with many species contributing to the dissimilarity between habitats. In our structural equation models, the influence of environmental factors on metacommunities showed no predictor related to dung beetle richness, but several variables influenced their abundance.

Fire modifies the composition and distribution of biodiversity, but the availability of broad elevational gradients for evaluating its effects is limited. Studies conducted along elevational gradients provide valuable insights into the impacts of large-scale disturbances. Due to their sensitivity to environmental changes and low palatability to invasive herbivores, bryophytes serve as effective bioindicators for analyzing disturbance levels in oceanic island ecosystems where herbivores have been introduced. Our research focused on examining how α and β diversity and bryophyte species composition change along an elevational gradient from 200 to 2000 m a.s.l. in areas affected by fire 20 years ago compared to control areas that have been fire-free for at least 50 years. This study was carried out using different functional bryophyte groups in the pine forest of La Palma Island (Canary Islands), where this ecosystem is well represented. The findings revealed the sensitivity of the Canarian pine forest ecosystem to fire. Pine forest areas burnt 20 years ago were significantly poorer in bryophyte species than those in areas free from fire for at least 50 years. α-diversity is proposed as the most indicative parameter for analyzing the impacts of fire on the studied functional groups along the entire gradient analyses. However, β-diversity is more dependent on environmental conditions, increasing in the wettest pine forests. The results suggest that the fire impacts vary depending on the specific functional group of bryophytes and the type of pine forest. • Bryophyte functional groups' responses to fire are studied in Canarian pine forests. • Fire modifies the richness, cover, diversity, and species composition of bryophytes. • Fire effects vary along the elevational gradient according to each functional group. • α-diversity is the most indicative parameter for analyzing the impacts of fire. • β-diversity is highly dependent on moisture, increasing in the wettest areas. [ABSTRACT FROM AUTHOR]

Understanding how human‐modified landscapes affect the phylogenetic composition and assembly mechanisms of biological communities is critical for effectively managing and restoring tropical ecosystems. We evaluated how forest coverage loss, fragmentation and landscape heterogeneity affect the phylogenetic diversity of dung beetles and their assembly mechanisms in Los Tuxtlas Biosphere Reserve, a protected but highly fragmented tropical landscape.We calculated Faith's phylogenetic diversity, mean pairwise phylogenetic distance and mean nearest taxon distance for 5,388 individuals in 36 species. The standardised effect sizes of these metrics were estimated to control their correlation with species richness. Phylogenetic diversity was also assessed separately for each dung beetle functional group. Finally, we compared the mean functional and phylogenetic pairwise distance and mean nearest taxon distance and measured the phylogenetic signal among dung beetle functional traits to determine the influence of niche conservatism on the phylogenetic structure of species assemblages.Faith's phylogenetic diversity of dung beetles was positively correlated with forest coverage, while their mean phylogenetic and nearest taxon distance values decreased with increasing landscape fragmentation. Necrophagous beetles and forest specialists responded most negatively to forest coverage loss and fragmentation.Alpha and beta diversity values showed phylogenetic overdispersion but functional convergence and weak phylogenetic signals in their functional traits, suggesting low niche conservatism. Landscapes with moderate forest coverage (≥40%) favoured higher phylogenetic beta diversity, whereas phylogenetic and functional beta diversity decreased significantly in landscapes with low forest coverage (<30%).Synthesis and applications. Forest habitats in fragmented landscapes are essential for safeguarding the evolutionary history of dung beetles, reducing biotic homogenisation processes by favouring phylogenetic overdispersion and complementarity between sites. Therefore, to secure the phylogenetic diversity of dung beetles within fragmented tropical reserves, we recommend protecting the existing forests, preventing further fragmentation of continuous forest areas and increasing matrix quality by implementing biodiversity‐friendly production systems. Finally, managers should consider assessing different functional groups in other species, as their response to landscape disturbance may not be phylogenetically similar. The above will allow more effective management practices to protect the species most susceptible to disturbances. [ABSTRACT FROM AUTHOR]

Abstract Gut microbiomes play an essential role in host survival and local adaptation and thus can facilitate the invasion of host species. Biological invasions have been shown to be linked to the genetic properties of alien host species. It is thus plausible that the holobiont, the host, and its associated microbiome act as an entity to drive invasion success. The bighead carp and silver carp (bigheaded carps), invasive species that exhibit extensive hybridization in the Mississippi River Basin (MRB), provided a unique model to test the holobiont hypothesis of invasion. Here, we investigated the microbiomes of foreguts and hindguts in bigheaded carps and their reciprocal hybrids reared in aquaculture ponds using 16S amplicons and the associated gene prediction. We found an admixed pattern in the gut microbiome community in bigheaded carp hybrids. The hybrid gut microbiomes showed special characteristics such as relatively high alpha diversity in the foregut, an increasing dissimilarity between foreguts and hindguts, and a remarkable proportion of genes coding for putative enzymes related to their digestion of main food resources (Cyanobacteria, cellulose, and chitin). The pond‐reared hybrids had advantageous features in genes coding for putative enzymes related to their diet. The above results collectively suggested that the gut microbiomes of hybrids could be beneficial to their local adaptation (e.g., food resource utilization), which might have facilitated their invasion in the MRB. The gut microbial findings, along with the intrinsic genomic features likely associated with life‐history traits revealed in our recent study, provide preliminary evidence supporting the holobiont hypothesis of invasion.

'Brejos de altitude' is an ecosystem that has been subjected to severe exploitation, leading to an intense reduction in Brazil. Understanding the patterns of bryophyte diversity and composition, particularly of specialized species such as the epiphylls, to anthropic and abiotic variables is crucial for implementing protection measures.We investigated the relationship between composition and diversity of epiphyllous bryophytes and anthropic (edge effects) and abiotic (altitude) variables at local (within each 'Brejo') and regional (set of three 'Brejos') scale. Abiotic and anthropic variables were correlated with alpha and beta diversity (decomposed into species replacement and richness differences) using GLM. Their effects on species composition were evaluated using PERMANOVA.The localities at higher elevations harboured a richer bryoflora and overall beta diversity patterns were associated with altitude and locality, which acted over different scales. Regionally, the contribution of richness differences was limited with increasing altitude. Yet, dissimilarities among localities were associated with richness differences and replacement, denoting the importance of local factors. The composition was explained by local factors interacting with the regional altitudinal gradient. Anthropic activity was significant only when interacting with local factors and altitudinal gradient.Environmental filtering associated with altitude played a more important role in shaping the diversity and composition of epiphyllous bryophytes, at both regional and local scales. Each 'Brejo' acts as an ecological refuge, harbouring part of the whole environmental gradient, and presents a unique floristic composition. Moreover, partitioning beta diversity highlighted the interplay of local and regional forces shaping diversity patterns. [ABSTRACT FROM AUTHOR]

Urban waters are often neglected in biodiversity research; nonetheless, the number of aquatic microhabitats present in a city and the surrounding urban area is impressive. Twenty-two waterbodies in the Belgrade functional urban area (FUA) were investigated for faunistic and diversity patterns and to assess the effects of environmental factors on the differentiation of Chironomidae assemblages. A total of 66 chironomid taxa within four subfamilies was identified. Water quality at the studied sites, expressed by the water pollution index (WPI), varied significantly. K-means clustering gave four homogenous groups of chironomid assemblages, which showed clear preferences to specific habitat conditions and tolerance to anthropogenic pressures. These groups had high values of alpha and beta diversity components. The main component of beta diversity was species turnover. Waterbody type, water temperature, pH, nutrients and overall pollution were the most important factors influencing the distribution and composition of chironomid assemblages, which revealed clear preferences of each assemblage type to the category of waterbody type and tolerances to environmental pressures. [ABSTRACT FROM AUTHOR]

Background and aims – In the tropics, some studies have found that the richness of epiphytic ferns present a peak at mountain mid-elevations. However, it is not well understood how transitions from tropical to subtropical conditions affect this peak, and even less is known about beta diversity of epiphytic ferns. Thus, the objective is to understand the effect of climatic gradients on the variation of local richness of ferns and beta diversity patterns along an elevational gradient in a mountain system in southern Mexico.Methods – We sampled 32 trees, each in four elevational bands (100–2200 m). Alpha diversity patterns were analysed using linear regression models. We used the Morisita index to quantify species turnover between bands. An additive partitioning approach was used to analyse the degree to which individual trees, plots, and bands contributed to total species richness. We evaluated the influence of climatic variables on species composition via linear regression models.Key results – A total of 30 species in five families were recorded. Each family contributed in different magnitude to the elevational richness pattern, with Polypodiaceae dominating due to its richness and presence along the entire transect. Alpha diversity at the three scales (αtree, αplot, αband) increased with elevation and rainfall, and with decreasing temperature. Species turnover was high along the gradient, but was scale-dependent, with βtransect (65–75%) and βband (14%) with the greatest contributing to total diversity. Although the contribution of the individual trees was lower, it increased with elevation. Conclusions – We emphasize the importance of including different scale levels in analyses of diversity along elevational gradients. In the region, cloud forest on the mountain peaks harbours the highest diversity of epiphytic fern communities. Due to a limited extent of this mountain range, the epiphyte ferns are susceptible to the effects of climate change.

Despite many studies that have explored the effect of livestock grazing on plant communities, the response of species composition and diversity to livestock grazing in arid rangelands remains ambiguous. This study examined the effects of livestock grazing on plant communities in arid steppe rangelands of North Africa. Plant diversity of annual species, perennial species, and all species combined were measured and compared between grazed and grazing‐excluded areas. We also examined the relative importance of species turnover and community nestedness. Moreover, the effects of livestock grazing on beta diversity at local among transects and landscape among sites scales were examined using the multiplicative diversity partitioning. Results revealed that livestock grazing significantly decreased the alpha diversity of all species combined and the diversity of annual plants. Livestock grazing induced a shift in plant community composition where most species composition variation (~74%) was due to infrequent species replacement 'turnover' between the two management types rather than nestedness (~26%). Results revealed also that among transects, beta diversity was higher in grazed steppes than in grazing‐excluded steppes. Whereas, among sites, beta diversity was lower in grazed steppes compared to grazing‐excluded steppes. These findings suggest that livestock grazing in arid steppe rangelands increases the variation in plant species composition at a local spatial scale and engenders vegetation homogeneity at a landscape spatial scale. Therefore, the implementation of appropriate management practices such as short‐term grazing exclusion is mandatory to prevent these ecosystems from large‐scale biotic homogenization. [ABSTRACT FROM AUTHOR]

This paper continues the studies on the role of bacteria in the environment of summer truffle (Tuber aestivum), focusing on ascomata at three sites in the Nida Basin (southern Poland). Bacterial taxa and the number of OTU sequences identified were determined based on analysis of peridium and gleba collected in 2017 and 2018. The aim of the presented work is to learn the structure of bacterial communities associated with the ascomata of the summer truffle T. aestivum forming in specific stands in south Poland and fine roots of surrounding trees. Sanger DNA sequencing, and next-generation sequencing (NGS) were used. NGS sequencing platforms short-read (300 bases) was selected, using a MiSeq Illumina. The Kruskall-Wallis test was used for alpha diversity analysis and the PERMANOVA test for beta diversity. Alpha and beta biodiversity analyzes were performed using various indices (Chao1, Simpson, Shannon, Faith's phylogenetic, observed OTUs, Heip's evenness measure - alpha diversity; UniFrac, Jaccard, Bray–Curtis - beta diversity). The Sanger method identified six bacterial taxa that were dominant in the community: Bacillus (86.7 %), Pseudomonas (51.5 %), Stenotrophomonas (15.5 %), Paenibacillus (7.9 %), Rhizobium (7.3 %), and Chryseobacterium (8.5 %). In contrast, NGS results showed the dominance (at OTUs >10,000) of taxa: Bradyrhizobiaceae, Sphingobacteriaceae, Micrococcaceae, Yersiniaceae, Sphingomonadaceae, Rhizobiaceae, Flavobacteriaceae, and Comamonadaceae. The PERMANOVA test for the Bray-Curtis and Jaccard indices showed dissimilarities between samples from two of the sites with respect to beta diversity. Significant differences were found in the bacterial communities colonizing the ascomata of T. aestivum and in the root communities with T. aestivum ectomycorrhizae the purpose of this study. The results obtained may be helpful in selecting and monitoring sites suitable for the formation of ascomata of T. aestivum. [ABSTRACT FROM AUTHOR]

Anthropogenic climate change has been shown to be one of the most pervasive threats to biodiversity. However, few studies have considered its effects on whole communities. Here, using ecological niche models (ENM) and projected future climate scenarios, we analyzed how these environmental changes could promote reductions in the alpha and beta taxonomic, phylogenetic, and functional diversities of mammals in the Cerrado Biodiversity Hotspot. We found that, on average, species richness tends to decrease in most Cerrado areas under future climate scenarios. However, this pattern is not uniform throughout the biome. Overall, southern Brazilian Cerrado may become biotically homogenized – through the extinction of native specialists and expansion of exotic generalists – in the near future, while the rest of biome may become very heterogeneous in taxonomic, phylogenetic and functional aspects. This scenario is very problematic considering that this region has been highly transformed and fragmented by human activities in the past. Based on our ENM approach of species inhabiting present Cerrado, we provided a more accurate analysis about the effects of anthropogenic and/or natural processes at large scales on the communities for this endangered Biodiversity Hotspot. This information could represent invaluable tool to guide future establishment of new and efficient conservation efforts.

High mountain environments are often characterised by low temperatures and short growing seasons, yet support high plant endemism and biodiversity. While such ecosystems are considered among the most vulnerable to climatic warming, the impacts of climate change on diversity and composition can be complex. To develop a deeper understanding of these dynamics, changes in vegetation over time along five alpine summits that are part of the Global Observation Research Initiative in Alpine Environment (GLORIA), were assessed including species richness, α-diversity, β-diversity, vegetation and growth form cover as well as composition. The five summits of Mount Clarke in the Australian Alps were surveyed in 2004, 2011 and 2019. Despite increases in species richness over time, there was an overall decline in diversity through biotic homogenisation across the summits. Near complete vegetation cover was recorded in 2004 but increased over the 15 years via in-filling and densification, driven by increasing cover of graminoids and shrubs. Consequently, there was also a shift in species composition which was greatest at higher elevations. The results indicate that there has been a shift towards more competitive and thermophilic composition, which may have implications for flammability in a warming and drying climate. Further assessments will be required to more fully explore the effect of climate variation from climate change, and implications for conservation of this and other alpine floras globally. [ABSTRACT FROM AUTHOR]

An increasing number of studies have shown that warming also influences the animal gut microbiome (altering the community structure and decreasing its diversity), which might further impact host fitness. Here, based on an analysis of the stomach and gut (the entire intestine: from the anterior intestine to the cloaca) microbiome in laboratory larva of giant salamanders (Andrias davidianus) under different living water temperatures (5, 15, and 25°C) at two sample time points (80 and 330 days after the acclimation), we investigated the potential effect of temperature on the gastrointestinal microbiome community. We found the significant Interaction between sampling time and temperature, or type (stomach and gut) on Shannon index in the gastrointestinal microbiome of the giant salamanders. We also found the significant difference in Shannon index among temperature groups within the same sample type (stomach or gut) at each sample time. 10% of variation in microbiome community could be explained by temperature alone in the total samples. Both the stomach and gut microbiomes displayed the highest similarity in the microbiome community (significantly lowest pairwise unweighted Unifrac distance) in the 25-degree group between the two sampling times compared to those in the 5-degree and 15-degree groups. Moreover, the salamanders in the 25°C treatment showed the highest food intake and body mess compared to that of other temperature treatments. A significant increase in the abundance of Firmicutes in the gastrointestinal microbiome on day 330 with increasing temperatures might be caused by increased host metabolism and food consumption. Therefore, we speculate that the high environmental temperature might indirectly affect both alpha and beta diversity of the gastrointestinal microbiome.

An increasing number of studies have shown that warming also influences the animal gut microbiome (altering the community structure and decreasing its diversity), which might further impact host fitness. Here, based on an analysis of the stomach and gut (the entire intestine: from the anterior intestine to the cloaca) microbiome in laboratory larva of giant salamanders (Andrias davidianus) under different living water temperatures (5, 15, and 25°C) at two sample time points (80 and 330 days after the acclimation), we investigated the potential effect of temperature on the gastrointestinal microbiome community. We found the significant Interaction between sampling time and temperature, or type (stomach and gut) on Shannon index in the gastrointestinal microbiome of the giant salamanders. We also found the significant difference in Shannon index among temperature groups within the same sample type (stomach or gut) at each sample time. 10% of variation in microbiome community could be explained by temperature alone in the total samples. Both the stomach and gut microbiomes displayed the highest similarity in the microbiome community (significantly lowest pairwise unweighted Unifrac distance) in the 25-degree group between the two sampling times compared to those in the 5-degree and 15-degree groups. Moreover, the salamanders in the 25°C treatment showed the highest food intake and body mess compared to that of other temperature treatments. A significant increase in the abundance of Firmicutes in the gastrointestinal microbiome on day 330 with increasing temperatures might be caused by increased host metabolism and food consumption. Therefore, we speculate that the high environmental temperature might indirectly affect both alpha and beta diversity of the gastrointestinal microbiome. [ABSTRACT FROM AUTHOR]

Gut microbiomes play an essential role in host survival and local adaptation and thus can facilitate the invasion of host species. Biological invasions have been shown to be linked to the genetic properties of alien host species. It is thus plausible that the holobiont, the host, and its associated microbiome act as an entity to drive invasion success. The bighead carp and silver carp (bigheaded carps), invasive species that exhibit extensive hybridization in the Mississippi River Basin (MRB), provided a unique model to test the holobiont hypothesis of invasion. Here, we investigated the microbiomes of foreguts and hindguts in bigheaded carps and their reciprocal hybrids reared in aquaculture ponds using 16S amplicons and the associated gene prediction. We found an admixed pattern in the gut microbiome community in bigheaded carp hybrids. The hybrid gut microbiomes showed special characteristics such as relatively high alpha diversity in the foregut, an increasing dissimilarity between foreguts and hindguts, and a remarkable proportion of genes coding for putative enzymes related to their digestion of main food resources (Cyanobacteria, cellulose, and chitin). The pond‐reared hybrids had advantageous features in genes coding for putative enzymes related to their diet. The above results collectively suggested that the gut microbiomes of hybrids could be beneficial to their local adaptation (e.g., food resource utilization), which might have facilitated their invasion in the MRB. The gut microbial findings, along with the intrinsic genomic features likely associated with life‐history traits revealed in our recent study, provide preliminary evidence supporting the holobiont hypothesis of invasion. [ABSTRACT FROM AUTHOR]

Representative samples of biota collected relative to environmental gradients are important for measuring present distributions and predicting shifts in distribution of taxa in response to climate change or reduced river connectivity. Based on river ecology theory and established measures of species diversity, we present a method to identify suitable river segments for sampling and monitoring changes in taxon diversity. Alpha and beta diversities of selected aquatic macroinvertebrates were assessed in seven South African rivers. Data were drawn from historical and field samples and represented longitudinal species patterns down longitudinal river axes. Representative sampling sites were identified using a logistic regression model to predict the probability of site pairs that were more than 50% similar as a function of up-/downstream distance. Alpha diversities peaked in the upper third of river lengths; beta diversities showed predictable exponential decay rates down river axes up to and excluding the start of estuarine conditions. Application of the model to a 370-km long river indicated that 14 sites should be selected for sampling to capture overall biodiversity patterns. Additional factors, such as confluences tributaries, which influence alpha diversity at sites, are identified and incorporated into site selection. [ABSTRACT FROM AUTHOR]

Grazing exclusion has been proved to be an effective approach for naturally restoring degraded rangelands. Still, the effect of this management practice on plant community composition and structure is ambiguous, especially under prolonged and repeated drought events. Here, we investigated the responses of community composition (i.e. incidence-based) and structure (i.e. abundance-based) to short-term sheep grazing exclusion under severe drought episode in the arid steppes of Alfa-grass (Stipa tenacissima L.) with a long evolutionary history of grazing. Individual species responses were tested based on species occurrence and abundance in either grazed or grazing-excluded steppes. Besides, indicator species analysis was used to identify species indicative of grazing-excluded steppes. Likewise, incidence-based and abundance-based α-diversity, β-diversity and functional groups’ diversities were quantified using Hill Numbers and compared between the two steppe managements types. Under severe drought conditions, sheep grazing exclusion allowed the apparition of a large number of increasers, colonizers, and native indicator plant species. It also improved the size of regional species pool and increased overall incidence-based and abundance-based α-diversity. Moreover, grazing exclusion decreased the abundance-based β-diversity at local scale but increased it at landscape scale. The incidence-based β-diversity significantly decreased at the landscape scale. Grazing exclusion enabled a significant spatial structuration of abundance-based β-diversity components by maintaining high balanced variation in species abundance at large spatial scale and greater abundance-gradient at fine-scale. Our results suggest that the implementation of short-term grazing exclusion in arid steppes would be the appropriate management practice for vegetation and habitat during prolonged droughts since it permits the recovery of native plant species and affects positively the size of the regional species pool, the overall incidence- and abundance-based α-diversity as well as the abundance-based β-diversity (chiefly at landscape scale).

Information on temporal dynamics of phytoplankton communities and their responses to environmental factors can provide insights into mechanisms driving succession of phytoplankton communities that is useful in programs to manage and or remediate undesirable assemblages. Populations of phytoplankton can be controlled by bottom-up factors such as nutrients and temperature or top-down such as predation by zooplankton. Traditionally, taxonomic diversity based on morphologies has been the measure used for analysis of responses to environmental factors. Recently, according to functional groupings, including functional groups (FG), morpho-FG (MFG), and morphology-based FG (MBFG), functional diversity has been used to represent functional aspects of phytoplankton communities. However, to what extent these taxonomic and functional groupings are congruent at seasonal time-scales and the main environmental factors, which drive succession, have remained less studied. Here, we analyzed absolute and relative proportions of a phytoplankton community during a 3-year period in Lake Erhai, a eutrophic highland lake in China. Alpha diversity and beta diversity, as measured by Shannon-Wiener and Bray-Curtis indices of taxonomic grouping and three functional groupings (FG, MFG, and MBFG) were applied to investigate environmental factors determining diversity. Significant, positive relationships were observed between taxonomic diversity and functional diversity that were strongly linked through seasons. In order to exclude the influence of dominant species' tolerance to extreme environments, the dominant species were excluded one by one, and the results showed that residual communities still exhibited similar patterns of succession. This synchronous temporal pattern was not principally driven by the dominant genera (Microcystis, Psephonema, and Mougeotia). Instead, the entire phytoplankton community assemblages were important in the pattern. Most diversity indices of taxonomic and functional groupings were significantly correlated with solar irradiance, but not nutrient concentrations. Because the lake is eutrophic and there were already sufficient nutrients available, additional nutrients had little effect on seasonal taxonomic and functional diversity of phytoplankton in Lake Erhai.

Information on temporal dynamics of phytoplankton communities and their responses to environmental factors can provide insights into mechanisms driving succession of phytoplankton communities that is useful in programs to manage and or remediate undesirable assemblages. Populations of phytoplankton can be controlled by bottom-up factors such as nutrients and temperature or top-down such as predation by zooplankton. Traditionally, taxonomic diversity based on morphologies has been the measure used for analysis of responses to environmental factors. Recently, according to functional groupings, including functional groups (FG), morpho-FG (MFG), and morphology-based FG (MBFG), functional diversity has been used to represent functional aspects of phytoplankton communities. However, to what extent these taxonomic and functional groupings are congruent at seasonal time-scales and the main environmental factors, which drive succession, have remained less studied. Here, we analyzed absolute and relative proportions of a phytoplankton community during a 3-year period in Lake Erhai, a eutrophic highland lake in China. Alpha diversity and beta diversity, as measured by Shannon-Wiener and Bray-Curtis indices of taxonomic grouping and three functional groupings (FG, MFG, and MBFG) were applied to investigate environmental factors determining diversity. Significant, positive relationships were observed between taxonomic diversity and functional diversity that were strongly linked through seasons. In order to exclude the influence of dominant species' tolerance to extreme environments, the dominant species were excluded one by one, and the results showed that residual communities still exhibited similar patterns of succession. This synchronous temporal pattern was not principally driven by the dominant genera (Microcystis , Psephonema , and Mougeotia). Instead, the entire phytoplankton community assemblages were important in the pattern. Most diversity indices of taxonomic and functional groupings were significantly correlated with solar irradiance, but not nutrient concentrations. Because the lake is eutrophic and there were already sufficient nutrients available, additional nutrients had little effect on seasonal taxonomic and functional diversity of phytoplankton in Lake Erhai. [ABSTRACT FROM AUTHOR]

Endosymbionts living in plants and insects are pervasive. Ficus (Moraceae) has very special inflorescences (which we also call figs) enclosed like an urn, and such inflorescence is usually parasitized by fig wasps. Ficus breeds fig wasp larvae in its figs and adult fig wasps pollinate for Ficus, Ficus and its obligated pollinator formed fig-fig wasp mutualism. Previous studies have found that this confined environment in figs may have provided protection for fig wasps and that this has left some imprints on the genome of fig wasps during the coevolution history of figs and fig wasps. Research on the diversity of both bacteria and fungi in figs are fewer. Our study explored the diversity of endosymbionts in Ficus hirta figs. We utilized high-throughput sequencing and biological database to identify the specific microorganism in figs, then conducted microorganism communities’ diversity analysis and function annotation analysis. As a result, we identified the dominant endosymbionts in figs, mainly some insect internal parasitic bacteria and fungi, plant pathogen, endophytes, and saprotroph. Then we also found bacteria in Ficus hirta figs were more diversified than fungi, and bacteria communities in female figs and functional male figs were different. These findings may give us more insight into the coevolution and interaction among endosymbiont, fig, and fig wasp.

The macrofungi thrive in different four areas namely Vansda, Waghai, Kaprada, Aamolia region. Maximum Microbial diversity was observed in sample collected from waghai location includes, Taxa_S-31, Individual-31, Dominance_D-0.032 , Simpson_1-D-0.96, Shannon_H-3.434 , Evenness- 1, Brillouin-2.519, Menhinick-5.568, Margalef-8.736, Equitability J-1, Fisher Alpha-0, Berger-Parker-0.322,Chao-496. The decrease numbers of specimens consistently found with the location Waghai, Whittaker- 0.16129, Harrison- 0.0046083, Cody- 4, Wilson-shmida- 4.6452, Mourelle- 0.13272 followed by Kaparada and Vansda region.

Habitat loss or degradation due to land cover change is regarded as one of the main drivers of amphibian decline; therefore, it is imperative to assess the effects of land-cover change on this group of vertebrates. In this study, we analyze changes in alpha and beta diversity of amphibian communities found in five land-cover types: mountain cloud forest, tropical evergreen forest, shade coffee, milpa huasteca, and grazing areas; six samples sites were established for each land-cover type, separated at least one km away. The study was conducted in the northwest part of the state of Hidalgo, in a transition zone between the Sierra Madre Oriental and the Gulf of Mexico, which is a region rich in amphibian species. The results indicate that alpha diversity decreases with loss of canopy cover, this being high in mountain cloud forest, tropical evergreen forest, and Shade coffee, and low in milpa huasteca and grazing areas. The land-cover type with the highest species evenness was found in milpa huasteca and the lowest in. The highest beta diversity was observed among tropical evergreen forest and grazing areas. Mountain cloud forest contains both exclusive species and the highest number of species currently regarded as threatened by national and international conservation assessment systems. In order to preserve amphibian diversity in the study area it is vital to protect the last remnants of native vegetation, especially mountain cloud forest, but also including Shade coffee, since the latter habitat harbors amphibian diversity similar to that found in native forests. Finally, implementation of policies that both reduce Grazing areas and increase their productivity is also necessary, since these highly modified areas turn out to be the ones that affect amphibian diversity the most.

Background and aims – In the tropics, some studies have found that the richness of epiphytic ferns present a peak at mountain mid-elevations. However, it is not well understood how transitions from tropical to subtropical conditions affect this peak, and even less is known about beta diversity of epiphytic ferns. Thus, the objective is to understand the effect of climatic gradients on the variation of local richness of ferns and beta diversity patterns along an elevational gradient in a mountain system in southern Mexico. Methods –We sampled 32 trees, each in four elevational bands (100–2200 m). Alpha diversity patterns were analysed using linear regression models. We used the Morisita index to quantify species turnover between bands. An additive partitioning approach was used to analyse the degree to which individual trees, plots, and bands contributed to total species richness. We evaluated the influence of climatic variables on species composition via linear regression models. Key results –A total of 30 species in five families were recorded. Each family contributed in different magnitude to the elevational richness pattern, with Polypodiaceae dominating due to its richness and presence along the entire transect. Alpha diversity at the three scales (αtree, αplot, αband) increased with elevation and rainfall, and with decreasing temperature. Species turnover was high along the gradient, but was scale-dependent, with βtransect (65–75%) and βband (14%) with the greatest contributing to total diversity. Although the contribution of the individual trees was lower, it increased with elevation. Conclusions – We emphasize the importance of including different scale levels in analyses of diversity along elevational gradients. In the region, cloud forest on the mountain peaks harbours the highest diversity of epiphytic fern communities. Due to a limited extent of this mountain range, the epiphyte ferns are susceptible to the effects of climate change. [ABSTRACT FROM AUTHOR]

Total of 26, 22 and 32 sites in Konya, Antalya and West Mediterranean basins in Turkey, respectively, were sampled twice during 2017 to compare the non-marine ostracod diversity. A total of 1787 individuals belonging to 31 species were recorded from all basins. Of which, nine species are common among basins when Fabaeformiscandona fragilis is new for Turkey. High species diversity was found at middle elevational intervals. The highest and lowest Shannon diversity index values were recorded for both Konya (H = 2.19) and Antalya (H = 1.90) basins, respectively. The highest beta diversities values are encountered between closed the Konya and other open basins. Species and environmental variables composition among basins and elevational intervals showed significant differences (p < 0.05, ANOSIM). Of species, cosmopolitans (e.g., Candona neglecta, Ilyocypris bradyi, Psychrodromus olivaceus) provide an important contribution to the differences in diversities among basins and elevational intervals. According to Canonical Correspondence Analysis, elevation appeared to be the common influential variables in all basins. Results suggest that alpha diversity is under the control of local and regional factors when beta diversity is primarily affected by regional factor. Although cosmopolitan species are positive indicators, they seem to make a significant contribution to alpha and beta diversities of ostracods. [ABSTRACT FROM AUTHOR]

Habitat loss or degradation due to land cover change is regarded as one of the main drivers of amphibian decline; therefore, it is imperative to assess the effects of land-cover change on this group of vertebrates. In this study, we analyze changes in alpha and beta diversity of amphibian communities found in five land-cover types: mountain cloud forest, tropical evergreen forest, shade coffee, milpa huasteca, and grazing areas; six samples sites were established for each land-cover type, separated at least one km away. The study was conducted in the northwest part of the state of Hidalgo, in a transition zone between the Sierra Madre Oriental and the Gulf of Mexico, which is a region rich in amphibian species. The results indicate that alpha diversity decreases with loss of canopy cover, this being high in mountain cloud forest, tropical evergreen forest, and Shade coffee, and low in milpa huasteca and grazing areas. The land-cover type with the highest species evenness was found in milpa huasteca and the lowest in. The highest beta diversity was observed among tropical evergreen forest and grazing areas. Mountain cloud forest contains both exclusive species and the highest number of species currently regarded as threatened by national and international conservation assessment systems. In order to preserve amphibian diversity in the study area it is vital to protect the last remnants of native vegetation, especially mountain cloud forest, but also including Shade coffee, since the latter habitat harbors amphibian diversity similar to that found in native forests. Finally, implementation of policies that both reduce Grazing areas and increase their productivity is also necessary, since these highly modified areas turn out to be the ones that affect amphibian diversity the most. [ABSTRACT FROM AUTHOR]

Studies of microbial communities by targeted sequencing of rRNA genes lead to recovering numerous rare low-abundance taxa with unknown biological roles. We propose to study associations of such rare organisms with their environments by a computational framework based on transformation of the data into qualitative variables. Namely, we analyze the sparse table of putative species or OTUs (operational taxonomic units) and samples generated in such studies, also known as an OTU table, by collecting statistics on co-occurrences of the species and on shared species richness across samples. Based on the statistics we built two association networks, of the rare putative species and of the samples respectively, using a known computational technique, Association networks (Anets) developed for analysis of qualitative data. Clusters of samples and clusters of OTUs are then integrated and combined with metadata of the study to produce a map of associated putative species in their environments. We tested and validated the framework on two types of microbiomes, of human body sites and that of the Populus tree root systems. We show that in both studies the associations of OTUs can separate samples according to environmental or physiological characteristics of the studied systems.

Introduction: The well-known eastern Asian (EA) and eastern North American (ENA) floristic disjunction provides a unique system for biogeographic and evolutionary studies. Despite considerable interest in the disjunction, few studies have investigated the patterns and their underlying drivers of allopatric divergence in sister species or lineages isolated in the two areas. Endophyte diversity and assembly in disjunct sister taxa, as an ecological trait, may have played an important role in the processes of allopatric evolution, but no studies have examined endophytes in these lineages. Here we compared foliar endophytic fungi and bacteria-archaea (FEF and FEB) in 17 EA-ENA disjunct species or clade pairs from genera representing conifers and 10 orders of five major groups of angiosperms and 23 species of Cornus from EA and North America., Methods: Metagenomic sequencing of fungal ITS and bacterial-archaeal 16S rDNA was used to capture the foliar endophytic communities. Alpha and beta diversity of fungi and bacteria were compared at multiple scales and dimensions to gain insights into the relative roles of historical geographic isolation, host identity, phylogeny, and environment from samples at different sites in shaping endophytic diversity patterns., Results: We found that beta diversity of endophytes varied greatly among plant individuals within species and between species among genera at the same sampling site, and among three sampling sites, but little variation between region-of-origin of all plant species (EA vs ENA) and between EA-ENA disjunct counterparts within genera. Various numbers of indicator fungal species differing in abundance were identified for each plant genus and Cornus species. An overall significant correlation between endophyte community dissimilarity and phylogenetic distance of plants was detected among the disjunct genera but not among species of Cornus . However, significant correlations between beta diversities at different taxonomic scales of endophytes and phylogenetic distances of Cornus species were observed., Discussion: Our results suggest important roles of host identity and environment (sampling sites), and a likely minor role of phylogenetic divergence and historical biogeographic isolation in shaping the pattern of foliar endophyte diversity and assembly in the EA-ENA disjunct genera and Cornus . The results lead to a hypothesis that the sister taxa in EA and ENA likely differ in FEF and FEB when growing in native habitats due to differences in local environments, which may potentially drive allopatric divergence of the functional features of species., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2023 Zhou, Shi, Soltis, Soltis and Xiang.)

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Aim: Understanding how spatial distributions of rare and common species are associated with environmental and spatial processes is essential to understanding community assembly. We addressed the following questions: (a) does the relative importance of space and topography vary from rare to common tree species? (b) Are the contributions of topography and space equal? (c) Are the variances explained by topography or space correlated with elevational ranges (ER) at the local scale? (d) Does cell‐size influence those postulated associations? Location: China and the Americas. Major taxa studied: Tree species. Methods: We partitioned the variation in species richness and composition of rare and common tree species by topography and space across a range of extents and grain sizes in eight communities. We calculated contribution ratio (CR) between space and topography to quantify their relative importance. We employed Kendall's rank correlation to determine the relation between CR and commonness. Mixed effect models were used to identify the influence of cell‐size on the results. Results: The majority of CR values were positively related to increasing commonness, especially for composition. The explained variances by space were always higher than that by topography regardless of commonness. At local scale, variances explained by space or topography were not correlated with ER. Main conclusions: Our results indicate that the relative importance of space compared to topography increases from rare to common species across forests. We suggest that future studies of community assembly need to account for both space and topography to adequately describe differences in rare and common species assembly mechanisms at range of spatial extents and grain sizes. [ABSTRACT FROM AUTHOR]

Abstract: Aim: We investigated habitat heterogeneity and patterns of avian taxonomic and functional diversity change across a decreasing patch‐size gradient in a critically endangered, fragmented forest‐system to elucidate: (1) habitat patch‐size and structural drivers of avian diversity change, (2) potential patch‐size thresholds at which avian diversity and habitat heterogeneity changes occurred and (3) avian species/communities within thresholds that indicated distinct patch‐size categories. Location: Indian Ocean Coastal Belt, South Africa. Methods: We conduced habitat‐structure and fixed‐radius point‐count surveys during the avian breeding season across 123 habitat patches (range 0.06–386.9 ha). We calculated taxonomic and functional diversity/patch (α) using a distance matrix of all traits present in the avian community (γ) and described community change across the patch‐size gradient (β). We compared linear regressions of patch‐size effects on avian functional α‐diversity and habitat‐structural heterogeneity to segmented regression at five bands, determined by mean patch sizes responsible for provisioning avian functional α‐diversity at <50%, 50%–62.5%, 62.5%–75%, 75%–87.5% and 87.5%–100% of avian functional γ‐diversity to explore patch‐size thresholds, and tested for significant avian indicator species of categories identified. Results: Avian taxonomic and functional α‐diversity significantly decreased with decreasing patch size and habitat heterogeneity; correlations between taxonomic and functional diversity declines and a positive significant influence of habitat heterogeneity on avian functional diversity indicated selective extinction pressure on niches and concomitant functional traits. Species turnover significantly increased in smaller patches. Segmented regressions of patch size‐effect on avian functional diversity and habitat heterogeneity out‐performed linear regressions at three patch‐size thresholds (157, 96 and 9 ha). Forest‐dependent specialists were significant indicators of high‐diversity patches >90 ha. Species characterizing small patches <9 ha were generalists, but many were also present in larger patches, highlighting nested‐community subsets of γ‐diversity. Main conclusions: Specialized niches and concomitant species became locally extinct at patch‐size thresholds. We present replicable methodology and recommendations for conservation of forest systems using a critically endangered biome containing disproportionately high avifauna. [ABSTRACT FROM AUTHOR]

At 1039 metres, Gunung Tebu is one of the highest hills in NE Peninsular Malaysia and the highest in Terengganu, surrounded by selectively logged community forest. Human disturbance and infrastructure development have been associated with a reduction in floral and faunal diversity. Sampling of butterflies and moths was carried out in July 2012 in two principal regions; comprising low altitude disturbed recreational forest and the higher-altitude, relatively undisturbed, forest of Gunung Tebu itself. A total of 113 individuals belonging to 101 species in 20 lepidopteran families were collected. The family Geometridae was the richest in terms of species (25%), followed by Erebidae (20%), and several families were each represented by only a single species. The Simpson Diversity Index (D) of species diversity was 1.963 x 10-3 and Fisher's alpha (α) index was 458.1 overall indicating very high diversity in Lepidoptera in the forest. For the two sites individually, D was 6.585 x 10-4 for Lata Belatan forest and 4.545 x 10-3 for Gunung Tebu forest. The Fisher's alpha, Shannon-Weiner Index and Species Evenness (E') for Lata Belatan forest were also higher than for Gunung Tebu forest. Presented here are the full results of this sampling, in tabular form, along with the outcomes of various diversity indices and a discussion of their implications. [ABSTRACT FROM AUTHOR]

Decline in tree species diversity is a widespread trend in eastern US forests, with implications for ecosystem functions and services, biodiversity and vulnerability to climate change and other stressors. While some impacts on diversity are widespread such as forest pests, forest management practices vary across the landscape. For example, forests in US national parks are managed to promote ecological integrity, develop under natural disturbance regimes, and are largely protected from timber harvesting. In this study we compared forests in 39 eastern US national parks with surrounding matrix forests to assess whether forest protection has led to differences in tree diversity patterns in parks. We calculated multiple alpha and beta diversity metrics using tree stem data. We examined alpha diversity metrics at the scale of the 7.31 m radius subplot and for an equal number of individuals, and examined beta diversity at multiple scales. This is the first study to compare tree diversity in protected lands with the surrounding forest matrix over such a large area of the US, and is only possible because of the 10+ years of data that are publicly available from US Forest Service (USFS) Forest Inventory and Analysis (FIA) and the National Park Service (NPS) Inventory and Monitoring (I&M) programs. Overall, results indicated that park forests have consistently greater alpha diversity. Park forests have higher tree species richness, particularly after the influence of the number of individuals was removed. Park forests also consistently had higher Shannon Evenness, lower McNaughton Dominance, and higher percentage of rare species. Beta diversity analyses also suggest that parks were less homogenous across sites, although results are exploratory due to differences in scale and small sample size. While a number of studies have documented higher diversity in protected areas, few studies have examined multiple diversity metrics or covered the large area of our study. Combining these results with a previous study, which found parks to have consistently greater structural complexity than surrounding forests, park forests may respond differently and potentially be more resilient to climate change and other stressors than unprotected forests, as there is a greater chance that some of the tree species or size cohorts present will persist through climate change. Continued monitoring is important to determine how forests respond to climate change and other stressors, and whether specific management actions, such as protecting more forests, translocating species, or altering management practices, are necessary to maintain forest biodiversity and function. [ABSTRACT FROM AUTHOR]