Differences In Species Composition Research Articles

Effect of freshwater on plant species diversity and interspecific associations in coastal wetlands invaded by Spartina alterniflora.

Plant invasions in coastal wetlands lead to the degradation of native vegetation; the introduction of freshwater in coastal wetlands would prevent the spread of invasive plants and facilitate the restoration of native vegetation. In this study, we evaluated the effects of freshwater on plant communities in the coastal wetlands of Yancheng, China, invaded by Spartina alterniflora Loisel. Two field investigations were conducted in 2008 and 2018 before and after the introduction of freshwater (started in 2011). The characteristics of plant communities were subjected to hierarchical cluster analysis and compared using several diversity indices. In addition, differences in habitat community composition and interspecific relationships of dominant species were analyzed. The results showed that S. alterniflora reduced the overall species diversity in the region. Plant species diversity increased after freshwater was introduced into the study site when compared to the areas without freshwater introduction. The introduction of freshwater caused a shift often changes in the interspecific relationships between Suaeda salsa (L.) Pall. and other species. The intensified invasion of S. alterniflora changed the interspecific relationship of native halophytes from negative to positive. Although freshwater effectively inhibited further invasion of S. alterniflora, it also increased the risk of expansion of the glycophytes in the community. The results of this study highlight the need for early intervention for restoration of coastal wetlands, preservation of biodiversity, and management of plant resources.

Forest management affects saproxylic beetles through tree species composition and canopy cover

Forest management has been shown to affect biodiversity, but the effects vary among taxa and studies. Due to their host-tree preferences, many saproxylic, i.e. deadwood-dependent, beetle species are likely affected by forest management via changes in tree species composition. However, further structural differences caused by forest management, such as microclimatic conditions, may interfere with effects of tree species. We lack a more detailed understanding of how forest management intensity influences saproxylic beetles through tree species composition and structural properties.We analyzed the effect of forest management on saproxylic beetles using an eight-year dataset collected from 379 experimental logs of 13 different tree species, which were exposed in forests of different management intensity in three regions of Germany. To quantify forest management intensity, we first used a composite index (ForMI) which considers the share of locally non-native tree species, the origin of deadwood and the harvesting rate and then replaced it by five forest structural and compositional properties. This two-step approach allowed to assess the overall effects of management summarizing different aspects and to identify the main forest attributes driving these overall effects. We further investigated whether the effects differ between beetle assemblages emerging from conifer and broadleaf logs (host level), and between generalists, conifer-specialists, and broadleaf-specialists (beetle specialization level).Abundance and species richness increased with increasing ForMI for all beetles, generalists, and conifer-specialists, but not for broadleaf-specialists.Effects of ForMI were stronger for assemblages emerging from conifer than broadleaf logs. Among the evaluated structural and compositional variables, strongest effects were observed for conifer share at stand level and canopy cover. Conifer share positively affected the species richness of all beetles, generalists and conifer specialists, but not of broadleaf specialists. Canopy cover negatively affected all beetles, generalists and conifer specialists, but did not affect broadleaf specialists.Our results show that major drivers behind effects of forest management on saproxylic beetles are differences in tree species composition and canopy cover. Effects differ between beetle groups depending on their host specialization. Forest management decisions regarding tree species composition should therefore more strongly consider their effects on saproxylic beetle diversity to meet conservation goals also in the future.

Agri-driven habitat modification and small mammal species assemblage nexus in the Atewa Range and Bimpong Forest Reserves, Ghana

This study provides first-hand information on how the changing microhabitat in evergreen forests influences the assemblage of small terrestrial mammals. 30 plots of 100 × 50 metres were randomly sampled in the closed forest, open forest and farmlands habitats. Four transects, 100 m in length, spaced at 10 m, were established in each plot. Ten traps spaced at 10 m from each other were placed on each transect. In the dry and wet seasons, small mammals were captured for three consecutive nights twice a year using Sherman collapsible traps baited with oatmeal and groundnut paste. Small mammals were photographed and identified to species level in situ. The multidimensional scaling method was used to identify clusters of sites based on the composition of their communities. Differences in species composition among habitat types were tested using Permutational Multivariate Analysis of Variance. To identify the species contributions to the major differences between habitat types, a SIMPER analysis was performed. Species richness was compared by subjecting the relative abundance data to an individual-based rarefaction technique. Species diversity of the habitat types in the study areas was compared using the Renyi diversity ordering approach. A total of 507 individual small mammals of 22 species were sampled from both study sites. Our analysis revealed that the composition of small mammal species differed significantly between habitat types in the two study areas. Praomys tullbergi, Mastomys natalensis and Mus minutoides contributed 27.5%, 16.8% and 14.4%, respectively to overall community dissimilarity between the habitat types. Together these three species contributed to 54.8% and 62.8% of observed dissimilarities in Atewa and Bimpong study areas respectively. Overall observed species richness in Atewa (16 species) was higher than Bimpong (14 species). Generally, farmlands and open forests were more abundant, species-rich and diverse than the closed forest habitats in both study areas. Our results supported the hypothesis that different habitat types (farmlands, open forest, and closed forest) in the study areas will differ in small mammal assemblage due to different levels of disturbances.

A multi-trophic marker approach reveals high feeding plasticity in Barents Sea under-ice fauna

Microalgae growing within and attached to the bottom of Arctic sea ice (sympagic algae) can serve as a nutritious food resource for animals inhabiting the sea-ice water interface (under-ice fauna), particularly during the bottom ice-algal bloom in spring. As a consequence, under-ice fauna is likely impacted by sea-ice decline and changes in ice-algal primary production. To investigate this, samples of pelagic (=PPOM) and ice-associated particulate organic matter (=IPOM) and the ice-associated amphipods Apherusa glacialis and Eusirus holmii, and polar cod (Boreogadus saida), collected below ridged sea ice at two locations with pronounced differences in productivity in the northern Barents Sea during May 2021, were assessed for their trophic marker content. Specifically, we investigated the composition of diatom- and dinoflagellate-produced fatty acids (FAs), pelagic and sympagic highly branched isoprenoid (HBI) lipids as well as sterols to determine the animals’ dietary preferences and trophic association to the sea-ice habitat during spring. Relative proportions of FAs differed strongly between PPOM and IPOM, indicating differences in species composition and degradation state between pelagic and sympagic habitats, respectively. FA signatures and sterol content of the consumers largely resembled known diet compositions with a strong reliance on diatom-derived carbon in A. glacialis, a higher degree of carnivory in E. holmii and evidence of Calanus-feeding in polar cod. Sympagic HBIs were detected at either low concentrations or not at all, in both producers and consumers, likely as a result of the very low abundance of their source diatoms. Pronounced trophic marker variability in A. glacialis collected at the highly productive shelf slope station versus the less productive central Arctic Basin station suggests a surprisingly high flexibility in carbon-source composition with a stronger reliance on pelagic food when available versus a higher importance of ice algal carbon when pelagic production is low. Nevertheless and despite the general lack (below detection limit) of sympagic HBIs in our dataset, high ice-algal biomass and elevated proportions of polyunsaturated FAs in IPOM compared to other seasons indicate that ice algae constitute a valuable nutritional carbon source as alternative to pelagic carbon during spring.

GRID2 aberration leads to disturbance in neuroactive ligand-receptor interactions via changes to the species richness and composition of gut microbes

ObjectiveTo explore the association between phenotype and the gut microbiome following damage to the GRID2 gene. MethodsTen wild-type (WT) mice and 11 GRID2 knockout heterozygous mice (GRID2(±)) of a similar age and weight were randomly selected. Fresh feces were collected from both groups of mice under specified pathogen-free (SPF) conditions. The bacterial genomes were extracted from the feces, the 16S rRNA genes were sequenced, and the data were analyzed to determine clustering, diversity, abundance, LEfSe, and functional differences. Differential expression and enrichment analyses of the RNA-seq and protein levels of the GRID2 gene were also performed using data in the GENE database and the new version of the Human Protein Atlas portal (www.proteinatlas.org). ResultsThe diversity analysis showed differences in species composition between the two groups at different levels. At phylum level, compared with the WT group, the distribution was more bacteriophages but showed a lower content of Tenericutes in the GRID2(±) group. At the order level, compared with the WT group, a higher content of Actinomycetales and Bacteriophages were found in the GRID2(±) group. The species difference analysis showed that 17 species, including E. faecalis and Paracoccus spp., showed differences in content between the two groups. LEfSe analysis showed that the abundance of Clostridiaceae, Allobaculum, and other groups decreased in the GRID2(±) group compared with the WT group, while Mycoplasma, Sphingomonas, and Alphaproteobacteria increased in abundance. Functional analysis revealed eight differential functions between the WT and GRID2(±) group (P < 0.05). The most significantly disrupted were neuroactive ligand-receptor interactions (P < 9.99e-4). In addition, the differential expression and enrichment analyses performed at RNA-seq and protein levels revealed that the GRID2 gene showed organ-specific expression and was mainly enriched in the brain tissue. ConclusionsCompared with the WT group, the defective GRID2 gene affected the species richness and composition of gut microbes in the GRID2(±) mice, which in turn affected the function of gut microbes, leading to the disruption of neuroactive ligand-receptor interactions. Our findings indicate that the host gene, GRID2, can influence the abundance of a subset of gut microbes but the exact mechanisms still need further investigation.

Functional-group approach with scarab beetles (Coleoptera: Scarabaeidae): a low-cost alternative for monitoring biodiversity in El Salvador

Summary Planning, implementing, and systematic revision of conservation policies are necessary to protect the biodiversity of a territory. This is critical in countries heavily impacted by anthropogenic activities, like El Salvador, where conserving biodiversity remnants must be a priority. Monitoring indicator groups represents a feasible option to review the status of biodiversity and the processes taking place in the country's conservation areas. We evaluated the suitability of Scarabaeidae beetle functional groups as ecological indicators to detect differences in the conservation status of two protected areas in El Salvador. We conducted monthly sampling for one year at each site, using pitfall, aerial, and UV-light traps to capture beetles. We detected differences in species richness, abundance, species composition, and turnover between the two areas. The results suggest the possibility of using this approach to monitor protected areas, to estimate the forest conservation status, and to evaluate the conservation strategies implemented to date. For the future, it is essential to determine if this is possible by replicating studies throughout the territory using standardized methodologies to obtain comparable results. The cost–benefit ratio of using a single indicator group is key in countries like El Salvador, where the economic aspect is a limiting factor for biological prospecting.

Eukaryotic Diversity Based on High-Throughput 18S rRNA Sequencing and Its Relationship with Environmental Factors in a Salt Lake in Tibet, China

Eukaryotes exist widely in aquatic ecosystems. It is of great importance to study their species composition, diversity, and relationship with environmental factors to protect and maintain ecosystem balance. Salt lakes are essential lakes rich in biological and mineral resources and have significant research value. To understand the characteristics of eukaryotic diversity in salt lake sediments, we conducted a sampling survey of the benthos in Kyêbxang Co, Tibet, in July and August 2020. The sampling area was divided into littoral, sublittoral, and profundal zones. A total of 42 species of Metazoa, 159 species of Protozoa, 63 species of Viridiplantae, and 46 species of Fungi were identified by the high-throughput sequencing of 18S ribosomes. Alpha diversity analysis revealed significant differences in species composition among the three study zones. The littoral zone had the highest Sobs index and Chao index, indicating that the eukaryotic diversity and richness in this zone were significantly higher than those in the profundal and sublittoral zones. Redundancy analysis (RDA) showed that water depth, temperature, and sediment organic matter content significantly affected the community structure of eukaryotes zones, especially the distribution of dominant genera such as Dunaliella, Psilotricha and Brachionus. Cooccurrence network analysis showed that Dunaliella, Aphelidium, temperature, water depth, and organic matter represent essential nodes in the entire network. This study can provide baseline data and new insights for eukaryotic diversity research for salt lakes.

Raised bog biodiversity loss: A case‐study of ground beetles (Coleoptera, Carabidae) as indicators of ecosystem degradation after peat mining

AbstractPeatlands are unique ecosystems inhabited by highly specialized biota. Due to extraction and drainage, these valuable ecosystems decline or represent only fragmented habitat patches. The aim of this study was to compare the carabid species composition, diversity, and life history traits between bog habitat types: 20 and 40 year post‐extraction sites and undisturbed one. We tried to determine whether populations of rare carabid bog specialists would persist in the post‐extraction habitats. The study was conducted in the raised bog, where 30 sampling transects with a total of 90 pitfall traps were established. 1616 individuals belonging to 30 carabid species were collected. The results revealed the significance differences in carabid species composition between studied habitat types and increasing the abundance and species richness in post‐extraction sites. According to spontaneous succession in post‐mining sites, the shift in life history traits of carabids towards forest assemblages was observed. We observed decline of the most valuable bog species in post‐mining sites. Agonum ericeti, Pterostichus rhaeticus and Bembidion humerale were present on the reference bog, with large covers of Sphagnum and shrubs, but sporadically at the 20 year post‐extraction site (except for A. ericeti), or not at all at the 40 year post‐extraction site overgrown by trees. Therefore measures should be undertaken in post‐extraction areas to enable the restoration of such specific conditions and a properly functioning raised bog ecosystem. This mainly requires restoration of a suitable hydrological regime, which is the key factor for the preservation of groups of bog specialist plants and animals.

Impact of Stump Removal on Communities of Ectomycorrhizal and Other Soil Fungi in Norway Spruce Stands of Latvia

Heterobasidion root rot is one of the most economically important conifer diseases in the Northern Hemisphere, and stump removal is considered to be one of most effective control methods. However, the impact of stump removal on the diversity of mycorrhizal and soil fungi should be evaluated. From 2011 to 2012, a stump removal trial was established in six different sample plots in two regions of Latvia. The stump removal sites and control sites were replanted with spruce seedlings in 2012. Seven years later, soil samples were collected in the stump removal and control sample plots to compare the diversity of mycorrhizal and soil fungi. Fungal communities were analyzed using next-generation sequencing methods. Our results showed that there are no significant differences in mycorrhizal and soil fungal communities between the stump removal area and the clear-felled control area seven years later. The mycorrhizal fungi were the most commonly sequenced fungal ecological group, and their diversity was similar to clear-felled control sites. However, there were some differences in the fungal species composition.

Long-term effects of forest fires on fungal community and soil properties along a hemiboreal Scots pine forest fire chronosequence

We studied long-term effects of forest fires on the dynamics of soil fungal community along a post-fire chronosequence in hemiboreal Scots pine stands in north-western Estonia. Effects of fire on soil and fungi were studied on six sites that differed in time since fire (10, 21, 36, 67, 78 and 181 years ago), without further management interventions. Soil fungal communities along the chronosequence were dominated by soil saprotrophs and ectomycorrhizal (EcM) fungi. Across the chronosequence, the most dominant phylum was Ascomycota. The most abundant OTUs were identified as Umbelopsis sp., Hyaloscyphaceae sp. and Pezoloma ericae with relative abundances of 9.5, 8.9 and 6.8 %, respectively. Fungal species richness was similar among sample areas except in the area where fire occurred 36 years ago, where it was significantly lower. There were considerable differences in EcM fungal species composition along the chronosequence. The most recently burned site had Piloderma sphaerosporum, Pseudotomentella sp. and Clavulinaceae sp. as most abundant EcM OTUs while in three oldest burned areas Clavulinaceae sp. and Cortinarius sp. were abundant. Soil C and N stocks were lower in the most recently burned area but differences with other areas were not statistically significant. Soil pH had a significant effect on fungal species composition. Older areas had substantially lower pH compared to more recently burned areas.

Diversity and distribution of Lentibulariaceae in Bahia state, Brazil: implications for phytogeography and conservation

Bahia state harbours an immense diversity of plant species with several cases of endemism, especially in the savanna wetlands, typical ecosystems where most Lentibulariaceae representatives occur. In this context, we aimed to improve the characterization of these savanna wetlands in terms of species richness of Lentibulariaceae, their phytogeographic patterns, endemism, forms of rarity, threats to their habitats, and conservation efforts. Herein we present the synopsis of the 42 species of Lentibulariaceae that occur in Bahia state, providing short diagnostic characterization, photographs of living specimens, updated geographic distribution displayed in maps, new records, and discussion concerning phytogeographic patterns, endemism, rarity, habitat characterization and current scenario of threats and conservation. Our results show a disjunct distribution and similarity in Lentibulariaceae species composition between savanna wetlands, corroborating previous hypotheses of vegetation connections during moister climatic conditions in the past. Moreover, differences in species composition among different restinga areas are consistent with biogeographical and paleomodelling studies pointing the São Francisco River as a geographic barrier influencing speciation and genetic diversity. Finally, we emphasize the situation of abandonment in some Protected Areas, lacking proper infrastructure, managers, management plans and board, and insufficient results for the effective conservation and protection of the environment and species.

Species-area relationship and richness persistence as a proxy of environmental carrying capacity: A case study in a neotropical show cave

Community stability and carrying capacity are essential core concepts in ecology because they reflect the interactions between organisms and their environment and provide clues to predictability. Since caves are considered stable habitats, we used long-term invertebrate monitoring to understand temporal and spatial carrying capacity in a neotropical cave based on species richness and beta diversity. Invertebrates were monitored from the entrance to the inner parts of the cave in plots (25m long each) in five sampling events over 10 years. Overall, 181 species were recorded. Although the turnover in species composition was considered high, the number of species remained almost constant along time, obviously considering the species oscillations between dry and rainy periods. The partitioning of beta diversity showed that in the rainy period and in the inner regions, the species replacement (turnover) was responsible for the differences in species composition over time. The richness stability and the turnover along time seem to indicate a maximum number of species that may coexist in the cave (∼64 species), probably a proxy of environmental carrying capacity. Then, despite the environmental stability of the caves, the permanent absence of light and scarcity of food resources makes these habitats restrictive to colonization, printing an intense temporal turnover in faunal composition, although with constant richness. Hence, at least for the studied cave, it seems that there is a maximum number of species it can shelter, regardless of which taxa.

Can the Karaman-Chappuis method significantly enhance understanding of stygofauna ecology?

Comprehensive surveys on subterranean fauna are an emerging need for assessing species diversity patterns and for developing biodiversity conservation strategies considering anthropogenic changes to the environment (e.g., mineral and water extraction, climate change). Subterranean habitats comprise mainly terrestrial and aquatic aspects of caves and fissures, as well as interstitial waters. Sampling stygofauna in Northern Western Australia is different to other parts of the world due to the predominance of meso- and micro-caverns, and thus methods are largely constrained to net hauling or pumping of either drill holes or bores installed for mineral or groundwater exploration. Water is also encountered at shallower depths beneath water courses (the interstitial or hyporheic zone) and although it is known to share fauna with subterranean systems, is largely excluded in stygofauna studies. Interstitial fauna can be sampled with the well-known Karaman-Chappuis (KC) method, which involves digging a hole in saturated alluvial deposits, letting interstitial water accumulate, and use of a scoop net to collect invertebrates. However, the application of the KC as a standard complementary method for stygofauna surveys has to date been largely unexplored. In collaboration with Rio Tinto, we included the KC method alongside traditional subterranean fauna sampling at five study areas in the Hamersley Range of Pilbara region, Western Australia. We aimed to determine its utility to better understand the ecology of subterranean fauna recorded, and therefore improve conservation outcomes. Here, we summarise the faunal groups collected using the KC method (43 samples) from surveys conducted between 2016 and 2019. We found that the stygofaunal groups more frequently collected by the KC method were Ostracoda (30.4%), Cyclopoida (28.0%), Haplotaxida (12.5%) and Amphipoda (10.7%), but other groups – Harpacticoida, Syncarida, Aphanoneura, Isopoda, Enchytraeida and Trombidiformes – were also collected in lower frequency (total of 4.9% of the records). Notably, the KC method also collected troglofaunal groups as by catch. Pauropoda (28.1%), Symphyla (21.9%), Hemiptera (12.5%), Diplura (12.5%), Zygentoma (9.4%) and Chilopoda (6.3%) were the groups most frequently collected using the KC method, but Isopoda, Palpigradi and Polyxenida were also recorded (total of 9.3% of the records). Additionally, for one project where low level taxonomic data was available (based on morphological and molecular identification), we also assessed differences in species composition of stygofauna sampled with the KC method (10 samples) compared to the traditional haul net sampling method (139 samples). We found significant differences in stygofauna species composition between the KC and haul net methods, with 13 species (out of 78 species) collected exclusively with the KC method. However, there was also a considerable overlap of species collected by the two methods (11 species). Despite the current limited data, our findings demonstrate that the KC method could be complementary to traditional stygofauna sampling methods. It also allows sampling of potentially connected groundwater habitats to occur beyond the areas drilled for minerals or water. While this method usually targets stygofauna, the collection of troglofauna as by catch is significant and provides a potential way to evaluate the ecology of troglobitic taxa. Further study is needed to assess the KC method as a valuable addition to sampling methods aiming to produce comprehensive inventories of stygofauna that integrate species found in interstitial subterranean environments.

Landscape openness has different effects on the structure, diversity and functional composition of Brazilian rainforests

Landscape openness leads to harsher environmental conditions and reduced propagule dispersal, but how it affects different forest attributes and over what spatial scale remains unclear. We evaluate the effects of landscape openness (i.e., increased forest loss and fragmentation) on nine forest attributes related to structure, diversity, and composition for four different spatial scales, and three regions in Brazilian Atlantic forest. For 35 0.1 ha forest plots we calculated nine forest attributes related to structure (basal area, maximum height, structural heterogeneity), tree biodiversity (species richness, Simpson diversity, functional richness) and functional composition (proportion of animal-dispersed and shade-tolerant species, seed size). To assess at what spatial scales landscape characteristics play a role, we calculated for each plot local matrix openness and forest patch density using four concentric circles of 400 to 3200 m radius. Landscape openness negatively affected most forest attributes, but the magnitude of effect varied with 1) landscape attribute, 2) forest attribute, and 3) region. First, matrix openness had a negative stronger effect than patch density, indicating that landscape forest loss is more detrimental than forest fragmentation. Second, landscape openness reduced most strongly forest structure and animal-dispersed species, probably because open landscapes increase edge effects which especially affect large-sized trees, and reduce the abundance and activity of zoochorous seed dispersers, while landscape openness had opposite effects on diversity in different regions. Third, landscape openness had different effects in different regions, probably because of regional differences in tree species composition, landscape configuration and composition. Finally, landscape openness affected forest structural attributes at all spatial scales, animal-dispersed species at larger spatial scales (>1600 m), and seed size at small spatial scales (<400 m). In sum, landscape openness reduced most forest attributes, although the strength varied with the landscape attribute, forest attribute, and landscape context. Conservation and restoration projects should therefore restore landscape forest cover to improve forest structure, diversity and composition, and take into account the landscape context.

Functional and phylogenetic diversity of an agricultural matrix avifauna: The role of habitat heterogeneity in Afrotropical farmland.

Varied strategies to alleviate the loss of farmland biodiversity have been tested, yet there is still insufficient evidence supporting their effectiveness, especially when considering phylogenetic and functional diversity alongside traditional taxonomic diversity metrics. This conservation challenge is accentuated in the Afrotropics by the rapid agricultural expansion and intensification for the production of cash crops and by a comparative lack of research. In this study, we assessed how farming practices influence avian phylogenetic and functional diversity. We conducted point‐count surveys to assess avian diversity in monocultures of tea and mixed crop farming systems surrounding the Nyungwe rainforest in south‐west Rwanda, allowing us to investigate the drivers of avian diversity at farm level. Species composition was found to be moderately different between farm types, with mixed crop farms supporting higher phylogenetic diversity than tea plantations. There were no significant seasonal differences in species composition, functional or phylogenetic diversity. Overall, functional diversity did not differ between farm types, but the dispersion of trophic‐related traits was significantly higher in mixed crop farms. Both functional and phylogenetic diversity were influenced by floristic diversity, vegetation height, tree number, and elevation to varying degrees. Our results also (i) highlight the role of farmland heterogeneity (e.g., crop species composition, height, and tree cover extent) in encouraging avian functional and phylogenetic diversity in the Afrotropics and (ii) indicate that the generally negative biodiversity impacts of monoculture agriculture can be partially alleviated by extensive agroforestry with an emphasis on indigenous tree species.

Urban plant diversity in Kazakhstan: Effects of habitat type, city size and macroclimate

AbstractQuestionsUrbanisation has accelerated the spread of alien and apophytic species around the world including the drylands of continental inland Asia. However, few studies have examined the patterns and drivers of urban plant diversity in this region. We ask how habitat type, city size and macroclimate affect species richness and composition of alien, apophytic and non‐apophytic indigenous plants in cities of the steppe and forest‐steppe zones of Kazakhstan.LocationTen cities in central and northeastern Kazakhstan, Middle Asia.MethodsUsing a standardized sampling protocol, we recorded spontaneously occurring vascular plant species in 1‐ha plots in seven habitat types (central square, boulevard, residential area, park, early‐successional vacant site, mid‐successional vacant site and railway station) in five large (&gt;100,000 inhabitants) and five small (&lt;100,000 inhabitants) cities. We used linear mixed‐effect models to quantify the effects of habitat type, city size and macroclimate on species richness and the proportion of alien, apophytic and non‐apophytic indigenous plants.ResultsPlant species richness differed significantly among habitat types, with the lowest richness in central squares, and the highest in railway stations and residential areas. Apophytic species were most numerous in railway stations and alien species in residential areas. The richness of alien, apophytic and non‐apophytic indigenous species varied more among habitats than among cities. The proportion of apophytes increased linearly with annual precipitation. The largest differences in species composition were between disturbed sites in city centres (squares, boulevards and parks) and early‐successional, mid‐successional and railway station sites. Large and small cities also differed in species composition.ConclusionsPlant diversity in cities of northern Kazakhstan depends mainly on habitat type and less on macroclimate. Overall, cities in inland continental Asia follow patterns of urban species diversity observed in other Asian and European cities.

Spatial-temporal Variations of Discarded Ichthyofauna from a Small-scale Shrimp Fishery: Influence of Ecological Patterns in a Yucatan Coastal Lagoon

Sauz-Sánchez, J.J.; López-Rocha, J.A.; Arceo-Carranza, D., and Poot-López, G.R., 2022. Spatial-temporal variations of discarded ichthyofauna from a small-scale shrimp fishery: Influence of ecological patterns in a Yucatan coastal lagoon. Journal of Coastal Research, 38(4), 860–869. Coconut Creek (Florida), ISSN 0749-0208. Spatial-temporal variations of discarded catches associated with a shrimp-small scale fishery from the Celestun lagoon, Yucatan, Mexico, were analyzed throughout seasonal and spatial (inner, middle, and external estuarine zones) physicochemical gradients to observe the influence of ecological patterns on discarded ichthyofauna. Differences in abundance, biomass, composition, and physicochemical variables between seasons and among zones were tested using a two-way ANOVA and an analysis of dissimilarity, respectively. The best subset of environmental variables (BIOENV) function was used to observe the influence of physicochemical gradients on the discarded fish community. A total of 1611 individuals belonging to 36 species of discarded fish were identified, with mostly an abundance of juveniles occurring for the following species: Achirus lineatus, Archosargus probatocephalus, Cynoscion nebulosus, Eucinostomus gula, Floridichthys polyommus, Lagodon rhomboides, Lucania parva, Mayaheros urophthalmus, and Sphoeroides testudineus. Hence, the data shows a strong selection pressure on juvenile fish. Significant differences in abundance, species composition, and physicochemical variables were observed between seasons and zones. Results from the BIOENV indicated that temperature, salinity, and pH gradients, generated by underground freshwater discharges, influenced the spatial-temporal variations of discarded ichthyofauna from the Celestun lagoon. Furthermore, reproductive seasons, and capabilities to tolerate salinity concentrations also spatially structures a discarded fish community. The results showed the ecological complexity in which fish discards occur, in addition, suggesting measures to reduce discards by including ecological and social aspects to maintain the sustainability of this artisanal shrimp fishery.

Population demography maintains biogeographic boundaries.

Global biodiversity is organised into biogeographic regions that comprise distinct biotas. The contemporary factors maintaining differences in species composition between regions are poorly understood. Given evidence that populations with sufficient genetic variation can adapt to fill new habitats, it is surprising that more homogenisation of species assemblages across regions has not occurred. Theory suggests that expansion across biogeographic regions could be limited by reduced adaptive capacity due to demographic variation along environmental gradients, but this possibility has not been empirically explored. Using three independently curated data sets describing continental patterns of mammalian demography and population genetics, we show that populations near biogeographic boundaries have lower effective population sizes and genetic diversity, and are more genetically differentiated. These patterns are consistent with reduced adaptive capacity in areas where one biogeographic region transitions into the next. That these patterns are replicated across mammals suggests they are stable and generalisable in their contribution to long-term limits on biodiversity homogenisation. Understanding the contemporary processes that maintain compositional differences among regional biotas is crucial for our understanding of the current and future organisation of global biodiversity.

Fungal Diversity in Barley Under Different Storage Conditions.

The diversity of fungi in barley in simulated storage environments was analyzed. Barley was stored at different temperatures (15, 25, 35°C) and relative humidity (55, 65, 75, 85 RH) for 180 and 360 days. Alpha diversity, beta diversity, species composition, and species differences were analyzed using Illumina HiSeq technology. The fungal communities in all barley samples before and after storage belonged to 3 phyla, 18 classes, 39 orders, 71 families, 103 genera, and 152 species. The relative abundance of the dominant phylum Ascomycota was 77.98–99.19%. The relative abundance of Basidiomycota was 0.77–21.96%. At the genus level, the dominant genera of fungi in barley initially included Fusarium, Aspergillus, Microdochium, Alternaria, and Epicoccum. After 360 days of storage, the dominant genera became Epicoccum, Alternaria, Bipolar, Cladosporium, Fusarium, and Aspergillus. According to Venn diagrams and principal coordinates analysis, the fungal community diversity in barley initially was much higher than in barley stored at different temperatures and humidity. The application of PLS-DA could accurately distinguish between barley stored for 180 and 360 days. Some high-temperature and high-humidity environments accelerated storage. The dominant genera differed in different storage conditions and constantly changed with increasing storage duration. Epicoccum was one of the dominant genera after longer storage periods. This study provides theoretical support for optimizing safe storage conditions in barley.

Diversity and Structure of Demersal Fish Community Over the Northern Slope in the South China Sea

Three bottom trawl surveys over the northern continental slope in the South China Sea (18°50′–20°40′N, 112°50′–115°10′E) were carried out, in June 2015, March 2017 and September 2018, to investigate species composition, biodiversity and community structure of demersal fish. Surveys in 2015, 2017 and 2018 captured 97 fish species (representing 77 genera, 52 families, 26 orders), 108 fish species (representing 84 genera, 61 families, 19 orders) and 126 fish species (representing 105 genera, 74 families, 25 orders), respectively. Three surveys captured a total of 252 fish species, representing 164 genera, 97 families, 30 orders. Perciformes dominated. Species richness in station linking shallow continental shelf with deep slope was the lowest among stations. In three surveys, 16 species occurred in the catches of three surveys, accounting for 6.35% of all species. Species replacement rate between stations showed a significant linear relationship with the depth difference and latitude difference. Margalef’s species richness index (D), Shannon–Weiner diversity index (H’) and Pielou’s evenness index (J’) among stations ranged 2.65–6.74, 1.02–4.15 and 0.28–1.14, respectively. Differences of D, H’ and J’ were insignificant among seasons. There were significant positive linear relations between H’ and J’ and latitude. D, H’ and J’ decreased with increasing sampling depth, however the relations were not significant. Based on multivariate statistical analysis, fish community at species level was divided into five groups with average dissimilarities of 95.69%–99.96%. In terms of genus and family, average dissimilarities among groups were more than 88.11% and 82.69%. There were significant differences in species composition between depths, but no significant differences between seasons and temperatures, as well as in genus and family composition.