High Species Diversity Research Articles

Functional adaptive resources for large herbivores in African savannas: an ecological-gradient based framework

The viability of large herbivore populations in the face of climate change, environmental variability, disease and predation will be determined by their freedom to assess and respond to these factors through access to a range of functional seasonal resources and habitats. Their responses will be contingent upon various organismal traits, such as body size, mouth and digestive anatomy, which also facilitate coexistence among sympatric species. In this paper we develop a functional adaptive forage resource framework based on plant biomass, quality and phenology responses on ecological productivity gradients. We show how large herbivores coexist and respond to environmental variability, disease and predation by their foraging responses in relation to functional adaptive resources, as mediated by their anatomical traits. Below a critical body size, where predation limits population size, large herbivores adopt a variety of predation avoidance strategies, which are linked to their anatomical traits and foraging strategies. Mouth anatomy, and its interaction with body size, appears to be the major anatomical trait determining large herbivore selection for grass height. Body size is the major trait determining vulnerability to predators. Ecological productivity gradients underlain by variation in soil moisture availability over the annual cycle support high quality forage in the least productive (driest) regions, which promote growth and reproduction (a fecundity resource). Reserves of adequate quality forage in moderate productivity regions and buffers of low-quality forage in wetter and more productive regions of the gradient prevent loss of body stores over the dry season and starvation during droughts. Fire and grazing contribute towards providing high quality forage by removing old, low-quality material and preventing forage maturation. Consuming a high diversity of plant species distributed across ecological gradients promotes phytochemical diversity in the diet, which functions as medicinal resources to promote health while combating disease and parasites. Large herbivores are becoming increasingly restricted by ecosystem fragmentation in their access to the full range of these functional resource classes. The negative consequences for large herbivore populations of reduced access to these resource classes is compounded by climate change, where conditions are hotter and drought frequency and intensity is expected to be higher.

EVALUACIÓN DEL ESTADO DE LA AGROBIODIVERSIDAD EN EL SISTEMA AGROALIMENTARIO DE MÉXICO

<p class="Default"><strong>Background</strong>. Agrobiodiversity is one of the main pillars of agriculture in Mexico, so its conservation is a priority for the sustainability and resilience of the agri-food system. <strong>Objective. </strong>To analyze the agrobiodiversity's state in the Mexican agricultural, food and genetic resources system. <strong>Methodology. </strong>Methodologically, the Agrobiodiversity Index was implemented, ten indicators and 16 variables were measured, which included species diversity, varietal diversity, underutilized species, and landscape complexity in the agrifood system. <strong>Results. </strong>The State of Agrobiodiversity Index for Mexico was moderate (56.2/100), the score for the food system was high (66.6/100), the agricultural system presented high scores (63.1/100) and the conservation system gave low scores (38.4). /100). <strong>Implications</strong>. The conservation system has focused on commercial plant species, leaving a gap in the conservation and sustainable use of wild and non-commercial species. In the agricultural and conservation system, it is urgent to create platforms with more specific biological information (intraspecific levels, varieties, races, cultivars). With these platforms, a more precise estimate of the country's agrobiodiversity will be possible. <strong>Conclusion</strong> Although the country has a high diversity of animal and plant species that serve as a source of food, these options are underutilized in the food system.</p>

Broad-scale spatial distribution patterns of soft-sediment macrobenthic communities in the Red Sea

In sub-tropical and tropical regions, the diversity patterns of soft-sediment macrobenthic communities are still poorly understood, particularly when compared to temperate shelf environments. The present study investigates spatial patterns of variability in macrobenthic distribution along the eastern Red Sea margin, and the role of sediment composition and other explanatory variables in determining such patterns. This study has two main objectives: (i) to produce a baseline characterization of the Saudi Arabian Red Sea macrobenthic infauna, particularly along the central and southern regions, (ii) to assess the relative contribution of two major processes driving macrobenthic communities (i.e., dispersal-based and environmental filtering), based on changes on beta-diversity components (turnover and nestedness) across multiple scales (up to ~600km), using relevant modeling methodologies. Shallow soft-sediment macrobenthic communities in the Red Sea showed extremely high small-scale variability, highlighted by the percentage of rare species (44% of species present at a single sample) and the dominance of turnover (species replacement) over nestedness. Our results also suggest a strong influence of broad- over fine-scale variation in the species composition. However, sedimentary characteristics, particularly grain-size, played a critical role governing the distribution patterns of soft-sediment macrobenthic communities in the Red Sea. Our findings highlight the importance of regional factors in shaping the macrofaunal community composition whilst also highlighting the role of high species diversity at local scales. The current results suggest the need for conservation measures from regional levels (to maintain genetic diversity) to local levels (to preserve the high occurrence of rare species). To our knowledge, no other study investigated the distribution of Red Sea marine species over large spatial scales combining modeling methods and the partitioning of beta-diversity. The current approach applied to soft-sediment macroinvertebrates can be extended to other marine communities since conservation strategies can be more effective when mechanisms governing species distribution are considered.

Langbiangia, a new genus of Gesneriaceae endemic to Langbiang Plateau, southern Vietnam and a taxonomic endeavor to achieve key targets of the post-2020 global biodiversity framework.

Situated in the southern end of the Annamite Mountain Range, Langbiang Plateau is a major biodiversity hotspot of southern Vietnam known for high species diversity and endemicity. To achieve effective conservation, parts of the plateau were designated as the Langbiang Biosphere Reserve, an UNESCO World Network aiming to improve relationships between inhabitants and their environments. Amongst the rich endemic flora of the plateau are three gesneriads ascribed to Primulina, a calciphilous genus with high species diversity in the vast limestone karsts stretching from southern China to northern Vietnam. However, a recent phylogenetic study questioned the generic placement of the Langbiang Primulina, corroborating with observations on the geographical distribution, habitat preference, and phyllotaxy of the three species. Based on phylogenetic analyses of nuclear ITS and plastid trnL-F DNA sequences of a comprehensive sampling covering nearly all genera of the Old World Gesneriaceae, we demonstrate that the three Langbiang Primulina species form a fully supported clade distantly related to other Primulina. As this clade is biogeographically, ecologically, morphologically, and phylogenetically distinct worthy of generic recognition, we propose to name it Langbiangia gen. nov. to highlight the rich and unique biodiversity of the Langbiang Plateau. By means of this taxonomic endeavor, we are hoping to raise the conservation awareness of this biodiversity heritage of southern Vietnam and promote the importance of Langbiang Biosphere Reserve that is crucial for achieving action-oriented global targets of the post-2020 global biodiversity framework (GBF) of the UN Convention on Biological Diversity (CBD)-effective conservation and management of at least 30% of biodiverse terrestrial, inland water, and costal and marine areas by 2030-that has been agreed at the COP15 in Montréal in December 2022.

A New Species of Unibarra (Monogenoidea, Dactylogyridae) Parasite of Oxydoras niger From Juruá River, State of Acre, Brazil and New Data for U. paranoplatensis.

Monogenoids are ectoparasites that have a simple one-host lifecycle, high species diversity, and a relatively high host specificity. During studies on the helminth fauna of fishes from the Jurua River, in Acre State, Brazil, a new species of the monotypic genus Unibarra Suriano & Incorvaia, 1995 was found parasitizing Oxydoras niger Valenciennes, 1821. Unibarra juruaensis n. sp. is allocated in the genus based on the presence of a single haptoral bar, marginal hooks similar in shape and size, gonads partially overlapping, and a conspicuous filament which connects the base of the male copulatory organ with the accessory piece. The new species differs from the only species of the genus by the smaller size of the body and of the structures, by the morphology of copulatory complex, with an accessory piece thinner than that of U. paranoplatensis Suriano & Incorvaia, 1995 and by the presence of two eyespots. The type species, U. paranoplatensis, is referred in a new host, Pimelodus blochii Valenciennes, 1840, with new morphological data. A table of measurements of the new species and previous and the present reports of U. paranoplatensis is presented.

Seasonal and Periodical Assessment of the Abundance and Diversity of Epigaeic Invertebrates in an Urban Forest Remnant, Dar es Salaam, Tanzania

Urban Forest (UF) refers to a complex human-environment system encompassing urban and peri-urban vegetation such as gardens, rivers and coastal corridors, and uninhabited yards. Human beings benefit from a healthy UF in a variety of ways such as recreation, disasters management, and the lessening of the effects of environmental deterioration (caused by the ongoing anthropogenic activities) like air pollution and ozone concentration affecting many epigaeic fauna. Epigaeic Invertebrates (EIs) are above ground foraging or litter dwelling invertebrates carrying important roles in UFs ecosystems such as ecosystem engineers and pests’ natural enemies. The present study assessed the influence of dry and wet seasons and different periods of a day (morning, afternoon, and evening hours) towards the abundance and diversity of ground dwelling invertebrates around urban forest remnant in Dar es salaam city, Tanzania. Data collection used pitfall trap, baited traps, and dry leaf litter sifting methods. A total of 10,363 EIs individuals were collected with 133 morpho species, 87 families and 18 orders (Hymenoptera dominated by 71.4%). Wet season had significantly higher abundance (6,360 individuals with 121 morpho species) than dry season (4,003 individuals and 88 morpho species), possibly due to the higher availability of food resources during rainy times. However, quite unexpectedly dry season had higher species diversity, probably due to the over dominance of a very aggressive Formicidae species in wet season that displaced some intolerable species. Also, the overall variations of species diversity and abundance between morning, afternoon, and evening hours were significantly different but higher in the morning. This suggested that EIs were active at different times of the day but were more attracted to the morning sunshine and decreased as the land became hotter. This study depicts urban forests to be among world ecosystems with relatively high levels of EIs biodiversity and hence an urgent call for their conservation efforts before it is too late.

High Diversity of Bradyrhizobial Species Fix Nitrogen with Woody Legume Spartocytisus supranubius in a High Mountain Ecosystem.

The symbiosis between rhizobia and legumes is of pivotal importance in nitrogen-poor ecosystems. Furthermore, as it is a specific process (most legumes only establish a symbiosis with certain rhizobia), it is of great interest to know which rhizobia are able to nodulate key legumes in a specific habitat. This study describes the diversity of the rhizobia that are able to nodulate the shrub legume Spartocytisus supranubius in the harsh environmental conditions of the high mountain ecosystem of Teide National Park (Tenerife). The diversity of microsymbionts nodulating S. supranubius was estimated from a phylogenetic analysis of root nodule bacteria isolated from soils at three selected locations in the park. The results showed that a high diversity of species of Bradyrhizobium and two symbiovars can nodulate this legume. Phylogenies of ribosomal and housekeeping genes showed these strains distributed into three main clusters and a few isolates on separate branches. These clusters consist of strains representing three new phylogenetic lineages of the genus Bradyrhizobium. Two of these lineages belong to the B. japonicum superclade, which we refer to as B. canariense-like and B. hipponense-like, as the type strains of these species are the closest species to our isolates. The third main group was clustered within the B. elkanii superclade and is referred to as B. algeriense-like as B. algeriense is its closest species. This is the first time that bradyrhizobia of the B. elkanii superclade have been reported for the canarian genista. Furthermore, our results suggest that these three main groups might belong to potential new species of the genus Bradyrhizobium. Analysis of the soil physicochemical properties of the three study sites showed some significant differences in several parameters, which, however, did not have a major influence on the distribution of bradyrhizobial genotypes at the different locations. The B. algeriense-like group had a more restrictive distribution pattern, while the other two lineages were detected in all of the soils. This suggests that the microsymbionts are well adapted to the harsh environmental conditions of Teide National Park.

Keanekaragaman kupu-kupu (Lepidoptera: Papilionoidea) di Kawasan Pusat Pendidikan Konservasi Alam Bodogol, Taman Nasional Gunung Gede Pangrango, Jawa Barat

Kupu-kupu merupakan salah satu kelompok serangga dengan keanekaragaman spesies yang tinggi dan memiliki keterkaitan erat dengan faktor lingkungan yang mempengaruhi keberadaan dan kelimpahannya di suatu habitat. Tujuan penelitian ini adalah untuk menganalisis keanekaragaman dan kelimpahan populasi kupu-kupu di PPKA Bodogol, Sukabumi Jawa Barat. Pengamatan kupu-kupu dilakukan dengan metode transek sepanjang 700 m mengunakan kamera dan sweeping net di sepanjang jalur yang ada di dua lokasi, yakni hutan heterogen dan hutan homogen. Pengamatan kupu-kupu dilakukan mulai pukul 08.00 hingga pukul 12.00 pagi. Berdasarkan hasil penelitian di hutan heterogen ditemukan 78 spesies (261 individu), di hutan homogen ditemukan 39 spesies (158 individu), yang termasuk ke dalam 5 famili, yaitu Lycaenidae, Nymphalidae, Papilionidae, Pieridae, dan Rionidae. Famili Nymphalidae merupakan famili yang memiliki jumlah spesies dan individu paling tinggi dibanding famili lainnya. Nilai kesamaan komposisi kupu-kupu <50%, yang berarti komposisi kupu-kupu yang ditemukan di dua habitat tidak sama. Indeks keanekaragaman kupu-kupu di hutan heterogen lebih tinggi dibandingkan dengan hutan homogen. Dari uji hutchinson tidak terdapat perbedaan yang bermakna. Nilai indeks kemerataan spesies pada dua habitat menunjukan nilai yang hampir sama, yaitu 0,9 di hutan heterogen dan 0,8 di hutan homogen. Keberadaan, keanekaragaman, serta kelimpahan kupu-kupu di suatu habitat berkaitan erat dengan jenis habitat serta unsur-unsur abiotik maupun biotik yang ada di dalamnya.

Fish diversity of the Bengawan Solo River estuary, East Java, Indonesia

Abstract. Hasan V, Andraini NE, Isroni W, Sari LA, Nafisyah AL, Dewi NN, Putri DNA, Prasasti TAB, Ramadhani AA, Daniel K, South J, Vieira LO, Ottoni FP, Maftuch, Faqih AR, Wirabuana PYAP, Tamam MB, Valen FS. 2023. Fish diversity of the Bengawan Solo River estuary, East Java, Indonesia. Biodiversitas 24: 2207-2216. Bengawan Solo River is the longest river in Java which flows from Mount Lawu and empties into the North Coast of Java. The watershed is a hot spot for fish species diversity, especially in the estuary area. The purpose of this study was to initiate an inventory of fish species, their abundance, and biodiversity assessment based on the Shannon diversity index (H'), evenness index (E), and dominance index (C) in the Bengawan Solo River estuary. The research was conducted from September to November 2022 at three stations with different ecological types and environmental conditions. Fish sampling was carried out using a gill net attached to a boat. In this study, 44 fish species from 22 families were identified. The highest abundance of fish was obtained from the Ariidae family, namely the Spotted sea catfish Arius maculatus (Thunberg, 1792) and Sagor catfish Hexanematichthys sagor (Hamilton, 1822). The fish diversity index obtained was 1.2-3.01, the uniformity index obtained was 0.7-0.92, and the dominance index obtained was 0.07-0.33. The H', E, and C at Station 2 have higher values ??than the other stations. The diversity expressed in H' values ??at the three research stations indicates that the mangrove in the Bengawan Solo River estuary area has a high diversity of fish species.

Diversity and Relative Abundance of Entomofauna of Four Ecologically Different Areas of Chittagong University Campus, Bangladesh

The present study was conducted to find the relative abundance and diversity of insects in the four areas of the Chittagong University (CU) campus from January 2018 to December 2018. The entire study found six orders - Odonata, Orthoptera, Coleoptera, Lepidoptera, Diptera, and Hymenoptera. Three families under Odonata, two under Orthoptera, four under Coleoptera, five under Lepidoptera, five under Diptera, and three under Hymenoptera were collected from the four study spots. Among them, fifteen species of Odonata, seven species of Orthoptera, seven species of Coleoptera, thirty-five species of Lepidoptera, five species of Diptera, and four species of Hymenopteran were identified. The highest number of insects (478) were collected in January 2018, whereas the lowest number of insects (404) were collected in August 2018. The highest abundance (1598) of insects was found in spot 1 (ground area) and the lowest (990) in spot 2 (hilly area). Lepidoptera (2688) was the most dominant order in the four studied spots, followed by Odonata (1453), Orthoptera (505), Coleoptera (223), Diptera (202), and Hymenoptera (186). During the study period, the highest species richness was observed in Spot 3 (2.61 ± 0.01) and lowest in Spot 2 (2.03 ± 0.008); the highest species diversity was observed in Spot 1 (1.36 ± 0.02) and lowest in Spot 2 (1.09 ± 0.01); and the highest species evenness was observed in Spot 1 (0.53 ± 0.006) and lowest in Spot 2 (0.47 ± 0.006). Compared with the previous study, it can be concluded that the species diversity and abundance of Odonata, Orthoptera, and Lepidoptera were increased, whereas the diversity and abundance of Coleoptera and Hymenoptera were decreased. The abundance and diversity of insects depended on seasonal fluctuation and ecological and environmental conditions.

Metabarcoding analysis identifies high diversity of harmful algal bloom species in the coastal waters of the Beibu Gulf.

Harmful algal blooms (HABs) have occurred more frequently in recent years. In this study, to investigate their potential impact in the Beibu Gulf, short-read and long-read metabarcoding analyses were combined for annual marine phytoplankton community and HAB species identification. Short-read metabarcoding showed a high level of phytoplankton biodiversity in this area, with Dinophyceae dominating, especially Gymnodiniales. Multiple small phytoplankton, including Prymnesiophyceae and Prasinophyceae, were also identified, which complements the previous lack of identifying small phytoplankton and those unstable after fixation. Of the top 20 phytoplankton genera identified, 15 were HAB-forming genera, which accounted for 47.3%-71.5% of the relative abundance of phytoplankton. Based on long-read metabarcoding, a total of 147 OTUs (PID > 97%) belonging to phytoplankton were identified at the species level, including 118 species. Among them, 37 species belonged to HAB-forming species, and 98 species were reported for the first time in the Beibu Gulf. Contrasting the two metabarcoding approaches at the class level, they both showed a predominance of Dinophyceae, and both included high abundances of Bacillariophyceae, Prasinophyceae, and Prymnesiophyceae, but the relative contents of the classes varied. Notably, the results of the two metabarcoding approaches were quite different below the genus level. The high abundance and diversity of HAB species were probably due to their special life history and multiple nutritional modes. Annual HAB species variation revealed in this study provided a basis for evaluating their potential impact on aquaculture and even nuclear power plant safety in the Beibu Gulf.

Equid nutritional physiology and behavior: an evolutionary perspective.

Like other members of the even-toed ungulates (the perissodactyls), equids once had a higher species diversity in the fossil record than they have today. This is generally explained in comparison to the enormous diversity of bovid ruminants. Theories on putative competitive disadvantages of equids include the use of a single toe as opposed to two toes per leg, the lack of a specific brain cooling (and hence water-saving) mechanism, longer gestation periods that delay reproductive output, and in particular digestive physiology. To date, there is no empirical support for the theory that equids fare better on low-quality forage than ruminants. In contrast to the traditional juxtaposition of hindgut and foregut fermenters, we suggest that it is more insightful to sketch the evolution of equid and ruminant digestive physiology as a case of convergence: both evolved a particularly high chewing efficacy in their respective groups, which facilitates comparatively high feed and hence energy intakes. But because the ruminant system, less based on tooth anatomy but more on a forestomach sorting mechanism, is more effective, equids depend more on high feed intakes than ruminants and may well be more susceptible to feed shortages. Arguably, the most under-emphasized characteristic of equids may be that in contrast to many other herbivores including ruminants and coprophageous hindgut fermenters, equids do not use the microbial biomass growing in their gastrointestinal tract. Equids display behavioral and morphophysiological adaptations to high feed intakes, and their cranial anatomy that facilitates the cropping of forage while performing grinding chewing at the same time might be unique. Rather than looking for explanations how equids are better adapted to their present niches than other organisms, considering them remnants of a different morphophysiological solution may be more appropriate.

Reshaped Gut Microbial Composition and Functions Associated with the Antifatigue Effect of Salidroside in Exercise Mice.

Salidroside (SA) is an active compound derived from Rhodiola rosea and is widely used in healthcare foods. However, the underlying mechanism and its specific role in regulating the gut microbial community during exercise (Ex) remains unknown. Mice are subjected to a weight-loaded swimming test (WST) Ex to determine how gut microbiota affects the antifatigue activity of SA. The SA-treated group mice (100mgkg-1 .bw.) display a significant increase in swimming time compared to the control group (26.2 versus 10.5min, p<0.01), as well as an increase in respiratory enzymatic activities after swimming. The respiratory enzymatic activities are significantly higher in the SA-treated group than in the RS (regular rest) group after swimming. The bacteria profiles in the Ex+SA group change significantly with higher species diversity and abundance. Receiver operating characteristic (ROC) curves of Alistipes, Rikenellaceae, Parabacteroides, Candidatus Arthromitus, and Lactobacillus indicate a high diagnostic utility to distinguish SA treatment. Microbial function analysis shows that SA may improve Ex-induced fatigue by modulating energy metabolism-related processes. SA demonstrates antifatigue effects on various levels of regulating energy metabolism and microbial composition, providing insights into the underlying mechanisms of SA as a natural prebiotic.

High diversity of yeast species and strains responsible for vulvovaginal candidiasis in South-East Gabon.

Candida albicans generally remains the principal pathogenic yeast responsible for vulvovaginal candidiasis (VVC), although with variable prevalence. In this study, we evaluated the evolution of the prevalence of the non-Candida albicans Candida (NCAC) species and investigated the genotypic diversity and the population genetic structure of the circulating C. albicans strains associated with VVC in the vicinity of Franceville (Gabon). A total of 110 independent isolates were identified using both MALDI-TOF MS and conventional techniques. The population genetic structure of the C. albicans strains was determined by multiple locus variable-number tandem repeat analysis using 4 microsatellite markers. The mean and median age of the patients was 31 years. Seven patients had a mixed infection. C. albicans accounted for 62% (n=68) of the total isolates. NCAC were dominated by C. glabrata, followed by P. kudriavzevii, C. parapsilosis, C. tropicalis, M. guilliermondii, and C. nivariensis. The cluster analysis revealed a high diversity, with a total of 50 different genotypes. The most represented genotype was shared by only four strains, while the vast majority (39 strains) had a unique MLVA pattern. Geographic clusters were not detected. The study provides information on species distribution and possible changing epidemiology while reporting for the first time C. nivariensis in VVC in Africa. This study is also the first to investigate the genotypic diversity of the circulating C. albicans strains associated with VVC in Central Africa. Such analyses would help understand the molecular epidemiology of C. albicans.

High Diversity of Fusarium Species in Onychomycosis: Clinical Presentations, Molecular Identification, and Antifungal Susceptibility

Fusarium are uncommon but important pathogenic organisms; they cause non-dermatophyte mould (NDM) onychomycosis. Patients typically respond poorly to treatment owing to Fusarium's native resistance to multiple antifungal drugs. However, epidemiological data for Fusarium onychomycosis are lacking in Taiwan. We retrospectively reviewed the data of 84 patients with positive Fusarium nail sample cultures at Chang Gung Memorial Hospital, Linkou Branch between 2014 and 2020. We aimed to investigate the clinical presentations, microscopic and pathological characteristics, antifungal susceptibility, and species diversity of Fusarium in patients with Fusarium onychomycosis. We enrolled 29 patients using the six-parameter criteria for NDM onychomycosis to determine the clinical significance of Fusarium in these patients. All isolates were subjected to species identification by sequences and molecular phylogeny. A total of 47 Fusarium strains belonging to 13 species in four different Fusarium species complexes (with Fusarium keratoplasticum predominating) were isolated from 29 patients. Six types of histopathology findings were specific to Fusarium onychomycosis, which may be useful for differentiating dermatophytes from NDMs. The results of drug susceptibility testing showed high variation among species complexes, and efinaconazole, lanoconazole, and luliconazole showed excellent in vitro activity for the most part. This study's primary limitation was its single-centre retrospective design. Our study showed a high diversity of Fusarium species in diseased nails. Fusarium onychomycosis has clinical and pathological features distinct from those of dermatophyte onychomycosis. Thus, careful diagnosis and proper pathogen identification are essential in the management of NDM onychomycosis caused by Fusarium sp.

Benthic foraminiferal response to the Oceanic Anoxic Event 2 (Late Cretaceous) and evidence of bottom water re‐oxygenation during the Plenus Cold Event at Clot Chevalier (Vocontian Basin, SE France)

The Cenomanian-Turonian boundary interval is characterized by environmental perturbations related to the Oceanic Anoxic Event 2 (OAE 2) that severely affected the marine biota, including benthic and planktonic foraminifera. We present a continuous high-resolution benthic foraminiferal record in combination with published planktonic foraminiferal and geochemical data across the Cenomanian-Turonian boundary interval in the Clot Chevalier section (Vocontian Basin, SE France) with the aim to interpret paleoceanographic changes in bottom waters. Benthic foraminiferal assemblages are characterized by low diversity and indicate an outer shelf-upper bathyal environment. Changes in composition and abundance of the benthic assemblages throughout the stratigraphic section allow identification of seven distinct environments. In the middle Cenomanian, below the OAE 2, benthic foraminifera show high species diversity and abundance of infaunal and epifaunal taxa, suggesting an environment characterized by oxic conditions at the seafloor. The microfossil assemblages in the upper Cenomanian within the OAE 2 interval are dominated by radiolaria (> 50%) followed by benthic calcareous taxa (Gavelinella sp., Gyroidinoides sp., Praebulimina elata, Tappanina laciniosa). Benthic agglutinated taxa (Ammobaculites sp., Ammodiscus cretaceus, Gaudryina sp., Textulariopsis bettenstaedti) show high abundance in the lowest part of the OAE 2 and disappear close to the top of the interval. The assemblage composition and the highest values of Total Organic Carbon (TOC) registered in this interval suggest eutrophication and suboxic conditions at the seafloor. However, at ∼1 m above the onset of the OAE 2, the repopulation by inferred oxic benthic foraminiferal taxa (i.e., Frondicularia sp. and Ramulina aculeata) suggests ventilation of bottom water masses, recording the Plenus Cold Event (PCE). In the lowermost Turonian, the assemblages exhibit high species diversity and abundance with the re-appearance of calcareous taxa, indicating oxic conditions, and of agglutinated taxa associated to moderate oxygen concentrations. Results show that the distribution of benthic foraminifera follows fluctuations in oxygenation and carbon export flux at the seafloor interpreted as the environmental changes associated to the onset of the OAE 2 and of the PCE across the Cenomanian-Turonian boundary interval.

Risk of extinction, variability in fish species composition, and factors influencing fish biodiversity in the Malacca Strait.

Fish biodiversity in Malaysia is under pressure due to overexploitation, pollution, and climatic stressors. Nevertheless, the information on fish biodiversity and species vulnerability status is not well documented in the region. Therefore, a study on fish species composition and abundance in the Malacca Strait of Malaysia has been conducted for the purpose of monitoring biodiversity, determining the risk of species extinction, and identifying factors influencing biodiversity distribution. The sampling was conducted based on a random stratified sampling method from the three zones of sampling locations, i.e., estuary, mangrove, and open sea area of Tanjung Karang and Port Klang of Malacca Strait. Higher species diversity was recorded at Tanjung Karang coastal and mangrove areas (H' = 2.71; H' = 1.64) than Port Klang coastal and mangrove areas (H' = 1.50, H' = 0.29), an indication that the Port Klang area is comparatively more vulnerable. The study also explored sampling location, habitat, and IUCN red list as the influencing factors for fish biodiversity. Applying IUCN red list, this study identified one Endangered and one Vulnerable species with the forecasted increasing landing for both species. Our findings suggest the urgent need for the implementation of conservation measures as well as the continuous monitoring of fish biodiversity in the area.

Checklist of the arbuscular mycorrhizal fungi of Oaxaca, an important hotspot of biodiversity in Mexico

Background: Oaxaca, a southern State in Mexico, belongs to the Mesoamerican hotspot of biodiversity. The taxonomic and diversity knowledge of arbuscular mycorrhizal fungi (AMF) in Oaxaca State is scattered and accessibility to it is difficult.&#x0D; Questions: Which AMF species have been identified in Oaxaca and which is their distribution?&#x0D; Studied species: Arbuscular mycorrhizal fungi.&#x0D; Study site: State of Oaxaca, Mexico.&#x0D; Methods: It was prepared an updated and annotated checklist of the AMF species with frequency of occurrence and the sampling sites where the species had been registered. All studies carried out previously (to date, 2022) were considered. Information on AMF taxa was available in scattered form in different publications in physical and electronic media, theses, projects, technical reports, and scientific papers.&#x0D; Results: The checklist includes 78 species, distributed among 23 genera, 10 families, and four orders. The most diverse families were Glomeraceae (26 species), followed by Gigasporaceae (20) and Acaulosporaceae (15), whereas the most diverse genera were Acaulospora and Glomus (15 and eight species, respectively). The most frequent species were Funneliformis geosporus, Acaulospora scrobiculata, and A. spinosa. The highest species diversity has been reported under the rhizosphere of Agave angustifolia, A. karwinskii, and Zea mays (39, 36, and 34 species, respectively). A new AMF species was recently isolated from the rhizosphere of a microendemic agave.&#x0D; Conclusions: The recorded AMF species of Oaxaca State confirms its position as one of the states with the highest AMF species diversity of Mexico.

Contrasting patterns along tall grass dominance in mowed mountain grasslands

Semi-natural grasslands are a perfect system to study how biotic interactions influence coexistence thanks to their high species diversity in small areas resulting from millennia of anthropogenic management. Management cessation led to the increase of highly competitive tall-perennial tussock species with a marked drop of taxonomical (TD) and functional diversity (FD). The effect of highly competitive tall-perennial tussock species on plant community under management condition is largely understudied. In this study, we try to shed light on the effect of Brachypodium genuense which dominates sub-Mediterranean abandoned mountain grasslands TD and FD. For FD, we selected as traits plant height (H), specific leaf area (SLA) and leaf area (LA). We hypothesized i) TD decreases as the cover of B. genuense increases; ii): H converges towards higher values resulting from weaker competitive exclusion; iii) SLA and LA diverge resulting from limiting similarity. TD and FD were calculated using Rao's Quadratic Entropy. We computed the community weighted mean (CWM) that we analysed with fourth corner approach and built linear models using B. genuense as a predictor. We found that B. genuense ability in dominating the grassland plant community is altered by mowing in two different ways. On one hand, increase of B. genuense lead to a drop in TD whereas for FD the increase showed contrasting patterns with divergence for H and convergence for SLA. On the other, there were changes in the main dominant strategies with an overall increase in mean trait values of both H and SLA indicating species taller in size and more fast-growing. Overall, our results highlighted how tall-perennial tussock species under mowing conditions lead to a more stratified plant community convergent towards resource acquisition strategies. A multifaceted approach should be adopted to have a better understanding of the biotic drivers on different aspect of plant community.

Impact of management practices on the tropical riverine grasslands of Brahmaputra floodplains: Implications for conservation

Globally, the conservation value of tropical grasslands, unlike tropical forests, is underappreciated, and their degradation is widespread. Conservation of this vulnerable ecosystem requires scientifically validated management strategies. The present study examines the impact of flooding, herbivory, and other management practices on the riverine grasslands of Brahmaputra floodplains of Assam, India, for devising effective conservation strategies. Inundation period-based unsupervised classification was used to derive the types and extent of grasslands viz., short (SG) and tall (TG). Subsequently, the data on vegetation composition and nutrient status viz., soil carbon (C), nitrogen (N), phosphorus (P), and potassium (K), was collected from inside and outside of 15 exclosures that were subjected to different management regimes, including grazing (freely accessed by mega- and meso-herbivores), ungrazed (not accessed by mega- and meso-herbivores), ungrazed with controlled burning and ungrazed with invasive removal. A total of 1152 plots were monitored for two-year, from January 2014 to December 2015. The results of the study revealed that the areas inundated for a longer duration were dominated by SG and had higher species diversity, while areas inundated for the shorter duration were dominated by TG and had low species diversity. We further observed that grazing exclusion promoted heterogeneity, woody and invasive growth, and soil nutrient content. Burning and invasive removal reduced woody and invasive growth and enhanced soil nutrient conditions. Grazing and burning decreased heterogeneity, while invasive removal increased heterogeneity. Alteration of the flooding regime due to reduced water availability may affect the ratio of SG and TG extent in the long run, which may alter the vegetation composition and the productivity of these grasslands. We recommend short-term rotational grazing for SG and long-term for TG to promote heterogeneity and soil quality. Controlled burning can be carried out in dry and invaded areas post uprooting of invasives to mitigate the effect of succession.