Abundant Species Research Articles

Impacts and implications of anthropogenic activities on mangrove forests: A review

The purpose of this paper is to review and evaluate published literature on the causes, impacts, implications and mitigation strategies of anthropogenic activities on mangrove forests. A systematic method was utilized to access research works of literature on “Impacts and implications of anthropogenic activities on mangrove forests”. A total of fifty-three (53) research papers published between the years 1975 to 2024 was accumulated and used for this review. A subjective approach was used to select the topics: impact and implications of anthropogenic activities on mangrove forests. In this paper, five (5) roles of mangroves were assessed and presented. Anthropogenic activities that threaten mangrove forests such as land conversion, mining and logging activities and household and industrial activities were also evaluated. Further, four (4) detrimental anthropogenic activities and the potential impacts they have on natural mangrove forests and the ecosystems they thrive in was also reported on. In addition, this paper reviewed some mitigation strategies for sustainable management and conservation of our mangroves, their ecosystems and the coastlines. The published works of literature established that reduced mangrove forests, altered mangrove composition, unequal species abundance, mass mangrove mortality, pollution in mangrove areas, rising sea levels, global climate change and coastal erosion or abrasion are all effects of anthropogenic activity that have a negative impact on mangrove forests and the ecosystems. This review highlights the fact that more studies on the impact and implications of anthropogenic activities on mangroves should be done in neotropical countries since there are paucity of such information on research and published data in these biodiversity rich regions.

Using ancient sedimentary DNA to forecast ecosystem trajectories under climate change.

Ecosystem response to climate change is complex. In order to forecast ecosystem dynamics, we need high-quality data on changes in past species abundance that can inform process-based models. Sedimentary ancient DNA (sedaDNA) has revolutionised our ability to document past ecosystems' dynamics. It provides time series of increased taxonomic resolution compared to microfossils (pollen, spores), and can often give species-level information, especially for past vascular plant and mammal abundances. Time series are much richer in information than contemporary spatial distribution information, which have been traditionally used to train models for predicting biodiversity and ecosystem responses to climate change. Here, we outline the potential contribution of sedaDNA to forecast ecosystem changes. We showcase how species-level time series may allow quantification of the effect of biotic interactions in ecosystem dynamics, and be used to estimate dispersal rates when a dense network of sites is available. By combining palaeo-time series, process-based models, and inverse modelling, we can recover the biotic and abiotic processes underlying ecosystem dynamics, which are traditionally very challenging to characterise. Dynamic models informed by sedaDNA can further be used to extrapolate beyond current dynamics and provide robust forecasts of ecosystem responses to future climate change. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.

Evaluating the influence of marine protected areas on surf zone fish.

Marine protected areas (MPAs) globally serve conservation and fisheries management goals, generating positive effects in some marine ecosystems. Surf zones and sandy beaches, critical ecotones bridging land and sea, play a pivotal role in the life cycles of numerous fish species and serve as prime areas for subsistence and recreational fishing. Despite their significance, these areas remain understudied when evaluating the effects of MPAs. We compared surf zone fish assemblages inside and outside MPAs across 3 bioregions in California (USA). Using seines and baited remote underwater videos (BRUVs), we found differences in surf zone fish inside and outside MPAs in one region. Inside south region MPAs, we observed higher abundance (Tukey's honest significant difference [HSD]=0.83, p=0.0001) and richness (HSD=0.22, p=0.0001) in BRUVs and greater biomass (HSD=0.32, p=0.0002) in seine surveys compared with reference sites. Selected live-bearing, fished taxa were positively affected by MPAs. Elasmobranchs displayed greater abundance in BRUV surveys and higher biomass in seine surveys inside south region MPAs (HSD=0.35, p=0.0003 and HSD=0.23, p=0.008, respectively). Although we observed no overall MPA signal for Embiotocidae, abundances of juvenile and large adult barred surfperch (Amphistichus argenteus), the most abundant fished species, were higher inside MPAs (K-S test D=0.19, p<0.0001). Influence of habitat characteristics on MPA performance indicated surf zone width was positively associated with fish abundance and biomass but negatively associated with richness. The south region had the largest positive effect size on all MPA performance metrics. Our findings underscored the variability in species richness and composition across regions and survey methods that significantly affected differences observed inside and outside MPAs. A comprehensive assessment of MPA performance should consider specific taxa, their distribution, and the effects of habitat factors and geography.

Maize Kernel-Associated Metagenomes Reveal Potential Microbe–Microbe Interactions that Underlie Fusarium Ear Rot Disease

As an alternative to host resistance, transgenic expression of entomocidal and antimicrobial proteins from Bacillus thuringiensis ( Bt) in maize can mitigate Fusarium ear rot (FER). This study evaluated FER in Bt and conventional maize and the role of microbes in the kernel-associated metagenome using quantitative reduced representation sequencing. Our results revealed significant differences in FER severity across environments and varieties and between inoculation treatments. The lower FER scores of conventional maize Spectrum 6416 relative to other varieties highlighted resistant alleles in maize germplasm, whereas strong correlations indicated FER-induced yield loss. Mitigation of FER by transgenes was validated by about threefold enrichment of Fusarium verticillioides ( Fv) postinoculation compared with nonsignificant Fv enrichment in conventional maize. Although the major causal pathogen of FER, Fv, was the most abundant species in the metagenomes ( r = 0.41 to 0.49), a similar degree of correlation was observed between FER and several Fusarium spp. ( r = 0.2 to 0.56). The potential FER-suppressing properties of Talaromyces stipitatus and Ustilago maydis were indicated by negative correlations with FER ( r = –0.22 to –0.42), Fv, and some Fusarium spp. The more FER-resistant varieties consistently enriched for potential FER-suppressing Burkholderia cenocepacia (negatively correlated with Fv). This suggests host genetic background-dependent recruitment of beneficial microbes that suppress pathogens and that microbe–microbe interactions play a role in FER severity. Quantitative and species/strain-level metagenomic profiles hold promise for identifying robust disease-suppressing microbes and microbes that act in synergy with pathogens and for developing holobiont-aware breeding strategies that account for host–microbiome coevolution and host genotype, microbiome/metagenome, and environment interactions. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Dual RNA-seq in filarial nematodes and Wolbachia endosymbionts using RNase H based ribosomal RNA depletion

Lymphatic filariasis is caused by parasitic nematodes and is a leading cause of disability worldwide. Many filarial worms contain the bacterium Wolbachia as an obligate endosymbiont. RNA sequencing is a common technique used to study their molecular relationships and to identify potential drug targets against the nematode and bacteria. Ribosomal RNA (rRNA) is the most abundant RNA species, accounting for 80–90% of the RNA in a sample. To reduce sequencing costs, it is necessary to remove ribosomal reads through poly-A enrichment or ribosomal depletion. Bacterial RNA does not contain a poly-A tail, making it difficult to sequence both the nematode and Wolbachia from the same library preparation using standard poly-A selection. Ribosomal depletion can utilize species-specific oligonucleotide probes to remove rRNA through pull-down or degradation methods. While species-specific probes are commercially available for many commonly studied model organisms, there are currently limited depletion options for filarial parasites. Here, we performed total RNA sequencing from Brugia malayi containing the Wolbachia symbiont (wBm) and designed ssDNA depletion probes against their rRNA sequences. We compared the total RNA library to poly-A enriched, Terminator 5′-Phosphate-Dependent Exonuclease treated, NEBNext Human/Bacteria rRNA depleted and our custom nematode probe depleted libraries. The custom nematode depletion library had the lowest percentage of ribosomal reads across all methods, with a 300-fold decrease in rRNA when compared to the total RNA library. The nematode depletion libraries also contained the highest percentage of Wolbachia mRNA reads, resulting in a 16–1,000-fold increase in bacterial reads compared to the other enrichment and depletion methods. Finally, we found that the Brugia malayi depletion probes can remove rRNA from the filarial worm Dirofilaria immitis and the majority of rRNA from the more distantly related free living nematode Caenorhabditis elegans. These custom filarial probes will allow for future dual RNA-seq experiments between nematodes and their bacterial symbionts from a single sequencing library.

Customized 16S-23S rDNA ITS Amplicon Metagenomics for Acetic Acid Bacteria Species Identification in Vinegars and Kombuchas

Acetic acid bacteria (AAB) are involved in food and beverage production bioprocesses, like those in vinegar and kombucha. They oxidize sugars and alcohols into various metabolites, resulting in the final products’ pleasant taste and aroma. The 16S rDNA amplicon metagenomics using Illumina technology is usually used to follow the microbiological development of these processes. However, the 16S rRNA gene sequences among different species of AAB are very similar, thus not enabling a reliable identification down to the species level but only to the genus. In this study, we have constructed primers for amplifying half of the 16S-23S rRNA gene internal transcribed spacer (ITS) for library construction and further sequencing using Illumina technology. This approach was successfully used to estimate the relative abundance of AAB species in defined consortia. Further application of this method for the analysis of different vinegar and kombucha samples proves it suitable for assessing the relative abundance of AAB species when these bacteria represent a predominant part of a microbial community.

Temporal changes in the composition of parasitoid assemblages associated with the invasive chestnut gall wasp

Abstract Invasive alien species pose a challenge to ecosystem stability and crop production, so understanding their interactions with the natural communities they invade is crucial to mitigate negative effects. The oriental chestnut gall wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae), is an invasive insect that attacks chestnut trees. It was first recorded in Spain in 2012 and is now presumably present in the majority of chestnut stands in the country. We assessed variation in the abundance of D. kuriphilus galls and the composition of their associated parasitoid community (Hymenoptera: Chalcidoidea) during a 4‐year period (2014–2017) in 12 sampling sites in Catalonia (Spain, northeastern Iberian Peninsula), and identified which species contributed most significantly to the control of D. kuriphilus. The results show that the abundance of individual parasitoid species varied during the study period and that the number of species increased year after year. There was also a transition in the parasitoid community composition across the years. Our data suggest that the joint action of the non‐native parasitoid Torymus sinensis Kamijo and the native T. notatus (Walker) (Hymenoptera: Chalcidoidea: Torymidae) led to the decline of D. kuriphilus until it was no longer considered a pest. Also, the observed pool of parasitoid species ended up being relatively homogeneous across sites over the years, which may be due to the high natural dispersal of these parasitoids (both by active flight and passive wind dispersal).

PHREEQ C Modelling Tool Application to Determine the Effect of Anions on Speciation of Selected Metals in Water Systems within Kajiado North Constituency in Kenya

Heavy metals and anions in water pose a significant risk to living organisms, including humans, and must therefore be carefully monitored. There are numerous approaches and methods of analysis to choose from. Using the PHREEQ C chemical modeling technique, this study looked at the effect of certain anions on the speciation of selected metals in the water environment of Kajiado North. Twenty-five sampling points were used in the study, which covered five Kajiado North election wards. Samples were taken twice during the dry and rainy seasons, in November 2019 and March 2020. Using standard methods, physicochemical characteristics were analyzed, concentrations of selected heavy metals using the (ICP- OES) 7000 series, and selected anions using a multi parameter photometer, their concentration values compared to the specified maximum contaminant level and speciation analysis done using the Computer-based technique PHREEQ C. The range observed for pH, temperature, electrical conductivity, sulphate, chloride, fluoride, nitrate and carbonates was 7.43- 9.30, 23.0 -28.0oC, 335-1265μS/cm, 4.54-361.41mgL-1, 5.19-184.6 mgL-1, 0.01-2.90 mgL-1, 0.1-8.6 mgL-1, and 3.18-55.19 mgL-1 respectively. The range observed for heavy metals was 0.06-1.08 mgL-1 , 0.00 -0.05082 mgL-1, 0.01-0.02597 mgL-1, 0.01-0.01610 mgL-1, 0.00 -0.0327 mgL-1, 0.00-42.7842 mgL-1, and below detection limit, for Fe, Mn, Cu, Zn, Pb, Mg, and Cd respectively. The findings revealed that Cd, Zn, Cu, Cl-, NO2-, and eElectrical cconductivity concentrations were below the WHO levels. At certain sampling points, however, SO42-, F-, Pb, Fe, and Mn were above WHO limits. In some water systems, traces of SO42-, F-, Cu, Fe, Cd, and Mn were found to pose significant health risks, according to PHREEQ C speciation analysis. Anion concentrations, pH, temperature, and metal concentrations are all important variables in modeling. Metals formed anion complexes and the total abundance of metal species was classified at the highest levels as Fe(OH)3, PbCO3, Zn(CO3)2, Cu(CO3)2, Mn+2, MgF-, and Mg+2. At a water system temperature of 25oC without anions, it was found to have the highest chemical species. CuCO3, CuNO3, and CuOH+ complexes are also formed at low pH. Based on the data for different metal species at different pH values, the bioavailability of metal species definitely depends on pH.

Study on the Diversity and Distribution of Spider Fauna at Sree Krishna College Campus of Thrissur District, Kerala, India

Field survey was conducted to record the diversity of spiders at different sites in the Sree Krishna College Campus of Thrissur district during September 2022 to February 2023. Around 51 species of spiders belonging to 36 genera under 14 families were recorded. Salticidae family was represented with twelve species followed by Araneidae (10 sps.), Oxyopidae (5 sps.), Theridiidae (4 sps.), Lycosidae, (3 sps.), Tetragnathidae (3 sps.) and Sparassidae (3 sps.), Thomisidae (2 sps.), Pholcidae (2 sps.). But, Hersilidae, Linyphiidae, Uloboridae, Cheiracanthiidae and Sicariidae family members were very less. Spider population in different sites exhibited variation in species abundance and richness. Shannon index, Simpson index, Margalef Richness index, Berger-Parker index and Menhinick’s Index evaluated were 3.423, 0.9580, 9.540, 0.9101and 3.709 respectively. The abundance and percent occurrence of different spider species revealed variation in their distribution. For the study the entire campus has been surveyed, by dividing the area into four sites, Site A, Site B, Site C and Site D. Species composition and diversity indices studies revealed that more diversity in the site C followed by Site D, Site B and Site A. These types of surveys are important for the study of the prevalence of the spider population in given habitats and to create a biodiversity database of spider.

Pollination and pollen plant diversity by Apis cerana cerana during olive flowering based on DNA metabarcoding

AbstractTo understand the role of Apis cerana cerana in olive tree (Olea europaea L.) pollination, pollinators and pollen carried by bees were collected from 11 experimental plots during the flowering period. The abundance and diversity of pollen plant species were investigated using DNA metabarcoding. A total of 583 pollinators were collected and A. cerana cerana accounts for 46.83%. Further analysis revealed a total of 56 families, 136 genera and 195 plant species in bee pollens. O. europaea is the dominant species accounting for 42.02 ± 34.89% and then followed by Sedum japonicum (8.70 ± 16.42%). Diversity index showed that the abundance and diversity of pollen plant species were the highest in Wanzhou (WZ) and lowest in Hechuan (HC). This suggests that Wanzhou sample plot has a greater abundance of plant species to supplement the bee diet. Excessive presence of miscellaneous flowering plants in olive plantations can distract bees from collecting olive tree pollens. Therefore, their abundances can be reduced appropriately while ensuring food diversity for the bees. Based on the abundance of plants in pollens, we recommend that appropriately planting of S. japonicum, Youngia japonica and Vicia villosa in olive plantations with fewer flowering plants could be an effective supplement of bee food. Our results not only contribute to future studies on olive tree pollination but also provide new ideas for enriching flowering plants in or around olive plantations.

Biochar addition can negatively affect plant community performance when altering soil properties in saline-alkali wetlands

Biochar is a widely proposed solution for improving degraded soil in coastal wetland ecosystems. However, the impacts of biochar addition on the soil and plant communities in the wetland remains largely unknown. In this study, we conducted a greenhouse experiment using soil seed bank from a coastal saline-alkaline wetland. Three types of biochar, including Juglans regia biochar (JBC), Spartina alterniflora biochar (SBC) and Flaveria bidentis biochar (FBC), were added to the saline-alkaline soil at ratios of 1%, 3% and 5% (w/w). Our findings revealed that biochar addition significantly increased soil pH, and increased available potassium (AK) by 3.74% - 170.91%, while reduced soil salinity (expect for 3% SBC and 5%SBC) by 28.08% - 46.93%. Among the different biochar types, the application of 5% FBC was found to be the most effective in increasing nutrients and reducing salinity. Furthermore, biochar addition generally resulted in a decrease of 7.27% - 90.94% in species abundance, 17.26% - 61.21% in community height, 12.28% - 56.42% in stem diameter, 55.34% - 90.11% in total biomass and 29.22% - 78.55% in root tissue density (RTD). In particular, such negative effects was the worst in the SBC samples. However, 3% and 5% SBC increased specific root length (SRL) by 177.89% and 265.65%, and specific root surface area (SRSA) by 477.02% and 286.57%, respectively. The findings suggested that the plant community performance was primarily affected by soil pH, salinity and nutrients levels. Furthermore, biochar addition also influenced species diversity and functional diversity, ultimately affecting ecosystem stability. Therefore, it is important to consider the negative findings indirectly indicate the ecological risks associated with biochar addition in coastal salt-alkaline soils. Furthermore, Spartina alterniflora was needed to desalt before carbonization to prevent soil salinization when using S. alterniflora biochar, as it is a halophyte.

Rodents mediate the relationship between seed rain, seed bank, and plant community with increased grazing disturbance.

Seed rain and the soil seed bank represent the dispersal of seeds in space and time, respectively, and can be important sources of recruitment of new individuals during plant community regeneration. However, the temporal dynamics of seed rain and the mechanisms by which the seed rain and soil seed bank may play a role in plant community regeneration with increased grazing disturbance remain unclear. Seed rain, soil seed bank, aboveground vegetation, and rodent density were sampled along a grazing gradient in an alpine marsh on the eastern Tibetan Plateau. We described the temporal dynamics of seed dispersal using Bayesian generalized mixed models, and nonmetric multidimensional scaling and the structural equation model were used to examine the effects of grazing disturbance on the relative role of seed rain and soil seed bank on aboveground plant community regeneration. The temporal dynamics of seed rain changed from a unimodal to a bimodal pattern with increased grazing disturbance. Both species diversity and seed density of the seed rain and seed bank increased significantly with increased grazing disturbance. Increased grazing disturbance indirectly increased the similarity of composition between seed rain, seed bank, and aboveground plant community by directly increasing species diversity and abundance of aboveground plant community. However, increased grazing disturbance also indirectly decreased the similarity of seed rain, soil seed bank, and aboveground plant community by directly increasing rodent density. The similarity between seed rain and aboveground plant community was greater than that of the soil seed bank and aboveground plant community with increased grazing disturbance. Grazing disturbance spreads the risk of seed germination and seedling establishment by changing the temporal dynamics of seed dispersal. Plants (positive) and rodents (negative) mediated the role of seed rain and soil seed bank in plant community regeneration. The role of seed rain in plant community regeneration is higher than the seed bank in disturbed alpine marshes. Our findings increase our understanding of the regeneration process of the plant community, and they provide valuable information for the conservation and restoration of alpine marsh ecosystems.

Phenomenology of the Composition of PM2.5 at an Urban Site in Northern France

In this work, PM2.5 was sampled at Dunkerque, a medium-sized city located in northern France. The mean concentration of PM2.5 during the sampling period was 12.6 ± 9.5 μg·m−3. Samples were analyzed for elemental and organic carbon (EC/OC), water-soluble organic carbon (WSOC), humic-like substances (HULIS-C), water-soluble inorganic ions, and major and trace elements. The origin and the variations of species concentrations were examined using elemental enrichment factors, bivariate polar plot representations, and diagnostic concentration ratios. Secondary inorganic ions were the most abundant species (36% of PM2.5), followed by OC (12.5% of PM2.5). Secondary organic carbon (SOC) concentrations were estimated to account for 52% of OC. A good correlation between SOC and WSOC indicated that secondary formation processes significantly contribute to the WSOC concentrations. HULIS-C also represents almost 50% of WSOC. The determination of diagnostic ratios revealed the influence of anthropogenic emission sources such as integrated steelworks and fuel oil combustion. The clustering of 72 h air masses backward trajectories data evidenced that higher concentrations of PM2.5, OC, and secondary inorganic aerosols were recorded when air masses came from north-eastern Europe and the French continental sector, showing the considerable impact of long-range transport on the air quality in northern France.

Cascade loop of ferroptosis induction and immunotherapy based on metal‐phenolic networks for combined therapy of colorectal cancer

AbstractCancer immunotherapy is the most promising method for tumor therapy, while ferroptosis could activate the immunogenicity of cancer and strengthen the cellular immune response. However, limited by the complex tumor microenvironment, the abundant glutathione (GSH) and low reactive oxygen species (ROS) seriously weaken ferroptosis and the immune response. Herein, the authors report photothermal metal‐phenolic networks (MPNs) supplied with buthionine sulfoximine (BSO) by reducing levels of GSH and then trapping the tumor cells in the ferroptosis and immunotherapy cascade loop to eliminate colorectal cancer (CRC). The MPNs coated with the model antigen ovalbumin can accumulate at the tumor site, mediate immunogenic cell death (ICD) under NIR irradiation, and initiate tumoricidal immunity. Then the activated CD8+ T cells would release IFN‐γ to inhibit GPX4 and promote the immunogenic ferroptosis induced by Fe3+ and BSO. Finally, the tumor cells at intertumoral and intratumoral levels would be involved in the ferroptosis‐dominated cancer‐immunity circle for CRC eradication, resulting in outstanding therapeutic outcomes in both primary and distant tumor models. Overall, this strategy employs a photothermal nanoplatform to rapidly stimulate ICD and restrain the oxidation defense system, which provides a promising approach to significantly amplify the “cascade loop” of ferroptosis induction and immunotherapy for treatment of CRC.

Quantum dynamics of the P(2D) + H2 (X1[formula omitted]) → PH (X3Σ-) + H(2S) reaction

The title reaction is thought to be important for the astronomical PO formation, which may contribute to the generation of bioavailable H3PO3. Using quasi-classical trajectory (QCT) method, the state-specified (v = 0, j = 0) rate constant of this reaction was calculated. The comparison with previous temperature-averaged QCT rate constant shows that the effect of ro-vibrational excitation is relatively small below 2000 K. Then, the time-dependent wave packet (TDWP) method was applied to investigate the quantum reaction mechanisms, obtaining the state-specified (v = 0, j = 0) reaction probability, integral cross sections and rate constants. The number of partial waves and the integral interval of collision energy considered were rigorously tested to ensure the convergence of the TDWP rate constant below 2000 K. The TDWP rate constant agrees better to the latest experimental results at 291 to 685 K than those from the two QCT calculations. Also, the TDWP calculations can produce relatively reliable rate constants at 700 to 2000 K, where the Arrhenius formula fitted by experimental results ignores the temperature dependence of the activation energy. The calculated rate constants are helpful for modelling the phosphorus chemistry and determining the abundances of the P-bearing species in interstellar media (ISM).

Distribution and ecological aspects of sand fly species from Kousseri, an endemic focus of visceral leishmaniasis in Northern Cameroon

IntroductionKousseri in the Far North Region of Cameroon has long been known as an endemic focus of visceral leishmaniasis (VL), although the study on sand flies in this focus is scarce. The present study investigates the spatial distribution, seasonality, and ecological aspects of sand flies from Kousseri. This study is based on the need to optimize the effectiveness of leishmaniasis control programs in the northern part of the country. MethodsSand flies were sampled monthly over 12 months in five selected sites using CDC light traps. Only captured females were morphologically identified at species level based on valid keys. Results and discussionOverall, 4,214 sand fly specimens were collected during 360 trapping nights. The male/female sex ratio slightly favored females (1:1.04). The eudominant Sergentomyia antennata followed by both dominant Sergentomyia schwetzi and Sergentomyia squamipleuris were the most common and abundant species, accounting for 76.1% of the collection. Phlebotomus duboscqi, the confirmed vector of cutaneous leishmaniasis (CL) in West African foci, although rare in the collection, was found in four of the five surveyed sites. This sand fly species with Se. schwetzi abounded in peri-urban areas and, respectively, in animal shed and in uninhabited house biotopes, while Se. antennata and Se. squamipleuris prevailed in rural areas and, respectively, in animal shelter biotopes and outside dwellings. All caught sand fly species except Se. schwetzi, Sergentomyia clydei, Sergentomyia inermis, and Sergentomyia adleri prevailed during the dry season. The highest Shannon–Wiener index of sand flies due to the maximal richness and evenness was found in the urban area, in outdoor biotopes, and during the rainy season (H′ = 1.68, 1.80, and 1.74, respectively). These data provide evidence that less urbanized areas, animal shelters around the compounds, and the absence of precipitation (dry season) favored the dispersion of abundant sand fly species in Kousseri. Based on previous reports on Leishmania transmission, a surveillance plan is required to prevent an outbreak of VL or an establishment of CL or canine leishmaniasis (CnL) in this focus. Further research identifying the blood meal source and the Leishmania parasites in these insects is critical for providing insightful data to fight leishmaniasis in Northern Cameroon.

Amphistome Infection and Species Diversity of Freshwater Snails Collected from Selected Wildlife Drinking Water Sources in Matebeleland Region of Zimbabwe

This study aimed at determining the identity of freshwater snails collected from selected water habitats frequented by wildlife as source of drinking water in the Matebeleland region of Zimbabwe and further screening the identified snails for natural infections with amphistomes using PCR. A total of 487 freshwater snails were collected from six areas in the Matebeleland region of Zimbabwe for identification and screening of amphistome infection. Eight freshwater snail species were morphologically identified and Biomphalaria pfeifferi, Bul. tropicus, Bul. truncatus, Bul. globosus, and L. (R.) natalensis were confirmed using the COI gene. Bulinus tropicus and Phy. acuta were the most abundant species at 33.9% (165/487) and 31.2% (155/487), respectively. DNA of amphistome was detected in 11.9% (58/487) of the collected snails. The highest infection rate was detected in Bul. globosus (44.4%). West Nicholson recorded the highest infection rate (33.9%), and infection was not detected in L. (R.) natalensis, Phy. acuta, and Bellamya spp. Amphistome DNA from M. tuberculata was successfully sequenced and identified as Calicophoron microbothrium. An additional band was detected in M. tuberculata, Bul. tropicus, and Bul. trancatus, which showed a 96.42% similarity to Paragonimus sp. sequence in the GenBank.

Top predator status and trends: ecological implications, monitoring and mitigation strategies to promote ecosystem-based management

The conservation and management of marine ecosystems hinge on a comprehensive understanding of the status and trends of top predators. This review delves into the ecological significance of marine top predators, examining their roles in maintaining ecosystem stability and functioning through an integrated analysis of current scientific literature. We first assess the efficacy of various monitoring methods, ranging from traditional field observations to cutting-edge technologies like satellite tracking and environmental DNA (eDNA) analysis and evaluating their strengths and limitations in terms of accuracy, spatial coverage, and cost-effectiveness, providing resource managers with essential insights for informed decision-making. Then, by synthesizing data from diverse marine ecosystems, this study offers a comprehensive overview of the trends affecting top predator populations worldwide. We explore the multifaceted impacts of human activities, climate change, and habitat degradation on the abundance and distribution of these key species. In doing so, we shed light on the broader implications of declining top predator populations, such as trophic cascades and altered community structures. Following a thorough assessment of successful strategies for reversing the decline of top predators, a compilation of recommendations is presented, encompassing effective governance interventions. A crucial aspect of effective ecosystem-based management is the implementation of robust monitoring strategies. Mitigation measures are imperative to reverse the adverse impacts on marine top predators. We present a comprehensive array of mitigation options based on successful case studies. These include the establishment of marine protected areas, the enforcement of fisheries regulations, and the promotion of sustainable fishing practices. We deepen the synergies between these strategies and their potential to mitigate human-induced stressors on top predator populations to safeguard their pivotal role in maintaining marine ecosystem structure and function. By examining marine top predators’ ecological significance, analyzing population trends, discussing monitoring techniques, and outlining effective mitigation strategies, we provide a comprehensive resource for researchers, policymakers, and stakeholders engaged in fostering ecosystem-based management approaches. We conclude that integrating these insights into current management frameworks will be essential to safeguard both top predators and the broader marine environment for future generations.

Influence of canopy structural complexity on urban woodland butterfly species richness

AbstractAs urban land use expands, understanding the conservation of biodiversity in urban settings becomes increasingly important. Urban areas contain a wide range of remnant natural, semi-natural and anthropogenic woodlands but the biodiversity of these woodlands is not well studied. Urban woodlands are usually constrained in size and subject to management which may not be focused on promoting biodiversity. As a habitat of critical importance, the characteristics of urban woodlands need to be better understood to maximise their biodiversity within a limited footprint in the urban landscape. We used repeat line-transect surveys and rapid woodland structure habitat assessments to investigate the habitat associations of butterflies in ten woodland patches representing a range of sizes (between 1 and 40 ha), ages and woodland characteristics in the urban habitat matrix of Milton Keynes, UK. We found that ancient woodland sites supported every species detected, but the butterfly communities of amenity and roadside woodlands had similar species richness, diversity and abundance, regardless of size. Butterfly species richness was strongly associated with both woodland area and structural complexity at a site-scale, but only with structural complexity on a transect scale. Simpson diversity showed no correlation with any variable at the site scale, but strong correlation with structural complexity on transects. Abundance only correlated with area at the site scale. Our results suggest that management techniques that introduce structural complexity within urban woodlands may be an effective way to support butterfly richness and diversity in contexts where woodland areas cannot be increased.

The ecological and biodiversity conservation values of farm dams: A systematic review.

Biodiversity is in rapid decline globally with agriculture being one of the leading causes. Within agricultural landscapes, some features provide a benefit to biodiversity that is disproportionate to their spatial area. An interesting example is artificial ponds-or farm dams-which can support a large variety of taxa. Here, we present a global review of farm dam research related to biodiversity conservation objectives to provide an overview of the topics, key research insights, and the characteristics of current research. We used a three-stage process to screen literature and identified 104 relevant papers across 27 countries encompassing studies of 13 different taxa. Most of the studies were short-term (less than 5 years) with small sample sizes (less than 20 sites). Of the 104 papers, 88 were focussed primarily on ecological outcomes, such as species richness or abundance, and 15 on primary production outcomes, such as crop and livestock yield, despite addressing or measuring ecological metrics. Only one study measured both ecological and primary production outcomes. Studies frequently examined how the features of dams (79 studies) and attributes of the surrounding landscape (47 studies) impact particular species and communities. Terrestrial mammals (1 study) were under-represented in the literature with macrophytes (28 studies), macroinvertebrates (26 studies), and amphibians (19 studies) receiving the most attention. Our results reveal a growing trend towards recognizing farm dams as habitats for various taxa, including amphibians, beetles, dragonflies, and other macroinvertebrates within agricultural environments. Significant knowledge gaps exist in understanding how dam age, invasive species, and effective management practices impact the biodiversity conservation values of farm dams. Future research should emphasize enhancing biodiversity by collaborating with landholders to increase habitat through strategic vegetation planning, minimizing runoff and nutrient inflow, and restricting stock access.