The global loss of avian functional and phylogenetic diversity from anthropogenic extinctions.

Humans have been driving a global erosion of species richness for millennia, but the consequences of past extinctions for other dimensions of biodiversity-functional and phylogenetic diversity-are poorly understood. In this work, we show that, since the Late Pleistocene, the extinction of 610 bird species has caused a disproportionate loss of the global avian functional space along with ~3 billion years of unique evolutionary history. For island endemics, proportional losses have been even greater. Projected future extinctions of more than 1000 species over the next two centuries will incur further substantial reductions in functional and phylogenetic diversity. These results highlight the severe consequences of the ongoing biodiversity crisis and the urgent need to identify the ecological functions being lost through extinction.

Islands are key for protecting the world's plant endemism.

Islands are renowned as evolutionary laboratories and support many species that are not found elsewhere1,2. Islands are also of great conservation concern, with many of their endemic species currently threatened or extinct3. Here we present a standardized checklist of all known vascular plants that occur on islands and document their geographical and phylogenetic distribution and conservation risk. Our analyses of 304,103 plant species reveal that 94,052 species (31%) are native to islands, which constitute 5.3% of the global landmass4. Of these, 63,280 are island endemic species, which represent 21% of global plant diversity. Three-quarters of these are restricted to large or isolated islands. Compared with the world flora, island endemics are non-randomly distributed within the tree of life, with a total of 1,005 billion years of unique phylogenetic history with 17 families and 1,702 genera being entirely endemic to islands. Of all vascular plants assigned International Union for Conservation of Nature conservation categories5, 22% are island endemics. Among these endemic species, 51% are threatened, and 55% of all documented global extinctions have occurred on islands. We find that of all single-island endemic species, only 6% occur on islands meeting the United Nations 30×30 conservation target. Urgent measures including habitat restoration, invasive species removal and ex situ programmes are needed to protect the world's island flora. Our checklist quantifies the uniqueness of island life, provides a basis for future studies of island floras, and highlights the urgent need to take actions for conserving them.

The effect of intensive praziquantel administration on vaccine-specific responses among schoolchildren in Ugandan schistosomiasis-endemic islands (POPVAC A): an open-label, randomised controlled trial.

BACKGROUND: Vaccine responses differ between populations and are often impaired in rural and low-income settings. The reasons for this are not fully understood, but observational data suggest that the immunomodulating effects of parasitic helminths might contribute. We hypothesised that Schistosoma mansoni infection suppresses responses to unrelated vaccines, and that suppression could be reversed-at least in part-by intensive praziquantel administration. METHODS: We conducted an open-label, randomised controlled trial of intensive versus standard intervention against S mansoni among schoolchildren aged 9-17 years from eight primary schools in Koome islands, Uganda. Children were randomly allocated to either an intensive group or a standard group with a computer-generated 1:1 randomisation using permuted blocks sizes 4, 6, 8, and 10. Participants in the intensive group received three praziquantel doses (approximately 40 mg/kg) 2 weeks apart before first vaccination at week 0, and every 3 months thereafter. Participants in the standard group were given one dose of approximately 40 mg/kg praziquantel after the week 8 primary endpoint. Participants in both groups received the BCG vaccine (Serum Institute of India, Pune, India) at week 0; the yellow fever (Sanofi Pasteur, Lyon, France), oral typhoid (PaxVax, London, UK), and first human papillomavirus (HPV) vaccination (Merck, Rahway, NJ, USA) at week 4; and the HPV booster and tetanus-diphtheria vaccine (Serum Institute of India) at week 28. The primary outcome was vaccine response at week 8 (except for tetanus and diphtheria, which was assessed at week 52). The primary analysis population was participants who were infected with S mansoni at baseline, determined retrospectively using either plasma circulating anodic antigen (CAA) or stool PCR. The safety population comprised all randomly allocated participants. The trial was registered at the ISRCTN Registry (ISRCTN60517191) and is complete. FINDINGS: Between July 9 and Aug 14, 2019, we enrolled 478 participants, with 239 children per group. 276 (58%) participants were male and 202 (42%) participants were female. Among participants who were positive for S mansoni at baseline (171 [72%] in the intensive group and 164 [69%] in the standard group) intensive praziquantel administration significantly reduced pre-vaccination infection intensity (to median 30 CAA pg/mL [IQR 7-223] vs 1317 [243-8562], p<0·001) compared with standard treatment. Intensive praziquantel administration also reduced week 8 HPV-16-specific IgG response (geometric mean ratio 0·71 [95% CI 0·54-0·94], p=0·017), but had no effect on other primary outcomes. Among all participants (regardless of S mansoni status at baseline) intensive praziquantel administration significantly improved week 8 BCG-specific IFNγ ELISpot response (1·20 [1·01-1·43], p=0·038). Recognised adverse effects of praziquantel were reported more frequently in the intensive group. There were no recorded serious adverse events in either group. INTERPRETATION: We show evidence suggesting that praziquantel administration improves the BCG-specific cellular response, but not humoral responses to other vaccines. Despite observational evidence that helminths impair vaccine response, these results show minimal immediate benefits of reducing helminth burden. The effect of longer-term helminth control should be investigated. FUNDING: UK Medical Research Council. TRANSLATION: For the Luganda translation of the abstract see Supplementary Materials section.

Plastid phylogenomics of Robinsonia (Senecioneae; Asteraceae), endemic to the Juan Fernández Islands: insights into structural organization and molecular evolution.

BACKGROUND: The genus Robinsonia DC. (tribe Senecioneae, Asteraceae) endemic to the Juan Fernández Islands in Chile is one of the most conspicuous insular plant groups in the world. Unlike typical herbaceous Asteraceae plants, these plants demonstrate spectacular and unusual rosette tree growth forms as shown by the alpine giant senecios (genus Dendrosenecio, tribe Senecioneae) endemic to the East African mountains. However, monophyly of the genus and phylogenetic relationships among species of Robinsonia as well as their plastome evolution remain elusive. This study aims to explore their phylogeny, species diversification, and molecular evolution based on the complete plastome sequences in the context of adaptive radiation on oceanic islands. RESULTS: The insular Robinsonia plastomes are highly conserved in their structures and organization of contents. Five divergence hotspots as potential chloroplast markers and five positively selected coding genes (accD, ndhF, rpoA, ycf1, and ycf2) are identified. Robinsonia plastomes has an overall nucleotide diversity higher than that of the sky island Dendrosenecio, but much lower than herbaceous Senecio. Phylogenetic analysis demonstrates the monophyly of Robinsonia and identifies two major infrageneric lineages. Both Robinsonia and Dendrosenecio are deeply nested within large genus Senecio. CONCLUSIONS: While plastid genomes of Robinsonia are highly conserved, their sequences strongly demonstrated the monophyly of the genus and inferred robust interspecific relationships, including herbaceous Senecio and woody Dendrosenecio. Different sets of positively selected chloroplast genes, five for Robinsonia and two for Dendrosenecio, may play an important role in the adaptation strategies of these fascinating woody species in insular and continental sky island habitats. Overall phylogenetic positions and sister lineages of Robinsonia and Dendrosenecio require additional study based on broader sampling of Senecio.

The ethnomycological knowledge of Karajá indigenous people from Bananal Island, Brazil.

The Cerrado is home to a diversity of traditional communities, among which indigenous and quilombola peoples stand out. The Karajá are one of the ethnic groups in this biome, with a rich history and culture that goes back centuries. They mainly inhabit the regions of the Araguaia and Javaés rivers, occupying lands in the states of Goiás, Mato Grosso, Pará and Tocantins. Considering the importance of studies on ethnomycological knowledge in indigenous communities for preserving culture and the environment, especially in relation to fungi, our objective was to investigate the ethnomycological relationships of the Karajá indigenous people who inhabit Bananal Island, located in Tocantins. Data were collected from applying a semi-structured questionnaire and interviews with 140 people who compose the Macaúba (39%), Fontoura (31%) and Santa Isabel do Morro (30%) communities; they had an average age of 33.9 years, and 62% are male. We observed that the Karajá people recognize the fungi of the environment in which they live, showing a clearer perception of typical morphological groups, such as mushrooms and bracket fungi (wood ears). Although fungi are not used as a component of their diet, the Karajá recognize that some species may have this potential. Furthermore, they use fungi as adornments and decorations in festivities in a playful way, and occasionally for medicinal purposes. Therefore, we can state that this ethnic group does not have a total aversion to fungi, being considered partially mycophilic. This study is a pioneer among Cerrado indigenous people, and reinforces the need to expand research to other communities in different regions in order to expand ethnomycological knowledge among different ethnicities. These investigations could contribute to both an appreciation and conservation of the traditions and knowledge of original Brazilian people, as well as the biodiversity in which they are inserted.

Assessment of potentially toxic element contamination in wetland sediments of Boracay Island, Philippines.

Boracay Island, Philippines, famous for its white sand beaches, has wetlands increasingly threatened by human activities. This study evaluated the ecological state of Boracay Island's wetlands and assessed the consequences of anthropogenic activities on sediment quality. Results showed that sediments from Wetland Nos. 3 and 4 have higher concentrations of potentially toxic elements (PTEs) than Wetland No. 1. Comparative analysis with other Southeast Asian wetlands revealed that Boracay's sediments contain the highest average values of As, Cd, Cu, Ni, Zn. Enrichment factor values suggest that the moderate enrichment of Cd, Cr, Cu, Mo, Pb, and Zn in the wetland sediments can be attributed to anthropogenic activities on the island. Elevated concentrations of Cr, Cu, and Zn above interim sediment quality guidelines indicate occasional adverse biological effects on aquatic biota. These findings provide a crucial baseline for future pollution monitoring and highlight the need for ongoing conservation efforts in Boracay's wetlands.

Regime shift of skeletal δ13C after 1997/1998 El Nino event in Porites coral from Green Island, Taiwan.

The 1997/1998 El Niño event caused mass coral bleaching and mortality in many tropical and subtropical regions, including corals on Green Island, Taiwan, in the northwestern Pacific Ocean. This study analyzed coral carbon isotope ratios (δ13C), oxygen isotope ratios (δ18O), and Sr/Ca ratios for 29 years, including the 1997/1998 El Niño period, to examine how high water temperature events are recorded in coral geochemical indicators. Sr/Ca ratios in coral skeletons from Green Island show the lowest peak, means the highest temperature during the 1997/1998 El Niño period. However, we couldn't observe high-temperature events on δ18O. Furthermore, a negative δ13C shift was observed after El Niño events. The regime shift of δ13C might have been caused by temporal bleaching and/or a decrease in symbiotic algae due to high water temperature stress under the continuous decrease in δ13C in DIC due to the Suess effect.

Extending Species-Area Relationships Into the Realm of Ecoacoustics: The Soundscape-Area Relationship.

The rise in species richness with area is one of the few ironclad ecological relationships. Yet, little is known about the spatial scaling of alternative dimensions of diversity. Here, we provide empirical evidence for a relationship between the richness of acoustic traits emanating from a landscape, or soundscape richness, and island area, which we term the SoundScape-Area Relationship (SSAR). We show a positive relationship between the gamma soundscape richness and island area. This relationship breaks down at the smallest spatial scales, indicating a small-island effect. Moreover, we demonstrate a positive spatial scaling of the plot-scale alpha soundscape richness, but not the beta soundscape turnover, suggesting a direct effect of species on acoustic trait diversity. We conclude that the general scaling of biodiversity can be extended into the realm of ecoacoustics, implying soundscape metrics are sensitive to fundamental ecological patterns and useful in disentangling their complex mechanistic drivers.

Effect of coastal and island geographic environments on patients with acute ischemic stroke in southeastern China.

OBJECTIVE: To analyze the geographic variation in characteristics and treatment processes of patients with acute ischemic stroke (AIS) in coastal, island, and inland regions. METHODS: We conducted a retrospective, cross-sectional analysis of data from patients with AIS in southeastern China. We collected demographic and clinical information, including the time from stroke onset to treatment for those receiving reperfusion therapy, using a time-tracking table. RESULTS: Among 8069 patients with AIS, 26.6% received reperfusion therapy, with a higher proportion undergoing endovascular therapy in maritime hospitals than in inland hospitals (14.2% vs. 6.7%). Maritime hospitals had a higher prevalence of atrial fibrillation (15.1% vs. 11.9%) and cardioembolism (17.2% vs. 13.6%) than inland hospitals. Patients in maritime hospitals had shorter in-hospital processing times than those in inland hospitals (39 vs. 46 minutes). Island hospitals showed different patterns, with a shorter time from stroke onset to emergency room arrival (80 vs. 120 minutes) but a longer in-hospital process time (51 vs. 36 minutes), than coastline hospitals. CONCLUSIONS: Our study suggests geographic variation in AIS characteristics and treatment processes across southeastern China, emphasizing the need for region-specific strategies. These findings are essential for tailoring public health policies and guidelines to improve stroke outcomes in various regions.

Seasonal variation in the stomach microbiota of two sympatrically breeding Pygoscelis penguin species at Signy Island, South Orkney Islands.

The gut microbiomes of Antarctic penguins are important for the fitness of the host birds and their chicks. The compositions of microbial communities in Antarctic penguin guts are strongly associated with the birds' diet, physiological adaptation and phylogeny. Whilst seasonal changes in food resources, distribution and population parameters of Antarctic penguins have been well addressed, little research is available on the stability or variability of penguin stomach microbiomes over time. Here, we focused on two Pygoscelis penguin species breeding sympatrically in the maritime Antarctic and analysed their stomach contents to assess whether penguin gut microbiota differed over three austral summer breeding seasons. We used a high-throughput DNA sequencing approach to study bacterial diversity in stomach regurgitates of Adélie (Pygoscelis adeliae) and chinstrap (Pygoscelis antarctica) penguins that have a similar foraging regime on Signy Island (South Orkney Islands). Our data revealed significant differences in bacterial alpha and beta diversity between the study seasons. We also identified bacterial genera that were significantly associated with specific breeding seasons, diet compositions, chick-rearing stages and sampling events. This study provides a baseline for establishing future monitoring of penguin gut microbiomes in a rapidly changing environment.

Trade and socioeconomic importance of an invasive giant snail in the endemic-rich island of São Tomé, Central Africa.

Managing invasive species is crucial to mitigate their negative impacts on ecosystems, yet conflicts may arise when their social benefits are disregarded. Human pressure on the endemic-rich forests of São Tomé has been high since the island was discovered by the Portuguese in the 15th century, and numerous species have been introduced. These include the invasive West African giant land snail (Archachatina marginata), which was introduced in the mid-20th century, is now widespread on the island, and is a potential threat to native flora and fauna. We assessed the frequency of consumption of this species and its socioeconomic importance to people across the island with household questionnaires, focus group discussions, and semistructured interviews. We explored the prevalence and potential drivers of use (e.g., wealth, household composition, and diversity of occupations) and characterized the commodity chain to identify demographic groups linked to the snail trade. We interviewed 672 people (1 person per household), conducted 6 focus groups, and interviewed 80 key actors belonging to 5 subcategories. The snail was the most widely consumed bushmeat and an important source of income, particularly for women and unemployed youth. Insecure and scarce livelihood alternatives, mostly in rural areas, were reported as drivers for trade involvement. Snail harvesting was more frequent in poorer households with low occupational diversity. Selling tended to occur in households that were well-established in the community and had a higher proportion of children. Both were stimulated by the proximity of communities to the native forest. Buying snails was common in all demographic groups, but it was linked to wealth and occupational diversity. Interventions to manage the impact of this introduced species on the valuable ecosystems of the island should involve multiple sectors of society to ensure societal support. This requires robust consideration of the welfare of vulnerable demographic groups that benefit from the species.

Importancia socioeconómica y comercial de un caracol invasor en la isla rica en endemismos de Santo Tomé, África Central Resumen La gestión de las especies invasoras es crucial para mitigar sus efectos negativos en los ecosistemas, aunque pueden surgir conflictos cuando no se tienen en cuenta sus beneficios sociales. La presión humana sobre los bosques de Santo Tomé, ricos en endemismos, ha sido alta desde que la isla fue colonizada por los portugueses en el siglo XV y desde entonces se han introducido numerosas especies. Una de ellas es el caracol terrestre gigante de África Occidental (Archachatina marginata), introducido a mediados del siglo XX y que ahora tiene una distribución amplia en la isla y es una amenaza potencial para la flora y la fauna autóctonas al ser invasor. Evaluamos la frecuencia de consumo de esta especie y su importancia socioeconómica para la población de toda la isla mediante encuestas en hogares, grupos de discusión y entrevistas semiestructuradas a actores clave de cinco categorías. Exploramos la prevalencia y los posibles factores impulsores del consumo (por ejemplo, la riqueza, la composición de los hogares y la diversidad de ocupaciones) y caracterizamos la cadena comercial para identificar los grupos demográficos vinculados al comercio de caracoles. Entrevistamos a 672 personas (una persona por hogar), realizamos seis grupos de discusión y entrevistamos a 80 actores clave. El caracol fue la carne de caza más consumida y una importante fuente de ingresos, sobre todo para las mujeres y los jóvenes desempleados. La inseguridad y la escasez de medios de subsistencia, sobre todo en las zonas rurales, fueron los factores que impulsaron la participación en el mercado. La colecta de caracoles fue más frecuente en los hogares más pobres y con escasa diversidad ocupacional. La venta tendía a producirse en hogares bien establecidos en la comunidad y con una mayor proporción de niños. Ambos factores se vieron estimulados por la proximidad de las comunidades al bosque nativo. La compra de caracoles fue común en todos los grupos demográficos, pero estuvo vinculada a la riqueza y a la diversidad ocupacional. Las intervenciones para gestionar el impacto de esta especie introducida en los valiosos ecosistemas de la isla deben implicar a múltiples sectores de la sociedad para garantizar su apoyo. Para ello es necesario tener muy en cuenta el bienestar de los grupos demográficos vulnerables que se benefician de la especie.

Impact of six-month COVID-19 travel moratorium on Plasmodium falciparum prevalence on Bioko Island, Equatorial Guinea.

Importation of malaria infections is a suspected driver of sustained malaria prevalence on areas of Bioko Island, Equatorial Guinea. Quantifying the impact of imported infections is difficult because of the dynamic nature of the disease and complexity of designing a randomized trial. We leverage a six-month travel moratorium in and out of Bioko Island during the initial COVID-19 pandemic response to evaluate the contribution of imported infections to malaria prevalence on Bioko Island. Using a difference in differences design and data from island wide household surveys conducted before (2019) and after (2020) the travel moratorium, we compare the change in prevalence between areas of low historical travel to those with high historical travel. Here, we report that in the absence of a travel moratorium, the prevalence of infection in high travel areas was expected to be 9% higher than observed, highlighting the importance of control measures that target imported infections.

The global war on island rats.

Invasive rodents wreak havoc on island wildlife. How we learned to fight back.

Agricultural Biotechnological Potential of Bacillus velezensis C3-3 and Cytobacillus sp. T106 from Resource Islands of a Semi-arid Zone of La Guajira-Colombia.

Resource islands are vegetative formations in arid and semi-arid ecosystems that harbor microorganisms facing extreme conditions. However, there is a limitation in the knowledge of the agricultural biotechnological potential of microorganisms present in these islands. This study aimed to determine the capacity of Bacillus velezensis C3-3 and Cytobacillus sp. T106 isolates from resource islands to promote plant growth and control the phytopathogen Rhizoctonia solani. The bacteria were sequenced, and both grew at 50 °C, resisted 5% NaCl, withstood UV exposure, and grew in extreme pH conditions. Sixty-six genes in C3-3 and 71 in T106 were identified associated with plant growth promotion, and C3-3 was shown to promote leaf growth in lettuce plants. This promotional effect was associated with the production of indole-3-acetic acid (IAA), phosphorus solubilization, and the presence of genes related to the assimilation of rhizosphere exudates. Both strains inhibited R. solani through the production of volatile compounds and antagonism. Forty-five and 40 of these genes in C3-3 and T106, respectively, were associated with the production of proteases, lipases, siderophores, antimicrobial compounds, degradation enzymes, and secretion systems. Notably, Cytobacillus sp. has not been previously reported as a biocontrol agent. This work contributes to the evidence of the biotechnological potential of semi-arid region bacteria, offering prospects for improving agricultural production in areas with limiting conditions.

Chromosomal-level reference genome assembly of muskox (Ovibos moschatus) from Banks Island in the Canadian Arctic, a resource for conservation genomics.

The muskox (Ovibos moschatus), an integral component and iconic symbol of arctic biocultural diversity, is under threat by rapid environmental disruptions from climate change. We report a chromosomal-level haploid genome assembly of a muskox from Banks Island in the Canadian Arctic Archipelago. The assembly has a contig N50 of 44.7 Mbp, a scaffold N50 of 112.3 Mbp, a complete representation (100%) of the BUSCO v5.2.2 set of 9225 mammalian marker genes and is anchored to the 24 chromosomes of the muskox. Tabulation of heterozygous single nucleotide variants in our specimen revealed a very low level of genetic diversity, which is consistent with recent reports of the muskox having the lowest genome-wide heterozygosity among the ungulates. While muskox populations are currently showing no overt signs of inbreeding depression, environmental disruptions are expected to strain the genomic resilience of the species. One notable impact of rapid climate change in the Arctic is the spread of emerging infectious and parasitic diseases in the muskox, as exemplified by the range expansion of muskox lungworms, and the recent fatal outbreaks of Erysipelothrix rhusiopathiae, a pathogen normally associated with domestic swine and poultry. As a genomics resource for conservation management of the muskox against existing and emerging disease modalities, we annotated the genes of the major histocompatibility complex on chromosome 2 and performed an initial assessment of the genetic diversity of this complex. This resource is further supported by the annotation of the principal genes of the innate immunity system, genes that are rapidly evolving and under positive selection in the muskox, genes associated with environmental adaptations, and the genes associated with socioeconomic benefits for Arctic communities such as wool (qiviut) attributes. These annotations will benefit muskox management and conservation.

Distribution of total mercury in coastal sediments of Honda Bay, Palawan Island, the Philippines.

Honda Bay is considered as one of the mercury hotspots in the world due to its proximity to the abandoned Palawan Quicksilver Mine. In this study, a detailed sediment sampling conducted in between 2021 and 2022 where a total of 166 sediment samples were collected along the coast and analyzed for total mercury (THg) concentration. The study assessed mercury toxicity using the geoaccumulation index and compared Hg levels to sediment quality guidelines. The findings revealed a wide range of THg concentrations, from 0.0040 to 11.4702 mg/kg, with hotspots identified at the Honda Bay wharf and Tagburos River mouth. Mercury spreads to a large coastal area brought by tidal currents and the wave energy actions. The geoaccumulation index indicated moderate to strong Hg contamination in the vicinity of the hotspots and around 24.7-36.1 % of samples exceeded the sediment quality guidelines suggesting adverse biological effects in aquatic biota will frequently occur.

Diverse baleen whale acoustic occurrence around two sub-Antarctic islands: A tale of residents and visitors.

Knowledge on the occurrence and behaviour of baleen whales around sub-Antarctic regions is limited, and usually based on short, seasonal sighting research from shore or research vessels and whaling records, neither of which provide accurate and comprehensive year-round perspectives of these animals' ecology. We investigated the seasonal acoustic occurrence and diel vocalizing pattern of baleen whales around the sub-Antarctic Prince Edward Islands (PEIs) using passive acoustic monitoring data from mid-2021 to mid-2023, detecting six distinct baleen whale songs from Antarctic blue whales, Madagascan pygmy blue whales, fin whales, Antarctic minke whales, humpback whales, and sei whales. Antarctic blue and fin whales were detected year-round whereas the other species' songs were detected seasonally, including a new Antarctic minke whale bio-duck song sub-type described here for the first time. Antarctic minke and sei whales were more vocally active at night-time whereas the other species had no clear diel vocalizing patterns. Random forest models identified month and/or sea surface temperature as the most important predictors of all baleen whale acoustic occurrence. These novel results highlight the PEIs as a useful habitat for baleen whales given the number of species that inhabit or transit through this region.

Phosphorus dynamics in volcanic soils of Weizhou Island, China: implications for environmental and agricultural applications.

The dynamics of phosphorus are intricately governed by geological and ecological processes. Examining phosphorus dynamics in volcanic islands can enhance our comprehension of its behavior within such unique geological systems. However, research on phosphorus dynamics in volcanic islands remains limited. We investigated the phosphorus content of volcaniclastic rocks and basalt soils from Weizhou Island, China, to understand the influencing factors on phosphorus dynamics. The results indicate that in the volcaniclastic profile, phosphorus concentrates at 20-40 cm (17 mg/kg), decreases at 40-60 cm (11.9 mg/kg), and increases at 80-200 cm up to 46.4 mg/kg proximate to the bedrock, for the basalt profile, phosphorus content increases from the surface (80.2 mg/kg) towards the bedrock (83.9 mg/kg). The differences in phosphorus distribution between volcaniclastic rocks and basalts reflect the influence of parent material, rock weathering degree, carbonate content, topographic elevation, sea level changes, and geological activities. A strong positive correlation (R = 0.96907) between total and available phosphorus has been observed, suggesting that total phosphorus content effectively predicts available phosphorus content. Volcaniclastic rocks in wharves and high-elevation areas show low total phosphorus, while forest land with dense vegetation and neutral to alkaline soil supports higher total phosphorus due to enhanced bioavailability for plant absorption and utilization. Overall, the basalt soil of the volcanic island Weizhou Island demonstrates superior long-term fertility compared to the volcaniclastic soil. Despite its low total phosphorus content, it mainly exists in a highly bioavailable form, facilitating plant absorption, which is crucial for enhancing agricultural yields and ecosystem restoration on volcanic islands.

Molecular characterization of anopheline species diversity in the Andaman and Nicobar archipelago, with a particular emphasis on Anopheles barbirostris.

This study investigates anopheline species diversity in the Andaman and Nicobar Islands, employing morphological and molecular methods, focusing on the D3 domain of 28S rRNA (D3) and second internal spacer (ITS2). Ten Anopheline species were identified morphologically and confirmed with molecular markers. While the D3 region demonstrated low level of inter- and intra-specific genetic distance in all the species, ITS2 revealed clear barcoding gap. Among the ten species, A. barbirostris exhibited significant diversity when compared with the sequences from other countries available in GenBank. Further analyses of additional samples of A. barbirostris were carried out using ITS2 and cytochrome oxidase I (COI) markers. Limited variations among the sequences from the islands were observed, suggesting a prevalent single molecular form. However, when compared with the GenBank sequences, our samples formed a separate cluster closely related to the A3 species. The genetic distance between our samples and the A3 cluster was 0.02 for COI but very high (0.104) for ITS2, suggesting a potentially new molecular form or species in the island region. This warrants a more comprehensive and detailed analysis of A. barbirostris in these islands at both genetic and morphometric levels. Overall, these observations added-up the new knowledge in the understanding of anopheline diversity in the Andaman and Nicobar archipelago and highlight the necessity for continuous molecular investigations to unravel complexities within mosquito population dynamics.