Search Results (103)

The Caribbean Coastal Marine Productivity (CARICOMP) program was conceptualized in 1985 to monitor coral reefs, seagrass beds, and mangrove forests at multiple sites across the wider Caribbean. Mangrove monitoring was focused on the dominant Caribbean species, red mangrove (Rhizophora mangle). Forest structure and productivity were monitored at 21 sites (18 countries) across different geomorphological settings, from tropical to subtropical mainland and island systems. Here, we provide the key findings from the CARICOMP mangrove data collected, mostly from 1992 to 2013, to assess spatial and temporal variability across the region. Red mangrove above-ground biomass averaged 190 t ha⁻¹ (far higher than previously reported) but ranged widely across sites from 33 to 590 t ha⁻¹, equating to an average above-ground ‘blue carbon’ of 84 t ha⁻¹ (range 15–260 t ha⁻¹). Tree density averaged 3237 trees ha⁻¹, tree basal area averaged 19.7 m² ha⁻¹, tree height averaged 6.1 ± 2.8 m, and seedling density varied from 1.2 to 74 seedlings m⁻² across the sites. Among the environmental factors that influence mangroves, local temperature and rainfall explained 48% of the variability in measured tree structure parameters. Annual litterfall, as a proxy for productivity, measured on average 1.24 ± 0.70 kg m⁻² yr⁻¹, with 60% of the total litterfall composed of leaves. Litterfall varied seasonally by 42%. No relationship was apparent between litterfall and seasonal ocean–atmosphere climate indices (ONI and AMM). With exception of the three most southwesterly CARICOMP sites, hurricanes and tropical storms impacted the mangrove sites repeatedly, resulting in considerable damage. A direct strike by a category-4 hurricane in 1998 in Dominican Republic killed 67% of the red mangrove trees, lowered above-ground biomass by 91%, basal area by 89%, litterfall by 63%, and resulted in the subsequent growth of many tall and thin saplings, totally changing the structure of the forest ecosystem in the first few years after the hurricane. In comparing mangrove systems, major differences may be explained by time elapsed since the last destructive event (hurricane) affecting each site. This highlights the fact that despite an increasing focus on preserving these valuable ecosystems, they are still highly vulnerable to natural hazards and likely to face a poor outcome under ongoing climate change. Full article

Avocado (Persea americana Mill.) is cultivated in a wide range of environments, from tropical and semitropical to subtropical regions. Its fruit, of high nutritional value, is increasingly demanded worldwide. Spain is the main European producer, but avocado cultivation in certain areas, such as the Canary Islands, requires the genetic identification of West-Indian rootstocks because they often show tolerance to low-quality water and soil salinization. In the present study, eight novel Retrotransposon-Based Insertion Polymorphism assays, derived from previously characterized inter-Primer Binding Site markers, have been developed and evaluated by multiplex PCR across 58 P. americana cultivars. The results showed 100% specificity and sensitivity in detecting the West-Indian genomic component, both in pure and hybrid avocado cultivars. This cost-effective and fast molecular tool provides a valuable resource for characterization and selection programs of avocado cultivars genetically related to the West-Indian horticultural race. Full article

Background and Clinical Significance: Simultaneous, multiple infections coinfections caused by zoonotic or fecal-orally transmitted diseases are common in tropical and subtropical regions. Published data report that leptospirosis may coexist with other infections, complicating the clinical presentation and trajectory due to overlapping symptoms and leading to more severe clinical progress. Case Presentation: We describe a clinical case of a 34-year-old female diagnosed with a triple infection caused by Leptospira, Hepatitis A Virus, and Hepatitis E Virus. To our knowledge, this is the first case described in the literature in a non-endemic area without travel history to tropical or subtropical regions. The patient presented with one-week history of influenced clinical status, myalgia, headaches, nausea, high fever, bloody diarrheas, and abdominal pain. During the last two days, she also developed jaundice. Swimming in the rock pools of the island where she lives was indicated as the source of the infection. The laboratory tests revealed increased values of inflammatory markers, thrombocytopenia, and severe abnormalities of liver function. Serological and PCR tests for a wide range of pathogens proved an acute infection caused by Leptospira interogans, Hepatitis A virus, and Hepatitis E Virus. The patient received intravenous fluids and antibiotic treatment with ceftriaxone for seven days leading to gradual clinical improvement and normalization of liver function tests with subsequent reduction in jaundice within 30 days. Conclusions: This case report suggests that clinical suspicion and laboratory investigation should include the probability of coinfections even in non-endemic areas based on medical history of the patients. An early diagnosis of a zoonotic disease and other infective agents of acute hepatitis are vital in order to choose the appropriate treatment option and avoid severe complications. Full article

Cyperus polystachyos Rottb. is a species primarily distributed across tropical and subtropical regions of the world, while in Europe it remains very rare, with confirmed records only from two Italian sites, i.e., Tor Caldara Natural Regional Reserve (on the southern Lazio coast, central Italy) and Ischia Island (Campania region, southern Italy), where it grows in an open habitat on sulphur-rich soils and in Hungary, along the Danube River (an historical occurrence based on a herbarium collection dated October 1891). Following a detailed examination of specimens preserved in several European herbaria, we identified a previously overlooked historical collection from Sicily, a region where the species had long been considered absent but where this specimen provides the first confirmed evidence of its historical presence. Morphologically, C. polystachyos is highly polymorphic, leading to the description of many taxa over the centuries. Of these, only two varieties are currently accepted, i.e., var. polystachyos and var. holosericeus (Link) C.B.Clarke. To clarify the application of these varietal names, we conducted a nomenclatural study of Rottbøll’s C. polystachyos and Link’s C. holosericeus Link (the basionym of C. polystachyos var. holosericeus). We designate a specimen housed at C (barcode C10010299), collected by König in India, as the lectotype of C. polystachyos and a specimen deposited at K (barcode K002543977), collected by Drummond in the United States, as the neotype of C. holosericeus (no original material appears to survive for Link’s name). For nomenclatural purposes, we also examined the names C. fascicularis Poir. and C. scopellatus Rich., two of the earliest names associated with C. polystachyos. These are lectotypified here on specimens P00644234 (Poiret’s collection) and P00254684 (Richard’s collection), respectively. Full article

Background: Hansen’s disease or leprosy is one of the 21 neglected tropical diseases (NTDs). In Ecuador, leprosy is considered eliminated as a public health problem; however, new cases are reported annually. Additionally, Mycobacterium leprae infection was detected in nine-banded armadillos across the country, suggesting a potential zoonotic reservoir. This literature review aims to provide an updated overview of the epidemiological situation of leprosy in Ecuador, identify knowledge gaps, and outline research priorities to support the development of a comprehensive national strategy for achieving zero autochthonous cases. Methods: This article analyses the current situation of leprosy in Ecuador based on international and national publications. A retrospective literature search using five international, regional, and national publications on leprosy published between 1954 and 2024 (70 years) with no restriction on language or publication date, was performed. Findings: Our review identified 28 publications with the earliest article dating back to 1954. Of these, 14 were published in international journals, 15 (53.6%) were in Spanish. Four nationwide studies documented leprosy cases across Ecuador’s three continental regions (Coast, Andes, and Amazon) with a predominance in the tropical coast. No cases have been reported from the Galápagos Islands. From 1983, Ecuador started multi-drug therapy. Data from the Ministry of Public Health (MoH) system identified 1539 incident cases, showing a significant decline in new cases from 2000 to 2024, with no cases in children. New cases detection rate by 100,000 inhabitants was 0.51 in 2019 according to the World Health Organization (WHO). No study has genotyped the Mycobacterium spp. in human cases, other animal species, or environment. According to the MoH, multibacillary leprosy accounts for 78.95% of diagnosed cases, with confirmation based on Ziehl–Neelsen staining and histopathology. No survey has assessed disabilities, knowledge, attitudes, and practices (KAP) or stigma related to leprosy. Research is needed on transmission routes, Mycobacterium genotyping, genetic susceptibility, and antibiotic resistance. BCG vaccination coverage fell to 75.3% in 2021. Cases are currently diagnosed and treated on an outpatient basis in large hospitals. Conclusions: This comprehensive review highlights persistent gaps in leprosy research and critical information, despite seven decades of documented cases in Ecuador. The disease is still endemic across the country, particularly at subnational level in the subtropics and tropics of the Pacific coast and the Amazon. There is a need for nationwide epidemiological research on reservoirs and the environment applying the One Health concept. Increased laboratory facilities and readily available official data are required to improve our understanding of leprosy in Ecuador. Strengthening community-level efforts is essential for Ecuador to meet the targets of the “WHO’s Towards Zero Leprosy: Strategy 2021–2030.” Full article

Recreational diving depends on healthy marine ecosystems, yet it can harm biodiversity through species displacement and habitat damage. Bombinhas, a biodiverse diving hotspot in southern Brazil, faces growing threats from human activity and climate change. This study assessed the ecological structure of Sepultura Beach (2018) for potential diving trails, comparing it with historical data from Porto Belo Island. Using visual censuses, transects, and photo-quadrats across six sampling campaigns, researchers documented 2419 organisms from five zoological groups, identifying 14 dominant species, including Haemulon aurolineatum and Diplodus argenteus. Cluster analysis revealed three ecological zones, with higher biodiversity at the site’s edges (Groups 1 and 3), but these areas also hosted endangered species like Epinephelus marginatus, complicating trail planning. A major concern was the widespread bleaching of the zoanthid Palythoa caribaeorum, a key ecosystem engineer, likely due to rising sea temperatures (+1.68 °C from 1961–2018) and declining chlorophyll-a levels post-2015. Comparisons with past data showed a 0.33 °C increase in species’ thermal preferences over 17 years, alongside lower trophic levels and greater ecological vulnerability, indicating tropicalization from the expanding Brazil Current. While Sepultura Beach’s biodiversity supports diving tourism, conservation efforts must address coral bleaching and endangered species protection. Long-term monitoring is crucial to track warming impacts, and adaptive management is needed for sustainable trail development. The study highlights the urgent need to balance ecotourism with climate resilience in subtropical marine ecosystems. Full article

Beachrocks are common coastal sedimentary rocks in tropical and subtropical seas. They are widely spread especially in islands and coastal areas. These rocks are important for island geological evolution research. Research on beachrocks aids in protecting island ecosystems and enhances islands’ ability to prevent and mitigate damage from natural disasters. This study uses unmanned aerial vehicle (UAV) images and the U-Net model based on deep learning to identify beachrocks. To enhance identification accuracy, the efficient channel attention (ECA) mechanism was integrated, leading to improvements of 0.49% in overall accuracy, 1.41% in precision, 0.97% in recall, 1.10% in F1-score, and 2.09% in intersection over union (IoU) compared to the baseline U-Net model. The final results demonstrate that the model effectively identified beachrocks, achieving 97.47% accuracy, 93.27% precision, 94.73% recall, 93.95% F1-score, and 88.65% IoU. This study offers a valuable tool for island geological evolution research and supports the development of large-scale island conservation efforts. Full article

Where and at what altitudes electromagnetic wave ducts within the atmosphere are likely to occur is important for a variety of communication and military applications. We examined the modified refractivity profiles and wave duct characteristics derived from nearly 50,000 observed upper air soundings obtained over four years from seven tropical and subtropical islands, as well as middle latitude sites at four US coastal locations, three sites near the Great Lakes, and four US inland sites. Across all location types, elevated ducts were found to be more common than surface-based ducts, and the median duct thicknesses were ~100 m. There was a weak correlation between duct thickness and strength and, essentially, no correlation between the duct strength and duct base height. EM ducts more frequently occurred at the tropical and subtropical island locations (~60%) and middle latitude coastal locations (70%) as compared to the less than 30% of the time that occurred at the Great Lake and US inland sites. The tropical and subtropical island sites were more likely than the other location types to have ducts at altitudes higher than 2 km, which is above the boundary layer height. Full article

Transposable elements (TEs) are crucial for genome evolution and ecological adaptation, but their dynamics in non-model plants are poorly understood. Using genomic, transcriptomic, and population genomic approaches, we analyzed the TE landscape of Barthea barthei (Melastomataceae), a species distributed across tropical and subtropical southern China. We identified 64,866 TE copies (16.76% of a 235 Mb genome), dominated by Ty3/Gypsy retrotransposons (8.82%) and DNA/Mutator elements (2.7%). A genome-wide analysis revealed 13 TE islands enriched in genes related to photosynthesis, tryptophan metabolism, and stress response. We identified 3859 high-confidence TE insertion polymorphisms (TIPs), including 29 fixed insertions between red and white flower ecotypes, affecting genes involved in cell wall modification, stress response, and secondary metabolism. A transcriptome analysis of the flower buds identified 343 differentially expressed TEs between the ecotypes, 30 of which were near or within differentially expressed genes. The non-random distribution (primarily within 5 kb of genes) and association with adaptive traits suggest a significant role in B. barthei’s successful colonization of diverse habitats. Our findings provide insights into how TEs contribute to plant genome evolution and ecological adaptation in tropical forests, particularly through their influence on regulatory networks governing stress response and development. Full article

Parasites play a significant role in biodiversity, yet research on these organisms remains limited, particularly in tropical and subtropical regions. Parasites are also an essential aspect of domestic animal husbandry, and their prevalence depends on various factors, such as husbandry conditions and the environment. However, no studies have been conducted on parasites affecting domestic animals on Socotra Island. This study aimed to investigate parasites in selected goat populations on the island using intravital fecal diagnosis. A total of 406 samples from adult goats across different locations (lowlands and highlands) and seasons (dry and rainy) were collected, fixed in 10% formalin, and transported to the Czech Republic for coprological examination using flotation and ether sedimentation methods. Statistical analyses, including partial canonical correspondence analysis (pCCA), the Monte Carlo permutation test, and the chi-squared test, revealed a high prevalence of gastrointestinal parasite infections, with 89% of goats infected. Eimeria spp. had the highest prevalence (76%). Co-infection was common, with 55.9% of goats infected with multiple parasites. Seasonality influenced parasitism, with other Protostrongylidae, Muellerius spp., and Trichuris spp. predominating during the rainy season, and Eimeria spp. and gastrointestinal strongylids predominating during the dry season. This first study on Socotra Island, Yemen, provides crucial insights into effective intervention strategies for controlling goat parasite infections. Full article

The larger benthic foraminifera is a group of marine protists harbouring symbiotic algae, that are geographically confined to shallow tropical and subtropical waters, often associated with coral reefs. The resulting controls on availability of habitat and rates of dispersion make these foraminifers, particularly the genus Amphistegina, useful proxies in the study of invasive marine biota, transported through hull fouling and ballast water contamination in modern commercial shipping. However, there is limited information on the importance of these dispersal mechanisms for foraminifers in the Pre-Industrial Era (pre-1850) for the Atlantic and Caribbean region. This paper examines possible constraints and vectors controlling the invasion of warm-water taxa from the Indo-Pacific region to the Atlantic and Caribbean region. Heterostegina depressa, first described from St. Helena, a remote island in the South Atlantic, provides a test case. The paper postulates that invasions through natural range expansion or ocean currents were unlikely along the possible available routes and hypothesises that anthropogenic vectors, particularly sailing ships, were the most likely means of transport. It concludes that the invasion of the Atlantic by H. depressa was accomplished within the Little Ice Age (1350–1850 C.E.), during the period between the start of Portuguese marine trade with east Africa in 1497 and the first description of H. depressa in 1826. This hypothesis is likely applicable to other foraminifers and other biota currently resident in the Atlantic and Caribbean region. The model presented provides well-defined parameters that can be tested using methods such as isotopic dating of foraminiferal assemblages in cores and genetic indices of similarity of geographic populations. Full article

Mikania micrantha Kunth is native to tropical America and has invaded tropical and subtropical Asia and numerous Pacific Islands. It forms dense thickets and reduces native species diversity and populations in its introduced range. This invasive vine also seriously impacts many agricultural crops and is listed as one of the world’s 100 worst invasive alien species. Its life history characteristics, such as the production of large numbers of wind-dispersed seeds, vegetative reproduction, rapid growth, and genetic diversity all contribute to its invasiveness. In this review, we focus on how mechanisms to defend against its natural enemies boost the invasiveness of M. micrantha. It possesses potent defenses against natural enemies such as pathogenic fungi, herbivorous insects, and parasitic nematodes, and exhibits allelopathic potential against plant competitors. These defensive abilities, in concert with its formidable life history characteristics, contribute to the invasiveness of M. micrantha, potentially leading to further naturalization. Several other reviews have summarized the biology and management of the species, but ours is the first review to focus on how the defensive mechanisms of M. micrantha likely enhance its invasiveness. Relatively little is known about the array of defensive capabilities of M. micrantha; therefore, there is considerable scope for further research on its chemical defenses. Full article

Moringa (Moringa oleifera Lam.) is a tree that grows in tropical and subtropical regions. In this study, the plants were grown in a temperate climate zone from seeds collected at the Island of St. Lucia. Cultivation was carried out in the field and in a greenhouse in Prešov, East Slovakia. Leaf samples were taken from young plants and dried naturally. In the ethanol and hot water extracts of the leaves, the dry matter, total phenolic substances, and antioxidant activity were determined using three methods: superoxide anion radical scavenging activity, hydroxyl radical scavenging activity, and ferric reducing ability of plasma (FRAP) assay. The highest amount of total phenols was detected in the ethanolic extract of the leaves from the field 911.14 mg GAE L⁻¹, resp. 69.70 mg GAE g⁻¹ DM. The lowest amount was noticed in the leaves from the greenhouse 408.88 mg GAE L⁻¹, resp. 13.07 mg GAE g⁻¹ DM. The amount was significantly lower in the aqueous extracts. A high antioxidant activity of the leaves from the field was detected in all ethanolic and hot water extracts. Both types of leaf extracts from the greenhouse showed statistically significant lower antioxidant activity. The obtained results indicate that outdoor cultivation in a temperate climate zone was stressful for the plants, leading to an increased formation of phenolic substances, and consequently to higher antioxidant activity. Full article

The generation of cloud-free satellite mosaics is essential for a range of remote sensing applications, including land use mapping, ecosystem monitoring, and resource management. This study focuses on remote sensing across the climatic diversity of Hawai’i Island, which encompasses ten Köppen climate zones from tropical to Arctic: periglacial. This diversity presents unique challenges for cloud-free image generation. We conducted a comparative analysis of three cloud-masking methods: two Google Earth Engine algorithms (CloudScore+ and s2cloudless) and a new proprietary deep learning-based algorithm (L3) applied to Sentinel-2 imagery. These methods were evaluated against the best monthly composite selected from high-frequency Planet imagery, which acquires daily images. All Sentinel-2 bands were enhanced to a 10 m resolution, and an advanced weather mask was applied to generate monthly mosaics from 2019 to 2023. We stratified the analysis by cloud cover frequency (low, moderate, high, and very high), applying one-way and two-way ANOVAs to assess cloud-free pixel success rates. Results indicate that CloudScore+ achieved the highest success rate at 89.4% cloud-free pixels, followed by L3 and s2cloudless at 79.3% and 80.8%, respectively. Cloud removal effectiveness decreased as cloud cover increased, with clear pixel success rates ranging from 94.6% under low cloud cover to 79.3% under very high cloud cover. Additionally, seasonality effects showed higher cloud removal rates in the wet season (88.6%), while no significant year-to-year differences were observed from 2019 to 2023. This study advances current methodologies for generating reliable cloud-free mosaics in tropical and subtropical regions, with potential applications for remote sensing in other cloud-dense environments. Full article

A total of 96 strains of Nostocales (Cyanobacteria) were established from the phyllosphere of the laurel forests in the Canary Islands (Spain) and the Azores (Portugal) using enrichment media lacking combined nitrogen. The strains were characterized by light microscopy and SSU rRNA gene comparisons. Morphologically, most strains belonged to two different morphotypes, termed “Nostoc-type” and “Tolypothrix-type”. Molecular phylogenetic analysis of 527 SSU rRNA gene sequences of cyanobacteria (95 sequences established during this study plus 392 sequences from Nostocales and 40 sequences from non-heterocyte-forming cyanobacteria retrieved from the databases) revealed that none of the SSU rRNA gene sequences from the phyllosphere of the laurel forests was identical to a database sequence. In addition, the genetic diversity of the isolated strains was high, with 42 different genotypes (44% of the sequences) recognized. Among the new genotypes were also terrestrial members of the genus Nodularia as well as members of the genus Brasilonema. It is concluded that heterocyte-forming cyanobacteria represent a component of the phyllosphere that is still largely undersampled in subtropical/tropical forests. Full article