Search Results (3,532)

Tourism is a major driver of economic growth in tropical island destinations but also places increasing pressure on fragile marine ecosystems. This study examined tourists’ environmental awareness, perceptions, and conservation-related behaviors on Cozumel Island, part of the Mesoamerican Reef System and home to multiple protected areas, including the Arrecifes de Cozumel National Park. Between June and September 2022, surveys were conducted with 144 tourists at major tourism hubs across the island. Although 86% of respondents identified themselves as environmentally conscious, awareness of local environmental impacts associated with tourism remained limited, and only 6% reported engaging in environmentally conscious actions during their visit. Awareness of the protected status and regulations of the Arrecifes de Cozumel National Park was also low (39%), and only 19% reported purchasing the required conservation bracelet or park pass. Short-stay cruise visitors represented 65% of respondents, potentially limiting opportunities for deeper environmental engagement and conservation education. These findings highlight the need for stronger pre-trip environmental communication, visible on-site interpretation, and targeted outreach strategies to support sustainable tourism and coral reef conservation in the Mexican Caribbean. Full article

Greenhouses in subtropical and tropical regions must be designed as agricultural engineering systems adapted to local climates, rather than simply replicating the “insulation” models of temperate areas. Under extreme climatic conditions such as persistent high temperatures, intense solar radiation, high humidity, heavy rainfall, and frequent extreme winds, greenhouses transform from enclosed insulation layers into selective climate filters, mitigating crop stress while maintaining close contact with the outdoor environment. This paper summarizes how these climate drivers are reshaping the use, structure, and control concepts of greenhouses, emphasizing that the performance of warm-zone greenhouses depends primarily on heat dissipation, humidity management, and biohazard control, rather than heating and insulation. In this review, we analyze the climatic boundary conditions that define warm-climate conservation cultivation, including long-term overheating risk, high UV radiation, vapor pressure deficit, and suppressed condensation tendency, as well as storm-induced uplift and dynamic loads. These constraints necessitate unique structural forms: tall, lightweight, well-ventilated building types with large roof and side openings, roof geometries that facilitate rainwater runoff, sophisticated drainage systems, and corrosion-resistant materials suitable for humid and coastal environments. Because insect netting significantly reduces ventilation, pest control and temperature regulation become co-design issues, requiring oversized vents, optimized airflow paths, and hybrid roof–mesh structures. Ventilation is considered the primary climate-control mechanism, supplemented by passive cooling measures such as shading and radiation/optical management (e.g., diffuse films and near-infrared-selective films). Active evaporative cooling is considered a conditional measure due to humidity limitations and disease risks. This paper also integrates the impacts on specific crops (fruits and vegetables, leafy greens, and orchids). It highlights emerging trends: typhoon-resistant and adaptive geometries, computational fluid dynamics (CFD)-based design, and sensor-rich IoT/digital twin control frameworks. These principles collectively establish a coherent design framework for achieving resilient, resource-efficient greenhouse production in warm climates. Full article

Subjected to high-intensity development, enclosed tropical islands frequently face severe spatial resource constraints and acute risks of ecological degradation. To seek a comprehensive solution to multidimensional spatial conflicts, this study selected Hainan Island—a region facing development pressure from the Free Trade Port construction—as the study area. By coupling the XGBoost-SHAP, NSGA-II, and PLUS models, we constructed an integrated modular spatial planning framework of “mechanism interpretation—macro optimization—micro reconstruction”. The main findings are as follows. (1) Over the past 15 years, the fragile ecosystem of the island has faced immense pressure. Lacking an external buffer hinterland, land-use transitions exhibited a distinct chain transmission characteristic of “built-up land occupying agricultural land, and agricultural land squeezing forest”. This internal spatial cascading substitution constituted the core mechanism of ESV decline. (2) The reconstruction of the spatial pattern is governed by dual thresholds of natural constraints and economic pulling. A rigid ecological defense baseline (NDVI ≥ 0.40) restricts disorderly urban sprawl, while spatial inflection points (8.46 km from the coastline and 271 m from roads) precisely delineate the coastal and traffic-oriented agglomeration boundaries for built-up land. (3) Among the predefined scenarios, the Sustainable Development (SD) scenario emerges as the optimal pathway. By proactively reducing inefficient agricultural land space at the macro level and strictly implementing identified threshold controls alongside “infill” urban agglomeration at the micro level, the SD scenario is expected to successfully achieve a Pareto-optimal synergy between socioeconomic growth and the restoration of regional ESV. This study not only establishes an objective benchmark for the refined multi-objective spatial governance of the Hainan Free Trade Port, but also provides a referential planning paradigm for vulnerable enclosed islands globally facing high-intensity anthropogenic stress. Full article

Rapid urbanization in tropical Asia has fundamentally transformed land use–land cover while intensifying urban thermal stress, yet the relationship between land cover change and thermal conditions is frequently assumed to be spatially uniform. This study challenges that assumption by demonstrating that land cover–thermal relationships in Colombo District, Sri Lanka, are highly spatially and temporally heterogeneous, with statistically significant associations detected in only 17–47% of the study area in any given year, underscoring that context, not land cover type alone, governs thermal outcomes. Using multi-temporal Landsat satellite imagery, LULC maps were derived, and the urban heat island effect (UHIE) and urban thermal field variance index (UTFVI) were calculated for seven time periods (1989, 1996, 2002, 2009, 2014, 2019, 2024). Geographically weighted regression (GWR) was applied to model local relationships between LULC classes, namely wetland vegetation, water bodies, impervious surfaces, and other pervious surfaces, and thermal indices across a 500 m spatial grid, revealing a 74% loss in wetland vegetation and a 326% increase in impervious surfaces over the study period. Water bodies exhibited spatially variable cooling effects relative to wetland vegetation, most pronounced in eastern regions during earlier periods, while impervious surfaces showed consistent, spatially persistent warming effects concentrated in western and southern urban cores. By coupling GWR with a 35-year multi-sensor time series, this study provides a spatially explicit, longitudinal account of how land cover–thermal relationships evolve as tropical urbanization intensifies, offering an evidence base for spatially targeted rather than uniform climate adaptation planning in rapidly urbanizing tropical cities. Full article

Brazilian cattle production relies predominantly on pasture systems, many of which are degraded by nutrient depletion, particularly nitrogen deficiency. Plant growth-promoting bacteria (PGPB) offer a sustainable strategy to improve pasture productivity, but their effects are often host-specific and remain poorly explored in Paspalum. This study evaluated the effect of inoculation with Azospirillum brasilense strains CNPSo 2083 (=Ab-V5) and CNPSo 2084 (=Ab-V6) and Pseudomonas fluorescens strain CNPSo 2719 (=CCTB 03), applied by seed inoculation or leaf spray, on the root morphology and shoot growth of four Paspalum accessions under controlled axenic greenhouse conditions, evaluated in an early growth stage at 35 days after emergence. Genotype-specific responses were the central finding of this study: Paspalum malacophyllum BGP-293 showed negligible responses to inoculation, whereas BGP-486—of the same species—increased root dry weight by up to 43% and root tissue density by up to 30% in all inoculated treatments. In Paspalum regnellii BGP-112, seed inoculation produced stronger root responses than foliar spray, increasing root dry weight by up to 38% and root area by up to 40%. In Paspalum rojasii BGP-149, inoculation induced root architectural remodeling without increasing root biomass—root area increased by up to 92% and total root length by up to 97%, relative to the control—indicating an efficient root-foraging strategy. P. fluorescens favored root-foraging traits and tissue density, whereas A. brasilense preferentially stimulated root-hair elongation. These accession-level contrasts, rather than a single generalizable trend, are the main contribution of this work: they support tailored, genotype-specific PGPB strategies for sustainable tropical pastures. Full article

The construction of the Hainan Free Trade Port (FTP) is guided by the core philosophy of “ecological priority and green development.” To meet the practical requirements of building a “Green and Beautiful FTP,” this study constructed a kernel Normalized Difference Vegetation Index (kNDVI) dataset using Landsat series satellite imagery. By integrating methods including the Mann–Kendall (MK) trend test, Hurst exponent, and coefficient of variation (CV), an in-depth analysis was conducted on the spatiotemporal evolution characteristics and trends of growing-season vegetation in Hainan Island from 1994 to 2023. Additionally, the Extreme Gradient Boosting (XGBoost) model and the SHapley Additive exPlanations (SHAP) interpretation method were employed to quantitatively unravel the driving mechanisms of climatic factors and human activities on kNDVI variations. The results indicate that: (1) Over the past three decades, the overall kNDVI of Hainan Island has exhibited a significant upward trend, characterized spatially by an evolution pattern of “stable recovery in the central region and localized degradation along the coast.” (2) The vegetation evolution demonstrates strong persistence and is highly consistent with community stability. The high stability in the central mountainous areas stems from a superior natural background and strict ecological protection; the transition zone is jointly influenced by vegetation types and anthropogenic management; meanwhile the coastal areas exhibit significant degradation characteristics driven by high-intensity human disturbances. (3) The analysis of driving mechanisms reveals a complex control logic of “topographical foundation—human reshaping—extreme climate triggering.” Static topographical factors, such as elevation and slope, occupy an absolute dominant position; human activities, represented by rubber plantation expansion and urbanization, exert a bidirectional reshaping effect characterized by “inland greening and coastal suppression”; furthermore, extreme drought and high temperatures in the later stages of the study demonstrated a significant pulse-like impact, exacerbating the risks of short-term climatic stress. This study clarifies the core patterns of vegetation evolution in Hainan Island, validates the effectiveness of ecological policies, and provides a quantitative scientific basis for ecological conservation and sustainable development in tropical island regions. Full article

Peat swamp forests play a critical role in maintaining the ecological integrity of tropical peatlands. The conservation and restoration efforts on these ecosystems have gained considerable attention considering their vulnerability. Accurate spatial mapping of aboveground biomass (AGB) is important to support such measures, and it can be accurately implemented using airborne LiDAR. However, the high operational cost of LiDAR surveys typically restricts their spatial coverage. This study estimated AGB of peat swamp forests by combining two remote sensing datasets, i.e., Planet NICFI imagery (2023–2024) and partially covered airborne LiDAR (10.56% of the total area), in the Katingan–Mentaya peat swamp forest, Central Kalimantan, Indonesia. Two workflows were proposed and compared. The first, DL-PowerReg, estimated canopy height model (CHM) using a U-Net deep learning model trained on Planet imagery, followed by AGB mapping through power regression. The second, StepwiseReg-DL, derived LiDAR-based AGB through stepwise regression of LiDAR metrics, then upscaled it to the full study area using U-Net with Planet imagery as input. DL-PowerReg (MAE = 52.24 t/ha) outperformed StepwiseReg-DL (MAE = 62.08 t/ha) and additionally produced an intermediate CHM map, providing complementary information on forest structure. The two approaches estimated total AGB storage in the study area at 47.75 Mt (mean = 239.91 t/ha) and 40.07 Mt (mean = 201.30 t/ha), respectively. This study demonstrates a methodological framework for leveraging spatially incomplete LiDAR data in high-resolution wall-to-wall forest biomass mapping. Full article

This study investigates the long-term impacts of climate change on crop yields by analyzing global historical data from 1961 to 2024 across 25 selected countries, to to reveal how historical weather patterns affected crop yields in the most vulnerable regions of the world. Utilizing crop yield data from FAOSTAT and weather time series from the World Bank Climate Knowledge Portal, three distinct climate risk groups of countries were defined: Group 1 (strong warming, stable precipitation), Group 2 (no significant warming, strong precipitation decrease), and Group 3 (mild warming, strong precipitation decrease). A Linear Mixed-Effects Model (LMM) was employed to quantify the non-linear impacts and interactions of climate variables, including annual temperature maximums, minimums, precipitation, warm and cold spell durations, and the Standardized Precipitation Evapotranspiration Index, on primary staple and cash crops. Results reveal a stark regional asymmetry. In temperate regions (Group 1), agrotechnological advancements have successfully cushioned climate shocks over the past decades, although this buffering effect faces biophysical limits due to non-linear temperature thresholds, particularly for root crops like potatoes and sugarbeet. In tropical–subtropical areas (Group 2) and the Mediterranean (Group 3), climate extremes exert severe pressure on vital crops. Prolonged warm spells significantly reduce yields for perennials like bananas, coffee, and dates, while other Mediterranean crops like olives thrive under longer warm spells. While country-specific institutional capacities often generate substantial yield heterogeneity, major exceptions emerge for staple crops like wheat in Group 2 and barley in Group 3, where low Intraclass Correlation Coefficients (ICC) demonstrate that regional climatic drivers override national boundaries. The findings underscore that universal climate strategies are inefficient, and policymakers must prioritize crop-specific and localized adaptation frameworks for future food security. Full article

India faces large, persistent yield gaps across eight major crops—wheat, rice, maize, soybean, pulses, mustard, cotton, and sugarcane—that collectively limit food security and rural income. This review synthesises evidence from over 100 peer-reviewed studies (1990–2024) to provide the first comprehensive, multi-crop, agro-climatically resolved yield gap analysis for India. Applying the three-tier framework of potential yield ($Y_p$), attainable yield ($Y_a$), and farmer yield ($Y_f$), exploitable yield gaps are quantified at national and agro-climatic zone level, ranked limiting factors are identified, and projected climate change impacts are assessed. Yield gaps range from 20 to 35% in irrigated rice of the north-western Indo-Gangetic Plain to 60–75% in rainfed cotton and pulses of the semi-arid tropics. Yield gaps of blackgram across 20 major districts average 515 kg ha⁻¹, driven by moisture stress, biotic pressure, and management constraints. Nitrogen management, irrigation access, variety adoption, and sowing-date optimisation collectively explain 80–85% of exploitable gaps, while nitrogen and irrigation alone account for 40–58%. Closing 50% of exploitable yield gaps could add approximately 100 million tonnes of food grain annually without expanding cultivated area, directly supporting Sustainable Development Goal (SDG 2). However, climate change is projected to widen yield gaps of rainfed rice by 15–30% by the 2040s under Representative Concentration Pathway (RCP) 8.5. Beyond this crop-by-crop synthesis, the review proposes a constraint-transition framework in which the dominant type of limiting factor shifts predictably from biophysical (water, climate) in the largest-gap rainfed systems to agronomic management (nitrogen, sowing date, variety) at intermediate gap levels and to institutional and socioeconomic constraints (credit, extension, land tenure, gender) as gaps narrow in the best-resourced irrigated systems, thus offering a conceptual lens for prioritising interventions by development stage rather than by crop alone. Full article

Tropical coastal ecosystems are highly productive but increasingly threatened by anthropogenic pressures, making environmental monitoring tools essential to determine the health status of the environment. In this study, the health status of three sites along the Pacific coast of Panama (Río Santa María, Cuchilluyo, and Montijo) was assessed using the bivalve mollusc Anadara tuberculosa as a sentinel species. A multilevel biomarker approach was employed, combining chemical analyses with biochemical and histological biomarkers. Metal concentrations in whole soft tissues were generally low-to-moderate, except for arsenic, and polycyclic aromatic hydrocarbon (PAH) concentrations were low in all sites, being dominated by low-molecular-weight compounds. Biomarker responses were consistent with the chemical data, with cockles from Montijo exhibiting lower glutathione S-transferase (GST) activity and reduced oxidative DNA damage. Histological analyses revealed only mild alterations, including hemocytic infiltration in the connective tissue of digestive glands and atrophy, with no major reproductive impairments. Overall, results indicate low to moderate pollution levels in the studied areas, with Montijo representing the least impacted site. The study supports the suitability of A. tuberculosa as a sentinel species and the relevance of a multilevel biomarker approach for assessing environmental health in tropical coastal ecosystems. Full article

Rainfall prediction models often lose skill when transferred across regions, particularly in data-sparse settings where local recalibration is not feasible. This study investigates whether topographically analogous landscapes exhibit consistent patterns of model portability in next-day rainfall occurrence prediction across contrasting climates. Random Forest and Logistic Regression classifiers trained on multi-year daily atmospheric data were evaluated across three hydrogeomorphic classes, Alluvial/Valley, Delta/Marsh, and Coastal Plain, using paired temperate sites in the United States and tropical sites in Malaysia. Portability was quantified using Transferability, representing a model’s ability to export predictive skill, and Adaptability, representing a site’s receptivity to externally trained models. Performance, sensitivity, and stability metrics were synthesized within a Behaviour Grid to support systematic interpretation. Results reveal a robust terrain-driven hierarchy: Delta/Marsh models are the strongest exporters, Alluvial/Valley sites the most adaptable receivers, and Coastal Plain sites are stable generalists. This general hierarchy is preserved across climates and years when evaluated using Area Under the Receiver Operating Characteristics Curve, indicating strong terrain structuring of portability, although fixed-threshold performance metrics show sensitivity to temporal variability. These findings indicate that terrain class provides a useful basis for evaluating cross-regional model transfer, supporting more informed regionalisation and deployment decisions across heterogeneous environmental settings. Full article

Land-use and land-cover (LULC) change is a major driver of ecosystem degradation and ecosystem service loss in tropical landscapes. This study assessed the impacts of LULC changes between 1985 and 2023 on the potential of different LULC classes to supply ecosystem services in the Upper Rio Pardo Basin (Rio Pardo and Rio São João do Paraíso watersheds), northern Minas Gerais, Brazil. LULC data from the MapBiomas Project were used to quantify transitions among LULC classes within the study area. The potential supply of ecosystem services was assessed using the Burkhard matrix, adapted to local environmental conditions and informed by expert knowledge, while the relative importance of ecosystem services was evaluated through a participatory assessment involving local communities. The expansion of pasturelands and commercial forest plantations was identified as the primary driver of ecosystem service loss in the study region. Native ecosystems showed the highest potential to provide regulating, supporting, provisioning, and cultural ecosystem services, particularly water regulation, soil protection, carbon sequestration, and biodiversity conservation. In contrast, anthropogenic land uses were primarily associated with provisioning services and showed limited capacity to sustain regulating and supporting services, indicating clear trade-offs between production and ecosystem functioning. Local communities identified water-related services as the highest priority, followed by climate regulation, soil fertility, and food provision. These findings demonstrate the value of integrating expert-based and participatory approaches to ecosystem service assessment and provide a basis for territorial planning strategies that prioritize the conservation and restoration of native vegetation, particularly in hydrologically sensitive areas. Full article

Background: The movement of endemic diseases from tropical and disadvantaged areas is gradually spreading to developed countries as well. Amoebiasis, in particular, represents a significant threat to public health, amplified by globalization and increasing contact between humans and animals or vectors. In this way, atypical diseases may emerge in our country, also through an unusual mode of transmission—likely sexual, as “sexually transmitted enteric (STE) diseases”. Objective: We report and discuss the clinic approach to a rare case of dual human infestations by ecto- and endo-parasites with multiple liver abscesses presentation in a young truck driver residing in Northern Italy. Methods: The patient underwent a comprehensive screening with laboratory and microbiological tests, and CT images. Results: In July, the patient was admitted to our hepatology unit following the ultrasound identification of two hypoechoic lesions in the right lobe of the liver. In his medical history, in April, after a seemingly harmless infestation of body lice, effectively treated, he suffered from a prolonged and debilitating episode of acute diarrhea, lasting a month. This status was also accompanied by intestinal cramps, weight loss, and recurring fever episodes. Afterwards also appeared a Quincke’s-like angioedema involving the lips and mouth mucosa, with evening time exacerbation. Conclusions: The differential diagnosis of this complex and unusual clinical picture, together with the temporal evolution of the patient’s signs and symptoms, led us to hypothesize the presence of concomitant infections. These were most likely borreliosis and a STE disease, the latter ultimately diagnosed as amebiasis with hepatic invasion, allowing appropriate treatment and a favorable clinical outcome. Full article

Habitat loss and deforestation are among the main drivers of biodiversity decline in tropical ecosystems, yet their effects on developmental stability remain poorly understood in many insect groups. Orchid bees (Apidae: Euglossini) have been proposed as potential bioindicators of environmental quality due to their close association with forested habitats and sensitivity to habitat disturbance. Here, we evaluated the relationship between forest cover, wing morphology, and developmental stability in the orchid bee Euglossa imperialis across five protected areas of Panama exhibiting different levels of deforestation. A total of 290 individuals were analyzed using geometric morphometrics and fluctuating asymmetry (FA) of the forewing. Morphological variation was assessed through Principal Component and Canonical Variate Analyses, whereas developmental instability was quantified using Procrustes ANOVA and FA scores. Wing shape showed moderate differentiation among sites, with La Tronosa, the most deforested protected area, exhibiting the greatest morphological divergence. In contrast, FA displayed a clear association with habitat degradation. La Tronosa presented the highest levels of developmental instability, and generalized linear models revealed a significant positive relationship between deforestation and FA at both local and landscape scales, with landscape-level deforestation showing the strongest effect. Our results indicate that developmental instability is more sensitive than overall wing morphology for detecting the biological consequences of habitat alteration. These findings support the use of fluctuating asymmetry as an early indicator of environmental degradation and provide new evidence for the value of orchid bees as bioindicators in tropical ecosystems. Full article

Ecological stoichiometric ratios of soil provide insights into the interactions and limitations among elements. This study examined the nutrient characteristics K, N, and P stoichiometric ratios in the soils collected from three distinct shelter forests (Casuarina equisetifolia, secondary forest, and Cocos nucifera) in a tropical coastal region of Hainan Province, China. Significant differences were observed among forest types in terms of stoichiometric ratios and nutrient levels in soil (p < 0.05). This may be related to the high species diversity in secondary forests and the complex composition of litter. soil nutrient levels in the secondary forest were higher than those in C. equisetifolia and C. nucifera. The effects of soil nutrient factors on soil ecological stoichiometric ratios differed across shelterbelt types. Soil organic matter, total potassium, available potassium, and ammonium nitrogen content substantially influenced the N:P, K:P, and N:K ratios (Q² > 0.5). Soil TN content was highly significantly positively correlated with N:P, N:K, in C. equisetifolia and C. nucifera (p < 0.01), whereas in the secondary forest, it was highly significantly positively correlated with SOM and NH₄⁺-N (p < 0.01). These results reflecting the complexity of nutrient cycling as well as the interdependence and mutual regulation between vegetation and soil in coastal shelter forest ecosystems. Full article