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Purpose: We examined fluid intake, the relation between body mass (BM) loss and performance, and core temperature in young triathletes during a competition in tropical climate. Methods: Fluid intake and pre and post BM were measured in 35 adolescent athletes, and core temperature was measured in one female and one male. Results: Mean urine specific gravity (1.024 [0.007]) indicated that athletes were in suboptimal state of hydration upon waking. Race time was 73.2 (8.0) minutes. BM decreased by 0.6 (0.3) kg (P <.05). Fluid intake (528.5 [221.6] mL) replaced 47% of the fluid loss (1184.9 [256.4] mL) and was higher during run (11.5 [6.6] mL·min−1) compared to bike (7.3 [3.1] mL·min−1), P <.01. Loss in BM was ≥1.0% in 66% and ≥1.5% in 29% of the athletes. Males showed a moderate association between percentage loss in BM and finishing time (r = −.52), higher sweat rates (1.0 [0.3] L·h−1), and faster times (69.4 [7.5] min; P <.05). Core temperature rose to 40.1 °C in the female and 39.6 °C in the male. Conclusion: Young triathletes competing in a hot/humid climate became mildly to moderately dehydrated and hyperthermic even when water and sports drinks were available but did not show symptoms of heat illness. [ABSTRACT FROM AUTHOR]

The objective was to investigate the effect of rainfall on sodium (Na) dissolution and total losses by runoff of loose mineral mixtures (MM) available in uncovered feeders to grazing cattle, as well as the possible impacts on their growth performance and fulfilment of Na nutritional needs. Experiments (n = 7) were conducted to quantify the amount of Na lost due to rainfall and to evaluate the effects of different Na levels in the MM (35, 70, 105, and 140 g Na/kg) on MM assumed intake and growth performance. Cattle grazed Brachiaria sp. pastures and received free-choice MM in uncovered feeders throughout four to nine evaluation periods lasting 14 to 21 d each. MM assumed intake from the feeder was measured in each period as the difference between the supplied MM mass and the unconsumed MM mass. A new methodology was proposed to measure MM losses by runoff (exclusion feeder). The mass of runoff MM and the volume of runoff rainwater were both determined and analysed for their mineral content. The dietary Na requirement was estimated using different feeding systems. The minimum MM Na content to meet dietary Na requirements was estimated in different scenarios. Sodium chloride composed 28% of the runoff MM mass, in average. The action of rain may reduce MM Na content by 28% in a single rainfall event. Na content strongly affected MM assumed intake and, possibly, growth rate. MM losses by runoff were estimated at 25.5%, according to the exclusion feeder methodology. The minimum required MM Na content for meeting dietary Na needs may reach up to 87.3 g Na/kg. About 27% of evaluated periods may have failed to fully meet cattle Na requirements. The action of rain in unsheltered loos MM may result in unbalanced mineral consumption and unmet Na needs, leading to impaired mineral nutrition of grazing cattle, especially in tropical conditions. [ABSTRACT FROM AUTHOR]

Numerous studies have shown the influence of the moon cycle on biological functions in farm animals, suggesting that predicting calving distribution could enhance survival rates by improving management practices in animal production. This study builds on previous research by examining the impact of the lunar cycle on calving frequency, gestation length, birth weight, and calf sex in artificially inseminated cows. We analyzed 121,276 records from dual-purpose crossbred cows across 36 farms along the western margin of Lake Maracaibo basin, Venezuela. The lunar cycle was divided into 30 periods of 0.984 days each and further categorized into four phases: 1) 1.97 days around the new moon; 2) 12.8 days during the crescent phase; 3) 1.97 days around the full moon; and 4) 12.8 days during the waning phase. Data were analyzed using a logistic regression and the general linear model in SAS, comparing proportions and means with contrast and general linear model tests, respectively. There was no association between the lunar cycle and the sex of calves. However, calvings distribution across the lunar month showed notable peaks 2 days around both the new and full moons, a pattern consistent regardless of the number of calvings or gestation lengths. In addition, significant differences were observed between the days surrounding the new (1) and full (3) moons compared to the other lunar phases (2 and 4). Moon cycle also influenced gestation length and calf birth weight. This study expands previous findings and demonstrates that the lunar cycle consistently affects certain reproductive traits in inseminated dual-purpose cows, including gestation length, calf birth weight, and calving distribution, with practical implications for cattle operations. [ABSTRACT FROM AUTHOR]

Aquaculture is important for food security and livelihoods, especially in the developing tropics. Many nutrients supplied by feed degrade water quality, waste resources and lead to nutrient loss. Halophytes have the potential to recover these nutrients from aquaculture effluents. Most studies have focused on temperate species, but there is a need for extractive species suitable for integration in tropical saline aquaculture. Sea purslane Sesuvium portulacastrum is a promising candidate providing biomass for human consumption with potential pharmaceutical applications, but to date, nutrient uptake has not been studied in this species. This study investigated the nutrient removal from milkfish wastewater by systems planted with S. portulacastrum in hydroponics versus planted in sand. Most nutrients were removed from the wastewater within 48 h. Phosphorus and nitrogen were most efficiently removed in treatments with plants and sand and on average lower in the hydroponic incubations. However, in hydroponic systems, plants assimilated 50.2% of the added labelled N with no significant difference in recovery after 48 h when 15NH4 or 15NO3 was added. The recovery of wastewater N into plant biomass was several-fold higher in hydroponics than in sand substrate. Integration of S. portulacastrum into aquaculture turns aquaculture effluents into a valuable resource. [ABSTRACT FROM AUTHOR]

Assessing if CMIP models can detect observed climate change signals is crucial for evaluating their realism and strengthening confidence in future projections. These signals can only be compared once distinguishable from the background climate "noise." Built for impact studies but not detection purpose, the time of emergence (ToE) estimates when this occurs using a fixed signal-to-noise ratio. To more accurately assess models' ability to reproduce observed climate change signals, we introduce the time of detection (ToD), which employs a statistical significance test of the nonlinear trend, accounting for the time series length. ToD and ToE are computed for sea surface temperature (SST) and relative SST (RSST) across four observational and 69 CMIP5/6 historical and shared socioeconomic pathways 5–8.5 (SSP5–8.5) scenario datasets. ToD precedes ToE and is less sensitive to the chosen threshold. While already detectable in most of the tropics, SST warming in the equatorial Pacific is detectable in ∼90% of models but only one out of four observational datasets, due to a stronger modeled warming. Because RSST signals are weaker than SST signals, they do not emerge anywhere but are detectable in two regions. The enhanced warming in the western Indian Ocean, detected in ∼45% of models, is not robust in observations when excluding pre-1960 dubious data. Conversely, the subdued southeast Pacific warming detected in observations and ∼80% of models is robust and consistent with a poleward extension of the Southern Hemisphere Hadley cell. The ToD's ability to detect subtle signals allows for assessing the realism of the CMIP warming pattern in this region. Significance Statement: Recent studies emphasize the importance of the climate change warming pattern and its apparent discrepancy between climate models and observations in the equatorial Pacific. We argue that our newly proposed time of detection (ToD) is better suited than the well-known time of emergence (ToE) for investigating where modeled and observed warming patterns can be confidently compared. In agreement with previous studies, our analysis indicates model–observations disagreement over the equatorial Pacific. Using ToD instead of ToE allows for detecting a robust subdued warming (i.e., weaker than the tropical average) in the southeast Pacific and therefore confirms the realism of the CMIP warming pattern in this region. [ABSTRACT FROM AUTHOR]

Marine heatwaves (MHWs) have adverse impacts on marine ecosystems and fisheries, yet extreme MHWs in the western tropical Pacific Ocean remain largely unexplored. Here, we investigate the evolution and drivers of the two strongest subsurface MHWs in the western tropical Pacific Ocean on record, in 2008 (MHW-08) and 2010–11 (MHW-11). The two events have similar evolutions, as they were both initiated and developed locally in tropical regions during their onset phase and gradually dissipated with multiple cores during the decay phase. We examined the physical processes during the evolution of MHW-08 and MHW-11 and performed a heat budget analysis for the subsurface layer in each case. We find that the onset of both events were mainly controlled by convergence and vertical heat advection due to anomalous Ekman downwelling, while the decay of both events was mainly controlled by horizontal heat advection due to anomalous horizontal currents and withdrawal of anomalous convergence. The relationship between the subsurface MHWs and El Niño–Southern Oscillation is discussed. We suggest that the anomalous heat advections plus the La Niña–related background warming lead to the extreme subsurface MHW events. Our findings may have important implications for environmental change and marine life in the western tropical Pacific Ocean. [ABSTRACT FROM AUTHOR]

Oil palm cultivation has experienced explosive expansion in recent decades. Although the oil palm boom has serious environmental and socioeconomic consequences, only environmental issues have garnered attention in public discussion and synthesis studies. In this study, we synthesize the literature on the socioeconomic impacts of oil palm expansion across various observation units and spatial and temporal scales, which is of significant relevance to policymakers, researchers, and the wider public. Our review demonstrates that oil palm expansion is a double-edged sword. On the one hand, it has significantly helped both producing and non-producing countries' economies by facilitating the (re)export of crude palm oil and its byproducts and by creating employment opportunities. This has stimulated rural economies, led to rural poverty reduction, and improved food security and diets for rural households in producer countries. On the other hand, it has increased conflicts and tension between local communities and agro-industrial companies, worsened workers' conditions, and widened domestic economic inequality between producing and non-producing areas within a given producer country. Monetary quantification of the costs of oil palm's negative environmental and social impacts indicates that the loss of ecosystem services and social services far outweighs the benefits derived from the increased production of oil palm. The direct income benefits through harvest sales and employment are more evident in the Southeast Asia production frontier, where oil palm cultivation and marketing are relatively advanced and well-integrated into global value chains. The negative outcomes are observed in all oil palm production regions, with more negative effects on food security in the African production frontiers. We propose multiple actionable research and policy recommendations that may jointly lead to inclusive and sustainable socioeconomic (and environmental) outcomes in oil palm cultivation. The socioeconomic consequences of oil palm expansion at the global level, in the African and American production frontiers, and the role of gender in oil palm production systems remain understudied. Hence, studies should be conducted. [ABSTRACT FROM AUTHOR]

Ecotones are the transition zones between ecosystems and can exhibit steep gradients in ecosystem properties controlling flows of energy and organisms between them. Ecotones are understood to be sensitive to climate and environmental changes, but the potential for spatiotemporal dynamics of ecotones to act as indicators of such changes is limited by methodological and logistical constraints. Here, we use a novel combination of satellite remote sensing and analyses of spatial synchrony to identify the tropical dry forest–rainforest ecotone in Area de Conservación Guanacaste, Costa Rica. We further examine how climate and topography influence the spatiotemporal dynamics of the ecotone, showing that ecotone is most prevalent at mid‐elevations where the topography leads to moisture accumulation and that climatic moisture availability influences up and downslope interannual variation in ecotone location. We found some evidence for long‐term (22 year) trends toward upslope or downslope ecotone shifts, but stronger evidence that regional climate mediates topographic controls on ecotone properties. Our findings suggest the ecotone boundary on the dry forest side may be less resilient to future precipitation reductions and that if drought frequency increases, ecotone reductions are more likely to occur along the dry forest boundary. [ABSTRACT FROM AUTHOR]

Milk production is a key component of the agriculture sector in the tropics and subtropics, contributing 47.32% to global milk production. This study aimed to quantify milk production and composition (fat and protein) in warm-climate regions located between 30 degrees north and south of the equator. A meta-analysis was conducted using the standardized mean (SM) for milk production, fat percentage, and protein percentage, all adjusted for dry matter intake (DMI), focusing on lactating ruminants. A total of 42, 11, 15, and 16 research papers were selected for cows, buffalo, sheep, and goats, respectively, encompassing 2421 animal records from experiments published between 1992 and 2024. The SM for milk production was 10.38, 9.77, 0.79, and 1.13 kg/day/animal for cows, buffalo, sheep, and goats, respectively. Due to the significant variance between different cow breeds, the study divided the cows into three main groups based on breed type crossbreds, foreign, and local breeds. The SM for milk production per animal was 11.49 kg/day for crossbreds, 22.95 kg/day for foreign breeds, and 7.13 kg/day for local breeds. The effect of DMI on the SM of milk production for cows, sheep, and goats was highly significant. For milk fat, the SM was 3.95, 6.64, 4.70, and 3.56% for cows, buffalo, sheep, and goats, respectively. Regarding milk protein, the SM was 3.36, 3.91, 4.34, and 3.45% for cows, buffalo, sheep, and goats, respectively. The results of this meta-analysis highlight that warm-climate regions are significant contributors to global dairy production. Furthermore, improving ruminant milk production and quality in hot climates need further efforts. [ABSTRACT FROM AUTHOR]

The poultry industry in developing countries is challenged by the high cost of conventional protein and energy feed ingredients. This problem has burdened researchers to use cheap and readily non-conventional feed ingredients such as tropical leaf meals (TLMs) to reduce the cost of feed. Tropical leaf meals are high in nutrients and important bioactive compounds, such as flavonoids and polyphenols. These important bioactive compounds in TLMs are responsible for their health promoting effects in animals. Research has shown that inclusion of moderate quantities of TLMs in livestock feed improves chicken performance and health. However, the inclusion of high levels of TLMs in poultry diets reduced chicken performance, which may be attributed to low palatability, high fibre content, poor digestibility, and the presence of antinational factors (ANFs) in TLMs. The potential of fermentation to enhance the nutrient content of feedstuffs high in fibre has been reported. Therefore, the objective of this research was to review the current knowledge on the effect of fermentation on nutritional and functional properties of TLMs and their feeding value on broiler chicken and laying hen performance. [ABSTRACT FROM AUTHOR]

Forest degradation is a major issue in ecosystem monitoring, and to take reformative measures, it is important to detect, map, and quantify the losses of forests. Synthetic Aperture Radar (SAR) time-series data have the potential to detect forest loss. However, its sensitivity is influenced by the ecoregion, forest type, and site conditions. In this work, we assessed the accuracy of open-source C-band time-series data from Sentinel-1 SAR for detecting deforestation across forests in Africa, South Asia, and Southeast Asia. The statistical Cumulative Sums of Change (CuSUM) algorithm was applied to determine the point of change in the time-series data. The algorithm's robustness was assessed for different forest site conditions, SAR polarizations, resolutions, and under varying moisture conditions. We observed that the change detection algorithm was affected by the site- and forest-management activities, and also by the precipitation. The forest type and eco-region affected the detection performance, which varied for the co- and cross-pol backscattering components. The cross-pol channel showed better deforested region delineation with less spurious detection. The results for Kalimantan showed a better accuracy at a 100 m spatial resolution, with a 25.1% increase in the average Kappa coefficient for the VH polarization channel in comparison with a 25 m spatial resolution. To avoid false detection due to the high impact of soil moisture in the case of Haldwani, a seasonal analysis was carried out based on dry and wet seasons. For the seasonal analysis, the cross-pol channel showed good accuracy, with an average Kappa coefficient of 0.85 at the 25 m spatial resolution. This work was carried out in support of the upcoming NISAR mission. The datasets were repackaged to the NISAR-like HDF5 format and processing was carried out with methods similar to NISAR ATBDs. [ABSTRACT FROM AUTHOR]

Background and Aims Leaf traits are known to be strong predictors of plant performance and can be expected to (co)vary along environmental gradients. We investigated the variation, integration, environmental relationships and evolutionary history of leaf functional traits in the genus Coffea , typically a rainforest understorey shrub, across Africa. A better understanding of the adaptive processes involved in leaf trait evolution can inform the use and conservation of coffee genetic resources in a changing climate. Methods We used phylogenetic comparative methods to investigate the evolution of six leaf traits measured from herbarium specimens of 58 African Coffea species. We added environmental data and data on maximum plant height for each species to test trait–environment correlations in various (sub)clades, and we compared continuous trait evolution models to identify variables driving trait diversification. Key Results Substantial leaf trait variation was detected across the genus Coffea in Africa, which was mostly interspecific. Of these traits, stomatal size and stomatal density exhibited a clear trade-off. We observed low densities of large stomata in early-branching lineages and higher densities of smaller stomata in more recent taxa, which we hypothesize to be related to declining CO2 levels since the mid-Miocene. Brownian motion evolution was rejected in favor of white noise or Ornstein–Uhlenbeck models for all traits, implying these traits are adaptively significant rather than driven by pure drift. The evolution of leaf area was likely driven by precipitation, with smaller leaves in drier climates across the genus. Conclusions Generally, Coffea leaf traits appear to be evolutionarily labile and governed by stabilizing selection, though evolutionary patterns and correlations differ depending on the traits and clades considered. Our study highlights the importance of a phylogenetic perspective when studying trait relationships across related taxa, as well as the consideration of various taxonomic ranges. [ABSTRACT FROM AUTHOR]

The East African "short rains" from October–December (OND) are crucial for the region's cultural and agricultural landscape. Traditional climate studies have often treated these rains as a single mode, representing the average rainfall across the region. This approach, however, fails to capture the complex geographical variations in seasonal rainfall. In our study, we analyse 4200 reforecasts from a seasonal prediction system spanning 1981–2022, identifying distinct clusters that represent different geographical patterns of the short rains. We explore the influence of tropical sea‐surface temperature patterns, upper‐level tropospheric flow, and low‐level moisture fluxes on these clusters. A key revelation of our research is the limited predictability of certain geographical rainfall structures based on large‐scale climatic drivers. This finding highlights a gap in current forecasting methodologies, emphasising the necessity for further research to understand and predict these intricate patterns. Our study illuminates the complexities of regional rainfall variability in East Africa, underlining the importance of continued investigation to improve climate resilience strategies in the region. [ABSTRACT FROM AUTHOR]

Amaranthus cruentus L. (varieties: Juana, Aurelia, Elena) and Amaranthus viridis L. (variety: Callaloo) have long been utilized in food products for human consumption in Central and South America. However, there is limited information on the chemical composition of these species' leaves and grains grown in Puerto Rico. This study aimed to fill this gap by evaluating the nutritional profile of these four amaranth varieties cultivated in Puerto Rico. A compositional analysis was conducted using official methods, focusing on lysine, protein, dietary fiber, and mineral content. The results showed high lysine content in both species. Significant differences (p < 0.05) were found in crude protein levels among the leaves, with Elena (23%) and Aurelia (21%) showing the highest values. While protein content among grains averaged 19%, there were no significant differences between varieties. The analysis of dietary fiber revealed significant differences (p < 0.05) in insoluble dietary fiber (IDF) and total dietary fiber (TDF) for the leaves and in IDF, soluble dietary fiber (SDF), and TDF for the grains. Additionally, calcium, magnesium, and phosphorus concentrations differed significantly (p < 0.05) in the leaves, while iron, potassium, and zinc showed no significant variation. Significant differences were found in the grains for calcium, magnesium, iron, and phosphorus. This research highlights the excellent nutritional value of amaranth leaves and grains grown in Puerto Rico, with Elena and Aurelia having exceptionally high protein content in their leaves. [ABSTRACT FROM AUTHOR]

Global Ecosystem Dynamics Investigation (GEDI) is a relatively new technology for global forest research, acquiring LiDAR measurements of vertical vegetation structure across Earth's tropical, sub-tropical, and temperate forests. Previous GEDI validation efforts have largely focused on top of canopy accuracy, and findings vary by geographic region and forest type. Despite this, many applications utilize measurements of vertical vegetation distribution from the lower canopy, with a wide diversity of uses for GEDI data appearing in the literature. Given the variability in data requirements across research applications and ecosystems, and the regional variability in GEDI data quality, it is imperative to understand GEDI error to draw strong inferences. Here, we quantify the accuracy of GEDI relative height metrics through canopy layers for the Brazilian Amazon. To assess the accuracy of on-orbit GEDI L2A relative height metrics, we utilize the GEDI waveform simulator to compare detailed airborne laser scanning (ALS) data from the Sustainable Landscapes Brazil project to GEDI data collected by the International Space Station. We also assess the impacts of data filtering based on biophysical and GEDI sensor conditions and geolocation correction on GEDI error metrics (RMSE, MAE, and Bias) through canopy levels. GEDI data accuracy attenuates through the lower percentiles in the relative height (RH) curve. While top of canopy (RH98) measurements have relatively high accuracy (R2 = 0.76, RMSE = 5.33 m), the accuracy of data decreases lower in the canopy (RH50: R2 = 0.54, RMSE = 5.59 m). While simulated geolocation correction yielded marginal improvements, this decrease in accuracy remained constant despite all error reduction measures. Some error rates for the Amazon are double those reported in studies from other regions. These findings have broad implications for the application of GEDI data, especially in studies where forest understory measurements are particularly challenging to acquire (e.g., dense tropical forests) and where understory accuracy is highly important. [ABSTRACT FROM AUTHOR]

Global pollution has exacerbated accumulation of toxicants like methylmercury (MeHg) in seafood. Human exposure to MeHg has been associated with long-term neurodevelopmental delays and impaired cardiovascular health, while many micronutrients in seafood are beneficial to health. The largest MeHg exposure source for many general populations originates from marine fish that are harvested from the global ocean and sold in the commercial seafood market. Here, we use high-resolution catch data for global fisheries and an empirically constrained spatial model for seafood MeHg to examine the spatial origins and magnitudes of MeHg extracted from the ocean. Results suggest that tropical and subtropical fisheries account for >70% of the MeHg extracted from the ocean because they are the major fishing grounds for large pelagic fishes and the natural biogeochemistry in this region facilitates seawater MeHg production. Compounding this issue, micronutrients (selenium and omega-3 fatty acids) are lowest in seafood harvested from warm, low-latitude regions and may be further depleted by future ocean warming. Our results imply that extensive harvests of large pelagic species by industrial fisheries, particularly in the tropics, drive global public health concerns related to MeHg exposure. We estimate that 84 to 99% of subsistence fishing entities globally likely exceed MeHg exposure thresholds based on typical rates of subsistence fish consumption. Results highlight the need for both stringent controls on global pollution and better accounting for human nutrition in fishing choices. [ABSTRACT FROM AUTHOR]

Societal Impact Statement Summary Highland forests of Mozambique have been strongly modified by human activities for millennia. Some highlands have sheer rock cliffs and are highly inaccessible to people and appear relatively undisturbed. Evidence from the forest and soils of inaccessible Mount Lico show that the fire regime has changed over the recent millennia. As climate and fire regimes continue to change, management of highland ecosystems will be crucial to sustain the high biodiversity and mountain‐water resources that provide key ecosystem services to people living close to these forests. The sheer rock cliffs of the Mount Lico inselberg, northern Mozambique, is relatively inaccessible to people. A 0.57 km2 forest covers the top of the isolated mountain, and the tree demographics and soil offer an opportunity to investigate the long‐term fire ecology of the forests of the western, leeside of the mountain and potential for changing regional hydroclimate of the Late Holocene. On the western side of the mountaintop, a 20 × 20 m plot was surveyed for tree taxa, heights and bole diameters. A 220 cm deep pit was dug into the forest soil and analysed to describe the soil texture and carbon content. Charcoal was quantified on sieved subsamples and classified into charcoal morphologies that were then grouped by how readily entrainable on an index score. Three radiocarbon dates were collected from pieces charcoal. The forest is a combination of montane and woodland tree taxa that differed from the older, more mesic eastern side and reflected differential disturbance patterns. The reddish loam soils dated to the Middle Holocene. Charcoal was present in all soil subsamples and varied little until increasing consistently during the past millennium. The charcoal morphologies suggested a combination of locally derived charcoal and charcoal derived from the surrounding lowlands with the latter increasing in the past centuries. Few Holocene paleoenvironmental records have been developed from tropical soils in Africa and are useful in locations that do not host lakes and wetlands. Both tree demographics and soil charcoal suggest that changing forest disturbance regimes began during the past millennium. An understanding of history informs future conservation and appropriate management of these special places. [ABSTRACT FROM AUTHOR]

The cultivation of sunflower (Helianthus annuus L.) as a cut flower stands out in floriculture due to its aesthetic beauty and commercial value. Understanding how cut sunflower genotypes adapt to different edaphoclimatic regions and management practices is essential to optimize flower quality and productivity. This study aimed to evaluate the effect of plant density and location on the development, growth, and quality of cut sunflower in tropical and subtropical environments. Plant densities of 10, 20, 30, 40, and 50 plants/m2 were evaluated in tropical climate and subtropical climate using a randomized block design in a factorial scheme. Results showed significant differences between locations for plant height, capitulum and stem diameter, final number of leaves, leaf area, leaf area index, phyllochron, and the developmental cycle. Plant density significantly influenced these variables except for plant height and developmental cycle. The interaction between location and plant density was significant only for capitulum diameter and final leaf number. The findings indicate that both planting density and location significantly influence the developmental cycle of cut sunflowers, with lower densities favoring more robust plants at harvest. A density of 30 plants/m2 is recommended for efficient space use without significantly compromising floral stem quality. All produced stems are marketable, suggesting that adjusting planting density can optimize production without compromising quality, adapting to specific regional conditions. [ABSTRACT FROM AUTHOR]

The garden-city model, characterised by sprawling urban expansion and extensive open spaces, features green and water surfaces alongside substantial road networks, large parking lots and unshaded lands. This diverse landscape contributes to uneven air temperature distribution within the city. Our study investigated urban heat island (UHI) patterns in various urban environments within Putrajaya, focusing on rural, business, residential and near-water areas. Atmospheric data were collected over a year. Putrajaya exhibits two distinct UHI patterns: cool-day-hot-night in residential zones and hot-noon-temperate-elsewhere in impermeable areas. Business areas display alternating patterns based on seasonal climatic conditions and anthropogenic factors. The efficacy of artificial water bodies as a UHI countermeasure in garden cities depends on the size of the water body and the nature of the surrounding land cover. Shaded and green areas exhibit UHI intensities limited to 3°C, while impermeable areas, regardless of proximity to water surfaces, experience UHI up to 6°C. Overall, the garden-city model tends to restrict UHI variations within −1 to 3°C compared to −2 to 4°C in nearby Kuala Lumpur. [ABSTRACT FROM AUTHOR]

The hydrogen isotopic compositions of leaf‐wax n‐alkanes (δDalk) and n‐alkanoic acids (δDacid) reflect ambient climatic conditions (including precipitation δD values, δDprecip). However, the understanding of climatic conditions of exactly which period (i.e., early or entire period of the leaf's lifespan) these biomarkers preserve is still evolving. Previous studies on the δDalk and δDacid values, done only in extra‐tropical regions, mostly indicate that δDalk values are biased toward the early growing season whereas δDacid values are not biased toward any season. To decipher the seasonal bias in δDalk and δDacid records from tropics, we conducted a long‐duration experiment wherein deciduous and evergreen species were grown using normal water (δD = −2‰) during early stages of the leaf growth and later using isotopically labeled water (δD = 1,000‰). Our experiment revealed (a) in deciduous and evergreen species, δDalk and δDacid values reflect δDprecip during early stages of the leaf growth, (b) synchronous synthesis of n‐alkanes and n‐alkanoic acids, and (c) in deciduous species, minor incorporation of the previous year's photosynthates in leaf wax pool of the current year's mature leaves. Our study suggests that δDalk and δDacid records in the tropics are biased toward the climatic conditions prevailing during early stages of leaf growth. This bias should be considered while comparing the δDprecip values generated from leaf wax proxy records and isotope‐enabled atmospheric circulation models. Plain Language Summary: The hydrogen isotopic composition of leaf wax n‐alkanes and n‐alkanoic acids preserved in sediments have been used extensively for reconstructing past climate variability. However, whether these records reflect a climate of a specific season or an entire year is not known. In our experiment, we grew various tropical plants using normal water during early growing season and heavy water during later growing season. Lack of isotopic signal associated with the heavy water in leaf wax compounds suggested that the bulk of leaf wax production occurred during the early growing season of the leaves. As the hydrogen isotopic composition of the leaf wax compounds reflects ambient climatic conditions, our results suggested that the hydrogen isotope record of tropical leaf wax compounds reflects the climatic conditions prevailing during the early stages of leaf growth. Key Points: Hydrogen isotope records of leaf wax n‐alkane and n‐alkanoic acid from the tropics reflect climatic conditions during the early leaf growthBoth deciduous and evergreen leaf wax hydrogen isotope records are biased toward the early stages of the leaf growthThis bias should be considered while comparing the hydrogen isotope of precipitation generated from climate models and leaf wax records [ABSTRACT FROM AUTHOR]

We propose the lag‐1 autocorrelation of daily precipitation as a simple diagnostic of tropical precipitation variability in climate models. This metric generally has a relatively uniform distribution of positive values across the tropics. However, selected land regions are characterized by exceptionally low autocorrelation values. Low values correspond to the dominance of high frequency variance in precipitation, and specifically of high frequency convectively coupled equatorial waves. Consistent with previous work, we show that CMIP6 climate models overestimate the autocorrelation. Global kilometer‐scale models capture the observed autocorrelation when deep convection is explicitly simulated. When a deep convection parameterization is used, though, the autocorrelation increases over land and ocean, suggesting that land surface‐atmosphere interactions are not responsible for the changes in autocorrelation. Furthermore, the metric also tracks the accuracy of the representation of the relative importance of high frequency and low frequency convectively coupled equatorial waves in the models. Plain Language Summary: Rainfall in the tropics is influenced by many atmospheric processes that depend on geographic location. We use the lag‐1 autocorrelation as a metric for the day‐to‐day persistence of rainfall. We find that rainfall is very persistent in most parts of the tropics with a few exceptions over land, for example, the Sahel, where high frequency rainfall events dominate. Our results show that models with a horizontal resolution of a few kilometers reproduce the autocorrelation, in contrast to coarser climate models. We also analyze atmospheric waves and find that they are important for the autocorrelation pattern in the observations and the simulations. Key Points: The lag‐1 autocorrelation pattern of daily precipitation in the tropics is robust across different observation‐based data setsThe lag‐1 autocorrelation reflects the relative variance of high frequency and low frequency convectively coupled equatorial wavesKilometer‐scale models capture the observed autocorrelation, but models with parameterized deep convection overestimate it [ABSTRACT FROM AUTHOR]

Biodiversity plays a vital role in ecosystem functioning, so understanding how species coexist is a cornerstone of ecology. However, despite decades of research, our current knowledge is incomplete due to methodological limitations and sampling bias, particularly in the species‐rich tropics. In this study, we combined bill and body morphological traits with stable isotopes in feathers to quantify niche differentiation among six co‐occurring greenbul taxa, a diverse group of frugivorous and insectivorous passerines with remarkable similarities in body shape, in the lowland rainforests of Mount Cameroon, West‐Central Africa. Our results showed that the greenbul's niche space was primarily differentiated by variations in body morphology, with yellow‐lored bristlebill Bleda notatus and eastern bearded greenbul Criniger chloronotus occupying ecological niches distinct from the remaining four taxa, while bill morphology indicated substantial overlap between the taxa. In addition, isotopic composition of the feathers revealed a separation of western greenbul Arizelocichla tephrolaema from the other taxa. Our results show that the integration of morphological and isotopic data can provide robust estimates of niche overlaps, providing evidence for the differentiation of ecological roles. This highlights the importance of integrating variable traits to improve our understanding of how animals exploit the multidimensional niche space that enables their coexistence. [ABSTRACT FROM AUTHOR]

This study investigates the germination requirements of 12 plant species native to the Argyle region of the east Kimberley, a biodiverse monsoonal tropical region characterized by high temperatures, high evaporation, and episodic seasonal rainfall. The research involved quality assessment of mature seeds, followed by dormancy alleviation and laboratory‐based germination to determine the responses of seeds to a range of temperatures (5–40°C) in terms of germination speed (T10), mean germination time, and maximum germination proportion. Data were then modeled to calculate the optimal temperature to support germination for each species. The results showed that germination rapidly commences in response to a wide range of temperatures typical of the wet season (November–February) in the east Kimberley, though germination for most species was still high (>50%) after exposure to temperatures as low as 15°C. Mean optimal temperature for germination across all species was 25.8 ± 1.5°C, with minimal variation between most species, the exception being Dodonaea physocarpa, which preferred cooler temperatures (Topt = 14.0°C). The speed of germination was also rapid (T10 = 1–3 days) across all species at the optimal germination temperature. The findings suggest that temperature is not a limiting factor for germination in this region and that the onset and intensity of the wet season are the most significant factors determining successful germination, emergence, and seedling establishment. The study underscores the importance of species‐specific understanding of environmental temperatures required for seed germination in seed‐based restoration efforts and informs the planning of direct seeding works, thus enhancing restoration outcomes. [ABSTRACT FROM AUTHOR]

The lack of toxicity tests using indigenous species in risk assessments of tropical regions has often been discussed. Thus, this study evaluated two tropical oligochaete species (Allonais inaequalis and Dero furcatus) for potential use as test species. To this end, the toxic effects of copper and manganese, both isolated and mixed, were evaluated for both species via acute tests. The test protocol developed by the Organisation for Economic Co-operation and Development (OECD) for temperate sediment-dwelling benthic oligochaetes could be successfully applied for both test species. The 96-h LC50 values (mean ± standard deviation) for D. furcatus were 31 ± 3 µg L−1 and 18 ± 0.061 mg L−1 for copper and manganese, respectively. The corresponding values for A. inaequalis were 26 ± 1 µg L−1 and 28 ± 0.063 mg L−1, respectively. Compared to the toxicity values for temperate arthropods, D. furcatus and A. inaequalis had comparable or greater sensitivity to the evaluated metals. The mixture toxicity tests indicated a dose ratio-dependent deviation of the concentration addition (CA) model, with antagonism occurring especially if the effects in the mixture were provoked by copper. Overall, these findings indicated that these taxa are sensitive candidates for use in tropical ecotoxicity testing. Future studies can elucidate the mechanisms of chemical mixture toxicity. [ABSTRACT FROM AUTHOR]

To meet the UN sustainable development goal targets by 2030, it is necessary to provide adequate, resilient, and affordable housing solutions which are also low-carbon. In the context of affordable housing in El Salvador, an improved vernacular construction system, following the composite bamboo shear wall (CBSW) technology, has been developed as a feasible option to fill the current housing deficit. A life cycle assessment (LCA) has been conducted comparing a house built using the CBSW system with a reinforced concrete hollow block masonry system, considering the A1 to A5 (raw material production and manufacture) and B4 (replacement) life cycle modules. The LCA scope was limited to modules where there was sufficient confidence in the inputs. End-of-life modules were excluded as there is a large degree of uncertainty in the end-of-life scenarios for these materials in the regional context. The LCA results show that the CBSW system has approximately 64% of the global warming potential (GWP) of the reinforced masonry house, and when considering biogenic carbon, this reduces to 53%. There is additional potential to minimise impacts and maximise end-of-life opportunities (e.g., re-use, biofuel, etc.) for the biomaterials within the CBSW system, if considering modules beyond the scope of this paper, and this needs further study. Nevertheless, the results from this LCA—of limited A1 to A5 and B4 scope—show that the CBSW system has significant sustainability advantages over conventional construction systems and is considered a promising solution to alleviate the housing deficit in El Salvador. [ABSTRACT FROM AUTHOR]

Climate change is no longer a hypothetical problem in the Caribbean but a new reality to which regional public health systems must adapt. One of its significant impacts is the increased transmission of infectious diseases, such as dengue fever, which is endemic in the region, and the presence of the Aedes aegypti mosquito vector responsible for transmitting the disease. (1) Methods: To assess the association between climatic factors and human dengue virus infections in the Caribbean, we conducted a systematic review of published studies on MEDLINE and Web of Science databases according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. (2) Results: In total, 153 papers were identified, with 27 studies selected that met the inclusion criteria ranging from the northern and southern Caribbean. Rainfall/precipitation and vapor pressure had a strong positive association with dengue incidence, whereas the evidence for the impact of temperatures was mixed. (3) Conclusions: The interaction between climate and human dengue disease in the Caribbean is complex and influenced by multiple factors, including waste management, infrastructure risks, land use changes, and challenged public health systems. Thus, more detailed research is necessary to understand the complexity of dengue within the wider Caribbean and achieve better dengue disease management. [ABSTRACT FROM AUTHOR]

Deep-plan buildings limit daylight use in spaces far from the building perimeter, leading to uneven daylight distribution. Integrating a Horizontal Light Pipe (HLP) as an optical daylighting system, reflective light shelves, and blinds as shading systems can reduce excessive daylight levels at the perimeter area of a building and improve daylight uniformity. Earlier investigations of HLP daylight performance concentrated on fixed building geometries, but few studies focused on the building aspect ratio, one of the design variables of building geometry that greatly influences daylight performance. This study aims to investigate the impact of the aspect ratio of buildings implementing HLP and shading systems on daylight performance. The research method was experimental, using IES-VE simulation as a tool. The daylight factor (DF), uniformity daylight factor (UDF), and useful daylight illuminance (UDI) of various aspect ratios and depths of office buildings implementing HLP and shading systems were analyzed. The results show that increasing the building aspect ratio from 1:1 to 2.1:1 sequentially increased the average DF and UDF values by 18.47% and 17.2%, respectively. Improving the building aspect ratio from 1:1 to 2.1:1 along the east-west axis improved the UDI by 3%, whereas the north-south axis decreased it by 10.2%.

Mammal populations are declining in biodiverse tropical regions. Global analyses have identified Indonesia as a hotspot of vertebrate decline, although relatively few data are available to substantiate these claims. We reviewed research articles published during 2000–2020 on 104 medium-sized to large terrestrial mammal species found in Indonesia to help inform conservation management and future research. We identified 308 peer-reviewed studies published in English or Bahasa Indonesia, with an increase in publication rate (articles published per year) over time. Studies of species distributions dominated the literature, followed by publications on abundance, species diversity and combinations of these topics. Most publications concerned single-species studies conducted at a single location and a single point in time. We identify four key issues that should be addressed by future research and conservation efforts: (1) disproportionate focus on a small number of species; (2) geographical bias towards west Indonesia (Sumatra, Kalimantan and Java–Bali), with few published studies from central (Sulawesi, Nusa Tenggara and Maluku) and east (Papua) Indonesia; (3) limitations to survey design, sampling effort and data analysis; and (4) lack of long-term wildlife population studies. We also note challenges local researchers face in publishing their studies in international journals because of language barriers and costs. Greater use of existing biodiversity data and continued capacity building for local researchers, particularly those in central and east Indonesia, are critical to effectively guide future wildlife monitoring and improve the conservation status of Indonesian mammals.

This study aims to numerically investigate the impact of air supply terminal devices (ASTDs) on the performance of novel variable refrigerant flow (VRF) integrated stratum ventilation (SV) system. The novel VRF-SV hybrid system was designed and analyzed in the authors' previous work, where different design configurations were tested and their performances were compared. However, the effect of ASTDs on the performance of novel system has not yet been thoroughly explored. Therefore, this study was designed to investigate the effect of four types of ASTDs, including bar grille, double deflection grille, drum louver and jet slot diffusers installed in the laboratory and meeting room environments. The temperature and velocity field distribution, thermal comfort and indoor air quality (IAQ) were examined as performance indicators. The Re-Normalization Group (RNG), Realizable and Standard k -ϵ turbulence models were also employed in this study to verify and validate the numerical predictions with the experimental measurements. The experimental results found relatively close to the predictions obtained through RNG k -ϵ model with maximum deviations at any location were found to be 0.28 m/s in terms of velocity and 1.6°C in terms of temperature magnitude. Further research demonstrated that among the studied ASTDs, the bar grille diffuser provided an adequate thermal environment for the occupants with an acceptable jet throw and IAQ. This benefit also suggests that if the bar grille is installed with the VRF-SV system, the system would require less fan power, and thus, it reduces the energy use by the fan. [ABSTRACT FROM AUTHOR]

Context: Beef cattle production in the tropics is based on the grazing system. Concentrate supplementation has a significant influence on carcass gain and meat quality. Additionally, the inclusion of some lipid feedstuffs, such as rumen-protected fat (RPF), can increase the net energy for weight gain, and be an alternative to increase the productive performance and carcass traits of grazing beef cattle. Aims: This study evaluated the effects of RPF on performance, carcass traits and feeding behaviour of Nellore bulls in an intensive grazing system during the rainy season. Methods: Twenty-four Nellore bulls (initial bodyweight of 454.0 ± 46.1 kg) were used in a randomised completed block design, based on initial bodyweight. The animals were distributed in 12 paddocks (two bulls per paddock) in a continuous grazing system and randomly assigned to one of two treatments: control (n = 6), a concentrate without added protected fat provided ad libitum , and RPF (n = 6), a concentrate with the addition of 3% protected fat (Nutricorp, Araras, São Paulo, Brazil) provided ad libitum. Statistical analysis was performed using the MIXED procedure of SAS 9.4 with paddock as the experimental unit (12 paddocks). The principal model included fixed effect of treatment and block as a random effect. For forage characteristics, the experimental period was a considered fixed effect. The study lasted 105 days, and was divided into four periods. At the end of each period, forage collections were performed, bulls were weighed and feeding behaviour was recorded. After 105 days, the bulls were slaughtered in a commercial slaughterhouse, and three 2.54-cm Longissimus dorsi steaks of each animal were collected to evaluate the colour, the chemical and physical composition, and the sensory analysis of the meat. Keys results: The inclusion of RPF in the concentrate did not affect (P > 0.05) the final bodyweight, average daily gain, concentrate intake and feed efficiency, but there was a tendency (P < 0.07) for higher carcass weight for the bulls that received RPF. Bulls supplemented with RPF had a greater (P < 0.05) average carcass gain. For meat quality, an effect (P < 0.01) was observed for hue (25.32 and 27.91 for control and RPF, respectively). Conclusions: The addition of 3% RPF in the concentrate ration has the potential to improve carcass traits and meat quality of beef cattle in an intensive pasture finishing system. Implications: The inclusion of RPF will increase dietary energy density of grazing beef cattle with a tendency to increase carcass gain. This can be an opportunity to increase the production per animal and income of farmers. The inclusion of rumen-protected fat in the diet of grazing beef cattle may be a strategy to increase dietary energy density, and consequently improve the performance and carcass characteristics without negative effects on ruminal microbiota and fibre digestibility. Twenty-four non-castrated animals were subjected to this test. The average daily carcass gain and meat quality were improved by the inclusion of protected fat in the diet of grazing cattle. [ABSTRACT FROM AUTHOR]

Annual wheat yields have steadily risen over the past century, but harvests remain highly variable and dependent on myriad weather conditions during a long growing season. In Kansas, for example, the 2014 crop year brought the lowest average yield in decades at 28 bushels per acre, while in 2016 farmers in the Wheat State, as Kansas is often called, enjoyed a historic high of 57 bushels per acre. It is broadly known that remote forces like El Niño–Southern Oscillation contribute to meteorological outcomes across North America, including in the wheat-growing regions of the U.S. Midwest, but the differential imprints of ENSO phases and flavors have not been well explored as leading indicators for harvest outcomes in highly specific agricultural regions, such as the more than 7 million acres upon which wheat is grown in Kansas. Here, we demonstrate a strong, steady, and long-term association between a simple "wheat yield index" and sea surface temperature anomalies, more than a year earlier, in the East Pacific, potentially offering insights into forthcoming harvest yields several seasons before planting commences. [ABSTRACT FROM AUTHOR]

The expanding use of community science platforms has led to an exponential increase in biodiversity data in global repositories. Yet, understanding of species distributions remains patchy. Biodiversity data from social media can potentially reduce the global biodiversity knowledge gap. However, practical guidelines and standardized methods for harvesting such data are nonexistent. Following data privacy and protection safeguards, we devised a standardized method for extracting species distribution records from Facebook groups that allow access to their data. It involves 3 steps: group selection, data extraction, and georeferencing the record location. We present how to structure keywords, search for species photographs, and georeference localities for such records. We further highlight some challenges users might face when extracting species distribution data from Facebook and suggest solutions. Following our proposed framework, we present a case study on Bangladesh's biodiversity—a tropical megadiverse South Asian country. We scraped nearly 45,000 unique georeferenced records across 967 species and found a median of 27 records per species. About 12% of the distribution data were for threatened species, representing 27% of all species. We also obtained data for 56 DataDeficient species for Bangladesh. If carefully harvested, social media data can significantly reduce global biodiversity knowledge gaps. Consequently, developing an automated tool to extract and interpret social media biodiversity data is a research priority. [ABSTRACT FROM AUTHOR]

Morphological patterns may vary spatially in response to adaptations to regional environmental conditions. In fossorial animals, edaphic gradients potentially predict intra and interspecific morphological variation because they can limit dispersal and select morphotypes. We measured morphological traits of South American worm lizards, including three Amphisbaena and two Leposternon species, to test whether inter- and intraspecific morphological variation and morphotype distribution are predicted by edaphic gradients measured at different soil profiles. Interspecifically, we found that the variation in head length is mainly predicted by the chemical edaphic structure, which can be explained by spatial variation in prey availability. The variation in the width of the prefrontal and frontal shields was mainly predicted by clay and sand-soil contents, which can be explained by relationships of force and friction associated with digging. Intraspecifically, we found that the effects of edaphic gradients on morphological variation reflects the level of specialization to dig, since the most adapted species were mainly affected by variables measured in deeper soil profiles. We also show that soil-mediated intraspecific morphological variation shape morphotype distribution across different biomes that form the South American dry diagonal, which are discussed in light of biological, ecological, and biogeographic premises. [ABSTRACT FROM AUTHOR]

Thermal Discomfort Index has traditionally relied on parameters such as air temperature and relative humidity, obtained either from meteorological ground stations or through land-physical approaches estimated independently by satellites. These methods often fall short in adequately capturing both seasonal and detailed local spatial variations. This study addresses these limitations by establishing the Surface Thermal Discomfort Index (STDI), a composite of the Meteorological Discomfort Index (MDI) and the Discomfort Index over the land surface (DI-Land). Focused on Ibu Kota Negara Nusantara (IKN) in East Kalimantan and neighboring cities, MDI is derived from reanalysis data (ERA5-Land), validated with ground station data, while DI-Land is produced primarily from Landsat-8. An equal weighting factor was applied to MDI and DI-Land for estimating STDI. Results indicate that STDI captures both seasonal and spatial variations, reaching peak level in May and October, and hitting a low point in July. The spatial distribution of STDI is influenced by landuse types. In 2023, IKN experienced an STDI of 26.2 °C, while Balikpapan and Samarinda recorded at 26.5 and 26.4 °C, respectively. Compared to previous study in Jakarta, IKN and neighboring cities's STDI are higher up to 0.2 °C, remaining within the partially comfortable range in the tropics. Projecting IKN's development until 2045, an annual MDI increase of 0.01 °C is anticipated. Moreover, a 4% rise in built-up areas is expected to elevate STDI by 0.1–0.2 °C. This study provides insights into the thermal discomfort status in cities across East Kalimantan, anticipating a gradual increase in discomfort levels during the development of IKN. [ABSTRACT FROM AUTHOR]

The life history aspects of dormancy of the weevil Anthonomus rufipennis LeConte (Coleoptera: Curculionidae) were studied a 57-month period in a seasonally dry tropical forest of central Mexico. Weevil populations and their physiological status were monitored on both the reproductive host tree, Senna polyantha (Collad.) H.S: Irwin & Barneby (Fabales: Fabaceae) and the highly favored refuge host, Tillandsia recurvata L. (Poales: Bromeliaceae) or "ball moss." During the dry season, weevils were only found on the refuge host with a mean total density of 1.014 ± 2.532 individuals/ball moss (N  = 1,681). Weevil densities on T. recurvata between early and late dry seasons were not significantly different, suggesting that dry season survival was relatively high. Weevils collected during these seasons revealed little reproductive development and relatively high-fat accumulation in both sexes. During 5 of 6 yr, densities of the weevils in T. recurvata dropped significantly during the early rainy seasons, when the reproductive host trees leafed out and began producing oviposition sites (flower buds). At this time, more males than females initially moved to vegetative trees and showed significant signs of reproductive development. Recolonization of ball moss by weevils began during the late rainy season when oviposition sites (flower buds) were still available. A proportion of the weevils remained on the reproductive host, suggesting that A. rufipennis is facultatively multivoltine. The methodologies and results of the study can serve as a model system for future studies of the dormancy of other insects in dry tropical forests and provide insight into the dormancy of other anthonomine weevils of economic importance. [ABSTRACT FROM AUTHOR]

The intertropical convergence zone (ITCZ) is associated with a zonal band of strong precipitation that migrates meridionally over the seasonal cycle. Tropical precipitation also migrates zonally, such as from the South Asian monsoon in Northern Hemisphere summer (JJA) to the precipitation maximum of the west Pacific in Northern Hemisphere winter (DJF). To explore this zonal movement in the Indo-Pacific sector, we analyze the seasonal cycle of tropical precipitation using a 2D energetic framework and study idealized atmosphere–ocean simulations with and without ocean dynamics. In the observed seasonal cycle, an atmospheric energy and precipitation anomaly forms over South Asia in northern spring and summer due to heating over land. It is then advected eastward into the west Pacific in northern autumn and remains there due to interactions with the Pacific cold tongue and equatorial easterlies. We interpret this phenomenon as a "monsoonal mode," a zonally propagating moist energy anomaly of continental and seasonal scale. To understand the behavior of the monsoonal mode, we develop and explore an analytical model in which the monsoonal mode is advected by low-level winds, is sustained by interaction with the ocean, and decays due to the free tropospheric mixing of energy. Significance Statement: Regional concentrations of tropical precipitation, such as the South Asian monsoon, provide water to billions of people. These features have strong seasonal cycles that have typically been framed in terms of meridional shifts of precipitation following the sun's movement. Here, we study zonal shifts of tropical precipitation over the seasonal cycle in observations and idealized simulations. We find that land–ocean contrasts trigger a monsoon with concentrated precipitation over Asia in northern summer and near-surface eastward winds carry this precipitation into the west Pacific during northern autumn in what we call a "monsoonal mode." This concentrated precipitation remains over the west Pacific during northern winter, as further migration is impeded by the cold sea surface temperatures (SSTs) and easterly winds of the east Pacific. [ABSTRACT FROM AUTHOR]

This article is a Commentary on Guilbeault‐Mayers & Laliberté (2024), 243: 636–647. [ABSTRACT FROM AUTHOR]

Background and Aims Understanding anatomical variations across plant phylogenies and environmental gradients is vital for comprehending plant evolution and adaptation. Previous studies on tropical woody plants have paid limited attention to quantitative differences in major xylem tissues, which serve specific roles in mechanical support (fibres), carbohydrate storage and radial conduction (radial parenchyma, rays), wood capacitance (axial parenchyma) and water transport (vessels). To address this gap, we investigate xylem fractions in 173 tropical tree species spanning 134 genera and 53 families along a 2200-m elevational gradient on Mount Cameroon, West Africa. Methods We determined how elevation, stem height and wood density affect interspecific differences in vessel, fibre, and specific axial (AP) and radial (RP) parenchyma fractions. We focus on quantifying distinct subcategories of homogeneous or heterogeneous rays and apotracheal, paratracheal and banded axial parenchyma. Key Results Elevation-related cooling correlated with reduced AP fractions and vessel diameters, while fibre fractions increased. Lower elevations exhibited elevated AP fractions due to abundant paratracheal and wide-banded parenchyma in tall trees from coastal and lowland forests. Vasicentric and aliform AP were predominantly associated with greater tree height and wider vessels, which might help cope with high evaporative demands via elastic wood capacitance. In contrast, montane trees featured a higher fibre proportion, scarce axial parenchyma, smaller vessel diameters and higher vessel densities. The lack of AP in montane trees was often compensated for by extended uniseriate ray sections with upright or squared ray cells or the presence of living fibres. Conclusions Elevation gradient influenced specific xylem fractions, with lower elevations showing elevated AP due to abundant paratracheal and wide-banded parenchyma, securing greater vessel-to-parenchyma connectivity and lower embolism risk. Montane trees featured a higher fibre proportion and smaller vessel diameters, which may aid survival under greater environmental seasonality and fire risk. [ABSTRACT FROM AUTHOR]

Climate change, a global environmental phenomenon, is recognized as a major threat to survival of species and integrity of ecosystem world-wide. Adaptation strategies by species assemblages in an ecosystem are therefore aimed at reducing mortality, while they are expected to increase survival flexibilities of the species or group of species to a given climate variability scenario. These scenarios are known to impact directly and/or indirectly on the distribution, abundance, diversity, reproduction, growth and species composition. This paper reviews the adaptive strategies that will or are expected to enhance the survival of phytoplankton, zooplankton on and benthic communities/assemblages in the tropical and sub-tropical coastal waters, their community structure, life processes and roles in the ecosystem. [ABSTRACT FROM AUTHOR]

The extreme dry and hot 2015/16 El Niño episode caused large losses in tropical live aboveground carbon (AGC) stocks. Followed by climatic conditions conducive to high vegetation productivity since 2016, tropical AGC are expected to recover from large losses during the El Niño episode; however, the recovery rate and its spatial distribution remain unknown. Here, we used low‐frequency microwave satellite data to track AGC changes, and showed that tropical AGC stocks returned to pre‐El Niño levels by the end of 2020, resulting in an AGC sink of 0.180.140.26$$ {0.18}_{0.14}^{0.26} $$ Pg C year−1 during 2014–2020. This sink was dominated by strong AGC increases (0.610.490.84$$ {0.61}_{0.49}^{0.84} $$ Pg C year−1) in non‐forest woody vegetation during 2016–2020, compensating the forest AGC losses attributed to the El Niño event, forest loss, and degradation. Our findings highlight that non‐forest woody vegetation is an increasingly important contributor to interannual to decadal variability in the global carbon cycle. [ABSTRACT FROM AUTHOR]

This study examines the climatology and trends in climate in Guatemala, Honduras, and El Salvador over the past four decades, against the background of potential impacts on rainfed agriculture, livelihoods, and migration. The results show that there has been a significant warming of surface temperatures, an earlier start to the monsoon, a drier and longer mid‐summer drought, and a delay in the second peak of precipitation from September to October. These changes have led to an increase in vapour pressure deficit (VPD) in northern Guatemala and along the Pacific coast in winter. High VPD can stress plants and lead to reduced yields. The study also finds that the thresholds that cause a decline in coffee yield have already been reached in El Salvador, but the average VPD has also risen in Guatemala and Honduras over the past 42 years. Maize yields have also been negatively affected with an inverse relationship with daily maximum temperatures during the summer flowering season. Observed changes and trends in these climate factors are believed to have direct implications for crop yields and livelihoods, potentially driving shifts in migration patterns. [ABSTRACT FROM AUTHOR]

Deep tropical oceanic convection (TOC) is a prevailing component of the tropical atmosphere and plays a significant role in modulating global weather and climate. Despite its importance, prediction challenges remain, partly attributed to a lack of understanding of how TOC relates to its near‐storm environments. Prior studies suggest location‐dependent relationships between TOC structure and associated environments, necessitating targeted regional studies. The NASA 2017 Convective Processes Experiment (CPEX) and 2021 CPEX—Aerosols & Winds (CPEX‐AW) field campaigns collected high‐resolution measurements of convective storms and their environments in the Gulf of Mexico, Caribbean, and western Atlantic basins, providing a rare opportunity to investigate near‐storm environmental relationships with 3‐D TOC structure where in situ non‐tropical cyclone‐related deep TOC research is comparatively lacking. Collocated CPEX and CPEX‐AW airborne observations from the multi‐wavelength Airborne Precipitation Radar, Doppler Aerosol Wind Lidar, and dropsondes revealed large near‐storm environmental variability across TOC of similar convective type (i.e., isolated, organized) and within individual convective systems. However, trends still emerged amongst the large environmental variability. Horizontal TOC structure was most consistently linked to planetary boundary layer and mid‐tropospheric near‐storm environments, with organized TOC being associated with generally greater relative humidity (RH) and vertical speed shear than isolated TOC. TOC intensity was linked to upper tropospheric (i.e., above melting level) near‐storm environments, with isolated TOC intensity most consistently associated with upper tropospheric CAPE and organized TOC intensity associated with upper tropospheric RH. Mesoscale low‐level convergence was also linked to greater organized TOC intensity, motivating further research using these unique data sets. Plain Language Summary: Thunderstorms are a common occurrence in the tropics and influence Earth's weather and climate. Predicting tropical thunderstorms remains challenging, partly due to an incomplete understanding of how atmospheric moisture and winds relate to tropical thunderstorm structure and strength. Prior studies suggest these environmental relationships are dependent on location in the tropics, thereby necessitating focused regional studies. This study helps address a notable regional research gap in the Gulf of Mexico, Caribbean, and western Atlantic basins, using rare, high‐resolution radar and lidar measurements of tropical thunderstorms and their environments from the NASA 2017 Convective Processes Experiment (CPEX) and 2021 CPEX—Aerosols & Winds (CPEX‐AW) field campaigns. Analysis of these uniquely collocated data sets links larger tropical thunderstorm structures to greater atmospheric moisture and wind shear, especially in the lower and middle troposphere. Meanwhile, stronger tropical thunderstorms were most consistently associated with greater upper tropospheric buoyancy and moisture, along with stronger localized ascent of air near the ocean surface. The results of this study offer insight into how atmospheric moisture and winds influence the structure and strength of tropical thunderstorms, while also providing necessary guidance for improving the prediction and representation of tropical thunderstorms in global weather and climate models. Key Points: Relative humidity (RH) and bulk wind shear below the melting level were generally greater for multi‐ versus single‐core convectionSingle‐ and multi‐core convective intensity were most linked to greater CAPE and RH above the melting level, respectivelyGreater peak mesoscale low‐level convergence likely promoted more intense tropical oceanic precipitation [ABSTRACT FROM AUTHOR]

Passive acoustic monitoring (PAM) is a powerful tool for studying ecosystems. However, its effective application in tropical environments, particularly for insects, poses distinct challenges. Neotropical katydids produce complex species-specific calls, spanning mere milliseconds to seconds and spread across broad audible and ultrasonic frequencies. However, subtle differences in inter-pulse intervals or central frequencies are often the only discriminatory traits. These extremities, coupled with low source levels and susceptibility to masking by ambient noise, challenge species identification in PAM recordings. This study aimed to develop a deep learning-based solution to automate the recognition of 31 katydid species of interest in a biodiverse Panamanian forest with over 80 katydid species. Besides the innate challenges, our efforts were also encumbered by a limited and imbalanced initial training dataset comprising domain-mismatched recordings. To overcome these, we applied rigorous data engineering, improving input variance through controlled playback re-recordings and by employing physics-based data augmentation techniques, and tuning signal-processing, model and training parameters to produce a custom well-fit solution. Methods developed here are incorporated into Koogu, an open-source Python-based toolbox for developing deep learning-based bioacoustic analysis solutions. The parametric implementations offer a valuable resource, enhancing the capabilities of PAM for studying insects in tropical ecosystems. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'. [ABSTRACT FROM AUTHOR]

Mobile organisms like seabirds can provide important nutrient flows between ecosystems, but this connectivity has been interrupted by the degradation of island ecosystems. Island restoration (via invasive species eradications and the restoration of native vegetation) can reestablish seabird populations and their nutrient transfers between their foraging areas, breeding colonies, and adjacent nearshore habitats. Its diverse benefits are making island restoration increasingly common and scalable to larger islands and whole archipelagos. We identified the factors that influence breeding seabird abundances throughout the Chagos Archipelago in the Indian Ocean and conducted predictive modeling to estimate the abundances of seabirds that the archipelago could support under invasive predator eradication and native vegetation restoration scenarios. We explored whether the prey base exists to support restored seabird populations across the archipelago, calculated the nitrogen that restored populations of seabirds might produce via their guano, and modeled the cascading conservation gains that island restoration could provide. Restoration was predicted to increase breeding pairs of seabirds to over 280,000, and prey was predicted to be ample to support the revived seabird populations. Restored nutrient fluxes were predicted to result in increases in coral growth rates, reef fish biomasses, and parrotfish grazing and bioerosion rates. Given these potential cross‐ecosystem benefits, our results support island restoration as a conservation priority that could enhance resilience to climatic change effects, such as sea‐level rise and coral bleaching. We encourage the incorporation of our estimates of cross‐ecosystem benefits in prioritization exercises for island restoration. [ABSTRACT FROM AUTHOR]

The response to Antarctic sea ice loss within a coupled modeling framework is examined in comparison to the response to Arctic sea ice loss and within the context of general greenhouse warming. Sea ice loss responses are found to be linear (particularly in response to Antarctic or global sea ice loss) with respect to the degree of imposed perturbation and additive when perturbations are applied in hemispheres separately and concurrently. Globally, and in the tropical Pacific in particular, Antarctic sea ice loss plays a relatively larger role than Arctic sea ice loss in both the atmosphere and the ocean, within the parameters of our experiments. The pattern of response to Antarctic sea ice loss is also found to more closely resemble that of greenhouse warming, again particularly in the tropics. An extension to multiparameter pattern scaling is developed to include a scaling factor for Antarctic change in addition to those for tropical warming and Arctic sea ice loss. The decomposition is applied to the modeled response to Antarctic sea ice loss to break it down into component partial responses that scale with Antarctic, tropical, and Arctic changes. This reveals the aspects of the response that are directly related to Antarctic change, such as an equatorward intensification of tropical precipitation in the Northern Hemisphere, and those that are modified via the induced changes in the tropics and Arctic, such as Northern Hemisphere temperature change. With this, we hope to gain a deeper understanding of the role of each of these changes for the development of physical mechanisms of the response. [ABSTRACT FROM AUTHOR]

Representatives of Schizomida, known as short-tailed whip scorpions, are an understudied group within Megoperculata. They are found subterraneanly in tropical and sub-tropical regions. They lack eyes, have superior mobility, and possess a flagellum which is relevant to their mating, but in general little is known about their general biology. Fossil representatives of Schizomida from a variety of time periods are available for study. Using 23 fossil specimens (14 of which are described here for the first time) and 86 extant individuals from the literature, changes in both body size and flagella shape in Schizomida were compared over time. Measurements of prosoma length and leg length were used as a proxy for body size, and a comparative size analysis was carried out. Individuals from the Cretaceous period were found to be significantly smaller than extant individuals, contrary to our expectations. For flagellum shape, images were used to create reconstructions, which were then analysed using an elliptic Fourier analysis followed by a principal component analysis. The morphological diversity of the male flagellum shape was found to have decreased significantly between the Cretaceous and modern fauna. We discuss potential explanations for our findings, although a greater understanding of the general biology of Schizomida is required to properly interpret our results. [ABSTRACT FROM AUTHOR]

The surveillance and treatment of parasites are important features of preventative healthcare plans in zoological institutes. The parasite control strategies employed in temperate regions often involve prophylactic anthelmintic treatments during seasons where the burden of gastrointestinal parasites in fecal testing is high. These strategies are, however, not applicable in the tropics, where temperatures remain high throughout the year, allowing continuous parasitic development. A risk-based parasite management strategy was adopted by a tropical zoological institute. For parasite surveillance, routine fecal direct smears and magnesium sulfate flotations were performed to determine parasitic prevalence. The frequency of fecal checks for the year was determined by the frequency at which clinically relevant parasitism (fecal tests that resulted in the animal being treated) was detected during routine fecal checks in the previous year. A yearly anthelmintic drug-class rotation schedule was also implemented. The total number of fecal tests performed per year and the number of animals with clinically significant parasitic disease decreased by 30.0% (637/2126) and 46.9% (207/451), respectively, over the four-year period of the study. Anthelmintic class rotation also improved the efficacy of fenbendazole in treating Strongyloides spp. infecting the group of orangutans. This parasite control strategy is a targeted approach to managing preventative healthcare, reducing the work required to perform routine surveillance tests whilst maintaining the health of the collection of animals. [ABSTRACT FROM AUTHOR]

Landslide event inventories are one of the most critical datasets to increase knowledge on landslide occurrences. However, they are rarely available in various regions, especially in countries of the Global South. This study aims to generate rainfall-induced landslide event inventories and define the rainfall thresholds responsible for landslide occurrence at the national scale of Malawi, Africa. We mainly followed a three-step methodology to generate landslide inventories. First, we went through media reports to identify documented landslide events. Second, we used Sentinel-2 images to identify possible areas affected by landslides using automated change detection algorithms based on vegetation indices. Third, we manually went through optical images provided by Planet Lab and Google Earth and mapped landslides via visual image interpretation. Overall, we mapped 27 rainfall-induced landslide inventories between 2003 and 2022, with a total of 4709 individual landslides. We then analysed the Malawian terrain and identified two different landscape clusters (i.e. Cluster 1 and Cluster 2) showing similar morphometric and climatic conditions. Ultimately, we calculated the rainfall threshold for each landscape cluster. The minimum rainfall amounts responsible for landsliding correspond to 66 mm/two-day and 51 mm/day in Clusters 1 and 2, respectively. In this context, our paper not only presents and shares the first national-scale, digital rainfall-induced landslide event inventory database of Malawi but also suitable rainfall thresholds to be potentially exploited for a national scale landslide early warning system. A similar framework could be applied to generate landslide inventories for other data scarce regions. [ABSTRACT FROM AUTHOR]

The global construction industry significantly contributes to energy consumption and greenhouse gas emissions, necessitating immediate action for sustainable development. Recognizing the impact of buildings on emissions, the United Nations has set ambitious energy-related goals for 2030. Retrofitting buildings emerges as a strategic method for reducing energy consumption, offering lower environmental impact and life cycle costs. However, retrofitting is a complex process influenced by diverse factors such as policies, available resources, techniques, building-specific data, and uncertainties. Thus, this paper reviews the existing literature on retrofitting strategies for tropical and humid climates to identify effective approaches for enhancing energy efficiency, thermal comfort, and overall building performance in these regions. Through comprehensive analyses, including bibliometric analysis using VOSviewer version 1.6.18 and systematic assessments, this study investigates various retrofitting strategies. This study categorizes tropical climates into Af (Tropical Rainforest Climate) and Aw (Tropical Savanna Climate) based on the Köppen climate classification. It reveals distinct emphases, with Af climates concentrating on office buildings and Aw climates prioritizing residential structures. Passive strategies were predominantly favored in office buildings, with glazing being the most commonly implemented approach. Residential structures, on the other hand, adopted a combination of passive strategies such as phase change materials along with active methods like appliance replacement. Educational buildings tended to rely on passive strategies, including roof covers, shading, and glazing. The absence of specific cost values underscores the importance of establishing baseline metrics, revealing significant challenges in retrofit techniques. This study further highlights an opportunity to explore passive methods in educational buildings, stressing the need for comprehensive guidelines, especially in institutional settings. Moreover, it emphasizes the urgency for ambitious regulations to address carbon emissions and optimize energy efficiency in tropical climates. [ABSTRACT FROM AUTHOR]