Warm Areas Research Articles

Decoding Carbon Footprints: How U.S. Climate Zones Shape Building Emissions

The construction industry accounts for over 40% of carbon emissions in the United States, with embodied carbon—emissions associated with building materials and construction processes—remaining underexplored, particularly regarding the impact of location and climate. This study addresses this gap by investigating the influence of different climate zones on the embodied carbon emissions of residential buildings. Using Building Information Modeling (BIM), 3D models were developed based on the 2021 International Energy Conservation Code (IECC) and International Residential Code (IRC). A lifecycle assessment (LCA) was conducted using Environmental Product Declarations (EPDs) to evaluate the embodied carbon of building materials during the product stage. The findings reveal that buildings in colder climates exhibit higher embodied carbon emissions, ranging from 25,768 kgCO2e in Zone 1 to 40,129 kgCO2e in Zone 8, due to increased insulation requirements. Exterior walls and roofs were identified as significant contributors, comprising up to 34% of total emissions. Sensitivity analysis further indicates that the window-to-wall ratio and interior wall design substantially affect embodied carbon, with baseline emissions around 170 kgCO2e/m2 in warm areas and 255 kgCO2e/m2 in cold areas. These results establish a baseline for lifecycle embodied carbon values across different climate zones in the United States and align with international standards. This study provides valuable insights for policymakers and designers, offering data to inform effective carbon reduction strategies and optimize building designs for sustainability.

PRA Melting-ICE Project: Svalbard 2022 Expeditions Report

Arctic regions are among the fastest warming areas of the planet. Increasing average temperatures over the last five decades have deepened the thawing of the upper-most layer of permafrost across the Arctic, which contains significant amounts of organic carbon. The progressive deepening of seasonal thawing releases carbon that is used by active microorganisms which also produce greenhouse gases, potentially onsetting a positive feedback on global warming. Despite their importance in controlling organic matter degradation and greenhouse gas fluxes to the atmosphere, there is a lack of data on activity and dynamics of microbial communities in High Arctic soils in response to seasonal thaw. This report describes three specific expeditions performed on the Svalbard archipelago, carried out within the framework of the PRA (Italian Arctic Research Program) project Melting-ICE, performed between February and October 2022, reporting site characteristics and samples collected. The project aims to investigate the diversity and activity of active layer microbial communities across a full season thaw cycle, correlating microbial diversity with gas fluxes and composition. During these expeditions, a total of eight different sites were selected to investigate the microbiology and geochemistry of soils, as well as to estimate the gas fluxes from the soil to the atmosphere. The data collected in the field, combined with the results obtained in the laboratory, will provide a snapshot of the seasonal activity of the microbial communities present in the permafrost’s active layer. The three campaigns will provide data to estimate the impact of permafrost melting on the carbon cycle and the role of microorganisms in the release of greenhouse gases.

Citizen Observations Shed New Light on Geographic Variation in Colour Polymorphism of a Widespread Reptile

ABSTRACTAimColour polymorphism within ectothermic species and populations is shaped by multiple selection pressures that can vary geographically. Here, we tested different hypotheses to better understand this variation in colour polymorphism. The thermal melanism hypothesis predicts that darker colouration is beneficial in colder regions, due to enhanced heat absorption, while the predation pressure hypothesis predicts that melanistic individuals are exposed to a higher predation risk because they are more visible to predators. Additionally, temperature, land cover and predation pressure could interact to influence colour morph frequencies due to trade‐offs regarding thermoregulation and predation risk.LocationEurasia.TaxonEuropean adder (Vipera berus).MethodsWe compiled a dataset of > 7000 citizen observations across the entire distribution of the European adder, scoring adder colouration to test the above‐mentioned hypotheses concerning geographic variation in colour polymorphism, using Bayesian generalised nonlinear regression models.ResultsWe found support for the thermal melanism hypothesis, with the frequency of melanism increasing in colder regions. Moreover, in colder areas, the proportion of melanistic snakes increased with avian predator density, whereas this pattern was weaker in warmer areas, potentially because melanistic snakes spend less time basking and therefore experience reduced predation rates compared to brown and grey snakes. Finally, we found the proportion of melanistic individuals to decline at higher elevations (> 1000 m), potentially due to increased access to basking opportunities or because higher elevations facilitate easier detection of melanistic snakes by predators.Main ConclusionsCombined, our results emphasise the large potential of citizen observations to obtain novel insights concerning biogeographic patterns of morphological divergence in colouration. Our findings increase the understanding of the underlying mechanisms affecting colour polymorphism in ectothermic animals, providing valuable information to predict how species might respond to global change.

A bitter cup of coffee? Assessing the impact of climate change on Arabica coffee production in Brazil

Brazil, the world's largest producer and exporter of Arabica coffee, faces increasing challenges from climate changes. To maintain the sustainability of this commodity, innovative management techniques will be essential. This study aimed to assess the impact of climate projections, considering two CMIP6 emission scenarios (SSP2–4.5 and SSP5–8.5) on the phenology and yield of Arabica coffee in 36 representative locations across Brazil for the periods 2041–2060, 2061–2080, and 2081–2100. Observed meteorological data from the BR-DWGD (Brazilian Daily Weather Gridded Data) and projected data from CLIMBra (Climate Change Dataset for Brazil) were employed. An agrometeorological model, calibrated for Brazilian conditions, estimated yield and phenology. Results indicate significant impacts on coffee cultivation areas, mainly due to rising temperatures and increased water deficits. Projections also suggest changes in coffee phenology, with anthesis advancing in colder regions and delaying in warmer areas, while maturation timing occurring earlier in all climates. Yield increases from CO₂ fertilization were more pronounced in category C climates (Cfa, Cfb, Cwa, and Cwb), particularly in Cwb climates, reaching 2.9 bags ha−1 (3.7 bags ha−1 with irrigation) under the SSP2–4.5 scenario and 2.5 bags ha−1 (3.5 bags ha−1 with irrigation) under SSP5–8.5. However, higher temperatures and water deficits could cause severe yield losses, especially in Aw climates and under high-emission scenarios, where losses may reach 100 %. Irrigation will play an important role in mitigating yield losses, especially in northern regions such as northern Minas Gerais and Bahia, where yields could exceed 30 bags ha−1. While southern Minas Gerais, São Paulo, and northern Paraná are projected to have the highest yields, these regions also face greater uncertainty and variability. This study underscores the need for adaptive agricultural practices, the development of resilient coffee cultivars, and supportive research policies to ensure the sustainability of coffee farming in the face of climate change.

Environmental DNA as a novel tool for monitoring fish community structure and diversity feature in the northern Antarctic Peninsula

The northern Antarctic Peninsula (NAP), one of the fastest warming area around the Southern Ocean, hosts a large variety of endemic fish and is influenced by complex hydrography. However, the dynamics of fish diversity kept unclear and without monitoring. Monitoring of environmental DNA (eDNA) is a noninvasive, ecofriendly, and accurate approach for detecting aquatic organisms, including fish. In this study, the fish composition and diversity were detected by high-throughput sequencing of eDNA for the first time in the NAP. Overall, 32 species (1 order, 6 families, and 25 genera) of fishes were detected in the environmental water samples from 18 stations around the NAP, in which number of fish species were similar in the Drake Passage and the northern shelf of the South Shetland Islands (DP-SSIs) and the Bransfield Strait (BS). Most of the fish species were identified in previous Antarctic fish surveys using conventional methods, which supports the applicability of eDNA-based survey. Moreover, Pogonophryne albipinna was detected firstly in the NAP. Among the identified fish species, Champsocephalus gunnari and Notothenia rossii had the highest abundance (45.04% and 27.59%, respectively). There was difference in fish composition between the DP-SSIs and BS stations, although alpha diversity indices did not differ. The dissolved oxygen content and water temperature were the main drivers for the differences in fish species composition between areas. Our results indicated that eDNA could be a rapid and accurate biomonitoring approach for the entire Southern Ocean, particularly in areas with difficult logistics, in the future.

Characteristics, symptoms, and outcomes of patients with Vibrio vulnificus infection in Hainan, China: A retrospective study

With global temperatures on the rise and an expanding seafood trade, infections by Vibrio vulnificus, particularly in warm coastal areas like Hainan, China, are increasingly prevalent. These bacteria are notorious for causing grave infections with a high fatality rate. This study aims to dissect the clinical features, laboratory findings, treatment modalities, and patient outcomes associated with V vulnificus infections in Hainan Province. The medical records and clinical data of intensive care unit patients from Hainan General Hospital were retrospectively analyzed. Conventional sequencing and metagenomic sequencing were used to identify V vulnificus. The study involved 10 patients (9 males and 1 female) with a median age of 60.5 years, predominantly fishermen, with infections mainly occurring between May and October. Of note, 2 cases were linked to plant-related injuries. The typical manifestations included fever, pain, swelling, hemorrhagic vesicles, septic shock, and multi-organ dysfunction. It was found that delayed hospital admissions were associated with elevated Sequential Organ Failure Assessment and Acute Physiology and Chronic Health Evaluation II scores and increased mortality. Laboratory results indicated a robust inflammatory response, and interventions comprised antibiotic therapy and surgical procedures. A mortality rate of 50% was recorded. Vigilance for V vulnificus infections is crucial in coastal locales. The study endorses immediate and assertive treatment strategies, including the use of targeted antibiotics and surgical interventions, to enhance patient survival rates. A call for heightened awareness, intensified surveillance, and expanded research is essential to combat this life-threatening condition.

Wetland CH4 and CO2 emissions show opposite temperature dependencies along global climate gradients

Methane (CH4) and carbon dioxide (CO2) are the two largest contributors to the anthropogenically-driven greenhouse effect, which are the dominant gaseous end-products of wetland C decomposition. However, given our limited understanding of the spatial heterogeneity of wetland CH4 and CO2 emissions, it is uncertain how future warming may impact the emissions of these dangerous emissions. Here, we show opposite temperature dependencies of CH4 and CO2 emissions along global climate gradients using data from 45 widely distributed wetlands in the FLUXNET-CH4 database. Specifically, the temperature dependence of CH4 emissions increased as mean annual temperature (MAT) rose, while the dependence of CO2 emissions decreased, suggesting that in warmer areas, there is a greater risk for increased wetland CH4 emissions accompanying lower CO2 emissions in response to global warming. The ratio of wetland CH4 to CO2 emissions increased linearly with increasing temperature only when MAT and mean annual precipitation (MAP) are greater than 4.7 °C and 483 mm, respectively. This response indicates that, compared with those in cold and dry climates, wetland ecosystems in warmer and wetter climates are more prone to methanogenesis as temperatures rise. Our results suggest that neglecting spatial variation of temperature dependencies in models may underestimate wetland CH4 and CO2 emissions compared to the use of a static and consistent temperature dependence parameter when only considering temperature effects. These findings highlight the importance of incorporating climate-related variation in the temperature dependencies of CH4 and CO2 emissions into models to improve predictions of wetland C-climate change feedbacks in the Anthropocene.

Optimizing arable land suitability evaluation using improved suitability functions in the Anning River Basin

Conducting arable land suitability evaluation (ALSE) is essential for identifying agricultural development opportunities and ensuring sustainable production and food security. Traditional ALSE methods, relying on suitability proportion functions, often encounter constraints due to land use structures. Therefore, it is necessary to develop new function methods to avoid the constraints imposed by land use structures, thus making ALSE more convenient. This study aims to propose a novel set of rules for constructing proportion functions, aiming to enhance the applicability of suitability functions in arable land suitability evaluation. The study findings reveal that: (1) In the Anning River Basin, the highly Suitable, Moderately Suitable, and Marginally Suitable current arable land (CAL) respectively account for 45.3%, 29.8%, and 18.9% of the arable land (AL). The proportion of areas deemed Temporarily Unsuitable and Permanently Unsuitable is only 6%. The distribution of suitability levels for the potential arable land (PAL) is relatively uniform, with a proportion of suitable areas reaching 66.1%, indicating substantial development potential. (2) The agricultural production conditions in the arid and warm river valley area of the Anning River Basin are exceptional. Highly Suitable CAL and Highly Suitable PAL cover 93.14% and 82.97% of this region, respectively, making it a focal point for regional agricultural development. (3) The spatial distribution patterns of ALSE results based on the original function and the improved function are essentially consistent. However, there are significant differences among the suitability levels. The correlation analysis results indicate that the evaluation results based on the improved function are closer to reality. This study enhanced the accuracy of ALSE results based on the suitability function. It provided a new approach for evaluating the suitability of AL and offers a beneficial reference for regional arable land resource utilization and sustainable agricultural development.

Research on systematic analysis and optimization method for ice storage cooling system based on model predictive control: A case study

Ice storage systems are commonly applied for space cooling in large-scale commercial buildings to realize cost-saving effects. However, the practical operation performance is far poorer than expected. This paper conducted field tests to study the operation performance of ice storage system in a commercial building located in hot summer and warm winter area in China. Where the mismatch between ice storage capacity of chiller plant and cooling demand of buildings was found the typical issue leading to insufficient ice storage in cooling season and over ice-storage in transition season. Thus the annual average COP of Ice-storage chillers and the annual EER of whole chiller plant only reached 3.19 and 2.53 respectively, and the cooling price reached 0.194 Yuan RMB/kWh. To address this, a control strategy based on a cooling load prediction model was implemented. The model inputs the easily obtainable parameters such as ambient meteorological conditions, working/rest days, and previous cooling load data to predict the cooling demand next day, and then to guide the daily ice storage capacity during valley electricity price period, as well as the cooperation of ice melting system and direct cooling system for space cooling. Therefore, significant energy and cost-saving effects were achieved, where the cost-saving rate reached 41.9%, and the cooling price decreased to 0.111 Yuan/kWh.

Shifts in Plant Phenology Significantly Affect the Carbon Allocation in Different Plant Organs.

Earlier start of the growing season (SGS) and delayed end of the growing season (EGS) affect plant carbon uptake. However, the effects of phenological changes on carbon allocation to different plant organs remain unclear. Here, we examined the effects and potential mechanisms of phenological changes on carbon allocation to different organs over the northern hemisphere (> 30° N). We found the earlier SGS facilitated allocating carbon to roots in warm areas, and delayed EGS benefited allocating carbon to roots in dry areas. Moreover, the effects of SGS and EGS on carbon accumulation in different organs significantly enhanced over time. Path analyses indicated that phenological changes contributed to root-stem ratio mainly by regulating the growing season length. Our findings further highlight that phenological changes alter plants' investment strategies in carbon allocation for above- and below-ground parts, and considering this role is critical for accurately estimating the carbon budget in terrestrial ecosystems.

Climate change and staple grain acreage: Regional adaptation in China's agricultural cluster

The regionally adaptative use of cropland for staple grain production forms a critical foundation for agricultural clustering, however, the effects of climate change on grain acreage across regions have received insufficient attention. This study uses recent county-level data from 2000 to 2019 in China and employs an empirical framework that incorporates 10-year averages of weather variables to analyze regional variations in grain acreage in response to changes in temperature and precipitation. Our findings reveal significant regional heterogeneity: increases in temperature and precipitation generally lead to an expansion of staple grain acreage in initially colder or drier regions. These findings remain robust after accounting for a range of confounding factors. Mechanism analysis indicates that these climate-induced changes in grain acreage stem from variations in land productivity. Furthermore, the study identifies shifts in comparative advantages among staple grains across regions: rising temperatures favor paddy over corn in colder regions and corn over wheat in warmer areas, while increased precipitation enhances corn's advantage over wheat in arid regions. These findings have important implications for designing effective adaptation policies to sustain grain productivity in China's agricultural clusters and ensure food security targets.

A Model that Explains the Contrasting SST Trends in the Southern Pacific Ocean

Sea surface temperature (SST) of the southern Pacific Ocean plays an important role in ocean-atmospheric interactions, influencing both regional and global climate and ecosystems. The contrasting SST trends in the southern Pacific Ocean during 1993-2021 are noted by analyzing satellite and in-situ datasets, consisting of SST warming trend (0.05℃·yr−1) in the region of 80°W-180,30°S-50°S and cooling trend (−0.04℃·yr−1) in the area of 60°W-150°W, 55°S-70°S. A detailed trend analysis for the wind and sea ice concentration suggest that Ekman transport and sea ice radiative positive feedback are the two key contributors to the contrasting SST trends. The intensified downwelling (upwelling), induced by the Ekman transport and strengthened westerlies, gives rise to warm (cold) water swarming in (upturning) from lower latitudes (deeper ocean), which causes SST warming (cooling). Moreover, the sea ice increase at higher latitudes, due to both the cold water transport from deeper ocean layers and broken ice transport from polar regions, strengthens the cooling trend through sea ice positive radiative feedback. In conclusion, these findings underscore the complexity of SST trends in the southern Pacific Ocean, highlighting the critical roles of Ekman transport and sea ice radiative feedback in shaping regional climate dynamics.Plain Language Summary: The southern Pacific Ocean is an indispensable part in the climate system while it still remained poorly observed. The SST trend is regarded as a critical indicator of global climate change. Using the satellite and in-situ datasets, we find that the contrasting SST trends from 1993 to 2021, one area in this region is warmed by 0.3℃ per decade, while another area is cooled by -0.1℃ per decade. Considering impacts of various factors such as wind, sea ice and radiation, the primarily explanation is that wind-driven warm (cold) water from the subtropics (deeper ocean) flows in and goes downward (goes upward and flow away) in the warm (cold) area through oceanic circulation and leads to the SST warming (cooling). Additionally, the cooling trend is also related to the cold water that flows to higher latitudes and forms ice there and at the same time, trash ice from polar regions driven by enhanced south wind speed will be transported there. As a result, ice increases, reflects more shortwave radiation to space, and surface downward shortwave radiation decreases which contributes to SST decreases.

Potential Distribution and Carbon Sequestration of Rhizophora mangle L. in El Vizcaíno Biosphere Reserve, Baja California Sur, Mexico

Mangroves are a type of vegetation distributed in warm areas of the planet. Despite their importance, this flora is seriously threatened by both human activities and climate change. One of the main benefits provided by mangroves is carbon capture and storage, which is key for climate change mitigation. The main objective of this study was to identify the potential distribution and carbon sequestration potential of Rhizophora mangle L. in El Vizcaíno Biosphere Reserve. Potential distribution models were obtained for Baja California Sur, Mexico, using the MaxLike algorithm. For each projection, we used bioclimatic variables from the WorldClim project for current and future conditions (2050 and 2070), two Shared Socioeconomic Pathways (SSP2-4.5 and SSP5-8.5) and three General Circulation Models (ACCESS-CM2, EC-Earth3-Veg and MPI-ESM1-2-HR). The potential distribution models were developed within the perimeter of El Vizcaíno Biosphere Reserve as a case study to establish the potential for carbon sequestration under different climate change scenarios. Our results show a possible future carbon sequestration from 10,177,174 Mg of CO2 and up to 14,022,367 Mg of CO2 for the ACCESS-CM2 SSP5-8.5 to 2070 and MPI-ESM1-2-HR SSP2-4.5 to 2070 projections, respectively. Mangrove species such as Rhizophora mangle can be an important part of climate change mitigation and adaptation.

A mammalian herbivore selects local and cooler provenance trees in a restoration common garden experiment: implications for community‐assisted migration efforts

Rapid changes in climate have the potential to alter habitats faster than evolution may respond, leading to maladapted tree populations. Assisted migration may help foundation tree species persist in future climates by identifying populations and genotypes that are robust to expected climate change‐induced alterations. Importantly, community‐assisted migration accounts for impacts of those populations and genotypes on the broader community, including herbivores, often adapted to local plants. These impacts have been examined in arthropod communities, but few studies have assessed mammals, and fewer still have leveraged an experimental design to disentangle genetic contributions to herbivore selection among genotypes and populations. We tested whether North American porcupine (Erethizon dorsatum) browsing on Fremont cottonwood (Populus fremontii) is under genetic control in a common garden to uncouple genetic and environmental contributions on browse selection. Porcupines selected trees from climatically similar and cooler areas, where trees from cooler climates suffered greater than 2× more herbivory than trees from warmer areas. Plant genotype was a significant factor for selection, with the most heavily browsed genotype having greater than 10× more herbivory than the least browsed. Broad‐sense heritability of porcupine tree selection was H2B = 0.27 among genotypes, indicating a genetic component to tree defenses against porcupine herbivory that can be predicted by source population climate. Our results have important implications for future mammalian herbivore populations, should climate change render local tree genotypes maladaptive. We recommend assisted migration efforts plant stock from areas up to 3°C warmer and climatically similar areas to maintain productivity and mammalian herbivore browsing.

Oceanographic features boost latitudinal patterns in copepod body size distribution in the South Atlantic

AbstractThe South Atlantic Ocean (SAO) is an under‐sampled ocean where the influence of environmental drivers on copepod body size is poorly understood. This study investigated the body size distribution of copepods from 13°S to 64°S to test Bergmann's rule, which predicts the occurrence of smaller organisms in warmer areas. We hypothesized that additional influence of oceanographic features strengthens this pattern. Zooplankton were sampled during the austral summer from the chlorophyll maximum depth up to the surface, at approximately 100 m depth, using a 200‐μm net. The samples were analyzed using the ZooScan imaging system and were classified using the Ecotaxa tool. We estimated copepod family abundance, biomass, and size structure, and their relationships with environmental variables were assessed through generalized linear mixed models (GLMM). Although most copepods increased in size at higher latitudes, not all families followed Bergmann's rule. Small adults of Clausocalanidae, Paracalanidae, Corycaeidae, and Oncaeidae contributed mostly in the Brazil Current (BC), while Calanidae copepodites disproportionately contributed to overall biomass, and Oithonidae adults were the most abundant in high latitudes. Copepod abundance or biomass hotspots were present in the southern limit of the warm BC, at the Subtropical Confluence Zone, and in the subantarctic waters at the Drake passage. Our results suggest that oceanographic features strengthen latitudinal body size relationships due to food availability, and the importance of different life history strategies.

Warming and disturbances affect Arctic-boreal vegetation resilience across northwestern North America.

Rapid warming and increasing disturbances in high-latitude regions have caused extensive vegetation shifts and uncertainty in future carbon budgets. Better predictions of vegetation dynamics and functions require characterizing resilience, which indicates the capability of an ecosystem to recover from perturbations. Here, using temporal autocorrelation of remotely sensed greenness, we quantify time-varying vegetation resilience during 2000-2019 across northwestern North American Arctic-boreal ecosystems. We find that vegetation resilience significantly decreased in southern boreal forests, including forests showing greening trends, while it increased in most of the Arctic tundra. Warm and dry areas with high elevation and dense vegetation cover were among the hotspots of reduced resilience. Resilience further declined both before and after forest losses and fires, especially in southern boreal forests. These findings indicate that warming and disturbance have been altering vegetation resilience, potentially undermining the expected long-term increase of high-latitude carbon uptake under future climate.

Effects of Extreme Climatic Events on the Autumn Phenology in Northern China Are Related to Vegetation Types and Background Climates

The increased intensity and frequency of extreme climate events (ECEs) have significantly impacted vegetation phenology, further profoundly affecting the structure and functioning of terrestrial ecosystems. However, the mechanisms by which ECEs affect the end of the growing season (EOS), a crucial phenological phase, remain unclear. In this study, we first evaluated the temporal variations in the EOS anomalies in Northern China (NC) based on the Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) from 2001 to 2018. We then used event coincidence analysis (ECA) to assess the susceptibility of EOS to four ECEs (i.e., extreme heat, extreme cold, extreme wet and extreme dry events). Finally, we examined the dependence of the response of EOS to ECEs on background climate conditions. Our results indicated a slight decrease in the proportion of areas experiencing extreme heat and dry events (1.10% and 0.66% per year, respectively) and a slight increase in the proportion of areas experiencing extreme wet events (0.77% per year) during the preseason period. Additionally, EOS exhibited a delaying trend at a rate of 0.25 days/a during the study period. The susceptibility of EOS to ECEs was closely related to local hydrothermal conditions, with higher susceptibility to extreme dry and extreme hot events in drier and warmer areas and higher susceptibility to extreme cold and extreme wet events in wetter regions. Grasslands, in contrast to forests, were more sensitive to extreme dry, hot and cold events due to their weaker resistance to water deficits and cold stress. This study sheds light on how phenology responds to ECEs across various ecosystems and hydrothermal conditions. Our results could also provide a valuable guide for ecosystem management in arid regions.

Population connectivity of the swordtip squid Uroteuthis edulis between southern Japan and northern Taiwan using statolith trace elemental analysis

Uroteuthis edulis (Hoyle, 1885) is an Indo-Pacific squid species widely distributing in the western Pacific, and commercially important especially in Japan and Taiwan. It has been suggested that some individuals are possibly transported from the spawning ground in north Taiwan to the coasts of Japan, however, the strength of population connectivity between those areas and its influence on U. edulis population dynamics were unveiled. To understand the U. edulis population connectivity in this area, the correlations between statolith trace elements and abiotic/biotic factors were examined first, and then squid experienced environments were postulated throughout their entire life cycle. Sr/Ca ratio showed a strongly negative correlation with ambient water temperature but no correlation with individual growth rate, suggesting that Sr/Ca ratio can be used to reflect squid experienced temperatures. Most squid caught in the Sea of Japan hatched in the areas having similar water temperature with where Taiwanese squid hatched, that would be off the north Taiwan or even warmer area. Statolith trace elements successfully distinguished the catch locations but not the hatching grounds, implying that hatching grounds of Japan and Taiwan squid were largely overlapped. Thus, we suggest that there is strong population connectivity of U. edulis population between southern Japan and northern Taiwan. As there was no clear evidence for existence of local population hatched in the Sea of Japan in this study, U. edulis population might display a source-sink population dynamics, that is, population in Taiwanese waters and/or further south as the source, and the one in the Sea of Japan as a sink population. As U. edulis should be considered as a metapopulation, collaboration among countries in the northwestern Pacific is required for sustainable fishery management of this species.

Boreal tree species diversity increases with global warming but is reversed by extremes.

Tree species diversity is essential to sustaining stable forest ecosystem functioning. However, it remains unclear how boreal tree species diversity has changed in response to climate change and how it is associated with productivity and the temporal stability of boreal forest ecosystems. By combining 5,312 field observations and 55,560 Landsat images, here we develop a framework to estimate boreal tree species diversity (represented by the Shannon diversity index, H') for the years 2000, 2010 and 2020. We document an average increase in H' by 12% from 2000 to 2020 across the boreal forests. This increase accounts for 53% of all boreal forest areas and mainly occurs in the eastern forest-boreal transition region, the Okhotsk-Manchurian taiga and the Scandinavian-Russian taiga. Tree species diversity responds positively to increasing temperatures, but the relationship is weakened for higher temperature changes, and in areas of extreme warming (>0.065 °C yr-1), a negative impact on tree species diversity is found. We further show that the observed spatiotemporal increase in diversity is significantly associated with increased productivity and temporal stability of boreal forest biomass. Our results highlight climate-warming-driven increases in boreal tree species diversity that positively affect boreal ecosystem functioning but are countered in areas of extreme warming.

Application of Diverse Silicon Sources to Soil for Reducing Wheat Blast Disease

Despite the economic potential of wheat for food security, blast disease is one of the major constraints to wheat production in warm and humid areas. Silicon (Si) increases crop yields and resistance to both biotic and abiotic stresses. The effect of various Si sources, including Na2SiO3, MgSiO3, CaSiO3, and rice hull ash (RHA), on suppressing wheat blast (WB) incidence was studied at Bangladesh Institute of Nuclear Agriculture field from November 2019 to March 2020 using a complete randomized design (CRD) with three replications. Total 42 plastic pots were filled with the recommended doses of fertilizers and Si. On 17 days after inoculation (DAI), the lowest WB incidence (83.16%) and severity matrix (80.20%) were found with the treatment of CaSiO3 @ 100 kg ha-1. At 15 DAI, the same treatment reduced the WB incidence and severity matrix by 21.10% and 41.73%, respectively. Most yield indicators were significantly improved by the Si fertilizers, except for grain spike-1 quantity, weight, and thousand grain weight (g). However, pots that were fertilized with Si distinguished out from both the control and absolute control groups. While CaSiO3 at 75 kg ha-1, RHA at 6.0 t ha-1, and MgSiO3 at 100 kg ha-1 produced respectable yields, the maximum was achieved by CaSiO3 at 100 kg ha-1. There was a significant positive relationship between the leaf concentrations of K and Si, with the highest concentration found in plants treated with CaSiO3. A large number of yield metrics showed moderate to strong positive associations with leaf K and Si concentrations, whereas the disease severity matrix revealed the maximum significant negative correlation with these elements. The best outcomes were obtained by applying Si as CaSiO3 @100 kg ha-1, which has potential as an environmentally acceptable source for controlling WB disease and increasing wheat yields. J Bangladesh Agril Univ 22(3): 295–309, 2024