Dry Climate Research Articles

Effect of Green Cowpea Manure on the Quality Properties of Sandy Soils Under the Specific Conditions of the Dry Climate in Romania

This study was carried out on the rotation of cowpea-rye + cowpea in successive crops for green manure-sorghum grains, with the objective of increasing the fertility of sandy soils by incorporating green cowpea manure into the soil in combination with chemical fertilization with NPK. In this sense, after harvesting the rye plant, the cowpea was sown, which was then incorporated into the soil during the formation of the beans in the pod. Before incorporating the cowpea biomass into the soil, the initial fertility status of the soil was assessed, and in the spring, the soil was sown with sorghum grain in two fertilization variants (N80P80K80 and N150P80K80). The soil chemical analyses carried out at the end of the vegetation cycle of the sorghum plant showed that by incorporating 52.4 t/ha green cowpea biomass (9.24 t/ha dry biomass), the quality properties of the soil were significantly improved, with annual increases of 0.17–0.29 g/kg in total nitrogen, 9.5–13.33 mg/kg in extractable phosphorus, 11.33–24 mg/kg in exchangeable potassium, and 0.08–0.12 g/kg in organic carbon, also depending on the sorghum fertilization system. It has also been shown to reduce the acidity of the soil pH and improve the water holding capacity of the soil.

Epidemiological, clinical and therapeutic aspects of pterygium at the district hospital of Commune VI, Bamako Mali

Pterygium is a benign conjunctivo-elastic neoformation of the ocular surface with a triangular shape, canthal base and corneal apex. It extends into the area of the palpebral cleft, preferably in the nasal sector, towards the corneal apex. It is therefore easy to imagine the harmful consequences of its progression on vision The distribution of pterygium is global, but its prevalence is higher in hot, dry climates. Populations living in warm, desert environments, located in peri-equatorial regions at latitudes of 37° north and south of the equator and highly exposed to ultraviolet radiation are at higher risk of developing this disease During our study, we collected 83 cases of pterygium, a frequency of 0.36%. More than half, or 70%, of our patients were women with a sex ratio M/F: 0.36. The age group over 60 years old was the most represented with 26.51%. Itching dominated the warning signs with 36.14%. Stage II was in the majority with 51.81%. Nasal pterygium was the most common with 90%. All our patients have benefited from an excision of the pterygium with autograft of the same eye. We recorded 7 cases of recidivism, i.e. 8.43%. Pterygium, although benign, is a public health problem since, for any type of surgery involved, it is impossible to avoid recurrences, which characterize the disease. In Bamako, at the hospital of the district of commune VI, the evolution was unpredictable but seems more favorable with the limboconjunctival autograft Keywords: surgery, pterygium, commune VI, Bamako.

Barn Owls (Tyto alba Scopoli, 1769) in the Saharan Region of Algeria (Souf): Valuable Predators for Rodent Control in Agriculture

Background: Barn Owls (Tyto alba Scopoli, 1769), which are nocturnal birds of prey, play a crucial role in controlling rodent populations that damage crops. They are valuable allies for farmers because they can effectively hunt small rodents. In Algeria, the Barn Owl is represented by two subspecies, Tyto alba alba and Tyto alba guttata. Methods: This study focuses on the Barn Owls' diet in the Saharan region, specifically in the Souf region, characterized by a dry climate. The research examines the contents of the Barn Owl's reject balls, which are regurgitated, to determine their diet. Result: The study reveals that each reject ball contains 1 to 9 prey items. The researchers identified 23 prey species, with rodents being the most abundant, making up 88.3% of the diet. The most commonly found prey species in Barn Owl balls are G. gerbillus, G. campestris, M. musculus, G. nanus and G. tarabuli. Overall, the Barn Owl's diet in the Saharan region is crucial for maintaining ecosystem balance by controlling rodent populations.

Controls on channel planform changes in rivers of the Atlantic Coastal Plain: Findings from the Congaree river valley (South Carolina, USA)

Rivers shaped the landscape of the Atlantic Coastal Plain during the last tens of thousands years. However, their spatial and temporal evolution is understudied. We conducted geophysical, geological and remote sensing surveys in the Congaree River valley, characterized by numerous traces of palaeochannels preserved in the floodplain. The age of the former channels was determined by AMS radiocarbon dating. The main goal of our study was to identify factors controlling the river planform changes and compare the findings with other rivers of the Atlantic Coastal Plain. We found that the Congaree floodplain was shaped by single-thread channels characterized by formation of levees and floodbasins at least 34,000 cal. BP. Large-scale meanders were active between 16,000 and 12,000 cal. BP. They were replaced by meandering channel belts shifting by avulsions between 12,000 and 3,000 cal. BP. Compound meanders have been formed during the last 3000 years. Traces of these channel planforms are also present in other rivers of the Atlantic Coastal Plain. The abandonment of the large-scale meanders was caused by increase in climate humidity, changes in vegetation cover, and inundation of the coastal plain by the ocean level rise, resulting in base-level rise. The avulsions of meander belts in the Early and Middle Holocene were formed in conditions of a humid climate, a series of flooding periods, and continued base-level rise. A relatively drier climate in the Late Holocene caused a change in the meanders’ evolution from the channel belts shifting by avulsions to compound meanders evolving by cutoffs. The last 200 years were dominated by a huge delivery and deposition of fines, caused by deforestation and land-use changes in the river valleys.

Environmental characterization and impact of climatic fluctuations on the diversity of extremophilic bacterial communities of a high-altitude seasonal meltwater pond on Ojos del Salado (Dry Andes, Chile)

Earth has unique environments where only microorganisms adapted to extreme conditions can survive. The focus of this study was a high-altitude seasonal meltwater pond on the Altiplano plateau at 5900 m (Dry Andes). The polyextremophilic bacteria of this habitat must adapt to a range of extremities, including cold and dry climate, high UV radiation, and low nutrient availability. A macro-scale analysis was performed to characterize the environment using satellite imagery. To study the composition of bacterial communities, samples were taken from permafrost, water, and sediment of a meltwater pond during three subsequent expedition years under different weather conditions (average, high precipitation, severe drought). The bacterial diversity of the samples was revealed by Illumina MiSeq 16S rRNA gene amplicon sequencing. The results showed that the relative abundance of dominant phyla, such as Pseudomonadota, Bacteroidota, Acidobacteriota, and Verrucomicrobiota varied according to sample types and weather conditions, supported by the satellite environmental state analysis that showed correlations between the availability of snow, water surfaces, and the corresponding surface temperature values. Strong moisture-dependent quantitative changes were detected in the phyla Cyanobacteriota and Actinomycetota. Predominant sequences were linked to orders Chitinophagales, Burkholderiales, Flavobacteriales, and Sphingomonadales, known for their ability to degrade various organic compounds.

Development of PCM tile for residential buildings in hot and dry climate: design and optimization

In recent years, the building sector has become more conscious of sustainability, and the use of phase change materials (PCMs) in concrete has gained more attraction. Integration of PCM with building facades is a successful method to reduce energy consumption and improve human comfort. However, no single PCM can work in an all-weather scenario. Hence, in this research work, an attempt is made to select a suitable PCM for Chennai city, India, and this methodology can be employed at any geographical location. The PCM tile is designed by including certain features to increase the thermal conductivity of the PCM zone. The optimum design of the PCM tile is achieved through multi-objective optimization techniques. L27 orthogonal array is employed, and all the tests were conducted through validated numerical simulation. Redesigned PCM tile includes a PCM layer of 2 cm thickness with a 10% mix of copper nanoparticles covered by plaster. Redesigned PCM tile reduces the peak indoor temperature by 6.62℃ compared with conventional roof systems.

Correlating Climate Conditions With Pseudomonas aeruginosa Prevalence in Diabetic Foot Infections Within the United States.

The 2023 "International Working Group on the Diabetic Foot/Infectious Disease Society of America Guidelines on the Diagnosis and Treatment of Diabetes-Related Foot Infections" (DFIs) provides recommendations for Pseudomonas coverage based on the climate region. This was a retrospective national study of veterans between 1/1/2010 and 3/23/2024 with diabetes mellitus and a culture below the malleolus wound. Prevalence of Pseudomonas was categorized based on climate zones according to the International Energy Conservation Code. Multivariable logistic regression was used to determine odds ratios and 97.5% CIs. The prevalence of Pseudomonas significantly varied between US climates. Pseudomonas was most prevalent within the Hot Humid climate, where it was isolated in 11.6% of DFI cultures. Pseudomonas was least prevalent within the Very Cold climate, where it was isolated in 6.2% of cultures. In the multivariable logistic regression model, hot and humid climates were associated with an odds of P. aeruginosa of 1.92 (97.5% CI, 1.69-2.20), a hot, dry climate was associated with an odds of 1.65 (97.5% CI, 1.44-1.90), and a humid climate was associated with an odds of 1.65 (97.5% CI, 1.45-1.89). A lower Charlson Comorbidity Index, inpatient admission, recent antipseudomonal antibiotic use, and swabs were less likely to have Pseudomonas. Recent admission increased the odds of P. aeruginosa (odds ratio [OR], 1.34; 97.5% CI, 1.27-1.41). History of P. aeruginosa was associated with an increase in P. aeruginosa (OR, 8.90; 97.5% CI, 8.29-9.56). The prevalence of DFI organisms varies within different US climates. Utilization of local climate information may allow for more accurate and targeted empiric antibiotic selection when treating DFIs.

A global analysis of nearshore and submarine springs: spatial distribution, controlling factors, and probability of presence

Coastal springs act as bi-directionally preferential flow paths between coastal aquifers and oceans. While these springs can supply coastal ecosystems with nutrients, they also present vulnerabilities such as contamination and seawater intrusion. Despite their significance, substantial knowledge gaps exist regarding coastal springs due to their complex hydrogeological nature. This study provides a comprehensive global assessment of coastal springs, focusing on their distribution, controlling factors, and likelihood of occurrence. A global dataset of known coastal springs was compiled and analyzed, revealing 66 % of identified springs in the Mediterranean region, mainly linked to karst systems. In contrast, fewer springs were noted in Africa, South America, and South Asia. Key factors influencing spring occurrence were examined using geostatistical methods and integrated into a multi-criteria decision-making framework to develop a Coastal Spring Probability Index (CSPI) along coastline. High-potential areas for coastal springs were identified in regions characterized by significant carbonate and volcanic rock formations, wetter climates, and active tectonic margins, such as southern Europe, the Caribbean, tropical islands, and eastern Asia. Conversely, regions with dry climates and high water demand, such as North Africa and South America, exhibited a lower likelihood of spring presence. These findings will serve as a baseline for local-scale studies and aimed at improving coastal spring inventories and establishing monitoring networks. It will contribute to vulnerability assessment studies, thereby enhancing the management of coastal groundwater resources. The study emphasizes the importance of multidisciplinary approaches to understand coastal spring dynamics and advocates for a strategic planning in groundwater management and conservation. Ongoing efforts to inventory and monitor coastal springs, coupled with targeted conservation measures, are essential for ensuring the long-term sustainability of coastal water resources and ecosystems.

Performance assessment of a high-efficiency indirect dew-point evaporative cooler through three-dimensional modeling

The escalating demand for eco-friendly air cooling, driven by concerns over global warming, necessitates sustainable alternatives to air conditioners. Dew-point evaporative coolers offer a green alternative yet face challenges due to high flow resistances caused by the U-turn of the working air. Recently, we have developed a new compact counterflow dew-point cooler that eliminates the U-turn of the working air, mitigating flow resistance. In this paper, a precise three-dimensional simulation, based on fluid dynamics, heat transfer and mass transportation, is developed to assess the cooler's performance. The validation against experiments shows maximum 8 % deviation in input pressure and 3 % in product air temperature. The simulation provides insights into the cooler's operation, efficiency, and performance, which are not easily obtained experimentally. Optimal cooling coefficients of performance occurs at working ratios of 0.5–0.6. Notably, while metallic channel separator excels at higher flow rates, plastic ones like high-density polyethylene and polycarbonate match performance at lower rates. Furthermore, the cooler performs better in hotter, drier climates. In locales like Xian and New Delhi, the cooler is suitable for standalone use, while in regions like Dubai, Texas, Singapore, Beijing, and Monterrey, it can be coupled with air conditioners to enhance the ventilation and energy efficiency.

Sedimentary Environment of the Permian Marine Shale in the Kaijiang‐Liangping Trough, Sichuan Basin, China: Implications for Organic Matter (OM) Accumulation

ABSTRACTThe Permian shales in the Kaijiang‐Liangping Trough within the Sichuan Basin represent a promising frontier for marine shale gas exploration, whereas there has been limited systematic research on their sedimentary environment and organic matter (OM) enrichment mechanisms. Therefore, we present total organic carbon (TOC) analysis, major/trace element analyses and scanning electron microscope experiments for the Permian marine shales from the trough to determine their paleoenvironmental conditions and influencing factors of OM enrichment. The results show that the paleoclimate changed from dry climate to humid and warm climate (P3w1 [the first member of the Wujiaping Formation]) and semi‐humid to semi‐arid climate (P3w2 [the second member of the Wujiaping Formation]) and P3d‐I (Dalong Formation‐I) and then to arid climate again during the shale deposition period from the P2g (Gufeng Formation) to the P3d‐II. The shales with the highest TOC contents (TOC > 3%, P3d‐I and P2g), lower TOC contents (TOC < 1%, P3w1 and P3w2) and higher TOC contents (1% < TOC < 2%, P3d‐II) were formed under the control of anoxic environment and high paleoproductivity, oxic‐suboxic environment and high paleoproductivity, anoxic‐euxinic environment and lower productivity, respectively. Only appropriate sedimentation rates promote OM enrichment. Terrestrial input, paleoclimate, volcanic activity and hydrothermal upwelling mainly indirectly affect OM accumulation by influencing paleoproductivity. The degree of redox conditions is the primary factor affecting OM enrichment, followed by paleoproductivity. Nonetheless, anoxic to euxinic environments are most appropriate for OM preservation. Weak volcanic activity can boost paleoproductivity, but severe volcanic activity might introduce excessive harmful compounds that limit organism survival, resulting in a fall in paleoproductivity. Additionally, element P brought by volcanic ashes doesn't contribute to OM accumulation.

Global and regional prediction of heterakidosis population prevalence in extensive backyard chickens in low-income and middle-income countries

Extensive backyard chickens are one of the most common production systems in low-income and middle-income countries (LMICs). In this production system, chickens are exposed to infectious forms of parasites as a result of the outdoor access and scavenging behaviour. Heterakis gallinarum is one of the most common nematode parasites present in the environment, and estimating its global and regional prevalence is essential for attributing the economic losses in extensive backyard chickens. The objective of this study is to predict the prevalence of heterakidosis in extensive backyard chickens at global and regional levels in LMICs using regression imputation methods. A binomial random effect model was developed using empirical data on heterakidosis prevalence and climatic factors as main predictors. Prevalence data were then imputed in all regions based on the regression model. Global and country prevalence were estimated based on regional predictions and their beta distributions. Minimum precipitation, minimum temperature and maximum temperature were selected as significant predictors. The population prevalence of heterakidosis was 0.24 (0.19–0.29). Countries with continental and dry climates had a higher mean prevalence, whereas countries with tropical climates had a lower mean prevalence of heterakidosis. As more empirical data on heterakidosis prevalence become available, this model and predictions should be redefined and updated to capture a more representative association and increase the accuracy of the predictions. The results of this study can be used to attribute the economic losses of extensive backyard chickens, taking into account a holistic approach as promoted by the GBADs programme and therefore, to identify which diseases are more costly to backyard farmers. Furthermore, results can be also served as a proxy for the risk of histomoniasis in extensive backyard chickens.

Groundwater Potential Zone Delineation through Analytical Hierarchy Process: Diyala River Basin, Iraq

Groundwater recharge zone identification is vital for managing water resources, particularly in semi-arid and dry climates. Accurate and quantifiable assessment is necessary for the sustainable management of groundwater resources, and it is possible to carry this method out using modern techniques and technical standards. To identify likely groundwater locations in the Diyala River Catchment, Iraq, which serves as an example study basin, the current research examines a new methodology that employs a geographic information system, and an Analytical Hierarchy Process connected with remote sensing data. The technique of ArcGIS was employed to generate spatially distributed thematic layers of rainfall, lithology, slope, drainage density, land use/land cover, relief and soil. The raster data from these layers were then converted and categorized. The weights assigned to thematic strata depended on their significance relative to groundwater occurrence. A pairwise judgement matrix for the Analytical Hierarchy Process was used, with the categorized ranking, to assess the standardized weights of the layers under consideration. The layers for the formation of groundwater zones have then been placed using the overlay-weighted summation approach. Three regions, which are classed as excellent, good and moderate, have been identified on the resulting groundwater potential zones map, representing roughly 29, 69 and 2% of the basin’s total area, respectively. The study’s conclusions indicate that, in such a climate, the adopted strategy would produce favourable results to promote the organizing of opinions and the sustainable use of groundwater resources.

Climatic Oscillations and Dynastic Trends: A Multiproxy analysis of the past two millennia in the Indian Subcontinent

The study examines centennial-scale climatic oscillations over the past two millennia in the monsoon-dominated Indian subcontinent by multiproxy analysis of pollen along with stable carbon isotope, total organic carbon, magnetic susceptibility, and grain size from a 274 cm deep sediment profile in Sarsapukhra Lake, Varanasi, in the Central Ganga Plain (CGP) to portray vegetation changes and their impact on rise and fall of dominant dynasties. Between ∼1800 to 1600 cal yr BP, the coarser silty sand with few Poaceae and Asteraceae pollen with other proxy data, indicate that the region experienced a strong Indian Summer Monsoon (ISM). Subsequently, from ∼1600 to 1350 cal yr BP, presence of mixed moist deciduous taxa such as Shorea robusta, Madhuca indica, Rubiaceae, Morus alba, Syzygium, and Moraceae indicate a moderate ISM while between 1350 to 1200 cal yr BP, the dominance of dry deciduous taxa viz. Acacia sp., Bombax ceiba, Holoptelea, Rutaceae, Madhuca indica, Mangifera indica etc. suggested weak ISM conditions. A pulsative ameliorating trend from ∼1200 to 1030 cal yr BP showed the dominance of deciduous taxa such as Holoptelea, Rutaceae, Ziziphus, Rubiaceae, Maytenus and Acanthaceae etc. indicating warm and moist climatic conditions, followed by a weak ISM until ∼900 cal yr BP and improved ISM until 620 cal yr BP. Subsequently, an improving trend in the ISM from ∼620 to 450 cal yr BP was observed, with increased dominance of wetland taxa, followed by acute dry climate beyond ∼450 cal yr BP indicating poor ISM conditions.Additionally, the alternating warm and cold episodes had a direct impact on vegetation, forcing human civilizations to migrate from their original locations and contributing to the downfall of prominent dynasties. Furthermore, this study lays the foundation for future research into issues related to vegetation change, the amount of ISM shift, and human culture−climate relationship.

Molecular study of some vector–borne diseases in cattle raised in western Türkiye

Unfortunately, global warming, especially the global climate crisis, increases the rate of vector–borne infections. Among the causes of this infection are microorganisms in the Rickettsiales Order, which are Gram–negative and small coccobacillus microorganisms that can multiply within host cells and are dependent on their metabolism, in addition to bacterial infections, protozoa such as Babesia spp. and Theileria spp. are transmitted through vectors and cause serious diseases in animals. This study aimed to investigate the presence of some vector–borne bacterial and protozoan microorganisms in blood samples taken from cattle raised in Mugla province, located in the West of Türkiye, and to reveal relevant disease data for the region. In this study, blood samples taken from 100 cattle were examined using molecular methods. While Anaplasma phagocytophilum was detected in 15 blood samples (15%), Anaplasma ovis agent was detected in eight samples (8%). Anaplasma bovis agent (1%) was identified in only one blood sample. In the samples examined within the scope of the study, Ehrlichia and Rickettsia species from bacteria and Theileria spp. and Babesia spp. from parasitic agents could not be detected. Mugla province, located west of Türkiye, has a subtropical dry summer climate, so the probability of infections transmitted through arthropods is high. Since the agents are transmitted through ticks, conducting more studies on vector–borne diseases is essential. This includes mapping the region’s vector ticks and determining and evaluating the tick carrier and disease maps in cattle. The data obtained is thought to help create regional and national vector–borne disease maps.

From landraces to haplotypes, exploiting a genomic and phenomic approach to identify heat tolerant genotypes within durum wheat landraces

Dry and hot climates severely impact wheat yields, necessitating the development of innovative solutions to accelerate the breeding and selection of more adaptable durum wheat genotypes. The aim of this study was to identify new wheat ecotypes that can bridge the gap between commercial varieties and adaptability to ongoing climate change. In this study, advanced genomic and phenomic techniques were combined to characterize a set of durum wheat landraces derived from single seed descent (SSD). This approach enabled the identification of novel variability in the TdHsp26-A1 and -B1 genes. As a result, 38 durum wheat genotypes were analyzed using targeted enrichment PCR, leading to the identification of 17 novel haplotype combinations with SNPs in the TdHsp26 genes. The response of these SSD haplotypes to heat stress was characterized at both the seedling and tillering growth stages. Phenotypic analysis of contrasting genotypes led to the selection of two distinct genotypes: SSD69 and SSD397. During heat stress, SSD69 exhibited altered accumulation of H2O2 and MDA content under both growth conditions, providing new insights into the oxidative response to heat stress. Additionally, this work identifies phenotypic traits that are suitable for detecting differences between variants. The geographic distribution of the different alleles aligned with the spread of durum wheat from its center of origin.

Drought risk assessment based on hazard, vulnerability, and coping capacity concepts for hot and dry climate regions of Iran

Due to the complex and multi-dimensional nature of droughts, it is not possible to assess drought-induced damage and its consequences for various social, economic, and environmental aspects of societies by relying only on a univariate index such as precipitation-based drought indices. The present study aimed to develop a practical and scientific framework based on hazard, vulnerability (social, economic, and environmental), and coping capacity to generate a drought risk map for the hot and dry climate regions of Iran. Accordingly, the Drought Hazard Index (DHI), Drought Vulnerability Index (DVI), and Drought Coping Capacity Index (DCCI) were derived from “the Standardized Precipitation Evapotranspiration Index (SPEI)”, “16 social, economic and environmental variables” and “three social, economic variables”, respectively. The layers of all variables of the three indices in the GIS were provided, and they were combined in the form of an equation to produce a drought hazard map of central and southeastern Iran. The results indicate that the counties most and least vulnerable to drought were located in the southeast and west of the case study area, respectively. A number of large households, long distances from provincial centers, and soil erosion were the most important social, economic, and environmental factors making the southeast of the case study (including south of Sistan and Baluchestan and south of Kerman provinces) most vulnerable to drought. Due to their high drought coping capacity, counties located in the west of the case study (west of Kerman and south of Yazd provinces) were least vulnerable to drought. Extended support for low-income households by charitable organizations, tertiary education, and most importantly, a variety of jobs and career opportunities were the most important factors in reducing vulnerability in this part of Iran. Furthermore, our methodology by taking social, economic, and environmental dimensions into account as risk, vulnerability, and coping capacity indices can be far more efficient than the methods considering only risk and vulnerability factors.

Amazon severe drought in 2023 triggered surface water loss

Abstract The Amazon underwent a severe austral springtime drought attributed to the onset of El Niño in 2023 and the warmer North Atlantic, Indian, and North Pacific Oceans. The Amazon rivers, lakes, small streams, wetlands, and reservoirs quickly lowered their water level below historical records due to decreased rainfall and warmth in the region. Based on satellite imagery, this study presents the first estimate of the water loss extent in the 4.2 million km2 of the Brazilian Amazon biome (∼62% of the Amazon total biome) in 2023. We estimated the loss of 3.3 million hectares of surface water relative to 2022, with an overall accuracy of 92%. The surface water losses were concentrated in the states of Amazonas (59.4%) and Pará (25.5), adding up to 2.8 million hectares. The warmer and drier climate in the region affected the main rivers in the Amazon. Among them, the Solimões, Negro, Purus, Acre, and Branco suffered extreme drops in their levels in some regions, resulting in a high negative impact on the aquatic biodiversity, yet estimated only in local areas. A total of 1.14 million hectares of surface water loss (i.e. 35%) was detected within protected areas territories, affecting extractivist, indegenous, African-Brazilian, and fishing and traditional communities. Proximity analysis revealed that 75% of the 2023 surface water loss was within 25 km of small towns, 48% and 65.8% at 50 km from indigenous villages and urban areas, respectively. Our results reinforce people’s vulnerability to climate change, anticipating a plausible adverse impact scenario in the Amazon region and urging solutions to adaptation and mitigation. Therefore, an integrated monitoring system based on climate and water dynamics from satellite and ground stations is necessary to improve understanding of the problem for timing response of climatic change negative impacts.

Combining tree-ring growth and carbon isotope data enhances the understanding of climate sensitivity and physiological responses for Chinese fir in a common garden

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is one of China's most important tree species, and possible adverse factors affecting its growth and physiology is of particular concern for climate change adaptation. In this context, growth performance (BAI: basal area increment and MAXD: maximum density), climate sensitivity, and the relative contributions of climatic and physiological determinants to growth were evaluated across the 30 Chinese fir provenances using a combination of dendroclimatology and carbon isotope analysis (δ13C). Over the past 27 years, intrinsic water-use efficiency (iWUE) increased significantly by 12.71–33.56 %, while radial growth decreased (−63.38 % to −88.93 %). Strong growth decreases reflected increasing water stress due to climate warming, which was not offset by greater iWUE. A similar trend was observed in the theoretical gas exchange scenario as a response to increasing Ca as stomata opened and Ci increased proportionally to Ca. This study identified temperature and relative humidity as determinants of growth and physiology. However, meteorological factors (temperature, relative humidity, and sunshine hours) contributed much less to growth than physiological factors (iWUE). Variation in performance and climate sensitivity among populations significantly correlated with the mean annual temperature of the seed source origin. In general, seed sources from warmer and more humid climates in the center region grew faster and had higher iWUE. Provenances from drier climates had slower growth, higher wood density, and higher carbon isotope discrimination (Δ13C) compared to those from wetter climate conditions. Compared to provenances from cooler regions, the seed sources from warmer climates were less sensitive to temperature but more sensitive to sunshine hours for BAI and MAXD. These results contribute to a better understanding of the climate sensitivity and physiological responses of the Chinese fir provenances to long-term changing climate.

Sedimentary organic matter and paleoenvironmental reconstruction of the Santana Group (Lower Cretaceous), Araripe Basin, Northeast Brazil

Depositional controls of the Santana Group in the Araripe Basin are still being debated. The main controversial subject is their marine influence and paleoenvironmental evolution. In this study, palynofacies analysis was performed on 59 samples from one core drilled at Sítio Romualdo in the Araripe Basin to investigate sedimentary organic matter. Three palynofacies associations (structureless, continental particles, and aquatic + opaque) were identified. The Santana Group consist of Barbalha, Crato, Ipubi and Romualdo formations. Based on palynofacies associations we conclude that the depositional setting of the Barbalha Formation reflects a fluvially-fed lacustrine system under oxic conditions. The Crato Formation, associated with tidal flats, coastal lakes, and lagoons within an open bay environment, represents a bayhead delta system. The Ipubi Formation corresponds to a coastal plain typical of sabkha paleoenvironments, characterized by low energy under reducing conditions, during drier climate conditions. The Romualdo Formation records mainly an estuarine paleoenvironment characterized by dysoxic to anoxic conditions. The presence of palynomorph groups typifies a late Aptian age for the Santana Group, which is based on the range of guide species marked mainly by the presence of Sergipea variverrucata biozone (P-270), as well as the occurrence of Complicatisaccus cearensis and Equisetosporites maculosus. The identification of marine palynomorphs (dinoflagellate cysts Subtilisphaera and foraminiferal test linings) are indicative of several, local marine incursions.

The Magdalenian horse (Equus ferus arcelini) from Roc-aux-Sorciers (Angles-sur-l’Anglin, France): Seasonality and paleoecology

Roc-aux-Sorciers is one of the most emblematic sites of Magdalenian culture, particularly known for its bas-relief and high-relief sculpted frieze depicting animals and humans, dated to the Middle Magdalenian. The stratigraphic sequence contains archaeological deposits corresponding to the occupations from the Middle Magdalenian, overlain by deposits from the Upper Magdalenian. The study of the horse Equus ferus arcelini, the preferentially hunted species, was conducted through various approaches (paleontological, zooarchaeological, palaeoenvironmental, dental wear analyses) to highlight a possible adaptation of these animal populations to the climatic and environmental changes recorded within the Magdalenian sequence, and to better understand the subsistence strategies of Magdalenian groups towards this fauna. In the Middle Magdalenian, in a steppe environment under cold and dry climate conditions, the site was repeatedly occupied for long durations by Magdalenian sculptors. Seasonality data indicate horse hunting in all seasons, suggesting sedentary to semi-sedentary equine populations in the territory. The results are consistent with dental wear analyses. In the Upper Magdalenian, the climate was cold and wet, and the environment more diversified and semi-open. Dental wear analyses show that horses were adapted to a more diversified and less abrasive diet compared to those of the Middle Magdalenian. Occupations were characterised as brief and seasonal.