Search Results (1,771)

The objective of this study was to analyze the climate change experienced in Spain between 1971 and 2022 and to estimate the future climate (2050). The main objectives were as follows: (1) to analyze the temporal evolution of temperature from 1971 to the present, to quantify the warming process experienced in the case study and to evaluate the increase in extreme heat events (heatwaves); (2) to study the evolution of the precipitation regime to determine whether there is a statistically representative trend towards a drier climate and an increase in extreme precipitation; (3) to investigate the interaction between annual precipitation and the continuous increase in temperature; and (4) to estimate the future climate scenario for mainland Spain and the Balearic Islands towards 2050, analyzing the trends in land aridity and predicting a possible change from a Mediterranean climate to a warm steppe climate, according to the Köppen classification. The aim of this study was to test the hypothesis that the increase in temperature resulting from the global warming process implies a tendency towards progressive drought. Given the extreme annual variability of the climate, in addition to the ordinary least squares methodology, the techniques mainly used in this study were the Mann–Kendall test and the Kendall–Theil–Sen (KTS) regression. The Mann–Kendall test confirmed the very high statistical significance of the relationship between precipitation (RR) and maximum temperature (TX). If the warming trend experienced in recent years (1971–2022) continues, it is foreseeable that, by 2050, there will be a reduction in precipitation in Spain of between 14% and 23% with respect to the precipitation of the reference period (understood as the average between 1971 and 2000). Spain’s climate is likely to change from Mediterranean to warm steppe in the Köppen classification system (from “C” to “B”). Full article

Pedunculate oak (Quercus robur L.) is widely distributed across Europe and serves critical ecological, economic, and recreational functions. Investigating its responses to stressors such as drought, extreme temperatures, pests, and pathogens provides valuable insights into its capacity to adapt to climate change. Genetic and dendrochronological studies offer complementary perspectives on this adaptability. Tree-ring analysis (dendrochronology) reveals how Q. robur has historically responded to environmental stressors, linking growth patterns to specific conditions such as drought or temperature extremes. By examining tree-ring width, density, and dynamics, researchers can identify periods of growth suppression or enhancement and predict forest responses to future climatic events. Genetic studies further complement this by uncovering adaptive genetic diversity and inheritance patterns. Identifying genetic markers associated with stress tolerance enables forest managers to prioritize the conservation of populations with higher adaptive potential. These insights can guide reforestation efforts and support the development of climate-resilient oak populations. By integrating genetic and dendrochronological data, researchers gain a holistic understanding of Q. robur’s mechanisms of resilience. This knowledge is vital for adaptive forest management and sustainable planning in the face of environmental challenges, ultimately helping to ensure the long-term viability of oak populations and their ecosystems. The topics covered in this review are very broad. We tried to include the most relevant, important, and significant studies, but focused mainly on the relatively recent Eastern European studies because they include the most of the species’ area. However, although more than 270 published works have been cited in this review, we have, of course, missed some published studies. We apologize in advance to authors of those relevant works that have not been cited. Full article

Tourism and climate change exhibit a binomial relationship, in which the former contributes to and is affected by the latter. In this context, the vulnerabilities of the tourism sector to climate change are assessed, focusing on cities in Portugal and Brazil, based on a literature review. A literature review was conducted using the keywords “tourism”, “climate change”, “Brazil”, “Portugal”, and their derivatives in Portuguese on Web of Science, Scopus, and Google Scholar databases. In both countries, extreme rainfall events cause delays or interrupt travel, and affect infrastructure, equipment, and services for tourists. In addition, heat waves and droughts have caused thermal discomfort and water shortages for residents and tourists. Adaptation and mitigation strategies are therefore urgently needed in both territories. Full article

Increasingly frequent weather extremes induce changes in the quantity and quality of surface waters, complicating their use and resource management. These challenges are particularly relevant to dam reservoirs, designed to provide high-quality water for various recipients. The impact of extreme drought on lowland eutrophic reservoir–river systems remains poorly understood. Our research showed that the effects of extreme droughts, resulting in a decrease in the water level in a lowland reservoir and its outflow, are more severe than those of floods. During extreme droughts, reservoir pressure increases because the large load of cyanobacteria released from the reservoir, in conditions of low river discharge, is not diluted. unlike during floods. The increase in the total biomass of potamoplankton and, especially, cyanobacteria responsible for the production of toxic microcystins was positively correlated with reservoir outflow. Additionally, a shift in the dominant cyanobacteria species was observed, from Planktothrix agardhii to Microcystis spp., leading to changes in the oligopeptide profile, including microcystins. Full article

Several ornamental species have demonstrated adaptive features that could increase their resilience to the current climate emergency but could also be linked to invasiveness in non-native environments. The present review examines the responses of ornamental plants’ grown in the Mediterranean region to relevant abiotic stress conditions such as drought, salinity, extreme temperatures, heavy metal toxicity, and atmospheric N deposition, emphasising physiological and biochemical responses that allow them to adapt to unfavourable environments. These response mechanisms, although useful for landscaping under challenging climate change effects, would help non-native ornamental plants outcompete native flora, change ecosystem functioning, and ultimately contribute to a loss in biodiversity. Effective management practices for sustainable landscaping ensure the sensible use of native species and the development of non-invasive cultivars to minimise ecological risks. This review attempts to provide information on the ornamental and environmental functions of plants in landscape architecture through the relationships between aesthetic and ecological values under abiotic stress, including their negative environmental impact due to their invasive potential. Full article

Droughts have always been one of the most dangerous hazards for civilizations, especially when they impact the headwaters of a watershed, as their effects can spread downstream. In this context, observed droughts (1981–2015) and projected droughts (2016–2100) were assessed in Candarave, the headwaters of the Locumba basin. Regarding observed droughts, SPI-3 and SPEI-3 detected seven extreme droughts (1983, 1992, 1996, 1998, 2010, 2011, and 2012), with the most intense occurring in 1992 and 1998. SPI-6 and SPEI-6 identified the same extreme drought events, highlighting 1992 as the most intense. Additionally, it was concluded that the VCI also detected the droughts identified by the SPEI; however, a more detailed analysis of its use is necessary due to the limited availability of suitable satellite images in the area. On the other hand, a high-resolution dataset of climate models from the sixth phase of the Coupled Model Intercomparison Project (CMIP6) under the SSP3-7.0 scenario was used to project future droughts. Of the models in that dataset, CanESM5, IPSL–CM6A–LR, and UKESM1–0–LL did not perform well in the study area. SPI and SPEI projected more than ten episodes of extreme drought, indicating that extreme droughts will become more frequent, severe, and intense in the last 30 years of this century. Full article

Climate forecasting is essential for energy production, agricultural activities, transportation, and civil defense sectors, serving as a foundation for decision-making and risk management. This study addresses the challenge of accurately predicting extreme droughts in South America, a region highly vulnerable to climate variability. By employing a supervised neural network (NN) within a machine learning framework, we developed a methodology to forecast precipitation and subsequently calculate the Standardized Precipitation Index (SPI) for predicting drought conditions across the continent. The proposed model was trained with precipitation data from the Global Precipitation Climatology Project (GPCP) for the period 1983–2023. It provided monthly drought forecasts, which were validated against observational data and compared with predictions from the North American Multi-Model Ensemble (NMME). Key findings indicate the neural network’s ability to capture complex precipitation patterns and predict drought conditions. The model’s architecture effectively integrates precipitation data, demonstrating superior performance metrics compared to traditional approaches like the NMME. This study reinforces the relevance of using machine learning algorithms as a robust tool for drought prediction, providing critical information that can assist in decision-making for sustainable water resource management. Full article

Populus euphratica Oliv. typically has four kinds of heteromorphic leaves: linear (Li), lanceolate (La), ovate (Ov) and broad ovate (Bo). Heteromorphic leaves help P. euphratica adapt to extreme desert environments and further contribute to protection against land desertification in Northwest China. In the authors’ previous research, growth-regulating factors (GRFs) were speculated to be related to the development of P. euphratica heteromorphic leaves via multi-omics integrated analysis. However, the genomic features and biological role of the P. euphratica GRF gene family in heteromorphic leaves are still unclear. In this study, 19 PeGRF genes were genome-widely identified and characterized in P. euphratica, and their physicochemical properties, gene structure and phylogenetic evolution were analyzed. An analysis of the research showed that PeGRFs were unevenly distributed on 11 chromosomes and that PeGRF proteins contained conserved motif 1 (WRC) and motif 2 (QLQ). Moreover, 19, 15, 19 and 22 GRFs were identified in Populus deltoides Marshall, Populus pruinosa Schrenk, Salix sinopurpurea C. Wang et C. Y. Yang and Salix suchowensis W. C. Cheng, respectively. A collinearity analysis showed that the PeGRF family evolved slowly within Populus species. A phylogenetic tree of the GRF family was also constructed, and GRFs were divided into four subfamilies. A large number of cis-acting elements were related to plant growth and development, plant hormone response and stress response on the promoter of PeGRFs. The expression pattern of PeGRFs showed significant up-regulation in broad leaves (Ov and Bo) compared with narrow leaves (Li and La). In combination with the predicted gene regulatory network, PeGRF9 (PeuTF06G01147.1) may have an important contribution to the leaf shape development of P. euphratica. The heterologous expression of PeGRF9 in wild-type plants (Col-0) of Arabidopsis thaliana (L.) Heynh was also studied, showing a significant increase in the leaf area of overexpressing plants compared with the wild type. Nineteen PeGRF gene members were identified and characterized in P. euphratica, and a comparison of the genomic analysis of Populus GRF members revealed their evolutionary features. The further overexpression of PeGRF9 in A. thaliana revealed its biological role in the heteromorphic leaves of P. euphratica. This study not only provides new insights into the evolution and function of PeGRFs in P. euphratica heteromorphic leaves but also helps in an understanding of the adaptive evolution of P. euphratica in drought desert environments. Full article

The aim of this study is to characterize the compound extremes of rainfall and temperature in Côte d’Ivoire. For this purpose, we analyzed the outputs of fourteen (14) climate models from the CORDEX-Africa project. Results show an increase (approximately 4.3 °C) in the surface temperature and a decrease (5.90%) of the mean rainfall in the near (2036–2065) and far futures (2071–2100) over Côte d’Ivoire during the January–February–March (JFM) period. The analysis of the compound extremes of the wet/warm type highlights an increase in the frequency of this climatic hazard in the northern and central parts of the country during the January–March (JFM) season in the near and far futures. The dry/warm mode will increase in the central and southern parts of the country in the near future and in the whole country in the far future. These increases in compound extremes could lead to an increase in droughts and natural disasters across the country and could have a negative impact on socio-economic activities, such as transportation and agricultural production. This work could provide decision support for political decision-makers in formulating future public policies for managing agricultural production, food security, and natural disasters. Full article

Microbial biostimulants that promote plant growth and abiotic stress tolerance are promising alternatives to chemical fertilizers and pesticides. Although Trichoderma fungi are known biocontrol agents, their biostimulatory potential has been scarcely studied in field conditions. Here, the mixture of two endophytic Trichoderma strains (Trichoderma afroharzianum TR04 and Trichoderma simmonsii TR05) was tested as biostimulant in the form of foliar spray on young (BBCH 15-16) maize (5.7 ha) and sunflower (5.7 and 11.3 ha) fields in Hungary. The stimulatory effect was characterized by changes in plant height, the number of viable leaves, and the chlorophyll content, combined with yield sensor collected harvest data. In all trials, the foliar treatment with Trichoderma spores increased photosynthetic potential: the number of viable leaves increased by up to 6.7% and the SPAD index by up to 19.1% relative to the control. In extreme drought conditions, maize yield was doubled (from 0.587 to 1.62 t/ha, p < 0.001). The moisture content of the harvested seeds, as well as sunflower height, consistently increased post-treatment. We concluded that foliar spraying of young plants with well-selected endophytic Trichoderma strains can stimulate growth, photosynthesis, and drought tolerance in both monocot maize and dicots sunflower crops in field conditions. Full article

Recent research identified 2022 as being the year of lowest seasonal April–May–June–July (AMJJ) observed streamflow for the Po River Basin (PRB) in the past two centuries. Expanding upon this research, we applied filters (2-year to 30-year filters) to the AMJJ observed streamflow and identified the late 20th and 21st century as displaying extreme drought. In this study, we introduce PALEO-RECON, an automated reconstruction tool developed to leverage tree ring-based proxies and streamline regression processes. Using PALEO-RECON, we reconstructed the AMJJ streamflow, applying traditional regression techniques and using a nested approach in which 30-, 40-, and 50-year windows within the ~200-year observed streamflow record (1807 to 2022) were evaluated to capture uncertainty. Focusing on the 21st century (2000 to 2022), while several droughts in the ~2000-year paleo record may have exceeded the 2000 to 2022 drought, the recent PRB drought ending in 2022 was the lowest 23-year period in approximately 500 years, acknowledging that uncertainty increases as we move further back in time. When examining paleo and observed AMJJ streamflow records, deficit and surplus periods were evaluated, focusing on the potential “whiplash” between drought and pluvial events. We observed an increase in the frequency of whiplash events, which may be associated with a changing climate. Full article

With global climate change, the frequency of extreme precipitation events in the Zishui River Basin (ZRB) is increasing, presenting significant challenges for water resource management. This study focuses on analyzing the evolution of extreme precipitation trends during the flood season from 1979 to 2018 and investigating their remote correlations with 18 large-scale climate indicators (LCIs) using three-dimensional (3D) Vine Copula. The results indicate a significant downward trend in the sustained wetness index (CWD) during the flood season, while trends in other extreme precipitation indices (EPIs) are not significant. Notably, a significant correlation exists between Maximum Precipitation for One Day (RX1day) and the Pacific Decadal Oscillation (PDO), Pacific North American pattern (PNO), and Sustained Drought Index (CDD), as well as between Atlantic Multi-decadal Oscillation (AMO) and PDO. Excluding the optimal marginal distribution of PDO, which follows a Laplace distribution, the optimal marginal distributions of the other indices conform to a Beta distribution. The C-Vine Copula function was employed to establish the functional relationships among RX1day, PDO, PNO, CDD, and AMO, allowing for an analysis of the impact of model fitting on EPIs under different LCI scenarios. The findings of this study are significant for the ZRB and other inland monsoon climate zones, providing a scientific foundation for addressing climate extremes and enhancing flood monitoring and prediction capabilities in the region. Full article

Drought stress has a significant impact on agricultural productivity, affecting key crops such as soybeans, the second most widely cultivated crop in the United States. Endophytic and rhizospheric microbial diversity analyses were conducted with soybean plants cultivated during the 2023 growing season amid extreme weather conditions of prolonged high temperatures and drought in Louisiana. Specifically, surviving and non-surviving soybean plants were collected from two plots of a Louisiana soybean field severely damaged by extreme heat and drought conditions in 2023. Although no significant difference was observed between surviving and non-surviving plants in microbial diversity of the rhizosphere, obvious differences were found in the structure of the endophytic microbial community in root tissues between the two plant conditions. In particular, the bacterial genera belonging to Proteobacteria, Pseudomonas and Pantoea, were predominant in the surviving root tissues, while the bacterial genus Streptomyces was conspicuously dominant in the non-surviving (dead) root tissues. Co-occurrence patterns and network centrality analyses enabled us to discern the intricate characteristics of operational taxonomic units (OTUs) within endophytic and rhizospheric networks. Additionally, we isolated and identified bacterial strains that enhanced soybean tolerance to drought stresses, which were sourced from soybean plants under a drought field condition. The 16S rDNA sequence analysis revealed that the beneficial bacterial strains belong to the genera Acinetobacter, Pseudomonas, Enterobacter, and Stenotrophomonas. Specific bacterial strains, particularly those identified as Acinetobacter pittii and Pseudomonas sp., significantly enhanced plant growth metrics and reduced drought stress indices in soybean plants through seed treatment. Overall, this study advances our understanding of the soybean-associated microbiome structure under drought stress, paving the way for future research to develop innovative strategies and biological tools for enhancing soybean resilience to drought. Full article

In light of the increasingly adverse environmental conditions and the concomitant challenges to the survival of important crops, there is a pressing need to enhance the resilience of pepper seedlings to extreme weather. Carotenoid plays an important role in plants’ resistance to abiotic stress. Nevertheless, the relationship between carotenoid biosynthesis and sweet pepper seedlings’ resistance to different abiotic stresses remains uncertain. In this study, the carotenoid content in abiotic-stressed sweet pepper seedling roots was determined, revealing that carotenoid content was extremely significantly elevated by more than 16-fold under salt stress, followed by drought stress (8-fold), and slightly elevated by only about 1-fold under waterlogging stress. After that, serine/threonine-protein phosphatase 2A (PP2A) was found to be the suitable reference gene (RG) in sweet pepper seedling roots under different abiotic stresses by using RT-qPCR and RefFinder analysis. Subsequently, using PP2A as the RG, RT-qPCR analysis showed that the expression level of most genes associated with carotenoid biosynthesis was extremely significantly up-regulated in sweet pepper seedlings under salt and drought stress. Specifically, violoxanthin deepoxidase (VDE) was significantly up-regulated by more than 481- and 36-fold under salt and drought stress, respectively; lycopene epsilon cyclase (LCYE) was significantly up-regulated by more than 840- and 23-fold under salt and drought stress, respectively. This study contributes to a more comprehensive understanding of the carotenoid biosynthesis pathway serving as a major source of retrograde signals in pepper subjected to different abiotic stresses. Full article

This study examines the impacts of climate-induced externalities on the stability of agroecosystems and the ecosystem services they provide. Using the PRISMA approach, we review literature published from 2015 to 2024. The study identifies how extreme weather events such as droughts, floods, heatwaves, and altered precipitation patterns disrupt the provisioning, regulating, and supporting services critical to food security, soil fertility, water purification, and biodiversity. Our findings show a continued increase in climate extremes, raising concerns about food security, environmental resilience, and socio-economic stability. It also reveals that regions dependent on rain-fed agriculture, such as parts of Africa, Asia, and the Mediterranean, are particularly vulnerable to these stressors. Adaptation strategies, including conservation agriculture, crop diversification, agroforestry, and improved water management, are identified as crucial for mitigating these impacts. This study emphasises the importance of proactive, policy-driven approaches to foster climate resilience, support agroecosystem productivity, and secure ecosystem services critical to human well-being and environmental health. Full article