Search Results (2,437)

Drought is a critical hazard to agricultural productivity in semi-arid regions such as the Antalya Agricultural Basin of Türkiye. This study assessed agricultural drought from 2001 to 2023 using multiple remote sensing-based indices processed in Google Earth Engine (GEE). Vegetation indicators (Normalized Difference Vegetation Index, Normalized Difference Water Index, Normalized Difference Drought Index, Vegetation Condition Index, Temperature Condition Index, and Vegetation Health Index) were derived from MODIS datasets, while the Precipitation Condition Index was calculated from CHIRPS precipitation data. Composite indicators included the Scaled Drought Composite Index, integrating vegetation, temperature, and precipitation factors, and the Soil Moisture Condition Index derived from reanalysis soil moisture data. Results revealed recurrent moderate drought with strong seasonal and interannual variability, with 2008 identified as the driest year and 2009 and 2012 as wet years. Summer was the most drought-prone season, with precipitation averaging 5.5 mm, PCI 1.1, SDCI 15.6, and SMCI 38.4, while winter exhibited recharge conditions (precipitation 197 mm, PCI 40.9, SDCI 57.3, SMCI 89.6). Interannual extremes were detected in 2008 (severe drought) and wetter conditions in 2009 and 2012. Vegetation stress was also notable in 2016 and 2018. The integration of multi-source datasets ensured consistency and robustness across indices. Overall, the findings improve understanding of agricultural drought dynamics and provide practical insights for irrigation modernization, efficient water allocation, and drought-resilient planning in line with Türkiye’s National Water Efficiency Strategy (2023–2033). Full article

Drought stress during the reproductive phase substantially reduces seed yield and quality, posing a major challenge to sustainable crop production under climate change. This study investigated the effects of drought stress at the flowering stage on selected biochemical and physiological parameters in 18 carrot accessions. To describe the long-term consequences of drought comprehensively, we examined seed quality parameters. Our analyses revealed that stress responses are highly dependent on the genotype and the parameter examined. Regarding antioxidant responses and potential tissue damage caused by drought, ‘Dolanka’, DC97, DC265, DC359, DC522, DC701, DC704, and DC720 exhibited the highest tolerance. The photosynthetic apparatus and pigments were maintained under stress in DC233, DC522, DC717, and DC728. Germination parameters served as reliable indicators of stress tolerance in DC97, DC359, DC432, DC522, DC701, and DC722 accessions. Based on these findings and detailed discussion of the results, we conclude that tolerance/sensitivity assessment of carrot genotypes should consider the holistic response of the plant rather than individual parameters. Through overall assessment, we recommended DC522 accession as the most drought-tolerant, given its enhanced ROS (Reactive Oxygen Species) scavenging mechanisms, increased chloroplast pigments accumulation, and superior germination parameters under drought conditions. Conversely, DC295 should not be cultivated under water-deficient conditions due to its impaired ability to detoxify ROS, altered photosynthetic activity, and disrupted seed germination under such conditions. These results collectively highlight the potential for selecting drought-tolerant carrot genotypes in breeding programs targeting improved seed performance under water-limited conditions, thereby supporting the development of resilient cultivars adapted to future climate challenges. Full article

Leaf stomatal density directly regulates the rates of gas exchange and water loss and is a core indicator of plants’ water-retention capacity and drought adaptability. Because detecting leaves over a macroscopic range requires large-stroke motion, whereas accurate identification of stomata demands high-precision positioning, the operational platform for stomatal-density detection faces the dual challenge of large strokes and high resolution. This paper proposes a novel two-degree-of-freedom (2-DOF) cross-scale piezoelectric platform that employs a new three-degree-of-freedom (3-DOF) piezoelectric stator to address the backlash issue in inertial drive and combines it with finite-element simulation for verification. The prototype of the 2-DOF cross-scale piezoelectric positioning platform is developed, and a series of experiments are conducted to evaluate its performance. The experimental results show a motion range of 15 mm × 15 mm; the displacement backlash rates in the X and Y directions range from 0% to 9.84% and 0% to 28.42%, respectively; and the displacement resolutions reach 11.39 nm and 13.61 nm, respectively. In addition, an application experiment on leaf stomatal-density detection is carried out on the developed 2-DOF platform, demonstrating its potential for botanical micro-detection. Full article

Zambia continues to experience increasingly frequent and intense droughts, with the 2023/2024 season among the most severe in recent history. These events have threatened livelihoods, strained water and food systems, and placed immense pressure on already limited national and local resources. Given the limited knowledge in the literature on drought management in Zambia, this study investigated the state of localized district efforts across the country. By using mixed methods with a total of 161 interviews, it assessed the participation of district governments and sector players across key components of drought governance, including early warning, monitoring, vulnerability and impact assessment, mitigation, and response. Although Zambia has made notable progress in establishing national institutional frameworks and climate policies, key findings reveal a pattern of limited proactive engagement, with most participation occurring only in response to extreme events like the 2023/2024 drought. This reactive posture at the district level is further compounded by inadequate resources, limited coordination, a lack of localized drought planning, and systemic bureaucratic constraints that undermine a timely and effective response. Nonetheless, numerous opportunities exist to strengthen drought management by localizing decision-making, integrating indigenous knowledge into existing early warning systems, and leveraging community-based infrastructures to maximize scarce resources and build long-term resilience. The paper concludes with recommendations for enhancing Zambia’s drought preparedness and response capacity through inclusive, risk-based, and proactive strategies; insights that can be adapted to other developing country contexts. Full article

Pinus (~113 species, generally early-seral) and Quercus (~435 species, generally late-seral), currently co-occur over a wide range of climates and biomes in the Northern Hemisphere. Climate change is expected to threaten the coexistence dynamics of pine and oak species. Here, we analyze the responses of Pinus and Quercus to water stress, with the objective of determining how they vary globally in their responses to drought at the genus level. The results show that pines tend to tightly close stomata before stress becomes severe and may deplete their stored carbon; on the other hand, oaks begin stomatal control at a lower water potential and hence do not suffer from carbon depletion. Pines exhibit a wider hydraulic safety margin (average: 3.33 MPa) than oaks (average: 1.41 MPa) because of lower Ψ₅₀ (average: −3.62 MPa) and earlier stomatal closure (average: −2.19 MPa). For oaks, stomatal closure and Ψ₅₀ occur at −2.61 MPa and −3.07 MPa, respectively. We discuss and show that these contrasting drought responses are consistent with their seral roles. While the difference in the basic strategies to drought in the two genera is unmistakable, the species studied are still too few to make convincing generalizations. Research is also needed on other components related to drought adaptations. Full article

Background/Objectives: γ-aminobutyric acid (GABA), a non-protein amino, is synthesized from glutamic acid through the catalytic activity of glutamate decarboxylase (GAD). As a key signaling molecule, GABA plays a vital role in plant responses to abiotic stresses. To explore the potential involvement of the GABA gene family in Juglans regia’s response to environmental stressors, a comprehensive genome-wide identification and analysis of GABA-related genes was performed. Methods: The study examined their protein features, evolutionary relationships, chromosomal locations, and promoter cis-regulatory elements. Additionally, the expression patterns of GABA family genes were analyzed in J. regia seedlings subjected to salt and drought stress. Results: Genome analysis identified three main components of the GABA metabolic pathway in J. regia: glutamate decarboxylases (GADs), GABA transaminases (GABA-Ts), and succinic semialdehyde dehydrogenases (SSADHs). These genes were unevenly distributed across 14 chromosomes, with chromosome 10 containing the highest number. Promoter analysis revealed that about 80% of cis-acting elements were linked to plant hormone regulation, such as abscisic acid (ABA), and stress responses, including drought and high-salinity. Phylogenetic analysis showed that JrGAD1 was distantly related to other JrGAD members, while certain JrGABA-T and JrSSADH genes formed closely related pairs. Under salt and drought stress, JrSSADH23 expression was highly upregulated (2.60-fold and 2.24-fold, respectively), a trend observed for most JrSSADH genes. Conclusions: These findings offer valuable insights into the molecular basis of GABA metabolism in J. regia’s stress adaptation and identify promising genetic targets for developing stress-tolerant varieties. Full article

Membrane lipid remodeling represents a crucial adaptive mechanism for plants in response to drought stress. This study investigated the regulatory influence of melatonin on the photosynthetic attributes, oxidative damage, and lipid metabolism of foxtail millet seedlings subjected to drought stress, with particular emphasis on alterations in lipid composition and fatty acid unsaturation. The findings indicated that melatonin treatment markedly enhanced the drought tolerance of foxtail millet seedlings, resulting in increases in chlorophyll content, net photosynthetic rate, and total dry weight by 51.2%, 39.8%, and 51.1%, respectively. Melatonin increased the levels of monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), sulfoquinovosyldiacylglycerol (SQDG), and phosphatidylcholine (PC), while promoting the accumulation of unsaturated fatty acid (18:3) and leading to an increase in the double bond index (DBI). Concurrently, there were significant alterations in the expression of genes associated with glycolipid and phospholipid biosynthesis, aligning with the observed changes in lipid components. These findings indicate that melatonin potentially enhances the drought tolerance of foxtail millet seedlings through the regulation of lipid metabolic reprogramming. This process involves an increase in the content of unsaturated fatty acids and an optimization of the lipid unsaturation index, which collectively contribute to the greater stability, fluidity, and integrity of cellular membranes. Full article

Agricultural and ecological systems are threatened by extreme and compound climate extremes such as hotter droughts. These events are characterized by elevated maximum temperatures, leading to atmospheric drought, and reduced precipitation, leading to soil drought. Such conditions reduce plant productivity and are increasing mortality trees in forests worldwide. Some forest types are particularly vulnerable to hotter droughts such as some European mountain silver fir (Abies alba) forests. However, we still lack conceptual frameworks linking hotter droughts and rising VPD with growth decline and tree death. This review elucidates physiological responses to drought in conifers with a focus on silver fir. In silver fir declining populations, prolonged stomatal closure under elevated VPD can lead to reduced growth, and impaired xylem development, potentially triggering positive feedback that exacerbates hydraulic limitations. We also review the ecological significance of xylem vulnerability to embolism, identifying the critical water potential thresholds that determine silver fir survival and hydraulic failure risk under soil water deficit. These findings underscore the importance of both atmospheric and soil drought as physiological stressors causing forest decline, and highlight the need for further research into adaptive strategies and early warning indicators in tree species. Full article

Plants continuously adapt to dynamic environmental conditions, which include abiotic stress such as drought, salinity, and high temperature. Translocation, availability, and uptake of essential nutrients are suggested to be disrupted, thereby impairing growth, development, and productivity of the plant. The interplay between the root architecture, membrane transporters, and hormonal regulation is suggested to have efficient nutrient acquisition. For mediating nutrient uptake and redistribution under abiotic stress conditions, transporter proteins such as nitrate (NRT), ammonium (AMT), phosphate (PHT), and potassium (HAK) families play a crucial role for the major essential elements (N, P, K). Abiotic stress triggers specific transcriptional and post-transcriptional regulation of these transporters, modulating their activity in response to external nutrient availability. Under nutrient-deficient conditions, phytohormones such as abscisic acid (ABA), cytokinin, and ethylene play a pivotal role in orchestrating plant responses. Moreover, the plant stress tolerance is suggested to be influenced by stress-induced signalling mechanisms, which are mediated by reactive oxygen species (ROS). The current review synthesizes current knowledge of nutrient dynamics under abiotic stress, focusing on the molecular mechanisms governing transporter regulation and phytohormonal crosstalk. By unravelling these complex regulatory networks, this article aims to pave the way for sustainable agricultural practices. Full article

Understanding the impact of climate change and altered hydrologic cycles on regional water storage trends is crucial for predicting changes in recharge and streamflow and informing decisions regarding drought resilience and flood mitigation. While many regions have become drier under global climate change, the northeast United States has experienced an increased precipitation intensity, driving groundwater rise. This study integrates terrestrial water storage data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites and soil moisture data from Soil Moisture Active Passive (SMAP), as well as long-term instrumental groundwater records from USGS groundwater monitoring wells, to understand the nature of storage trends. The results show that while aquifer-wide groundwater storage anomalies have stabilized in recent years, shallow groundwater and certain surface water bodies have accumulated about 0.6 cm of water annually, adding over 10 cm to the landscape, since 2005. These findings indicate that excess water from heavy rainfall is mainly stored in the shallow subsurface as perched aquifers and temporary wetlands rather than deep (5–30 m) aquifers. Understanding this change in storage is crucial for improving water resource management and adapting more effectively to a changing climate in the region. Full article

Global climate change-induced precipitation reduction severely threatens the sustainability of sandy grassland ecosystems. Understanding the adaptive strategies of native psammophytes is crucial for desertification control. We integrated leaf anatomy and transcriptomics (RNA-seq/WGCNA) to decipher drought resistance in three dominant psammophytes from Horqin Sandy Grassland. The finding revealed that the C3 annual/biennial herb Artemisia scoparia exhibited the most robust transcriptomic response, with co-expression modules linking tyrosine metabolism to cuticular thickening; the C3 semi-shrub Lespedeza davurica showed superior anatomical adaptation, underpinned by phenylpropanoid biosynthesis, while the C4 perennial herb Cleistogenes squarrosa exhibited molecular signatures of high drought sensitivity, with severe drought disrupting its flavonoid biosynthesis and circadian rhythms. In this study, the C4 herbaceous species showed stronger precipitation dependence than the C3 herbs. Our study provides molecular–anatomical insights into the ecological restoration of sandy grasslands under global change, suggesting the use of shrubs as primary stabilizers for sand fixation, alongside breeding herbaceous genotypes with optimized anatomical and transcriptomic traits to meet the needs of sustainable vegetation recovery in sandy grasslands under climate change. Full article

Canephora coffee genotypes developed in other growing regions, with traits of interest such as drought tolerance and high coffee bean yield, need to be introduced and characterized in other locations to check adaptability. The aim of this study was to check the agronomic performance and determine the genetic parameters of the clonal canephora coffee cultivar Marilândia ES 8143, composed by twelve genotypes, developed by the Capixaba Institute of Research, Technical Assistance and Rural Extension (Instituto Capixaba de Pesquisa, Assistência Técnica e Extensão Rural—Incaper), in an irrigated system of the Central Cerrado region of Brazil. The study was conducted in the experimental areas of Embrapa Cerrados at 1050 m altitude in a center pivot irrigation system using a management system with water stress controlled for around 65 days. A randomized block experimental design was used with three replications, and each plot consisted of eight plants. The clones were planted in February 2019 and in 2021 and 2022. Phenotyping was carried out to evaluate the following traits: coffee bean yields, sieve retention percentages, plant height, canopy projection, number of pairs of plagiotropic branches, and frost damage using a scoring scale. Clone 5 stood out in mean value in the two years evaluated for bean yield. Clones 5, 6, 7, 8, and 9 had higher mean values for flat-type coffee beans in both years. Clones 1 and 5 exhibited mean values indicating good vegetative development. Clones 5 and 12 showed no visible symptoms for low air temperatures and frost effects. Highly significant differences were observed among the genotypes for all the morphoagronomic traits evaluated, and high values of heritability, genetic coefficients of variation, and selective accuracy showed conditions favorable to the selection of clones for the agronomic traits analyzed. Clones 1, 2 and 6 have values in lower groups for chlorogenic acids and caffeine, and in higher groups for protein and soluble solids, thus showing greater potential for obtaining quality beverages. Full article

Although rhizobacteria are known to improve plant adaptation to abiotic stressors, their possible contribution to the inherent resilience exhibited by crops such as Sorghum bicolor is still poorly quantified. Here, three sorghum pre-release lines and three check varieties were established and evaluated at two low-altitude sites of less than 600 masl. Treatments were laid out in a randomized complete block design, replicated two times. Twenty-four rhizospheric soil samples comprising six sorghum genotypes with two replications across two sites were collected, processed using Zymo Research DNA extraction protocols, and the 16S rRNA amplicon sequences were generated for bacterial diversity quantifications following the Divisive Amplicon Denoising Algorithm 2 (DADA2) workflow. Grain yield data were also recorded and expressed in tonnes per hectare. Rhizobacteria recruitment and GY performance significantly (p < 0.05) varied with sorghum genotypes. Bacterial abundance significantly (p < 0.05) associated with sorghum grain yield performance with Actinobacteriota and Firmicutes being identified to be of economic importance, explaining between 52.23 and 85.64% of the variation in grain yield performance. The modelled relationships between rhizobacteria and grain yield performance revealed R² predicted values of up to 75.25% and a 10-fold R² of 75.54%, implying no model overfitting. Sorghum genotypes did not consistently exhibit direct variation between genetic worth values and grain yield performance. Superior grain yield performers, namely ICSV111IN, CHITICHI, and SV4, consistently associated with high incidences of occurrence of the bacteria phyla Chloroflexi (class = Chloroflexia) and Firmicutes (class = Bacilli), whilst integrating the conventional selection method with microbial diversity data, changed the genotype performance ranking, in which all the three pre-release lines, namely, IESV91070DL, ASARECA12-3-1, and ICSV111IN, exhibited superiority over the check varieties. The results demonstrated that the inherent stress resilience exhibited by some sorghum genotypes under climate change-induced stresses such as CDHS may be influenced by specific bacterial taxa recruited in the rhizosphere environment of the plants. Hence, more effort should be made to further exploit these beneficial plant–microbe interactions for enhanced sorghum productivity under abiotic stress conditions. Full article

The hydrological response to meteorological drought is often nonlinear, due to physiographic features and human activities, necessitating methodologies that surpass simple drought indices. This study investigates whether drought propagation can be statistically modeled, identifies factors influencing the time lag between meteorological and hydrological droughts, and evaluates the most suitable temporal scales of drought indicators. Meteorological droughts were detected using Standardized Precipitation Index (SPI), while hydrological droughts were identified by the Adapted Threshold Level Method (ATLM), which balances available reservoir volume and the water demand, including withdrawals and evaporation losses. Castanhão, Banabuiú, and Orós reservoirs, in the State of Ceará, Brazil, were used to study drought events, across three aggregated time scales of 12, 24, and 36 months. The propagation time was determined using three indicators, corresponding to onset (Δb), peak (Δp), and conclusion (Δe) lags. Longer meteorological droughts were found to propagate more slowly to hydrological systems, with temporal lags following a consistent order of Δp > Δb > Δe. The combination of SPI-12 and ATLM-36 droughts provided the strongest and most consistent positive correlations (95% confidence level) between drought duration and all three lag markers. This combination offers a robust framework for modeling drought propagation dynamics and improving water resource management strategies. Full article

This study assessed the vulnerability of canola, spring wheat, and barley yields in the Canadian Prairies to drought stress under future climate scenarios, integrating DSSAT crop models with NEX-GDDP CMIP6 projections and probabilistic copula analysis. The DSSAT simulations reproduced historical yields with high accuracy (d > 0.7, nRMSE < 15–20%), confirming its applicability for Prairie agroecosystems. Results indicate distinct crop-specific sensitivities to warming: barley showed relative resilience with modest yield gains (~10%) at 1.5–2 °C of global warming (GW), wheat exhibited heterogeneous responses with early minor gains (~1%) followed by declines (~8%) beyond 3 °C of GW, and canola displayed consistent and substantial losses (20–37%) even under moderate warming. Spatial analysis highlighted relatively stable regions in northern Alberta, central Saskatchewan, and southern Manitoba (Gray and Black soil zones), while the southern and southwestern Prairie areas (Brown and Black-Brown zones) showed the greatest yield declines. Copula-based analysis further revealed that canola is most vulnerable to dry conditions, with yield exceedance probabilities falling from 62% (wet years) to ~25–28% (dry years) under GW. These findings underscore that Prairie crop production faces increasingly heterogeneous risks, with canola emerging as the most climate-sensitive crop. Targeted adaptation strategies such as stress-tolerant cultivars, shifting cropping zones, and improved water management will be essential to mitigate projected drought impacts and sustain Prairie agricultural productivity. Full article