Climate Change-induced Drought Research Articles

Sink-source driven metabolic acclimation of winter oilseed rape leaves (Brassica napus L.) to drought

The crop cycle of winter oilseed rape (WOSR) incorporates source-to-sink remobilisation during the vegetative stage as a principal factor influencing the ultimate seed yield. These processes are supported by the coordinated activity of the plant’s central metabolism. However, climate change-induced drought will affect the metabolic acclimation of WOSR sink/source relationships at this vegetative stage, with consequences that remain to be determined. In this study, we subjected WOSR to severe soil dehydration for 18 days and analysed the physiological and metabolic acclimation of sink and source leaves along the kinetics in combination with measurements of enzymatic activities and transcript levels. Overall, the acclimation of WOSR to drought led to subtle regulations of central metabolism in relation to leaf growth and Pro-induced osmotic adjustment. Notably, sink leaves drastically reduced their growth and transiently accumulated starch. Subsequent starch degradation correlated with the induction of beta-amylases, sucrose transporters, pyrroline-5-carboxylate synthases and proline accumulation. The functioning of the tricarboxylic acid cycle was also altered in sink leaves, as evidenced by variations in citrate, malate and associated enzymatic activities. The metabolic origin of Pro in sink leaves is discussed in relation to Pro accumulation in source leaves and the up-regulation of amino acid permease 1 and glutamine synthetase genes.

Exploring the relationship between field available water capacity (AWC) and atypical aging (ATA) development in base wines.

Hydric stress is a leading cause of atypical aging (ATA) in wine, characterized by unpleasant olfactory notes. The main sensorial and chemical marker of ATA is 2-aminoacetophenone (AAP). Early detection of ATA before the second fermentation in sparkling wines (SWs) is crucial for producing high-quality products. Climate change-induced droughts significantly impact agriculture, including grape farming, particularly in vineyards with shallow soils and reduced available water capacity (AWC). This study examined the relationship between AWC and ATA in base wines (BWs) intended for SW production. Ten vineyards were classified into three AWC categories (low, medium, and high). Hydric stress levels were monitored over two growing seasons to explore their effects on vegeto-productive behavior and AAP development. During the first vintage, drought conditions led to potentially ATA-tainted BWs across all AWC classes. The impact varied with AWC, with low-AWC vineyards experiencing higher stress and producing BWs with elevated AAP levels and vegeto-productive imbalance. In contrast, the following season had unusual rainfall, resulting in some potentially ATA-affected BWs, but no significant differences in AAP content or vegeto-productive balance among the AWC classes were observed. In conclusion, grapevines on low-AWC soils are at a higher risk of producing faulty BWs, particularly in dry vintages.

GIS-based method for assessing the viability of solar-powered irrigation

To attain food security, sub-Saharan Africa needs to increase its use of irrigation to improve agricultural productivity and resilience to climate change-induced droughts and erratic rain patterns. Stand-alone solar-powered irrigation systems are a promising technology to power irrigation where grid electrification is unavailable. However, these systems’ economic viability and sustainability are affected by spatially varying factors such as climate, water availability, and solar potential, making it challenging to plan their roll-out. This study addresses the planning challenge by developing a novel open-source reproducible geospatial methodology to determine irrigation water demand, peak power demand, life cycle cost, and locations where solar-powered irrigation systems would be cheaper than alternative off-grid irrigation technologies. The method considers spatial–temporal data for meteorological conditions, soil quality, water distance and depth, solar resource potential, technology efficiency and local equipment and fuel costs. Maize cultivation in Kenya is taken as a case study to demonstrate the method. We find the median peak irrigation water demand in Kenya to be 65,000 l/ha/day and the median peak power demand to be 2.6 kW/ha. The levelized cost of solar-powered irrigation systems ranges from US$ 0.09/kWh to US$ 0.25/kWh, making solar irrigation cheaper than diesel-powered irrigation in all Kenyan regions. The results from the method offer valuable insights to governments, farmers and investors on where water use regulations are required for sustainable water use, where subsidies and innovative financial models are needed for the affordability of solar irrigation and where alternative uses of energy from the solar systems beyond irrigation are possible.

Investigating the combined effects of β-sitosterol and biochar on nutritional value and drought tolerance in Phaseolus vulgaris under drought stress

Climate change-induced drought stress decreases crop productivity, but the application of β-sitosterol (BS) and biochar (BC) boosts crop growth and yield. A pot experiment was conducted to examine the effects of the alone and combined application of BS and BC on the growth and yield of Phaseolus vulgaris under drought stress. The synergistic application of BS and BC increased plant height (46.9 cm), shoot dry weight (6.9 g/pot), and root dry weight (2.5 g/pot) of P. vulgaris plants under drought stress. The trend of applied treatments for photosynthetic rate remained as BC (15%) < BS (28%) < BC + BS (32%), compared to drought-stressed control. Similarly, the trend of applied treatments for water use efficiency was BS < BC < BC + BS, compared to drought stress control. The levels of malondialdehyde and hydrogen peroxide were reduced by the combined application of BS and BC under drought stress, measuring at 22.8 and 66.4 μmol/g fresh weight, respectively. The combined use of BS and BC significantly alleviated drought stress more than when applied individually. Thus, employing BS and BC together as key agents in drought-stressed common bean plants could promote resilience, fostering growth amid ongoing climate change.

Effect of Planting Ground Treatments Using Artificial Rainfall Slope Simulating Degraded Forestland on Drought Stress Susceptibility of Pinus densiflora

Trees in degraded forest areas are generally exposed to water stress due to harsh environmental conditions, threatening their survival. This study simulated the environmental conditions of a degraded forest area by constructing an artificial rainfall slope and observing the physiological responses of Pinus densiflora to control, mulching, and waterbag treatments. P. densiflora exhibited distinct isohydric plant characteristics of reducing net photosynthetic rate and stomatal transpiration rate through regulating stomatal conductance in response to decreased soil moisture, particularly in the control and waterbag treatments. Additionally, the trees increased photochemical quenching, such as Y(NPQ), to dissipate excess energy as heat and minimize damage to the photosynthetic apparatus. However, these adaptive mechanisms have temporal limitations, necessitating appropriate measures. Under extreme drought stress (DS45), mulching treatment showed 4.5 times and 2.2 times higher in PIabs and SFIabs than in the control, and after the recovery period (R30), waterbag and mulching treatment showed similar levels, while PIabs and SFIabs in the control were only 45% and 75% of those in the mulching and waterbag treatments, respectively. Specifically, mulching extended the physiological mechanisms supporting survival by more than a week, making it the most effective method for enhancing the planting ground in degraded forest areas. Although the waterbag treatment was less effective than mulching treatment, it still significantly contributed to forming better growth conditions compared to the control. These findings highlight the potential for mulching and waterbag treatments to enhance forest restoration efforts, suggesting future research and application could lead to more resilient reforested areas capable of withstanding climate change-induced drought conditions.

Sectoral impacts of climate change in Iran: A dynamic analysis with emphasis on agriculture

Iranian agriculture, the largest consumer of water, is highly vulnerable to sever climate change-induced droughts. This study aimed to analyze the impact of climate change on various sectors, with a focus on agricultural output and gross domestic product (GDP). To achieve this, a dynamic Computable General Equilibrium (CGE) model incorporating a climate damage function was utilized to project the consequences of climate change on various sectors of Iran's economy. The damage function is based on the temperature anomaly. This study simulated the impact of shocks caused by climate scenarios by 2060. The modified Social Accounting Matrix served as the primary dataset for CGE modeling. By simulating climate scenarios up to 2060, the findings indicated that certain agricultural products, such as cereals and livestock, have the potential for an annual output expansion of 2–3.5 % under the most severe climatic scenarios. This expansion is attributed to their lower reliance on capital inputs and their increased final demand for agricultural commodities. Conversely, the growth rates of output expansion and final demand for services products are lower than those for agricultural products. With climate change options, there may be a shift in output composition, favoring crops, agricultural industries, and energy products, while the growth of services output remains comparatively lower. The GDP growth path also deviates from the current path of 1.8 %, reaching rates of 1.5–1.7 %. In the most restrictive scenario, the GDP is projected to decline in the mid-2050s. Similarly, the range for consumption growth is estimated to be 1.8–2.1 %. Climate change does not significantly alter the income distribution within rural and urban income groups. However, it exacerbates rural-urban inequality by favoring urban households with higher consumption levels. The current state of the Iranian economy, especially the agricultural sector, faces increased vulnerability due to climate change. Nevertheless, certain agricultural activities may experience a relatively greater increase in output because of the growing demand for these products.

Sustainable soil management under drought stress through biochar application: Immobilizing arsenic, ameliorating soil quality, and augmenting plant growth

Rise in climate change-induced drought occurrences have amplified pollution of metal(loid)s, deteriorated soil quality, and deterred growth of crops. Rice straw-derived biochars (RSB) and cow manure-enriched biochars (CEB) were used in the investigation (at doses of 0%, 2.5%, 5%, and 7.5%) to ameliorate the negative impacts of drought, improve soil fertility, minimize arsenic pollution, replace agro-chemical application, and maximize crop yields. Even in soils exposed to severe droughts, 3 months of RSB and CEB amendment (at 7.5% dose) revealed decreased bulk density (13.7% and 8.9%), and increased cation exchange capacity (6.0% and 6.3%), anion exchange capacity (56.3% and 28.0%), porosity (12.3% and 7.9%), water holding capacity (37.5% and 12.5%), soil respiration (17.8% and 21.8%), and nutrient contents (especially N and P). Additionally, RSB and CEB decreased mobile (30.3% and 35.7%), bio-available (54.7% and 45.3%), and leachable (55.0% and 56.5%) fractions of arsenic. Further, pot experiments with Bengal gram and coriander plants showed enhanced growth (62–188% biomass and 90–277% length) and reduced arsenic accumulation (49–54%) in above ground parts of the plants. Therefore, biochar application was found to improve physico-chemical properties of soil, minimize arsenic contamination, and augment crop growth even in drought-stressed soils. The investigation suggests utilisation of cow manure for eco-friendly fabrication of nutrient-rich CEB, which could eventually promote sustainable agriculture and circular economy. With the increasing need for sustainable agricultural practices, the use of biochar could provide a long-term solution to enhance soil quality, mitigate the effects of climate change, and ensure food security for future generations. Future research should focus on optimizing biochar application across various soil types and climatic conditions, as well as assessing its long-term effectiveness.

Climate change and plant rhizosphere microbiomes: an experiential course-embedded research project.

The current and ongoing challenges brought on by climate change will require future scientists who have hands-on experience using advanced molecular techniques, can work with large data sets, and can make correlations between metadata and microbial diversity. A course-embedded research project can prepare students to answer complex research questions that might help plants adapt to climate change. The project described herein uses plants as a host to study the impact of climate change-induced drought on host-microbe interactions through next-generation DNA sequencing and analysis using a command-line program. Specifically, the project studies the impact of simulated drought on the rhizosphere microbiome of Fast Plants rapid cycling Brassica rapa using inexpensive greenhouse supplies and 16S rRNA V3/V4 Illumina sequencing. Data analysis is performed with the freely accessible Python-based microbiome bioinformatics platform QIIME 2.

Small oases below the canopy: The cooling effects of water-filled tree holes on the local microclimate in oak-dominated stands

The relevance of forests in mitigating biodiversity loss and the negative effects of climate change on the biota is largely shaped by below-canopy microclimatic conditions, which are buffered, cooler and more humid compared to adjoining open habitats. Water-filled tree holes (dendrotelms, DTs) are special tree-related microhabitats that host semi-aquatic communities and are important substrates or water sources for numerous taxa (e.g., birds, mammals, insects, fungi, bryophytes). Despite their microrefugia-role might be more pronounced under climate change-induced drought events, little is known about their microclimate and its potential drivers.In an abandoned Turkey oak-dominated coppice stand in Hungary, the microclimates of 80 paired dendrotelms and adjacent forest plots were measured in the summer of 2021. Compared to nearby open areas, under closed forests, air temperature maxima were up to 5 °C cooler, DTs had an additional negative offset of 2.5 °C and increased air humidity by 15 percentage points (5% vs. 20 %). The local microclimate of DTs and the adjacent closed forest differed significantly in means and extremes of air temperature, relative humidity and vapour pressure deficit, which was mainly driven by DT entrance area and water volume and seemed independent from local stand structure. On the contrary, nearby below-canopy microclimate was shaped by the distance from forest edge, incoming light and tree density. Water volume in DTs also influenced local forest microclimates up to 0.5–1 m from the entrances.As the frequency and severity of extreme weather events such as heatwaves are likely to intensify due to climate change, the importance of microhabitats and habitat trees for invertebrates and vertebrates will increase further, and will additionally contribute to the microclimatic refugia role of forests. Active protection of veteran trees under the scheme of continuous cover forestry or conservation-oriented management is essential facing climate change to mitigate its negative effects on forest biodiversity.

Contrasting carbon cycle responses to dry (2015 El Niño) and wet (2008 La Niña) extreme events at an Amazon tropical forest

Land surface models diverge in their predictions of the Amazon forest's response to climate change-induced droughts, with some showing a catastrophic collapse of forests, while others simulating resilience. Therefore, observations of tropical ecosystem responses to real-world droughts and other extreme events are needed. We report long-term seasonal dynamics of photosynthesis, respiration, net carbon exchange, phenology, and tree demography and characterize the effect of dry and wet events on ecosystem form and function at the Tapajós National Forest, Brazil, using over two decades of eddy covariance observations that include the 2015–2016 El Niño drought and La Niña 2008–2009 wet periods. We found strong forest responses to both ENSO events: La Niña saw forest net carbon loss from reduced photosynthesis (due to lower incoming radiation from increased cloudiness) even as ecosystem respiration (Reco) was maintained at mean seasonal levels. El Niño induced the opposite short-term effect, net carbon gains, despite significant reductions in photosynthesis (from a drought-induced halving of canopy conductance to CO2 and significant losses of leaf area), because drought suppression of Reco losses was even greater. However, long-term responses to the two climate perturbations were very different: transient during La Niña –the forest returned to its “normal” state as soon as the climate did, and long-lasting during El Niño –leaf area loss and associated declines in photosynthetic capacity (Pc) and canopy conductance were exacerbated and extended by feedbacks from higher temperatures and atmospheric evaporative demand and persisted for ∼3+ years after normal rainfall resumed. These findings indicate that these forests are more vulnerable to drought than to excess rain, because drought drives significant changes in forest structure (e.g., leaf-abscission and mortality) and ecosystem function (e.g. reduced stomatal conductance). As future Amazonian climate change increases frequencies of hydrological extremes, these mechanisms will determine the long-term fate of tropical forests.

ENHANCING DECISION-MAKING IN WATER RESOURCES MANAGEMENT: AN INNOVATIVE ASSESSMENT OF EXPERT CONSISTENCY AND COMPETENCE

In the assessment of principles and guidelines to achieve specific goals before strategies in water resources and related sectors are formulated, the quality of experts participating in making group decisions should be evaluated. This paper introduces an innovative approach designed to evaluate the quality of group members based on their consistency and deviations from the group's decision. The group members are considered as alternatives within a multi-criteria framework, employing several typical performance indicators as criteria to assess their competence and compliance with the group. Considering the policy-making, the paper provides a rationale for possibly excluding certain members from the decision-making process to prevent making unsustainable decisions. A case study is presented about the evaluation of the importance of six Ramsar sites in Serbia, facing imminent threats from water regime disturbances and climate change-induced droughts. Seven experts participated in the process and the results revealed that several experts displayed the poorest performance across all three prioritization schemes. This suggests the necessity for re-evaluating their judgments or considering their exclusion from the final decision-making process. The proposed assessment procedure holds promise for enhancing the potential to derive sustainable solutions in any complex and critical domain of water resources policy-making and strategic planning.

Stretched sapwood, ultra-widening permeability, and ditching da Vinci: revising models of plant form and function.

The mechanisms leading to dieback and death of trees under drought remains unclear. For constructing an understanding of these mechanisms, addressing major empirical gaps regarding tree structure-function relations remains essential. We give reasons to think that a central factor shaping plant form and function is selection favoring both constant leaf specific conductance with height growth and isometric (1:1) scaling between leaf area and the volume of metabolically active sink tissues ("sapwood"). Sapwood volume-leaf area isometry implies that per-leaf area sapwood volumes become transversely narrower with height growth; we call this "stretching." Stretching means that selection must favor increases in permeability above and beyond that afforded by tip-to-base conduit widening (ultra-widening permeability), as via fewer and wider vessels or tracheids with larger pits or larger margo openings. Leaf area-metabolically active sink tissue isometry would mean that it is unlikely that larger trees die during drought because of carbon starvation due to greater sink-source relationships as compared to shorter plants. Instead, increase in permeability is most plausibly associated with greater risk of embolism, and this seems a likelier culprit of the preferential vulnerability of larger trees to climate change-induced drought. Other implications of selection favoring constant per-leaf area sapwood construction and maintenance costs are departure from the da Vinci rule expectation of similar sapwood areas across branching orders, and that extensive conduit furcation in the stem seems unlikely. Because all of these considerations impact the likelihood of vulnerability to hydraulic failure versus carbon starvation, both implicated as key suspects in forest mortality, we suggest that these predictions represent essential priorities for empirical testing.

Guard cell and subsidiary cell sizes are key determinants for stomatal kinetics and drought adaptation in cereal crops.

Climate change-induced drought is a major threat to agriculture. C4 crops have a higher water use efficiency (WUE) and better adaptability to drought than C3 crops due to their smaller stomatal morphology and faster response. However, our understanding of stomatal behaviours in both C3 and C4 Poaceae crops is limited by knowledge gaps in physical traits of guard cell (GC) and subsidiary cell (SC). We employed infrared gas exchange analysis and a stomatal assay to explore the relationship between GC/SC sizes and stomatal kinetics across diverse drought conditions in two C3 (wheat and barley) and three C4 (maize, sorghum and foxtail millet) upland Poaceae crops. Through statistical analyses, we proposed a GCSC-τ model to demonstrate how morphological differences affect stomatal kinetics in C4 Poaceae crops. Our findings reveal that morphological variations specifically correlate with stomatal kinetics in C4 Poaceae crops, but not in C3 ones. Subsequent modelling and experimental validation provide further evidence that GC/SC sizes significantly impact stomatal kinetics, which affects stomatal responses to different drought conditions and thereby WUE in C4 Poaceae crops. These findings emphasize the crucial advantage of GC/SC morphological characteristics and stomatal kinetics for the drought adaptability of C4 Poaceae crops, highlighting their potential as future climate-resilient crops.

Farmers’ Knowledge on Agricultural Irrigation Programs: The Case of Altınekin District of Konya Province

Climate change-induced droughts have various negative impacts on different sectors, especially on agricultural sector. Altınekin District, where the research was conducted, has the lowest precipitation in Konya Province, therefore is expected to be most affected by drought. For sustainable use of water resources, each stage of agricultural production should be carried out within the framework of a specific program. With this study, knowledge level of farmers engaged in irrigated agriculture in Altınekin district regarding irrigation and irrigation programs they applied were determined through a face-to-face survey. Present findings revealed that 38.7% of the participant farmers are aged 50 years and over and a large proportion of them (54.7%) are primary school graduates. Participant farmers were all (100%) using groundwater resources in agricultural production and 88% of them stated that they did not receive any training on irrigation. While 32% of the farmers participating in the survey stated that they had knowledge about the concept of irrigation program, 68% reported that they did not have any knowledge. Incorrect and improper practices regarding efficient use of irrigation water in the region, especially regarding the irrigation program, were identified and solutions were proposed for these problems.

Xylem plasticity of root, stem, and branch in Cunninghamia lanceolata under drought stress: implications for whole-plant hydraulic integrity.

A better understanding of xylem hydraulic characteristics in trees is critical to elucidate the mechanisms of forest decline and tree mortality from water deficit. As well as temperate forests and forests growing in arid regions, subtropical and tropical forests are also predicted to experience an increased frequency and intensity of climate change-induced drought in the near future. In this study, 1-year-old Cunninghamia lanceolata seedlings (a typical subtropical species in southern China) were selected for a continuous controlled drought pot experiment of 45 days duration. The experimental treatments were non-drought (control), light drought, moderate drought and severe drought stress, which were 80%, 60%, 50%, and 40%, respectively of soil field maximum moisture capacity. The hydraulic conductivity, specific conductivity and water potential of roots, stems, and branches of C. lanceolata all decreased with the prolonging of drought in the different drought intensities. The relative decrease in these hydraulic values were greater in roots than in stems and branches, indicating that roots are more sensitive to drought. Root tracheid diameters normally reduce to ensure security of water transport with prolonged drought, whilst the tracheid diameters of stems and branches expand initially to ensure water transport and then decrease to reduce the risk of embolism with continuing drought duration. The pit membrane diameter of roots, stems and branches generally increased to different extents during the 15-45 days drought duration, which is conducive to enhanced radial water transport ability. The tracheid density and pit density of stems generally decreased during drought stress, which decreased water transport efficiency and increased embolism occurrence. Correlation analysis indicated that anatomical plasticity greatly influenced the hydraulic properties, whilst the relationships varied among different organs. In roots, tracheid diameter decreased and tracheid density increased to enhance water transport security; stems and branches may increase tracheid diameter and pit membrane diameter to increase hydraulic conductivity ability, but may increase the occurrence of xylem embolism. In summary, under drought stress, the xylem anatomical characteristics of C. lanceolata organs were highly plastic to regulate water transport vertically and radially to maintain the trade-off between hydraulic conductivity efficiency and safety.

Chasing high and stable wheat grain mineral content: Mining diverse spring genotypes under induced drought stress.

Climate change-induced drought has an effect on the nutritional quality of wheat. Here, the impact of drought at different plant stages on mineral content in mature wheat was evaluated in 30 spring-wheat lines of diverse backgrounds (modern, old and wheat-rye-introgressions). Genotypes with rye chromosome 3R introgression showed a high accumulation of several important minerals, including Zn and Fe, and these also showed stability across drought conditions. High Se content was found in genotypes with chromosome 1R. Old cultivars (K, Mg, Na, P and S) and 2R introgression lines (Fe, Ca, Mn, Mg and Na) demonstrated high mineral yield at early and late drought, respectively. Based on the low nutritional value often reported for modern wheat and negative climate effects on the stability of mineral content and yield, genes conferring high Zn/Fe, Se, and stable mineral yield under drought at various plant stages should be explicitly explored among 3R, 1R, old and 2R genotypes, respectively.

Effect of Different Strains of Bacillus Species on Lipid Peroxidation and Antioxidant Enzymes in Rice Exposed to Drought Stress

The impact of climate change-induced droughts in various regions worldwide has led to a range of stresses in plants, resulting in a decline in overall yield. Numerous strategies have been employed to alleviate stress on plants, but the use of plant growth-promoting rhizobacteria has emerged as a cost-effective and efficient approach. This study explores the influence of three distinct isolates of Bacillus species on lipid peroxidation and selected antioxidant enzymes in drought-stressed rice. Standard procedures were employed to assess antioxidant enzymes. Catalase, Ascorbate peroxidase, and Superoxide dismutase—while Malondialdehyde levels were utilized to gauge lipid peroxidation over 0, 3, 6, and 9 days of drought stress exposure. Among the three isolates, Bacillus subtilis SA1 (accession number OM184294) exhibited superior properties in inducing antioxidant enzymes, effectively countering the impact of generated free radicals. Additionally, this same organism demonstrated exceptional efficacy in reducing lipid peroxidation levels in the plant's leaves, thereby mitigating the adverse effects of free radicals. Consequently, this particular organism proves promising for minimizing the impact of drought stress in rice, complementing its role as a plant growth-promoting rhizobacteria.

Climate change-induced drought and implications on maize cultivation area in the upper Nan River Basin, Thailand

Abstract The escalating frequency of climate change-induced droughts poses a severe threat to rainfed maize cultivation in Thailand's upper Nan River Basin (NRB). Utilizing the standardized precipitation evapotranspiration index, this study comprehensively examines spatial and temporal drought patterns and their potential agricultural impact. Findings indicate a significant shift in precipitation patterns with wetter wet seasons, drier dry seasons and rising temperatures. The upper NRB experiences prolonged and severe droughts, while the lower region faces higher drought intensity, signalling an increased likelihood of extended and severe drought episodes in the upper region. Assessing maize cultivation suitability, factoring in environmental variables and drought impact under observed and climate change scenarios, reveals the current moderate suitability at 42.2%, projected to expand, and unsuitable regions expected to double. Different shared socioeconomic pathways (SSPs) show varied outcomes, with SSP5-8.5 indicating increased suitability in highly suitable areas and SSP2-4.5 demonstrating improvements in moderately suitable areas. The study underscores the need for tailored adaptation strategies in water management during droughts to enhance crop production, especially in dry seasons, in the upper NRB amid a changing climate.

Nutrient and Growth Response of Fagus sylvatica L. Saplings to Drought Is Modified by Fertilisation

The increased frequency of climate change-induced droughts poses a survival challenge for forest trees, particularly for the common beech (Fagus sylvatica L.). Drought conditions adversely affect water supply and nutrient uptake, yet there is limited understanding of the intricate interplay between nutrient availability and drought stress on the physiology, growth, and biomass accumulation in young trees. We aimed to address this knowledge gap by examining the effects of irrigation and fertilisation and their interaction with various parameters in common beech saplings, including foliar and root N, P, and K concentrations; height and diameter increments; and aboveground and belowground biomass production. Our findings revealed that a higher fertilisation dose increased nutrient availability, also partially mitigating immediate drought impacts on foliar N concentrations. Also, higher fertilisation supported the post-drought recovery of foliar phosphorus levels in saplings. Prolonged drought affected nitrogen and potassium foliar concentrations, illustrating the lasting physiological impact of drought on beech trees. While drought-stressed beech saplings exhibited reduced height increment and biomass production, increased nutrient availability positively impacted root collar diameters. These insights have potential implications for forest management practices, afforestation strategies, and our broader understanding of the ecological consequences of climate change on forests.

Climate change beyond technocracy: citizenship and drought practices in the Indian Himalayas

ABSTRACT Climate knowledge production and climate change adaptation are dominated by technocratic narratives. Where climate change intersects with institutional structures outside contexts of formal interventions, these narratives also have crucial implications for the recognition of climate change-affected citizens. This article focuses on the experience of farmers in the Indian Himalayas who are seeking support from the state following a climate change-induced drought. We suggest that the narrow technocratic framework produces climate vulnerability by preventing Himalayan farmers from accessing relevant drought support. The recognition of climate change-affected citizens, we maintain, is a question of climate justice and requires consideration for alternative methodologies and different epistemologies about climate change.