Altered Climate Research Articles

Evaluating the hydrological regime alteration under extreme climate scenarios in Southeast China

Study regionThe Shanmei Reservoir Watershed (SRW), Southeast China. Study focusThis study investigated the climate and hydrological regimes alterations in a subtropical coastal watershed (SRW) during the 21st century in extreme scenarios. The extreme scenarios, i.e., warm-wet and cold-dry climates, were constructed using 18 global climate models (GCMs) from CMIP6 under shared socioeconomic pathways (SSP1–2.6, SSP2–4.5, SSP3–7.0 and SSP5–8.5). The Soil and Water Assessment Tool (SWAT) model and Indicators of Hydrologic Alteration (IHA) were applied to quantify the impacts of climate change on the eco-hydrological regimes during the projected period (2041–2100) compared to the base period (1980–2014). New hydrological insights for the regionThe results show that the average temperature rises by 0.6–3.8 ℃, and the average annual precipitation changes by −21.4 % - 32.4 % by the end of the 21st century under extreme scenarios. Contrasting hydrological regimes are expected in the SRW under extreme scenarios. Under the extreme warm-wet scenarios, the monthly runoff is lower during spring and higher during summer, the minimum flows are significantly higher, and the maximum and minimum flows occurs earlier. Water resource utilization and ecosystem health are expected to improve. However, the opposite holds true in the cold-dry scenarios. The hydrologic regime alteration under future extreme climate scenarios can guide local water planning and ecological restoration strategies.

Eco-fertility: examining the climate change-total fertility rate nexus in the context of sustainable developmental goals in a systematic review approach

Abstract Sustainable Development Goals (SDGs) are paramount as the global community confronts the ramifications of climate alterations, especially its implications on population dynamics. Initial studies suggest an intricate relationship between environmental determinants and reproductive choices. This systematic review elucidates the complex interplay between climate-related challenges and observed global fertility rate variations. A comprehensive search and analysis of literature published in the last 10 years (2013–2023), available in the PubMed database, delineates the relationship between environmental changes and fertility patterns in both human and animal populations. The review highlighted significant effects of climatic fluctuations on reproductive health, manifested as either adaptive or maladaptive responses to environmental stressors. This relationship not only influences population trajectories but may also have complications for the SDGs, specifically those pertaining to health, well-being, and gender equality. The study emphasizes the importance of intertwining demographic insights with ecological considerations. A deeper understanding of the nexus between climate and fertility can augment strategies aimed at global sustainability. The synthesized evidence underscores the urgency for further research, which seeks to seamlessly incorporate eco-fertility perspectives into wider climate and sustainability discussions.

Kelp forest community structure and demography in Kongsfjorden (Svalbard) across 25 years of Arctic warming.

The Arctic archipelago of Svalbard is a hotspot of global warming and many fjords experience a continuous increase in seawater temperature and glacial melt while sea-ice cover declines. In 1996/1998, 2012-2014, and 2021 macroalgal biomass and species diversity were quantified at the study site Hansneset, Kongsfjorden (W-Spitsbergen) in order to identify potential changes over time. In 2021, we repeated the earlier studies by stratified random sampling (1 × 1 m2, n = 3) along a sublittoral depth transect (0, 2.5, 5, 10, and 15 m) and investigated the lower depth limits of dominant brown algae between 3 and 19 m. The maximum fresh weight (FW) of all seaweeds was 11.5 kg m-2 at 2.5 m and to 99.9% constituted of kelp. Although biomass distribution along the depth transect in 2021 was not significantly different compared to 2012/2013, the digitate kelp community (Laminaria digitata/Hedophyllum nigripes) had transformed into an Alaria esculenta-dominated kelp forest. Consequently, a pronounced shift in kelp forest structure occurred over time as we demonstrate that biomass allocation to thallus parts is kelp species-specific. Over the past decade, kelp demography changed and in 2021 a balanced age structure of kelps (juveniles plus many older kelp individuals) was only apparent at 2.5 m. In addition, the abundances and lower depth limits of all dominant brown algae declined noticeably over the last 25 years while the red algal flora abundance remained unchanged at depth. We propose that the major factor driving the observed changes in the macroalgal community are alterations in underwater light climate, as insitu data showed increasing turbidity and decreasing irradiance since 2012 and 2017, respectively. As a consequence, the interplay between kelp forest retreat to lower depth levels caused by coastal darkening and potential macroalgal biomass gain with increasing temperatures will possibly intensify in the future with unforeseen consequences for melting Arctic coasts and fjord ecosystem services.

Biodiversity and Climate Extremes: Known Interactions and Research Gaps

AbstractClimate extremes are on the rise. Impacts of extreme climate and weather events on ecosystem services and ultimately human well‐being can be partially attenuated by the organismic, structural, and functional diversity of the affected land surface. However, the ongoing transformation of terrestrial ecosystems through intensified exploitation and management may put this buffering capacity at risk. Here, we summarize the evidence that reductions in biodiversity can destabilize the functioning of ecosystems facing climate extremes. We then explore if impaired ecosystem functioning could, in turn, exacerbate climate extremes. We argue that only a comprehensive approach, incorporating both ecological and hydrometeorological perspectives, enables us to understand and predict the entire feedback system between altered biodiversity and climate extremes. This ambition, however, requires a reformulation of current research priorities to emphasize the bidirectional effects that link ecology and atmospheric processes.

Studying long term relationship between carbon Emissions, Soil, and climate Change: Insights from a global Earth modeling Framework

The persistent increase in greenhouse gas (GHG) emissions, notably carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), since the mid-20th century has been a key driver of significant climate alterations. This study investigates the complex feedback mechanisms that both influence and are influenced by global climate dynamics, soil processes, and GHG emissions. Our statistical approach incorporates correlation measures, highlighting the limitations of such analyses, namely their inability to confirm causality, sensitivity to outliers, and the exclusive capture of linear relationships. Geographically Weighted Regression (GWR) models reveal spatial variations in the relationship between environmental factors and GHGs, while Path Analysis aids in delineating direct and indirect influences among variables. The research pinpoints significant spatial heterogeneity in the impacts of economic and environmental factors on GHGs, underscoring the necessity of localized strategies for climate change mitigation and sustainable land management. This study also identifies potential threats to agricultural productivity due to soil degradation, which hinder climate adaptation efforts. Our findings advocate for a concerted global response to reduce GHG emissions and address the challenges posed by the interplay of climate change, soil dynamics, and GHG emissions.

Evaluation of hydrological responses to climate change in the Gibe Gojeb catchment, southwestern Ethiopia

ABSTRACT The expected influences of climate alteration on hydrological responses in the Gibe Gojeb catchment, southwestern Ethiopia, were evaluated using the Soil and Water Assessment Tool (SWAT) model and regional climate models (RCMs). This study emphasizes the evaluation of the climate change impact on hydrological responses. The RCM data were downloaded from CORDEX-Africa. Power transformation and delta change methods were used for bias correction of precipitation and temperature, respectively. The calibration and validation of the SWAT model showed good agreement, and climate change impact was simulated. Accordingly, precipitation, soil water content, percolation, water yield, and groundwater are projected to decrease by 28.18, 7.5, 9.1, 5.4, and 9.2%, respectively, under RCP4.5 in the future (2021–2050). Besides, surface runoff and potential and actual evapotranspiration are projected to increase by 17.4, 11.32, and 5.06%, respectively. Soil water content, percolation, water yield, and precipitation are projected to decrease by 10.51, 5.63, 2.76, and 21.57%, respectively, under RCP8.5 in the future. Rain-fed crop production and hydropower generation in the catchment would be vulnerable to the effects of climate change. The results help to develop effective adaptation measures to reduce the impacts of climate change and draft long-term water resource management plans in the Gibe Gojeb catchment.

Quantifying the influence of climate change on streamflow of Rietspruit sub-basin, South Africa

ABSTRACT This study integrated climate projections from five global climate models (GCMs) into the soil and water assessment tool to evaluate the potential impact of climate alterations on the Rietspruit River sub-basin under two representative concentration pathways (RCP4.5 and 8.5). The model's performance was evaluated based on the coefficient of determination (R2), percent bias (PBIAS), Nash–Sutcliffe efficiency (NSE), probability (P)-factor and correlation coefficient (R)-factor. Calibration results showed an R2 of 0.62, NSE of 0.60, PBIAS of 20, P-factor of 0.86 and R-factor of 0.91, while validation produced an R2 of 0.64, NSE of 0.61, PBIAS of 40, P-factor of 0.85 and R-factor of 1.22. Precipitation is predicted to increase under both RCPs. Maximum temperature is projected to increase under both RCPs, with a major increase in the winter months. Minimum temperatures are projected to decrease under RCP4.5 in the near (−0.99 °C) and mid (−0.23 °C) futures, while the far future is projected to experience an increase of 0.14 °C. Precipitation and temperature changes correspond to increases in streamflow by an average of 53% (RCP4.5) and 47% (RCP8.5). These results indicate a need for an integrated approach in catchment water resource management amid potential climate and land use variations.

Investigating the projected changes in water balance components under climate change considering the effect of storage structures

ABSTRACT The objective of this study was the critical challenge of accurately predicting water balance components in the Upper Bhima River basin, which is also facing significant challenges due to climate change. A major challenge faced in water balance studies is inadequacy of existing hydrological models to account for the effects of storage structures. The study utilized the variable infiltration capacity–routing application for parallel computation of discharge hydrological model with a newly developed storage structure scheme to simulate water balance components for historical (1999–2010) and future (2019–2040) periods, with future climate forcing from 19 Coupled Model Intercomparison Project Phase 5 GCMs under Representative Concentration Pathway (RCP)4.5 and RCP8.5 scenarios. The performance of the model was evaluated against observed streamflow data and around 30% improvement is noticed for the Nash–Sutcliffe efficiency score. The results signify the adverse impacts of climate change in the region, particularly a significant decrease in monsoon precipitation which may intensify drought scenarios and affect monsoon-driven agriculture. Furthermore, the study emphasizes the high sensitivity of baseflow in the Upper Bhima River to climate alterations, indicating potential threats to biodiversity and river ecosystem health. This research offers indispensable findings crucial for future strategies concerning hydropower, flood management, and water resource management in the region.

Determining the impacts of climate change and human activities on vegetation change on the Chinese Loess Plateau considering human-induced vegetation type change and time-lag effects of climate on vegetation growth

ABSTRACT Since the initiation of the Grain for Green Project (GFGP) in 1999, dramatic change in vegetation status on the Loess Plateau. Spatially, geographical detector was employed to detect dominant variables influencing the spatial arrangement of normalized difference vegetation index (NDVI). Temporally, lagged or accumulated monthly precipitation, temperature and standardized precipitation evapotranspiration indices (SPEIs) sensitive to the monthly NDVI were first detected for every individual pixel, and the correlation between the NDVI and meteorological elements with time-lag effects was established a random forest model of unchanged land cover, followed by attributing impacts of climatic alterations and human interventions through residual examination across changed land cover. The findings indicate that (1) precipitation, slope, and soil dominantly influence the spatial arrangement of the NDVI. (2) Precipitation in current the month and cumulative temperatures of the previous 1–2 months steadily affect vegetation growth significantly, the optimal accumulation time interval for SPEI around 2000 are 8 months and 4 months, respectively. (3) Increases in the average NDVI within woodland and meadow vegetation on the Loess Plateau were primarily driven by climate change before 2000, accounting for 76.2%, whereas after 2000 it was dominantly driven by human activities, accounting for 64.16%.

A Study of Impact of Climate Change on Livelihood of Farmers in Kumaon Himalaya

Climate change in the Kumaon Himalaya can significantly affect farmers in various ways. Shifts in temperature and precipitation patterns may impact crop yields, disrupt traditional farming practices, and lead to increased vulnerability. Changes in water availability and the melting of glaciers can affect irrigation, essential for agriculture in the region. Additionally, the altered climate may influence the prevalence of pests and diseases, posing further challenges to crop production. Overall, adapting to these changes is crucial for sustaining agricultural livelihoods in the Kumaun Himalaya. The present study is based on both primary and secondary data survey to highlight the impact on farmers livelihood pattern in the study area.

INDICATORS OF THE QUALITATIVE AND QUANTITATIVE COMPOSITION OF THE GUT COMMENSAL MICROBIOTA AS BIOMARKERS OF HOMEOSTASIS (Part 1)

In recent years, practical medicine has faced a surge of information highlighting the emergence of new microbes in the human body's microbiota, leading to challenges in interpreting laboratory test results. This study aims to equip medical professionals, including doctors of various specialties, medical students, and interns, with a comprehensive understanding of the current knowledge on the human gastrointestinal microbial profile. Our analysis included 53 articles from international literature sources indexed in PubMed, Scopus, and Google Scholar databases. These articles were identified through an electronic search. The composition of the human microbiome is shaped by alterations in environmental conditions, living environments, diet, climate, genetics, and various other factors. Following birth, the pivotal role in microbiome formation involves the vertical, horizontal, and mixed transfer of microorganisms. Navigating the diversity of resident microbiota can be challenging, leading scientists to suggest biomarkers such as diversity indices, enterotypes, and established ratios at typical taxonomic levels (genus, species) for convenience. In clinical practice, these indicators serve as indirect markers of microflora properties that model health or disease. To understand the distribution of species within types, ecologists introduced concepts like α-, β-, and γ-diversity, grounded in different mathematical models. These indicators are also employed to assess the human body microbiota. The division into enterotypes was proposed by scientists on the basis that the phylogenetic (species) composition of each category determines its own functional feature, which is likely to be related to long-term eating habits. Conclusion. Scientists endeavor to assess the intricate microbiome system and its substantial impact on the human body, as well as the adverse effects of dysbiosis, employing mathematical models applied in microbiology.

Effects of climate change and human activities on vector-borne diseases.

Vector-borne diseases are transmitted by haematophagous arthropods (for example, mosquitoes, ticks and sandflies) to humans and wild and domestic animals, with the largest burden on global public health disproportionately affecting people in tropical and subtropical areas. Because vectors are ectothermic, climate and weather alterations (for example, temperature, rainfall and humidity) can affect their reproduction, survival, geographic distribution and, consequently, ability to transmit pathogens. However, the effects of climate change on vector-borne diseases can be multifaceted and complex, sometimes with ambiguous consequences. In this Review, we discuss the potential effects of climate change, weather and other anthropogenic factors, including land use, human mobility and behaviour, as possible contributors to the redistribution of vectors and spread of vector-borne diseases worldwide.

Microbial Assemblages and Metabolic Activity in Organic‐Rich Subterranean Estuaries: Impact of Climate and Land Use Changes

AbstractMicrobial communities in subterranean estuaries mediate biogeochemical reactions of coastal groundwater discharging into the oceans; however, studies on their response to abrupt environmental changes caused by climate and land use alterations are still limited. In this study, we conducted a controlled laboratory study using combined geochemical and metagenomic approaches to investigate microbial structures and their metabolic pathways under a wide range of nitrate () inputs, saline solutions, and incubation times. These factors served as proxies for land use, salinization of the shallow aquifer, and climate changes. We found a highly reducing habitat and an amplification of genes related to denitrification, sulfate reduction, and methanogenesis processes. Core communities consisting of Clostridia, Bacilli, Alphaproteobacteria, Gammaproteobacteria, and Desulfobaccia were observed across all treatments. The metabolic prediction of plant‐derived organic matter (i.e., tannin and lignin) degradation was not affected by inputs or salinity because of it being implemented by core communities and the abundance of electron donors and acceptors. Quantification of denitrification genes shows that they are susceptible to inputs and seawater ions. Long‐term incubation allowed sufficient time for microbes to degrade less labile DOM, promoting the re‐release of buried solid phase organic matter into the active carbon cycle and increasing the relative abundance of biofilm or spore‐forming taxa while decreasing that of rare taxa. Our results illustrate the sensitivity of microbial assemblages to environmental changes and their capacity to altering the C and N cycles in coastal areas, further affecting coastal water quality and ecosystem‐scale biogeochemistry.

Assessment of Climate Change Impact on Highland Areas in Kastamonu, Turkey

This study aimed to assess the potential impact of global climate change on the highland areas of Kastamonu, a significant province in Turkey known for its numerous and varied highlands. The investigation focused on 59 selected highland locations within the region. Using the De Martonne climate classification, projections were made for four future periods (2040, 2060, 2080, and 2100) under two scenarios: SSPs 245 and SSPs 585. The outcomes of the study indicate that the highlands under scrutiny are susceptible to substantial effects from global climate change. Notably, these climatic alterations are expected to become evident within the next two decades, predominantly manifesting as a shift towards arid climate classifications. These shifts are anticipated to have a profound impact on the composition and diversity of species in the highland ecosystems. Based on the findings, it is advisable to consider interventions for the most climate-sensitive highland areas, such as facilitating the migration of species adapted to the new climate conditions and implementing initiatives to enhance species diversity. These efforts could help mitigate the potential loss of species and populations resulting from climate change.

A framework model to integrate sources and pathways in the assessment of river water pollution

Metal and nutrient pollution, soil erosion, and alterations in climate and hydrology are prevalent issues that impact the water quality of riverine systems. However, integrated approaches to assess and isolate causes and paths of river water pollution are scarce, especially in the case of watersheds impacted by multiple hazardous activities. Therefore, a framework model for investigating the multiple sources of river water pollution was developed. The chosen study area was the Paraopeba River basin located in the Minas Gerais, Brazil. Besides multiple agriculture, industrial, and urban pollution sources, this region was profoundly affected by the rupture of the B1 tailings dam (in January 2019) at the Córrego do Feijão mine, resulting in the release of metal-rich waste. Considering this situation, thirty-nine physicochemical and hydromorphological parameters were examined in the Paraopeba River basin, in the 2019–2023 period. The analysis involved various statistical techniques, including bivariate and multivariate methods such as correlation analysis, principal component analysis, and clustering. The Paraopeba River was mainly impacted by metal contamination resulting from the dam collapse, whereas nutrient contamination, mainly from urban and industrial discharges, predominantly affected its tributaries. Additionally, the elevated concentrations of aluminum, iron, nitrate, and sulfate in both main river and tributaries can be attributed to diffuse and point source pollution. In terms of hydromorphology and soil type, the interaction between woody vegetation and erosion-resistant soils, especially latosols, contributes to the stability of riverbanks in the main river. Meanwhile, in the tributaries, the presence of neosols and sparse vegetation in urbanized areas promoted riverbank erosion potentially amplifying pollution. While the study was conducted in a particular watershed, the findings are based on a methodology that can be applied universally. Hence, the insights on surface water quality from this research can be a valuable resource for researchers studying watersheds with diverse pollution sources.

Spatiotemporal characteristics of meteorological drought events in 34 major global river basins during 1901–2021

Meteorological drought is a crucial driver of various types of droughts; thus, identifying the spatiotemporal characteristics of meteorological drought at the basin scale has implications for ecological and water resource security. However, differences in drought characteristics between river basins have not been clearly elucidated. In this study, we identify and compare meteorological drought events in 34 major river basins worldwide using a three-dimensional drought-clustering algorithm based on the standardised precipitation evapotranspiration index on a 12-month scale from 1901 to 2021. Despite synchronous increases in precipitation and potential evapotranspiration (PET), with precipitation increasing by more than three times the PET, 47 % (16/34) of the basins showed a tendency towards drought in over half their basin areas. Drought events occurred frequently, with more than half identified as short-term droughts (lasting less than or equal to three months). Small basins had a larger drought impact area, with major drought events often originating from the basin boundaries and migrating towards the basin centre. Meteorological droughts were driven by changes in sea surface temperature (SST), especially the El Niño Southern Oscillation (ENSO) or other climate indices. Anomalies in SST and atmospheric circulation caused by ENSO events may have led to altered climate patterns in different basins, resulting in drought events. These results provide important insights into the characteristics and mechanisms of meteorological droughts in different river basins worldwide.

Dominance of soil moisture over aridity in explaining vegetation greenness across global drylands

Drylands are one of the most sensitive areas to climate change. Despite being characterized by water scarcity and low precipitation, drylands support a wide range of green biodiversity and nearly 40 % of the global population. However, the climate change impacts on dryland characteristics and vegetation dynamics are debatable as the reasons remain poorly understood. Here, we use hydro-meteorological variables from ERA5 reanalysis and GIMMS-NDVI to analyze the changes in dryland aridity and vegetation greenness in the eight selected global dryland regions. The total dryland area (excluding hyperarid) has increased by 12 %, while arid, semiarid, and dry sub-humid areas have increased by 10.5 %, 8 %, and 25 %, respectively. We find a significant increase in aridity in drylands across the globe, except for South Asia. A decrease (increase) in precipitation is the major driver for a significant increase (decrease) in dryland aridity, with a notable contribution from climate warming. Despite decreasing trends in precipitation, vegetation greenness has significantly increased in most dryland regions due to increased soil moisture. Cropland expansion in Europe, Asia, and Australia resulted in the maximum increase in NDVI (Normalized Difference Vegetation Index) in dryland regions. The highest increase, with a ΔNDVI of 0.075, was observed in South Asia. The enhanced vegetation greenness observed is attributed to the expansion of croplands in recent decades, which has increased soil moisture. Overall, we show that monitoring soil moisture variability can provide a more robust explanation for vegetation greenness in the global drylands than aridity change. Moreover, human interventions of climatic alteration through land use change practices, such as cropland expansion, cannot be ignored while explaining the ecosystem dynamics of the drylands.

Climate anomalies and neighbourhood crowding interact in shaping tree growth in old‐growth and selectively logged tropical forests

Abstract Climate extremes and biotic interactions at the neighbourhood scale affect tropical forest dynamics with long‐term consequences for biodiversity, global carbon cycling and climate change mitigation. However, forest disturbance may change crowding intensity, and thus the relative contribution of climate extremes and neighbourhood interactions on tree growth, thereby influencing tropical forest resistance and resilience to climate change. Here, we aim to evaluate the separate and interactive effects of climate and neighbours on tree growth in old‐growth and disturbed tropical forests. We used 30 years of growth measurements for over 300 tropical tree species from 15 forest plots in French Guiana to investigate the separate and interactive effects of climate anomalies (in solar radiation, maximum temperature, vapour pressure deficit and climatic water deficit) and neighbourhood crowding on individual tree growth. Contrasting old‐growth and selectively logged forests, we also examined how disturbance history affects tree growth sensitivity to climate and neighbours. Finally, for the most abundant 100 species, we evaluated the role of 12 functional traits pertaining to water relations, light and carbon use in mediating tree growth sensitivity to climate anomalies, neighbourhood crowding and their interactions. Climate anomalies tied to heat and drought stress and neighbourhood crowding independently reduced tree growth, and showed positive interactive effects which attenuated their separate effects on tree growth. Their separate and interactive effects were stronger in disturbed than undisturbed forests. Fast‐growing species (i.e. higher intrinsic growth rates) were more abundant in disturbed forests and more sensitive to climate anomalies and neighbourhood crowding. Traits related to water relations, light and carbon use captured species sensitivities to different climate anomalies and neighbourhood crowding levels but were weak predictors of their interactions. Synthesis: Our results demonstrate that climate anomalies and neighbourhood crowding can interact to shape tropical tree growth, suggesting that considering the biotic context may improve predictions of tropical forest dynamics facing altered climate regimes. Furthermore, species traits can capture tree growth sensitivity to the separate effects of climate and neighbours, suggesting that better representing leading functional dimensions in tropical tree strategies offers a promising way towards a better understanding of the underlying ecological mechanisms that govern tropical forest dynamics.

Paleoecological and paleobiogeographic implications of a seagrass-indicating foralgal skeletal assemblage: Retracing the Burdigalian Quilon Limestone (Kerala Basin, SW India)

Seagrasses are marine angiosperms documented in shallow-marine, soft bottom settings across the Cenozoic. They proliferated globally after their divergence from other alismatid monocots in the late Cretaceous followed by an adaptation to the marine environment. Detailed evaluation of seagrasses in the geological archives is of utmost importance to understand their responses to climatic and environmental alterations in the deep time perspective. Here we examine the lower Miocene Quilon Limestone from the Kerala Basin (southwest India) that encompasses a Pseudotaberina-Halimeda floatstone signalling a robust photozoan foralgal skeletal assemblage. This is characterized by the dominant soritid foraminifer Pseudotaberina and the calcareous green alga Halimeda, in association with other foraminifera and representatives from various biotic groups that indicate a tropical seagrass paleoenvironment. Abundant soritids together with various bryopsidalean Halimeda species indicate light and temperature as the major ecological drivers regulating the Quilon Limestone seagrass paleocommunity during the early Miocene (Burdigalian). The spatio-temporal distribution patterns of Halimeda also indicate temperature as the most prominent ecological constraint determining its dispersal and evolution at multiple latitudes. A well illuminated substrate is envisaged to support the development and calcification of the Halimeda thalli. Abundance of K-strategist foraminifera with minor occurrence of suspension-feeding bryozoans and some gastropods, bivalves indicate a low-nutrient environment.

Exploring the nano-wonders: unveiling the role of Nanoparticles in enhancing salinity and drought tolerance in plants.

Plants experience diverse abiotic stresses, encompassing low or high temperature, drought, water logging and salinity. The challenge of maintaining worldwide crop cultivation and food sustenance becomes particularly serious due to drought and salinity stress. Sustainable agriculture has significant promise with the use of nano-biotechnology. Nanoparticles (NPs) have evolved into remarkable assets to improve agricultural productivity under the robust climate alteration and increasing drought and salinity stress severity. Drought and salinity stress adversely impact plant development, and physiological and metabolic pathways, leading to disturbances in cell membranes, antioxidant activities, photosynthetic system, and nutrient uptake. NPs protect the membrane and photosynthetic apparatus, enhance photosynthetic efficiency, optimize hormone and phenolic levels, boost nutrient intake and antioxidant activities, and regulate gene expression, thereby strengthening plant's resilience to drought and salinity stress. In this paper, we explored the classification of NPs and their biological effects, nanoparticle absorption, plant toxicity, the relationship between NPs and genetic engineering, their molecular pathways, impact of NPs in salinity and drought stress tolerance because the effects of NPs vary with size, shape, structure, and concentration. We emphasized several areas of research that need to be addressed in future investigations. This comprehensive review will be a valuable resource for upcoming researchers who wish to embrace nanotechnology as an environmentally friendly approach for enhancing drought and salinity tolerance.