Physiological Characteristics Research Articles

Review of Crop Phenotyping in Field Plot Experiments Using UAV-Mounted Sensors and Algorithms

The phenotyping of field crops quantifies a plant’s structural and physiological characteristics to facilitate crop breeding. High-throughput unmanned aerial vehicle (UAV)-based remote sensing platforms have been extensively researched as replacements for more laborious and time-consuming manual field phenotyping. This review aims to elucidate the advantages and challenges of UAV-based phenotyping techniques. This is a comprehensive overview summarizing the UAV platforms, sensors, and data processing while also introducing recent technological developments. Recently developed software and sensors greatly enhance the accessibility of UAV-based phenotyping, and a summary of recent research (publications 2019–2024) provides implications for future research. Researchers have focused on integrating multiple sensing data or utilizing machine learning algorithms, such as ensemble learning and deep learning, to enhance the prediction accuracies of crop physiological traits. However, this approach will require big data alongside laborious destructive measurements in the fields. Future research directions will involve standardizing the process of merging data from multiple field experiments and data repositories. Previous studies have focused mainly on UAV technology in major crops, but there is a high potential in minor crops or cropping systems for future sustainable crop production. This review can guide new practitioners who aim to implement and utilize UAV-based phenotyping.

Dynamics of selenium-mercury interaction under mercury stress in high and low selenium rice genotypes

Recent studies have demonstrated that selenium (Se) reduces the accumulation of heavy metals in rice tissues. However, the interaction between Se and mercury (Hg) in rice genotypes with high Se content remains to be further investigated. In this study, we used high Se genotypes Z2057B and Z5097B and low Se genotype Yuenong to explore the dynamics of Se and Hg in various tissues. The results showed that high Se genotypes, coupled with low concentrations of exogenously applied Se, significantly reduced the uptake of Hg in rice plants. The findings indicated the following order of Hg accumulation: Roots> third leaf > second leaf > first leaf > stem > grains. Observations revealed that both high Se genotypes and Se supplementation significantly restricted the majority of Hg concentration in roots and minimized its translocation to the aerial parts of the rice plant. In high Se genotypes subjected to mercury stress, MDA accumulation was significantly reduced, and SOD antioxidant activity was enhanced in stem and leaves at jointing, booting, heading, and maturity stages as compared to low Se genotypes. The application of 1.0 mg of Se per kg soil significantly improved the agronomic and physiological characteristics, reduced the Hg contents in aerial parts, and increased the Se contents in polished rice grains. Hence, the results lead to the conclusion that (i) cultivating high Se rice genotypes is a viable approach to decrease the Hg accumulation in rice grains and serves as a crucial strategy to fulfill daily Se requirements, particularly for populations suffering from Se deficiency (ii) supplementing ordinary rice with 1–3 mg kg−1 of Se can effectively reduce Hg accumulation and improve the quality of the grains.

Role of Provenance Trials in the Study of Population Differentiation

Wide distribution of many Linnean species across climatic, edaphic and biotic barriers may be either due to a wide ecological amplitude of the species as such, or to the presence of a number of distinct local populations, well adapted to the respective ecoclimates. These populations may show continuous variation along an envirormental gradient (ecocline) or discontinuous variation (ecotypes). The morphological or physiological adaptive characters are genetically fixed. Although a number of genecological techniques have been developed in the recent past, to differentiate such ecologic populations, the provenance trial technique has gained much importance. In the present communication the technique as well as some important results obtained through its use, both within and outside India, have been briefly discussed.

Response of photosynthetic characteristics and antioxidant system in the leaves of safflower to NaCl and NaHCO3.

Compared with NaCl, NaHCO3 caused more serious oxidative damage and photosynthesis inhibition in safflower by down-regulating the expression of related genes. Salt-alkali stress is one of the important factors that limit plant growth. NaCl and sodium bicarbonate (NaHCO3) are neutral and alkaline salts, respectively. This study investigated the physiological characteristics and molecular responses of safflower (Carthamus tinctorius L.) leaves treated with 200mmolL-1 of NaCl or NaHCO3. The plants treated with NaCl treatment were less effective at inhibiting the growth of safflower, but increased the content of malondialdehyde (MDA) in leaves. Meanwhile, safflower alleviated stress damage by increasing proline (Pro), soluble protein (SP), and soluble sugar (SS). Both fresh weight and dry weight of safflower was severely decreased when it was subjected to NaHCO3 stress, and there was a significant increase in the permeability of cell membranes and the contents of osmotic regulatory substances. An enrichment analysis of the differentially expressed genes (DEGs) using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes identified significant enrichment of photosynthesis and pathways related to oxidative stress. Furthermore, a weighted gene co-expression network analysis (WGCNA) showed that the darkgreen module had the highest correlation with photosynthesis and oxidative stress traits. Large numbers of transcription factors, primarily from the MYB, GRAS, WRKY, and C2H2 families, were predicted from the genes within the darkgreen module. An analysis of physiological indicators and DEGs, it was found that under saline-alkali stress, genes related to chlorophyll synthesis enzymes were downregulated, while those related to degradation were upregulated, resulting in inhibited chlorophyll biosynthesis and decreased chlorophyll content. Additionally, NaCl and NaHCO3 stress downregulated the expression of genes related to the Calvin cycle, photosynthetic antenna proteins, and the activity of photosynthetic reaction centers to varying degrees, hindering the photosynthetic electron transfer process, suppressing photosynthesis, with NaHCO3 stress causing more pronounced adverse effects. In terms of oxidative stress, the level of reactive oxygen species (ROS) did not change significantly under the NaCl treatment, but the contents of hydrogen peroxide and the rate of production of superoxide anions increased significantly under NaHCO3 stress. In addition, treatment with NaCl upregulated the levels of expression of the key genes for superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), the ascorbate-glutathione cycle, and the thioredoxin-peroxiredoxin pathway, and increased the activity of these enzymes, thus, reducing oxidative damage. Similarly, NaHCO3 stress increased the activities of SOD, CAT, and POD and the content of ascorbic acid and initiated the glutathione-S-transferase pathway to remove excess ROS but suppressed the regeneration of glutathione and the activity of peroxiredoxin. Overall, both neutral and alkaline salts inhibited the photosynthetic process of safflower, although alkaline salt caused a higher level of stress than neutral salt. Safflower alleviated the oxidative damage induced by stress by regulating its antioxidant system.

Ecology as an Aid to Floristics I : Adaptation and Ecotypes

The paper aims to demonstrate the role of the biological environment in shaping a plant species. Genetically and physiologically controlled demands and range of tolerance and their interactions produce a mosaic of populations. It is in these populations that 'ecads' and 'ecotypes are distinguished.The paper gives suitable examples of adaptations, ecads and ecotypes.This has opened a new line of work in taxonomic studies. Slight differences in morphological or even physiological characters of otherwise similar species should not be taken to separate the spécies taxonomically. Only ecological experimentation will provide the final answer.

Theoretical substantiation of aspects of physical culture, health and health-preserving activities of the individual

Physical education, health improvement and health-preserving activities are closely related and intertwined, since they are aimed at achieving and maintaining a person’s physical, mental and social well-being. Preserving and strengthening public health is an important task not only for individuals, but also for society as a whole and any modern state. This is facilitated by a healthcare system whose main goal is to improve the health and well-being of the population by providing comprehensive, high- quality and accessible care to all people, thereby ensuring the sustainability of the development of the country as a whole. Maintaining health at the individual level presupposes the choice of such forms of activity that contribute to the preservation and strengthening of human health. This choice is determined by the level of a person’s culture, acquired knowledge and life attitudes, such as: maintaining an optimal movement regime, taking into account gender, age and physiological characteristics; balanced, regular, rational nutrition; cessation of self-destructive behavior: cessation of smoking, use of psychoactive substances, alcohol abuse; compliance with the rules of personal and public hygiene; compliance with the rules of psychoprophylaxis and psychological hygiene; increasing the level of medical knowledge, mastering the skills of self-monitoring of one’s own health. The article analyzes the scientific literature on preserving and strengthening the health of the population through physical education and health activities. The increased interest of scientists in this problem is due to the increased social demand for the formation of a value-based attitude among the population towards their own health; formation of motivation aimed at health-saving activities of each person through physical activity.

Modern material and technical support of the educational and training process in rowing at the stage of basic training

The article examines modern views on the training of rowing athletes, as well as the importance of using modern technical means in the training process. As a result of the literature analysis, it was found that when working with rowers at the stage of basic training, insufficient attention is paid to the operational analysis of information obtained during the training process. The relevance of this study is also due to the fact that the issue of the possibility of using modern technical means and portable devices by rowing athletes has not been covered in the scientific literature. The purpose of the work was to determine which technical means are used by rowers in the training process and to determine their priority in the opinion of the athletes themselves. The article describes the results of a questionnaire about the use of material and technical means and equipment in the training process of rowers aged 14-16 at the stage of basic training. It was found that the priority element of the training process according to the rowers is the material and technical base, namely: a gym, a modern paddle and special sports clothes. At the same time, the vast majority of respondents said they would like to be able to train with modern technical equipment such as wearables and GPS. Information from portable devices makes it possible to analyze the capabilities and physiological characteristics of athletes. This helps the athlete and coach to receive automatic feedback on how to improve personal results and prevent injuries. The use of portable devices in combination with modern inventory requires further research. In the future, we plan to develop a training program for rowers 14-16 y.o. with the use of portable devices in the training process.

Comparative Analysis of Enzymatic Activities and Transcriptional Profiles of Various Hepatic Enzymes between Male and Female Yellowfin Tuna (Thunnus albacares)

Yellowfin tuna (Thunnus albacares) is a valuable pelagic migratory fish with potential for aquaculture. Despite this, there is limited understanding of the biological and physiological characteristics of this species, particularly regarding sex differences in growth performance. The liver, a crucial organ for digestion and metabolism, plays a significant role in regulating fish growth. This study aimed to compare liver enzyme activities and transcriptome profiles between female and male yellowfin tuna to uncover the molecular mechanisms underlying difference between the sexes. The results revealed that female yellowfin tuna exhibited higher amylase and lipid metabolism enzyme activities, while male yellowfin tuna showed higher glucose-6-phosphate dehydrogenase and antioxidant enzyme activities. Additionally, through Illumina sequencing technology, the study generated 37.74 Gb of clean data and identified 36,482 unique genes (UniGenes) in the liver transcriptome. A total of 2542 differentially expressed genes were found, with enriched Gene Ontology terms and pathways related to metabolic processes, particularly lipid metabolism and transport. These findings suggest that female yellowfin tuna have superior digestive enzyme activities and lipid metabolism, while male yellowfin tuna excel in sugar metabolism, ATP production, and antioxidant defense. This study provides valuable insights into sex differences in yellowfin tuna and could aid in advancing full-cycle aquaculture practices for this species.

The motivation of employees and their intention to work in the Greek tourism sector

PurposeThe purpose of this study is to investigate the motives that drive individuals' intentions to work within firms operating in the Greek tourism sector and to examine the impact of these motives on the intention to work.Design/methodology/approachTo achieve this objective, we conducted an empirical survey among 2,104 individuals with professional experience in the tourism business. Descriptive statistics and hierarchical regression analysis were employed, with motives as independent variables and the intention to work as the dependent construct, to answer the research question.FindingsThis study presents job motivation as a hierarchical set of criteria that need to be fulfilled or satisfied. It also identifies the significant motives impacting employees' intention to work in both the accommodation sector and food and beverage services.Research limitations/implicationsThe data were collected at a single point in time from Greece, which may limit the generalizability of our results. Future research could consider the psychological and physiological characteristics of employees.Practical implicationsManagers who provide social security, create a positive work environment, and promote collaboration among their employees can enhance the quality of work-life and positively influence their intention to work.Originality/valueThe proposed model offers valuable guidelines that advance research on employee motivation in the tourism industry.

Phytotoxicity and Residual Effect of Some Herbicides on three Egyptian Rice Cultivars (Oryza sativa L.)

The current study was carried out at the experimental farm of Rice Research Department, Sakha Agricultural Research Station and Central Agricultural Pesticide Laboratory, ARC, Egypt during the summer season of 2021 and 2022 to study the sensitivity of three Egyptian rice cultivars against four common herbicides and its effect on physiological and agronomic characteristics of rice as well as herbicide residues in rice seeds. The field study was laid out in split plot design with three replications. Three rice cultivars (Giza 177, Giza 179 and Sakha 108) were randomly distributed in main plots, while weed control treatments included four herbicides at recommended doses (penoxsulam 2.5% OD, bispyribac-sodium 2% SL, cyhalofop-butyl 10% EC and fenoxaprop-p-ethyl 7.5% EW) as compared to hand weeding were devoted in sub plots. The obtained results revealed that Sakha 108 as Japonica rice cultivar was resistant against tested herbicides and recorded the highest values of rice dry weight, chlorophyll content, number of panicles m-2, panicle weight and grain yield, while scored the lowest values of total phenols. On the other hand, Giza 177 as short duration Japonica rice cultivar showed the higher sensitivity against tested herbicides and achieved the lowest values of abovementioned agronomic traits and chlorophyll content. Cyhalofop-butyl as ACCase herbicide was safer on studied rice cultivars and recorded the highest values of studied agronomic characteristics for rice as well as chlorophyll content, while recorded the lowest values of total phenols during the study. On the other hand, bispyribac-sodium 2% SL resulted in more toxic effect for rice cultivars and recorded the lowest values of studied agronomic traits for rice. fenoxaprop-p-ethyl 7.5% EW achieved the lowest chlorophyll content and highest values of total phenols during the study. Giza 179 as Indica-Japonica rice cultivar appeared high sensitivity when sprayed with bispyribac-sodium and fenoxaprop-ethyl but made recovery after 12 days from herbicidal application and recorded the highest chlorophyll content, dry weight, panicles m-2 and grain yield with no significant differences between Sakha 108 rice cultivar during the study. In respect of herbicide residues in rice seeds, all tested herbicides didn’t have residues in rice seeds at 100 days after treatment. It means that tested herbicides didn’t have any residues in rice seeds.

Multimodal biometric authentication: A review

Critical applications ranging from sensitive military data to restricted area access demand selective user authentication. The prevalent methods of tokens, passwords, and other commonly used techniques proved deficient as they can be easily stolen, lost, or broken to gain illegitimate access, leading to data spillage. Since data safety against tricksters is a significant issue nowadays, biometrics is one of the unique human characteristic-based techniques that may give better solutions in this regard. The technique entails biometric authentication of users based on an individual’s inimitable physiological or behavioral characteristics to provide access to a specific application or data. This paper provides a detailed description of authentication and its approaches, focusing on biometric-based authentication methods, the primary challenges they encounter, and how they have been addressed. The tabular view shows the benefits and downsides of various multimodal biometric systems, and open research challenges. To put it another way, this article lays out a roadmap for the emergence of multimodal biometric-based authentication, covering both the challenges and the solutions that have been proposed. Further, the urge to develop various multi-trait-based methods for secure authentication and data privacy is focused. Lastly, some multimodal biometric systems comprising fingerprint and iris modalities have been compared based on False Accept Rate (FAR), False Reject Rate (FRR), and accuracy to find the best secure model with easy accessibility.

Precision Regulation and Forecasting of Greenhouse Tomato Growth Conditions Using an Improved GA-BP Model

Tomatoes are annual herbaceous plants of the family Solanaceae. They have very stringent requirements for their growing environment and climate conditions. To precisely control the greenhouse environment for tomato growth, this project designed and implemented a monitoring system utilizing programmable logic controllers and a data acquisition system for monitoring. Sensors are installed at key locations in the greenhouse, such as near the ground, in the plant canopy, and under the roof, to monitor environmental parameters such as temperature, humidity, light intensity, and carbon dioxide concentration in real time. A three-layer feedforward GA-BP neural network model was established using soil temperature, soil humidity, air humidity, and illumination as predictive parameters. This technology predicts optimal environmental parameters and performs real-time monitoring and intelligent control, overcoming the traditional BP neural network’s drawbacks of slow convergence, susceptibility to disturbance, and poor generalization ability, with the current model’s average prediction error being less than 5%. It provides a theoretical basis and decision support for precision control and related environmental forecasting in agricultural projects. Based on the growth characteristics, physiological and morphological features of tomatoes, and the comprehensive impact of planting conditions, the technology enhances tomato yield and quality while reducing production costs and labor inputs. It mainly includes the establishment of tomato growth models, measurement and control of environmental parameters, and the design and optimization of intelligent decision control systems. Research outcomes in this field are significant for improving agricultural production efficiency, ensuring food security, and promoting sustainable agricultural development.

A hemodynamic model of artery bypass graft considering microcirculation function.

The incidence of arterial stenosis is increasing year by year. In order to better diagnose and treat arterial stenosis, numerical simulation technology has become a popular method. A novel model is constructed to investigate the influence of microcirculation on the hemodynamics of artery bypass graft. In this paper, a severely narrow artery bypass graft model is considered. The geometric shape includes a narrow artery tube and a bypass graft of the same diameter with a 45° suture angle. The fluid-structure interaction model is considered by finite element numerical calculation, and the flow is simulated with microcirculation as the outlet boundary condition. The changes of blood flow velocity, pressure and wall shear stress are analyzed. The results show that blood almost entirely flows into the graft tube and there is no recirculation area at the anastomosis. The artery bypass graft model considering microcirculation function could simulate the physiological characteristics of blood flow more reasonably, and it provide helps for clinicians to diagnose and treat arterial stenosis.

Effects of Different Film Types on Cotton Growth and Yield under Drip Irrigation

To address residual plastic film in fields in which mulched drip irrigation technology is applied, a sprayable degradable film (consisting of 1–5% clay, 5–20% humic acid, 0.5–5% crosslinker, and 0.5–5% auxiliary and water) can be used as a superior alternative to the plastic film applied in drip-irrigated fields. A field experiment was conducted in Xinjiang, Northwest China, to test the impacts of five different mulching treatments (SF1, sprayable degradable film applied at 1900 kg ha−1; SF2, sprayable degradable film applied at 1900 kg ha−1; SF3, sprayable degradable film applied at 2500 kg ha−1; PF, plastic film; and NF, no film mulching) on cotton growth and development, yield, and water use efficiency. The results showed that, compared to the NF treatment, sprayable degradable film mulching (SF1, SF2, and SF3) positively impacted the soil hydrothermal environment, promoted root growth, significantly increased plant height and leaf area, and enhanced physiological characteristics, which, in turn, increased yield and water use efficiency by 11.79–15.00% and 21.88–30.21%, respectively. The maximum yield and water use efficiency were observed in the PF treatment, amounting to 5345 kg ha−1 and 1.28 kg m−3, respectively, and they had no significant differences from those in the SF3 treatment. In general, applying moderate amounts of sprayable degradable film at a rate of 2500 kg ha−1 represents an effective agronomic strategy for managing residual film contamination while maintaining stable cotton yields.

The tricarboxylic acid cycle is inhibited under acute stress from carbonate alkalinity in the gills of Eriocheir sinensis

Owing to population growth and environmental pollution, freshwater aquaculture has been rapidly shrinking in recent years. Aquaculture in saline-alkaline waters is a crucial strategy to meet the increasing demand for aquatic products. The Chinese mitten crab is an important economic food in China, but the molecular mechanism by which it tolerates carbonate alkalinity (CA) in water remains unclear. Here, we found that enzyme activities of the tricarboxylic acid (TCA) cycle in the gills, such as citrate synthase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, and malate dehydrogenase, were markedly reduced under CA stress induced by 40 mM NaHCO3. Secondly, the TCA cycle in the gills is inhibited under acute CA stress, according to proteomic and metabolomic analyses. The expressions of six enzymes, namely aconitate hydratase, isocitrate dehydrogenase, 2-oxoglutarate dehydrogenase, dihydrolipoyl dehydrogenase, succinate-CoA ligase, and malate dehydrogenase, were downregulated, resulting in the accumulation of phosphoenolpyruvic acid, citric acid, cis-aconitate, and α-ketoglutaric acid. Finally, we testified that if the TCA cycle is disturbed by malonate, the survival rate increases in CA water. To our knowledge, this is the first study to show that the TCA cycle in the gills is inhibited under CA stress. Overall, the results provide new insights into the molecular mechanism of tolerance to saline-alkaline water in crabs, which helped us expand the area for freshwater aquaculture and comprehensively understand the physiological characteristics of crab migration.

The role of hydrogen-rich water in delaying the pulp breakdown of litchi fruit during postharvest storage

Previous studies have indicated that hydrogen-rich water (HW) treatment can delay fruit ripening and senescence. However, little is known about the HW-delaying pulp breakdown. In this study, eight physiological characteristics revealed that HW treatment delayed both pericarp browning and pulp breakdown of litchi fruit. To gain a comprehensive understanding of the changes in litchi pulp, a combination of multiple metabolomics and gene expression analyses was conducted, assessing 67 primary metabolites, 103 volatiles, 31 amino acids, and 13 crucial metabolite-related genes. Results showed that HW treatment promoted starch degradation, decelerated cell wall degradation and glycolysis, and maintained the flavor and quality of litchi fruit. Furthermore, HW treatment stimulated the production of volatile alcohols, aldehydes, ketones, olefins, and amino acids, which might play a vital role in HW-delaying pulp breakdown. This study sheds light on the mechanism by which HW delayed pulp breakdown by investigating small molecule metabolites and metabolic pathways.

Nanoparticle aggregation and electro-osmotic propulsion in peristaltic transport of third-grade nanofluids through porous tube

In the modern era, the utilization of electro-kinetic-driven microfluidic pumping procedures spans various biomedical and physiological domains. The present study introduces a mathematical framework for characterizing the hemodynamics of peristaltic blood flow within a porous tube infused with ZrO2 nanoparticles. This model delves into the interactions between buoyancy, electro-osmotic forces, and aggregated nanoparticles to discern their influence on blood flow. We employ a third-grade fluid model to elucidate the rheological behavior of the pseudoplastic fluid which refers to its response to applied shear stress, specifically the relationship between shear rate and viscosity. The collective influence of accommodating heat convection, joule heating and aggregated nanoparticles contributes to the thermal behavior of fluids. The distribution of electric potential within the electric double layer (EDL) is predicted by solving the Poisson–Boltzmann equation. The rescaled equations are simplified using the lubrication and Debye-Hückel models as the underlying frameworks. The novel homotopy perturbation method is employed to obtain solutions for the finalized non-linear partial differential equation. Theoretical assessment of hemodynamic impacts involves plotting graphical configurations for various emerging parameters. As electro-osmotic parameter increase, the bloodstream encounters greater impedance, thereby enhancing the effectiveness of electro-osmotic assistance. Concurrently, elevated convective heat markedly reduces the rate of heat transfer, potentially resulting in a drop in blood temperature. It is important to note that maximum shear stress occurs when the artery is positioned horizontally, underscoring the significant impact of arterial alignment on wall shear stress. Skin friction intensifies with the increasing wall permeability as aggregated nanofluids pass through the arterial conduit. Therefore, aggregation of nanoparticles into the bloodstream yields a broader spectrum of distinctive physiological features. In summary, these findings enable more effective tool and device designs for addressing medication administration challenges and electro-therapies.

Influence of Silver Nanoparticles on the Metabolites of Two Transgenic Soybean Varieties: An NMR-Based Metabolomics Approach.

This study investigated the effect of AgNPs and AgNO3, at concentrations equivalent, on the production of primary and secondary metabolites on transgenic soybean plants through an NMR-based metabolomics. The plants were cultivated in a germination chamber following three different treatments: T0 (addition of water), T1 (addition of AgNPs), and T2 (addition of AgNO3). Physiological characteristics, anatomical analyses through microscopic structures, and metabolic profile studies were carried out to establish the effect of abiotic stress on these parameters in soybean plants. Analysis of the 1H NMR spectra revealed the presence of amino acids, organic acids, sugars, and polyphenols. The metabolic profiles of plants with AgNP and AgNO3 were qualitatively similar to the metabolic profile of the control group, suggesting that the application of silver does not affect secondary metabolites. From the PCA, it was possible to differentiate the three treatments applied, mainly based on the content of fatty acids, pinitol, choline, and betaine.

Applications of structural equation modeling in plant functional trait research

1.Plant functional traits, which encompass morphological, physiological, and ecological characteristics, are key to plant adaptation, growth, and development. In recent years, the structural equation model (SEM) has gained widespread use as a powerful statistical tool for studying plant functional traits and conducting research in this field. Its ability to distinguish between direct and indirect effects makes the SEM a robust method for investigating the complex relationships among environment components, traits and ecosystem functions. 2.Here, we review and discuss four commonly used SEMs: (1) the covariance-based structural equation model, (2) the piecewise structural equation model, (3) the Bayesian structural equation model, and (4) the partial least squares structural equation model. We also explore their applications in three typical ecosystems—forest, grassland, and wetland ecosystems—and investigate these forms of SEM in the context of their use in trait-ecosystem function research. 3.Our specific objectives were to: (i) compare the advantages and disadvantages of these four types of SEMs; (ii) analyze the current state of research on SEM applications in plant functional traits across diverse ecosystems; and (iii) highlight new approaches and potential research areas for the future application of SEM in plant functional traits. 4.In this paper, several key findings were obtained: (i) the selection of SEM type is influenced by the different spatial scales of the study. (ii) latent and composite variables were less commonly utilized in recent SEM studies. (iii) while SEMs have proven effective in distinguishing between direct and indirect effects to unravel the complex relationships among multiple variables, indirect effects deserve more attention in general studies. We propose that future applications of SEMs in plant functional traits should incorporate a broader spectrum of traits as well as the trade-offs between them. Larger and more diverse databases of plant functional traits would help make SEM analyses more accurate across different scales.

Assessing the response of marine fish communities to climate change and fishing.

Globally, marine fish communities are being altered by climate change and human disturbances. We examined data on global marine fish communities to assess changes in community-weighted mean temperature affinity (i.e., mean temperatures within geographic ranges), maximum length, and trophic levels, which, respectively, represent the physiological, morphological, and trophic characteristics of marine fish communities. Then, we explored the influence of climate change and fishing on these characteristics because of their long-term role in shaping fish communities, especially their interactive effects. We employed spatial linear mixed models to investigate their impacts on community-weighted mean trait values and on abundance of different fish lengths and trophic groups. Globally, we observed an initial increasing trend in the temperature affinity of marine fish communities, whereas the weighted mean length and trophic levels of fish communities showed a declining trend. However, these shift trends were not significant, likely due to the large variation in midlatitude communities. Fishing pressure increased fish communities' temperature affinity in regions experiencing climate warming. Furthermore, climate warming was associated with an increase in weighted mean length and trophic levels of fish communities. Low climate baseline temperature appeared to mitigate the effect of climate warming on temperature affinity and trophic levels. The effect of climate warming on the relative abundance of different trophic classes and size classes both exhibited a nonlinear pattern. The small and relatively large fish species may benefit from climate warming, whereas the medium and largest size groups may be disadvantaged. Our results highlight the urgency of establishing stepping-stone marine protected areas to facilitate the migration of fishes to habitats in a warming ocean. Moreover, reducing human disturbance is crucial to mitigate rapid tropicalization, particularly in vulnerable temperate regions.