Primary Production Research Articles

A Holistic Framework for Evaluating Food Loss and Waste Due to Marketing Standards across the Entire Food Supply Chain.

This paper addresses the critical and urgent need to reduce food losses and waste (FLW) resulting from stringent marketing standards. It proposes a comprehensive and actionable framework grounded in the three pillars of sustainability-environmental, economic, and social-to effectively evaluate FLW across the entire food supply chain. The paper involves a thorough review of existing marketing standards, including research on FLW due to marketing standards, and proposes the implementation of targeted key actions within four key food sectors: fruits, vegetables, dairy, and cereals. The study provides a detailed analysis of the significant impact marketing standards have on FLW at various stages of the supply chain, including primary production, processing, retail, and consumption. By focusing on these critical points, the research underscores the necessity of addressing marketing standards to achieve meaningful reductions in FLW. The proposed framework aims to foster improved business practices and drive the development of innovative, sector-specific solutions that balance sustainability goals with economic viability. The holistic approach followed for this research lays the foundation for ensuring that the proposed framework is adaptable and practical, leading to measurable improvements in reducing FLW and promoting sustainability across the food industry.

Cascaded reservoirs promote phosphorus bioavailability of surface sediments in the Upper Mekong River

As a key nutrient for primary productivity in freshwater ecosystems, the effect of upper cascade reservoirs on the downstream phosphorus (P) loading is subject to an ongoing scientific debate in the Mekong River. To investigate the effects of cascade reservoirs on the forms of P and its bioavailability in surface sediment, two rounds of field research were carried out both in a free-flowing river (Nu River) and in the Upper Mekong River (Lancang River) during winter and summer. Results showed that while the P was trapped with sediments and environmental parameters changed significantly, high relative abundance of bioavailable phosphorus (BioP, generally include Fe-bound P, Al-bound P, and Organic P) in sediment was detected in reservoirs and at near the border between China and Myanmar. The increased Bio-P in reservoirs may be caused by sediments sorting, anaerobic surface sediments, appropriate temperature, longer residence time and algae-nutrient positive feedback loops. Accumulated Bio-P in sediments may elevate the phosphorus release to overlying water and exacerbate eutrophication in reservoirs. Considered the intense anthropogenic phosphorus loading, nutrients enrichment risk in the lower Mekong River should receive more attention in further research.

Quantifying the Contributions of Vegetation Dynamics and Climate Factors to the Enhancement of Vegetation Productivity in Northern China (2001–2020)

Vegetation dynamics are critical to the terrestrial carbon and water cycle, with China recognized as one of the largest contributors to global greening due to significant variations in forest coverage. However, distinguishing the effects of vegetation changes from those of climate factors on vegetation productivity remains challenging. This study conducted a comprehensive analysis of vegetation productivity in Northwest China over the past two decades, focusing on the spatiotemporal patterns and drivers of gross primary production (GPP) within ecological restoration areas. Using trend analysis and ridge regression models, we assessed the relative contributions of climate factors and vegetation coverage changes to GPP dynamics. The results revealed a significant increase in both the GPP and vegetation coverage in Northern China from 2001 to 2020, with GPP rising by 6.7 g C m−2 yr−1 and forest coverage increasing by 0.08% per year. A strong positive correlation (r = 0.9) was observed between vegetation coverage changes and GPP. The increase in GPP was driven by both climate factors and changes in forest coverage, with climate factors contributing 61.0% and vegetation coverage changes contributing 39.0%. Among the climate factors, radiation, temperature, and precipitation contributed 15.4%, 6.4%, and 39.2%, respectively. The study highlights the critical role of ecological restoration efforts, particular in regions like the Less Plateau and Inner Mongolian Plateau, in enhancing vegetation productivity. These findings provide valuable insights for addressing desertification and inform strategies for ecological restoration and sustainable development in Northern China.

Riverine nutrient impact on global ocean nitrogen cycle feedbacks and marine primary production in an Earth system model

Abstract. Riverine nutrient export is an important process in marine coastal biogeochemistry and also impacts global marine biology. The nitrogen cycle is a key player here. Internal feedbacks are shown to regulate not only nitrogen distribution, but also primary production and thereby oxygen concentrations. Phosphorus is another essential nutrient and interacts with the nitrogen cycle via different feedback mechanisms. After a previous study of the marine nitrogen cycle response to riverine nitrogen supply, here we include phosphorus from river export with different phosphorus burial scenarios and study the impact of phosphorus alone and in combination with nitrogen in a global 3D ocean biogeochemistry model. Again, we analyse the effects on near-coastal and open-ocean biogeochemistry. We find that riverine export of bioavailable phosphorus alone or in conjunction with nitrogen affects marine biology on millennial timescales more than riverine nitrogen alone. Biogeochemical feedbacks in the marine nitrogen cycle are strongly influenced by additional phosphorus. Where bioavailable phosphorus increases with river input, nitrogen concentration increases as well, except for in regions with diminishing oxygen concentrations. High phosphorus burial rates decrease biological production significantly. Globally, the addition of riverine phosphorus in the modelled ocean leads to elevated primary production rates in the coastal and open oceans.

Algal Growth and Morphogenesis-Promoting Factors Released by Cold-Adapted Bacteria Contribute to the Resilience and Morphogenesis of the Seaweed Ulva (Chlorophyta) in Antarctica (Potter Cove)

AbstractMacroalgae are found in a variety of marine vegetation ecosystems around the world, contributing significantly to global net primary production. In particular, the sea lettuce species, i.e., members of the genus Ulva (Chlorophyta), are located in many ecological niches and are characterized by excellent adaptability to environmental changes but depend on essential associated bacteria, which release algal growth and morphogenesis-promoting-factors (AGMPFs). Our work investigated the hypothesis that bacteria need to be stress-adapted to provide sufficient amounts of AGMPFs for the growth and morphogenesis of Ulva throughout its life cycle, even under severe environmental conditions. Our study thus aimed to understand which bacteria contribute to overcoming a variety of stressors in polar regions. Green macroalgae were collected from Potter Cove, King George Island (Isla 25 de Mayo), Antarctica, to study the associated microbiome and, subsequently, to identify AGMPFs releasing bacteria. Therefore, microbiome analysis was combined with morphogenetic bioassays and chemical analysis, identifying bacteria essential for algal growth under Antarctic conditions. Hereby, axenic cultures of Ulva compressa (cultivar Ulva mutabilis, Ria Formosa, Portugal), previously developed as a model system for bacteria-induced algal growth and morphogenesis, were inoculated with freshly isolated and cultivable Antarctic bacteria to determine their morphogenetic activity. The exploratory microbiome investigation identified numerous cold-adapted AGMPF-producing bacteria. Unlike the temperate-adapted bacterial strains originally isolated from the U.mutabilis holobiont, the cold-adapted isolates Maribacter sp. BPC-D8 and Sulfitobacter sp. BPC-C4 released sufficient amounts of AGMPFs, such as thallusin and still unknown compounds, necessary for the morphogenesis of the Antarctic Ulva even at 2 °C. Our results illustrate the role of chemical mediators provided by bacteria in cross-kingdom interactions under cold conditions within aquatic systems. The newly isolated bacteria will enable further functional studies to understand the resilience of the holobiont Ulva and might be applied in algal aquaculture even under adverse conditions. The study highlights the importance of eco-physiological assays in microbiome analysis.

Analyses of sea surface chlorophyll a trends and variability from 1998 to 2020 in the German Bight (North Sea)

Abstract. Satellite remote sensing of ocean colour properties allows observation of the ocean with high temporal and spatial coverage, facilitating the better assessment of changes in marine primary production. Ocean productivity is often assessed using satellite-derived chlorophyll a concentrations, a commonly used proxy for phytoplankton concentration. We used the Copernicus GlobColour remote sensing chlorophyll a surface concentration to investigate seasonal and non-seasonal variability, temporal trends, and changes in spring bloom chlorophyll a magnitude. Complementary, we analysed the chlorophyll a relationship with sea surface temperature and mixed-layer depth in the German Bight from 1998 to 2020. Empirical orthogonal functions were employed in order to investigate dominant spatial and temporal patterns (modes) related to the main processes of chlorophyll a variability. Multi covariance analysis was used to extract the dominant structures that maximize the covariance between chlorophyll a and sea surface temperature mixed-layer depth fields. High levels of chlorophyll a were found near the coast, showing a decreasing gradient towards offshore waters. A significant chlorophyll a positive trend was observed close to the Elbe estuary and adjacent area, while 55 % of the German Bight was characterized by a significant chlorophyll a negative trend. The chlorophyll a non-seasonal variability showed that the first four modes explained around 45 %, with the first and second modes related to inter- and intra-annual variability, respectively, observed in the temporal principal components spectral analyses. Monthly chlorophyll a concentration anomalies co-varied by 45 % with sea surface temperature anomalies and 23 % with mixed-layer depth anomalies. The monthly averages of chlorophyll a anomaly fields were suitable to investigate long-term trends and variability. The rising water temperature, combined with its indirect effects on other variables, can partially explain the observed trends in chlorophyll a.

Composition and Biogeochemical Effects of Carbohydrates in Aerosols in Coastal Environment

We adopted a simple and rapid measurement method to analyze the concentrations of monosaccharides (MCHO) and polysaccharides (PCHO) in carbohydrates, a subset of organic carbon found in size-fractionated atmospheric particles. Seasonal and source-related factors influenced carbohydrate concentrations, with total water-soluble carbohydrates (TCHO) accounting for approximately 23% of the water-soluble organic carbon (WSOC) in spring when biological activity was high. We observed that the mode of aerosol transport significantly influenced the particle size distribution of carbohydrates, with MCHO exhibiting relatively high concentrations in fine particles (<1 μm) and PCHO showing higher concentrations in coarse particles (>1 μm). Moreover, our results revealed that MCHO and PCHO contributed 51% and 49%, respectively, to the TCHO concentration. This contribution varied by approximately ±19% depending on the season, suggesting the importance of both MCHO and PCHO. Additionally, through the combined use of principal component analysis (PCA) and positive matrix factorization (PMF), we determined that biomass burning accounts for 30% of the aerosol. Notably, biomass burning accounts for approximately 52% of the WSOC flux, with MCHO accounting for approximately 78% of the carbon from this source, indicating the substantial influence of biomass burning on aerosol composition. The average concentration of TCHO/WSOC in the atmosphere was approximately 18%, similar to the marine environment, reflecting the relationship between the biogeochemical cycles of the two environments. Finally, the fluxes of MCHO and PCHO were 1.10 and 5.28 mg C m−2 yr−1, respectively. We also found that the contribution of atmospheric deposition to marine primary productivity in winter was 15 times greater than that in summer, indicating that atmospheric deposition had a significant impact on marine ecosystems during nutrient-poor seasons. Additionally, we discovered that WSOC accounts for approximately 62% of the dissolved organic carbon (DOC) in the Min River, suggesting that atmospheric deposition could be a major source of organic carbon in the region.

Trajectories of Terrestrial Vegetation Productivity and Its Driving Factors in China's Drylands

AbstractClimate change and large‐scale ecological restoration programs have profoundly influenced vegetation greening and gross primary productivity (GPP) in China's drylands. However, the specific pathways through which climatic factors and vegetation greening influence GPP remain poorly understood. This study examines the spatiotemporal changes in GPP across China's drylands from 2001 to 2020 and investigates the direct and indirect effects of climatic factors and leaf area index (LAI) on GPP. The results reveal that the overall improvement in vegetation cover has positively increased GPP in these regions. Although the direct effects of climatic factors on GPP are minimal, they exert a substantial indirect effect by regulating vegetation growth, highlighting that LAI is a key intermediary in mediating the effects of climatic factors on GPP. Furthermore, these complex interactions vary significantly along the aridity gradient. This study emphasizes the necessity of comprehensively considering the intricate interactions among multiple climate and vegetation factors.

Wintertime productivity and carbon export potential across the Agulhas Current system

The Agulhas Current plays a major role in heat and salt exchange between the Indian and Atlantic Oceans, yet little is known of its influence on ocean fertility. To investigate carbon production and export potential in the Agulhas Current system, we measured net primary production (NPP), nitrate and ammonium uptake, N2 fixation, and nitrification along a transect of the current and adjacent subtropical subgyre (33.4°S–35.7°S) in winter when nutrient supply, and thus productivity, should be highest. Phytoplankton biomass was lowest in the current core, increasing into the subgyre as surface nitrate declined, and was dominated by nanoplankton (2.7–10 μm; 62 ± 5.1% of total biomass). NPP and nitrate uptake were generally high across the transect and increased from the current core into the subgyre; the rates were dominated by picoplankton (<2.7 μm; 53–93%) in the current core and nanoplankton elsewhere (63–69%). On average, euphotic zone nitrification supplied 7.6 ± 6.4% of the nitrate consumed by phytoplankton and N2 fixation was also low (2.1 ± 1.3% of new production); we thus consider nitrate uptake a reasonable proxy for new production, at least in winter. Nitrate uptake was highest at the southern edge of the current core, consistent with current-associated (sub)mesoscale mixing enhancing the upward nutrient supply. The fraction of NPP available for export (i.e., the f-ratio) was high across the transect, ranging from 0.44 to 0.69. Our data thus indicate that both total and new production are elevated across the Agulhas Current system in winter and suggest that the (sub)mesoscale dynamics associated with the current system may enhance carbon production and export in the otherwise oligotrophic southwest Indian Ocean.

Multiple-Win Effects and Beneficial Implications from Analyzing Long-Term Variations of Carbon Exchange in a Subtropical Coniferous Plantation in China

To improve our understanding of the carbon balance, it is significant to study long-term variations of all components of carbon exchange and their driving factors. Gross primary production (GPP), respiration (Re), and net ecosystem productivity (NEP) from the hourly to the annual sums in a subtropical coniferous forest in China during 2003–2017 were calculated using empirical models developed previously in terms of PAR (photosynthetically active radiation), and meteorological parameters, GPP, Re, and NEP were calculated. The calculated GPP, Re, and NEP were in reasonable agreement with the observations, and their seasonal and interannual variations were well reproduced. The model-estimated annual sums of GPP and Re over 2003–2017 were larger than the observations of 11.38% and 5.52%, respectively, and the model-simulated NEP was lower by 34.99%. The GPP, Re, and NEP showed clear interannual variations, and both the calculated and the observed annual sums of GPPs increased on average by 1.04% and 0.93%, respectively, while the Re values increased by 4.57% and 1.06% between 2003 and 2017. The calculated and the observed annual sums of NEPs/NEEs (net ecosystem exchange) decreased/increased by 1.04%/0.93%, respectively, which exhibited an increase of the carbon sink at the experimental site. During the period 2003–2017, the annual averages of PAR and the air temperature decreased by 0.28% and 0.02%, respectively, while the annual average water vapor pressure increased by 0.87%. The increase in water vapor contributed to the increases of GPP, Re, and NEE in 2003–2017. Good linear and non-linear relationships were found between the monthly calculated GPP and the satellite solar-induced fluorescence (SIF) and then applied to compute GPP with relative biases of annual sums of GPP of 5.20% and 4.88%, respectively. Large amounts of CO2 were produced in a clean atmosphere, indicating a clean atmospheric environment will enhance CO2 storage in plants, i.e., clean atmosphere is beneficial to human health and carbon sink, as well as slowing down climate warming.

Identifying Factors Mediating the Carnivore Richness–Productivity Relationship Across a Precipitation‐Driven Ecotone

ABSTRACTAimPrimary productivity is an important mechanism influencing the species richness of animal taxa such as mammals. However, the factors that mediate the relationship between carnivore species richness, for example, and productivity are not well understood. We examined whether the relationship between carnivore species richness and primary productivity followed a hump‐shaped relationship and explored potential pathways by which productivity influences carnivore communities.LocationWestern Great Basin, USA.MethodsWe deployed a camera‐trap grid across a strong precipitation—and the corresponding productivity—gradient and estimated carnivore species richness using a novel application of a multisession community occupancy model. To quantify the relationship between carnivore species richness and productivity, we included the linear and quadratic effects of average annual precipitation as covariates on carnivore species richness. We fit additional community models linking carnivore species richness to vegetation and land cover variables to identify factors that mediate the relationship between carnivore richness and productivity.ResultsThe linear effect of precipitation on carnivore richness was positive and the quadratic effect was negative, supporting the hump‐shaped relationship where richness declines at the highest levels of productivity. Similarly, carnivore species richness followed a quadratic relationship with vegetation height along the productivity gradient. The relationship between carnivore species richness and proportion tree cover was positive, with limited evidence that open vegetation types in the surrounding landscape increased site‐level richness.Main ConclusionsIn addition to supporting the notion that primary productivity has a strong and nonlinear influence on local‐scale carnivore species richness, our results suggest that vegetation structure may be an important mediator of this relationship. Although future changes in precipitation and productivity due to climate change are uncertain, our results indicate that targeting areas of intermediate productivity and vegetation height, such as woodlands, may be key for conserving species‐rich carnivore communities along productivity gradients.

Estimating Grassland Carrying Capacity in the Source Area of Nujiang River and Selinco Lake, Tibetan Plateau (2001–2020) Based on Multisource Remote Sensing

Estimating the spatiotemporal variations in natural grassland carrying capacity is crucial for maintaining the balance between grasslands and livestock. However, accurately assessing this capacity presents significant challenges due to the high costs of biomass measurement and the impact of human activities. In this study, we propose a novel method to estimate grassland carrying capacity based on potential net primary productivity (NPP), applied to the source area of the Nujiang River and Selinco Lake on the Tibetan Plateau. Initially, we utilize multisource remote sensing data—including soil, topography, and climate information—and employ the random forest regression algorithm to model potential NPP in areas where grazing is banned. The construction of the random forest model involves rigorous feature selection and hyperparameter optimization, enhancing the model’s accuracy. Next, we apply this trained model to areas with grazing, ensuring a more accurate estimation of grassland carrying capacity. Finally, we analyze the spatiotemporal variations in grassland carrying capacity. The main results showed that the model achieved a high level of precision, with a root mean square error (RMSE) of 4.89, indicating reliable predictions of grassland carrying capacity. From 2001 to 2020, the average carrying capacity was estimated at 9.44 SU/km2, demonstrating a spatial distribution that decreases from southeast to northwest. A slight overall increase in carrying capacity was observed, with 65.7% of the area exhibiting an increasing trend, suggesting that climate change has a modest positive effect on the recovery of grassland carrying capacity. Most of the grassland carrying capacity is found in areas below 5000 m in altitude, with alpine meadows and alpine meadow steppes below 4750 m being particularly suitable for grazing. Given that the overall grassland carrying capacity remains low, it is crucial to strictly control local grazing intensity to mitigate the adverse impacts of human activities. This study provides a solid scientific foundation for developing targeted grassland management and protection policies.

Combined Drought Index Using High-Resolution Hydrological Models and Explainable Artificial Intelligence Techniques in Türkiye

We developed a combined drought index to better monitor agricultural drought events. To develop the index, different combinations of the temperature condition index, precipitation condition index, vegetation condition index, soil moisture condition index, gross primary productivity, and normalized difference water index were used to obtain a single drought severity index. To obtain more effective results, a mesoscale hydrologic model was used to obtain soil moisture values. The SHapley Additive exPlanations (SHAP) algorithm was used to calculate the weights for the combined index. To provide input to the SHAP model, crop yield was predicted using a machine learning model, with the training set yielding a correlation coefficient (R) of 0.8, while the test set values were calculated to be 0.68. The representativeness of the new index in drought situations was compared with established indices, including the Standardized Precipitation-Evapotranspiration Index (SPEI) and the Self-Calibrated Palmer Drought Severity Index (scPDSI). The index showed the highest correlation with an R-value of 0.82, followed by the SPEI with 0.7 and scPDSI with 0.48. This study contributes a different perspective for effective detection of agricultural drought events. The integration of an increased volume of data from remote sensing systems with technological advances could facilitate the development of significantly more efficient agricultural drought monitoring systems.

Climate Predicts NDVI Better Than Plant Functional Group Attributes Along a Latitudinal Gradient in Nunavik

ABSTRACTAimThis study aims to describe the latitudinal pattern in plant functional groups' (PFGs') biomass and cover in Nunavik to test whether PFG attributes are better Normalized Difference Vegetation Index (NDVI) predictors than climate.LocationThe study spans a 700‐km latitudinal gradient from the lichen woodland to prostrate shrub tundra vegetation zones across Nunavik, Canada.TaxonOur analysis focuses on the following PFGs: erect and prostrate shrubs, herbaceous plants, bryophytes, and lichens.MethodsBiomass and cover data of the different PFGs were sampled in 40 sites distributed across the latitudinal gradient. NDVI data were obtained through remote sensing, while climatic, permafrost depth, and surficial deposits were derived from various databases. The PFG models were built to explore relationships between average NDVI (2016–2020) at the sampling site and ecological attributes such as PFG biomass or cover but also other variables such as surficial deposits and permafrost depth. A second series of models, the climatic models, were built using only climatic variables such as seasonal temperature and precipitation.ResultsThe most parsimonious PFG model was built with the biomass data of erect shrubs, herbaceous plants, bryophytes, and lichens and included surficial deposits and permafrost depth (R2 = 0.74). This biomass model performed better than the most parsimonious cover model (cover of erect shrubs and herbaceous, surficial deposits, permafrost depth; R2 = 0.63). However, the most parsimonious climatic model (fall temperature, annual, and winter precipitations) exhibited superior predictive power compared to the ecological ones (R2 = 0.87).ConclusionsPFG models built with PFGs aboveground biomass or cover are good predictors of NDVI of the plant formations sampled along the latitudinal gradient in Nunavik. Despite the intrinsic association between NDVI and vegetation attributes, our study emphasizes the importance of the regional climate in the control of primary productivity in Arctic and subarctic ecosystems. This study provides new insights into the interpretation of NDVI data and enhances our understanding of Arctic vegetation responses under rapid climate change. Furthermore, it underscores the balance between climatic drivers and ecological dynamics in shaping fragile Arctic ecosystems.

Analysis of Ecological Environment in the Shanxi Section of the Yellow River Basin and Coal Mining Area Based on Improved Remote Sensing Ecological Index.

As a major coal-producing area, the Shanxi section of the Yellow River Basin has been significantly affected by coal mining activities in the local ecological environment. Therefore, an in-depth study of the ecological evolution in this region holds great scientific significance and practical value. In this study, the Shanxi section of the Yellow River Basin, including its planned coal mining area, was selected as the research subject. An improved remotely sensed ecological index model (NRSEI) integrating the remotely sensed ecological index (RSEI) and net primary productivity (NPP) of vegetation was constructed utilizing the Google Earth Engine platform. The NRSEI time series data from 2003 to 2022 were calculated, and the Sen + Mann-Kendall analysis method was employed to comprehensively assess the ecological environment quality and its evolutionary trends in the study area. The findings in this paper indicate the following data: (1) The contribution of the first principal component of the NRSEI model is more than 70%, and the average correlation coefficient is higher than 0.79. The model effectively integrates the information of multiple ecological indicators and enhances the applicability of regional ecological environment evaluation. (2) Between 2003 and 2022, the ecological environment quality in the Shanxi section of the Yellow River Basin showed an overall upward trend, with the average NRSEI value experiencing phases of fluctuation, increase, decline, and stabilization. The NRSEI values in non-coal mining areas consistently remained higher than those in coal mining areas. (3) Over 60% of the areas have improved ecological conditions, especially in coal mining areas. (4) The impact of coal mining on the ecological environment is significant within a 6 km radius, while the effects gradually diminish in the 6 to 10 km range. This study not only offers a reliable methodology for evaluating ecological environment quality on a large scale and over a long time series but also holds significant guiding value for the ecological restoration and sustainable development of the Shanxi section of the Yellow River Basin and its coal mining area.

Detecting Drought-Related Temporal Effects on Global Net Primary Productivity

Drought has extensive, far-reaching, and long-lasting asymmetric effects on vegetation growth worldwide in the context of global warming. However, to date, few scholars have attempted the systematic quantification of the temporal effects of drought on global vegetation across various vegetation types and diverse climate zones. Addressing this gap, we quantitatively investigated the effects of drought on global vegetation growth under various scenarios, considering lagged and cumulative effects as well as combined effects in the 1982–2018 period. Our investigation was based on long-term net primary productivity (NPP) and two multiple-timescale drought indices: the standardised precipitation index (SPI) and the standardised precipitation and evapotranspiration index (SPEI). Our main findings were the following: (1) SPI and SPEI exhibited lagged effects on 52.08% and 37.05% of global vegetation, leading to average time lags of 2.48 months and 1.76 months, respectively. The cumulative effects of SPI and SPEI were observed in 80.01% and 72.16% of global vegetated areas, respectively, being associated with relatively longer cumulative timescales of 5.60 months and 5.16 months, respectively. (2) Compared to the scenario excluding temporal effects, there were increases in the explanatory powers of SPI and SPEI for variations in vegetation NPP based on the lagged, cumulative, and combined effects of drought: SPI increased by 0.82%, 6.65%, and 6.92%, respectively, whereas SPEI increased by 0.67%, 5.73%, and 6.07%, respectively. The cumulative effects of drought on global vegetation NPP were stronger than the lagged effects in approximately two-thirds (64.95% and 63.52% for SPI and SPEI, respectively) of global vegetated areas. (3) The effects of drought on vegetation NPP varied according to climate zones and vegetation types. Interestingly, vegetation in arid zones was the most sensitive and resilient to drought, as indicated by its rapid response to drought and the longest cumulative timescales. The vegetation NPP in tropical and temperate zones exhibited a relatively stronger response to drought than that in cold and polar zones. The strongest correlation of vegetation NPP with drought occurred in shrubland areas, followed by grassland, cropland, forest, and tundra areas. Moreover, for each vegetation type, the correlations between vegetation NPP and drought differed significantly among most climate zones. (4) The vegetation NPP in warming-induced drought regions displayed a higher correlation to drought than that in non-warming-induced drought regions, with shorter lagged and longer cumulative timescales. Our findings highlight the heterogeneity of the lagged, cumulative, and combined effects of drought across various climate zones and vegetation types; this could enhance our understanding of the coupling relationship between drought and global vegetation.

Intercomparison of gross primary productivity in spatio-temporal distribution over a typical tropical region based on different datasets.

Gross Primary Productivity (GPP) plays a vital role in the carbon cycle of terrestrial ecosystems. For the purpose of assessing the performance of various GPP products in a typical tropical area, this study conducted an intercomparison of seven different GPP products over Hainan Island, China, and analyzed spatiotemporal characteristics of GPP in different elevation regions and vegetation types over study area. The results showed that although the GPP spatial distribution pattern over Hainan Island, as presented by different GPP products, is similar- showing that GPP values in the southwest are higher than those in the northeast- there are significant differences in the spatial distributions and magnitudes of each GPP product. The multi-annual mean GPP values from the seven GPP products exhibited similar temporal variation trends, with GOSIF being obviously higher than other GPP products. The GPP products indicated significant differences in different elevation and vegetation type groups. The GPP gap between GLASS AVHRR and BESS V2 decreases slightly with the increase in elevation. Most GPP products show a consistent change trend over time. There were also significant differences in the results of significance tests for the change trends of GPP products. Though GOSIF is significantly higher than other GPP products, it demonstrated a relatively high correlation with all GPP products, while AGPP exhibited relatively low correlations with all GPP products. The quantitatively comparative analysis of seven different GPP products in this study is valuable for improving GPP retrieval models and can also serve as a scientific reference for the application of GPP products in tropical region vegetation studies.

Analysis of Earnings Quality and Enterprise Valuation of Microsoft by Earnings Quality and Residual Income Model

Artificial intelligence has had a remarkable influence in recent years and has developed many revolutionary solutions in many industries. OpenAI’s ChatGPT is one of the most popular products in this trend. As the largest stockholder of OpenAI, Microsoft has committed itself to integrating artificial intelligence into its primary products, like Microsoft Office and Azure. Although Microsoft experienced a continuous slump in stock in 2022, Microsoft’s current stock price has broken through $400 per share. This paper aims to conduct a financial analysis and forecast Microsoft’s future growth to figure out Microsoft’s intrinsic value. This article uses earnings quality analysis and residual income model to evaluate Microsoft’s financial performance and conduct valuation. Microsoft’s Cash Conversion Cycle has become negative since 2021, so Microsoft can reinvest the cash it receives from sales before using it to pay suppliers. The present value of the continuing value in the Residual Income Model indicates that Microsoft is undervalued compared to the current stock price. Economic conditions and the global supply chain will also influence investors’ expectations, except for quantitative factors. Therefore, Microsoft's stock price fluctuates and does not exceed the forecasted price. This article offers some insights on Microsoft and relevant industry valuation analysis.

The effect of a new 3-hydroxypyridine derivative LHT-2-20 on free radical oxidation in experimental periodontitis

Aim. To study the effect of a new complex compound LHT-2-20 (2-ethyl-6-methyl-3-hydroxypyridine-2-(3benzoyl phenyl)-propanoate) on free radical oxidation in experimental periodontitis.Materials and methods. The experimental study was performed on 195 white mongrel mice weighing 19–23 g and 137 white mongrel rats weighing 180–220 g. The effect of a new complex compound LHT-2-20 (2-ethyl-6methyl-3-hydroxypyridine-2-(3-benzoyl phenyl)-propanoate) on the intensity of free radical oxidation and the local state of periodontal tissues during a course of intragastric administration was studied on the experimental model of periodontitis. Statistical processing of the results was carried out using the SPSS Statistics 20.0 software package with the analysis of variance (ANOVA) and the parametric Tukey’s test.Results. The LHT-2-20 compound reduced elevated levels of primary and secondary lipoperoxidation products (conjugated dienes, malondialdehyde in plasma and in erythrocytes during spontaneous and iron-induced oxidation) already at the early stages of the experiment, bringing the studied parameters closer to the reference values by the end of the course of treatment. The use of the compound LHT-2-20 contributed to an increase in the activity of the main antioxidant enzymes (catalase and superoxide dismutase), normalizing them to baseline values by the end of the experiment. With the correction of free radical processes, the use of LHT-2-20 limited the local inflammatory response in periodontal tissues, which was confirmed by a decrease in gingival edema and hyperemia, bleeding, depth of periodontal pockets, and tooth mobility.Conclusion. The results of this study confirm the anti-inflammatory potential of the compound and the multiplicity of its effects due to the impact on the mechanisms of oxidative stress. The expediency of further study of the drug is justified by the prospect of creating a new drug and its subsequent wide clinical application as part of the complex therapy of periodontal inflammation.

Assessment of bi-metal paleo-redox proxies in the Bakken Formation black shales, Williston Basin, North Dakota, USA

The influence of paleoredox conditions and water-mass restriction on trace metal (TM) accumulation in the lower (LBS) and upper black shales (UBS) of the Devonian–Mississippian (D–M) Bakken Formation was assessed utilizing V/Cr, V/(V + Ni), Ni/Co, U/Th, and enrichment factors (EF) for Mo vs. U. These assessments were compared to previously published estimates based on degree of pyritization (DOPT), sulfur‑iron and C–S–Fe relationships, and sedimentological data. Bi–metal ratios suggest >80 % of samples were deposited under suboxic to anoxic/euxinic conditions, whereas DOPT results suggest >60 % of samples were deposited under dysoxic (0.42–0.75 DOPT) bottom–water conditions. DOPT results are in good agreement with C–S–Fe and total S vs. Fe assessments of paleoredox conditions and sedimentological evidence. Good agreement is also seen between Mo/TOC and Mo EF/U EF that both suggest the Bakken shales were deposited under a relatively unrestricted water mass conditions resulting in consistent renewal of TMs into the basin. With TM resupply outpacing drawdown, the basin could support enhanced primary productivity as well as high concentrations of TMs. Trace metal concentrations for the Bakken Fm. show considerable range for Co (0–10,324 ppm), Mo (0–2018 ppm), Ni (0–1574 ppm), U (0–1604 ppm), and V (0–3194 ppm), and bi–metal ratios for the Bakken Fm. are up to 5× greater than those reported for other D–M black shale formations. Bivariate and principal component analysis indicate Mo, Ni, U, and V accumulation was more closely associated with the organic fraction than with reducing conditions, thus accumulation of organic matter during deposition and generation, migration, and biodegradation of hydrocarbons during diagenesis may have influenced the accumulation and distribution of these TMs. Furthermore, changes in biogeochemical processes during the D–M transition may have fundamentally altered marine chemistry, with the evolution of vascular land plants and enhanced terrestrial weathering leading to an increased influx of nutrients into marine waters resulting in the Annulata, Dasberg, and Hangenberg black shale events. Factors controlling TM accumulation during time of deposition (e.g., TM availability, bottom-water redox conditions, adsorption onto organic matter) and during diagenesis and catagenesis (e.g., alteration and break down of organic matter, movement of fluid hydrocarbons or other basinal fluids) likely contribute to the lack of agreement between redox proxies, and subsequently, the lack of applicability of bi–metal ratios in assessing bottom–water conditions for the Bakken shales. Therefore, it is suggested that these bi-metal redox proxies are not an effective means to describe bottom-water conditions during the deposition of the Bakken shales.