Small changes in soil organic carbon (SOC) may have great influences on the climate-carbon (C) cycling feedback. However, there are large uncertainties in predicting the dynamics of SOC in soil ...profiles at the global scale, especially on the role of soil microbial biomass in regulating the vertical distribution of SOC. Here, we developed a database of soil microbial biomass carbon (SMBC), SOC, and soil microbial quotient (SMQ = SMBC/SOC) from 289 soil profiles globally, as well as climate, ecosystem types, and edaphic factors associated with these soil profiles. We assessed the vertical distribution patterns of SMBC and SMQ and the contributions of climate, ecosystem type, and edaphic condition to their vertical patterns. Our results showed that SMBC and SMQ decreased exponentially with soil depth, especially within the 0–40 cm soil depth. SOC also decreased exponentially with depth but in different magnitudes compared to SMBC and SMQ. Edaphic factors (e.g., soil clay content and C/N ratio) had the strongest control on the vertical distributions of SMBC and SMQ, probably by mediating substrate and nutrient supplies for microbial growth in soils. Mean annual temperature and ecosystem types (i.e., forests, grasslands, and croplands) had weak influences on SMBC and SMQ. In contrast, the vertical distribution of SOC was significantly affected by climate and edaphic factors. Climate and ecosystem types likely simultaneously affected multiple factors that control SMBC, such as the distribution of soil clay and nutrients along soil profiles. Overall, our data synthesis provides quantitative information of how SMBC, SMQ, and SOC changed along soil profiles at large spatial scales and identifies important factors that influence their vertical distributions. The findings can help improve the prediction of C cycling in terrestrial ecosystems by incorporating the contribution of soil microbes in Earth system models.
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•A comprehensive dataset was collected for soil organic C and microbial biomass along soil profiles.•Vertical distributions and main driving factors were assessed.•Soil microbial biomass and its ratio to soil organic C decreased with soil depth at large spatial scales.•Edaphic not climatic conditions drove vertical distributions of soil microbial biomass.•This synthesis highlights the importance of microbial roles in soil C cycling.
Many app firms have adopted gamification, aiming at making consumers more engaging and loyal. Given the ambivalent evidence on the effectiveness of gamification, this study proposes that the ...effectiveness of gamification is moderated by the types of game elements, i.e., commensurate and incommensurate. Commensurate elements, such as points, are directly associated with performances such as step counts, and may be perceived by consumers as external incentives to their efforts; whereas incommensurate elements, such as “likes”, are not directly related to performances, and may be considered as avenues to satisfy psychological needs, leading to stronger intrinsic motivation. Results from a longitudinal field study confirm that compared with apps using commensurate elements, apps using incommensurate elements can better help increase intrinsic motivation and further enhance engagement and loyalty.
Saline-sodic soils cover ∼10% of the global land surface and deliver various ecosystem services to human society in the arid/semiarid regions. Flue gas desulfurization gypsum (FGDG), a byproduct from ...coal-fired power plants, is widely used to ameliorate saline-sodic soils. Here, we aimed to quantify the impacts of FGDG application on multiple soil functions across climatic conditions, management practices, and soil types, and to explore how FGDG application affects plant productivity. We conducted a meta-analysis by compiling 2658 pairs of data points with and without FGDG application from 59 locations across China. We found that FGDG application significantly increased crop yield by 91.2% ± 22.5% (mean ± 95% CI) regardless of local climate and soil type, and improved soil quality by reducing soil exchangeable sodium percentage (ESP) by 37.4% ± 9.6% and pH by 8.1% ± 1.7%. Increases in soil productivity were strongly correlated with decreases in soil ESP and pH, suggesting that increases in soil productivity were due to alleviated stress for plant growth. Meanwhile, some heavy elements (e.g., Hg and Ni) increased after FGDG application, likely imposing threats to soil health. Overall, the FGDG application is effective in improving the quality and productivity of saline-sodic soils across China. Our findings suggest that simultaneous assessment of changes in soil water (e.g., water holding capacity and infiltration), nutrient transformation, soil organic matter dynamics, and microbial communities helps disentangle mechanisms that are responsible for optimizing ecosystem service provided by saline-sodic soils after FGDG amendment application.
•FGDG application significantly reduces soil pH and salinity in different magnitudes.•FGDG application significantly increases crop yield and plant seedling emergence.•Enhanced plant productivity after FGDG application is due to reduced soil salinity.•FGDG application may posit negative environmental impacts of saline-sodic soils.
Agroforestry (AF) has the potential to restore degraded lands, provide a broader range of ecosystem goods and services such as carbon (C) sequestration and high biodiversity, and increase soil ...fertility and ecosystem stability through additional C input from trees, erosion prevention, and microclimate improvement. Advantages and processes for global C sequestration in AF are unknown. We used a meta‐analysis of 427 soil C stock data pairs grouped into four main AF systems—alley cropping, windbreaks, silvopastures, and homegardens—and evaluated changes in AF and adjacent control cropland or pasture. Mean soil C stocks in AF (1‐m depth) were 126 Mg C·ha−1, which is 19% more than that in cropland or pasture. The highest C stocks in soil were in subtropical homegardens, AF with younger trees, and topsoil (0–20 cm). Increased soil C stocks in AF were lower than aboveground C stocks in most AF systems, except alley cropping. Homegardens stored the highest C in both aboveground and belowground, especially in the subsoil (20–100 cm). Advantages of AF ecosystem services focusing on mechanisms of belowground C sequestration were analyzed. AF could store 5.3 × 109 Mg additional C in soil on 944 Mha globally, with most in the tropics and subtropics. AF systems could greatly contribute to global soil C sequestration if used in larger areas. Future investigations of AF should include (a) mechanistic‐ and process‐based studies (instead of common monitoring and inventories), (b) models linking forest and crop growth with soil water and C and nutrient cycling, and (c) accurate assessments of the AF area worldwide based on the remote sensing approaches.
•Making the app “social” is more effective than making it “fun” in helping consumers sustain their efforts in physical activity.•Consumers using the app focusing on social value showed better ...performance in walking and higher intentions to continue using the app.•Fitness apps should help provide social value.
To effectively motivate consumers to continue exercising, many developers gamify the fitness apps, aiming at making work-outs more fun. However, the authors argue that making it fun may not be effective enough to motivate consumers to sustain their efforts. The authors propose that making the apps more social may provide better value and can be more effective in promoting consumers’ participation in physical activity. A longitudinal study was conducted, and participants were recruited for the seven-week fitness-tracking study. Participants were randomly assigned to use one of the two apps: one with game elements focusing on enhancing emotional value (Walkup) and the other with elements focusing on increasing social value (WeChat Sports). Both apps recorded participants’ daily step counts and tracked their physical activities. One week after the fitness-tracking study, participants’ intentions to continue using the app were measured. The results indicate that, compared with the participants using Walkup (focusing on fun), those using WeChat Sports (focusing on social) showed better performance in step counts in each of the seven weeks, and higher intentions to continue exercising with the app. The results indicate that, even though making the fitness app more fun can encourage consumers to adopt and participate in physical activity, making it more social can be more effective in helping them sustain a walking routine in their daily living.
Soil inorganic carbon (SIC) accounts for 30–70% of the total soil C in global drylands. Despite the slow turnover rate, recent studies indicate that SIC could be altered by land-use change as soil ...organic C (SOC). Neglecting SIC change could contribute greatly to the uncertainty of soil C dynamics in drylands. However, due to the spatial-temporal variation in SIC, the direction and magnitude of SIC change (rate) induced by land-use change at a large spatial scale is understudied and poorly understood. Here, we used the space-for-time approach to test how the SIC change varied with the duration and type of land-use change and soil depth across China's drylands. We assessed the temporal and spatial variations in the SIC change rate and explored the influencing factors based on a regional dataset comprising 424 pairs of data across North China. We found that the SIC change rate of 0–200 cm after land-use change was 12.80 (5.47‒20.03) g C m−2 yr−1 (mean with 95% confidence interval), which was comparable to the SOC change rate (14.72, (5.27-24.15 g C m−2 yr−1)). Increased SIC occurred only in deep soils (>30 cm) and in the conversion from deserts to croplands or woodlands. In addition, the SIC change rate decreased with the duration of land-use change, implying that quantifying the temporal pattern of SIC change is necessary to accurately estimate SIC dynamics. The SIC change was strongly related to changes in soil water content. The SIC change rate was weakly and negatively correlated with the SOC change rate, and this relationship varied with soil depth. Together, this study highlights that to improve the prediction of soil C dynamics following land-use change in drylands, we should quantify the temporal and vertical patterns of both soil inorganic and organic C changes in the region.
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•Inorganic C of deep soils increased after land-use change across China's drylands.•The SIC change rate displayed a decreasing trend with duration of land-use change.•The SIC change rates after land-use change were comparable to the SOC change rates.•SIC changes were negatively and weakly correlated with SOC changes.
IntroductionProgressive distal symmetrical axonal neuropathy, a complication of diabetes mellitus (DM), has an unknown cause. Normal physiological metabolism and diabetic dysmetabolism are associated ...with the generation of γ-diketones. γ-Diketones form pyrroles with protein amines, notably with axonal proteins required for the maintenance of nerve fiber integrity, especially elongate, large-diameter peripheral nerve fibers innervating the extremities. We tested the hypothesis that neuropathy-associated γ-diketone pyrroles are elevated in DM.Research design and methodsWe measured the urinary concentration of γ-diketone pyrroles in age-matched and gender-matched elderly (60–84 years) persons with (n=267) or without (n=267) indicators of DM based in a community population (9411 community older adults aged ≥60 years) in Shenzhen city, Guangdong, China. We used statistical methods, including a generalized linear model, multivariate logistic regression analysis and restricted cubic splines, to assess linear and nonlinear relationships between urinary γ-diketone pyrroles and indicators of DM.ResultsCompared with healthy controls, those with DM had significantly higher levels of fasting blood glucose, glycated hemoglobin A1c, urinary ketone bodies and urinary γ-diketone pyrroles. The median concentration of urinary γ-diketone pyrrole adducts was significantly higher (p<0.0001) in individuals with DM (7.5 (5.4) μM) compared with healthy controls (5.9 (4.3) μM). Both linear and non-linear relations were found between urinary γ-diketone pyrroles and indicators of DM.ConclusionsDiabetic dysmetabolism includes increased generation and excretion of neuropathy-associated γ-diketone pyrroles. These findings form the foundation for studies to test whether γ-diketone pyrrole concentration correlates with quantitative sensory (vibration and temperature) and electrodiagnostic testing.
By conducting 2 experiments, I investigated the influence of loneliness on consumers' attitudes toward the degree of anthropomorphism of products (high, medium, or low). In Study 1, I recruited 186 ...participants to categorize a cellphone as hedonic, neutral, or utilitarian, then rate
its anthropomorphism in order to examine the effect of loneliness on consumers' preferences. Results showed that nonlonely consumers preferred products with high, vs. low or medium, anthropomorphism. However, the relationship between the favorite products of lonely consumers and anthropomorphic
degree presented as an inverted U-shaped curve. In Study 2, I recruited 553 participants to extend Study 1 and investigate the moderating role of product category on the loneliness-anthropomorphism preference relationship. Results demonstrated that lonely people preferred hedonic products
with high anthropomorphism and utilitarian products with low anthropomorphism above all others. Thus, I have contributed to loneliness theory and highlighted associated managerial implications.
A central issue faced by many Chinese manufacturing firms is how to absorb and utilize green knowledge shared among supply chain members for superior green innovation. Invoking the indirect research ...stream of organizational learning theory, we develop a moderated mediation model in which absorptive capacity mediates the interactive effects of green knowledge sharing and stakeholder pressure on green innovation. Our hypotheses were tested using a sample of 247 Chinese manufacturing firms. The results from multiple regression and bootstrapping tests reveal that absorptive capacity fully mediates the link between green knowledge sharing and green innovation, and the mediation effect is positively contingent upon stakeholder pressure. These findings provide managerial implications for Chinese manufacturing firms, recommending that these firms effectively develop their absorptive capacities and closely monitor stakeholder pressure to realize the green innovation benefits of green knowledge sharing.
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