Changes in plant phenology affect the carbon flux of terrestrial forest ecosystems due to the link between the growing season length and vegetation productivity. Digital camera imagery, which can be ...acquired frequently, has been used to monitor seasonal and annual changes in forest canopy phenology and track critical phenological events. However, quantitative assessment of the structural and biochemical controls of the phenological patterns in camera images has rarely been done. In this study, we used an NDVI (Normalized Difference Vegetation Index) camera to monitor daily variations of vegetation reflectance at visible and near-infrared (NIR) bands with high spatial and temporal resolutions, and found that the infrared camera based NDVI (camera-NDVI) agreed well with the leaf expansion process that was measured by independent manual observations at Harvard Forest, Massachusetts, USA. We also measured the seasonality of canopy structural (leaf area index, LAI) and biochemical properties (leaf chlorophyll and nitrogen content). We found significant linear relationships between camera-NDVI and leaf chlorophyll concentration, and between camera-NDVI and leaf nitrogen content, though weaker relationships between camera-NDVI and LAI. Therefore, we recommend ground-based camera-NDVI as a powerful tool for long-term, near surface observations to monitor canopy development and to estimate leaf chlorophyll, nitrogen status, and LAI.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Accurate estimation of terrestrial gross primary productivity (GPP) remains a challenge despite its importance in the global carbon cycle. Chlorophyll fluorescence (ChlF) has been recently adopted to ...understand photosynthesis and its response to the environment, particularly with remote sensing data. However, it remains unclear how ChlF and photosynthesis are linked at different spatial scales across the growing season. We examined seasonal relationships between ChlF and photosynthesis at the leaf, canopy, and ecosystem scales and explored how leaf‐level ChlF was linked with canopy‐scale solar‐induced chlorophyll fluorescence (SIF) in a temperate deciduous forest at Harvard Forest, Massachusetts, USA. Our results show that ChlF captured the seasonal variations of photosynthesis with significant linear relationships between ChlF and photosynthesis across the growing season over different spatial scales (R2 = 0.73, 0.77, and 0.86 at leaf, canopy, and satellite scales, respectively; P < 0.0001). We developed a model to estimate GPP from the tower‐based measurement of SIF and leaf‐level ChlF parameters. The estimation of GPP from this model agreed well with flux tower observations of GPP (R2 = 0.68; P < 0.0001), demonstrating the potential of SIF for modeling GPP. At the leaf scale, we found that leaf Fq’/Fm’, the fraction of absorbed photons that are used for photochemistry for a light‐adapted measurement from a pulse amplitude modulation fluorometer, was the best leaf fluorescence parameter to correlate with canopy SIF yield (SIF/APAR, R2 = 0.79; P < 0.0001). We also found that canopy SIF and SIF‐derived GPP (GPPSIF) were strongly correlated to leaf‐level biochemistry and canopy structure, including chlorophyll content (R2 = 0.65 for canopy GPPSIF and chlorophyll content; P < 0.0001), leaf area index (LAI) (R2 = 0.35 for canopy GPPSIF and LAI; P < 0.0001), and normalized difference vegetation index (NDVI) (R2 = 0.36 for canopy GPPSIF and NDVI; P < 0.0001). Our results suggest that ChlF can be a powerful tool to track photosynthetic rates at leaf, canopy, and ecosystem scales.
We studied the relationship between fluorescence and photosynthesis at the leaf, canopy, and larger scales using both field‐based and satellite remote sensing data across the entire growing season. We found that fluorescence captured the seasonal variations of photosynthesis with a linear relationship over different spatial scales. Our results suggest that fluorescence is a useful proxy to monitor photosynthesis at leaf, canopy, and ecosystem scales.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Public pension insurance has become a major form of social protection around the world. However, little is known about the association between public pension expansion and individuals' fertility in ...developing economies. In this paper, we examine the effects of the New Rural Pension Scheme (NRPS) on the fertility of married women in rural China. Using data from the China Family Panel Studies (CFPS), the difference-in-differences approach is employed to estimate the impact of NRPS expansion on fertility outcomes. The robustness of results is checked through additional estimations, including difference-in-differences with propensity score matching, fixed-effects model, and instrumental variable approach. Results show that the NRPS expansion has a significantly negative effect on the number of children, and it reduces the likelihood of having a second child. The fertility-reducing effect of the NRPS is larger for the younger, well-educated women and those in high-income families. Considerations of the fertility effects and their population differences are needed in the impact evaluations of relevant public pension reform.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In light of the ongoing coronavirus disease (COVID-19) pandemic, this study aims to examine the relationship between the availability of public health resources and the mortality rate of this ...disease. We conducted empirical analyses using linear regression, a time-varying effect model, and a regression discontinuity design to investigate the association of medical resources with the mortality rate of the COVID-19 patients in Hubei, China. The results showed that the numbers of hospital beds, healthcare system beds, and medical staff per confirmed cases all had significant negative effects on the coronavirus disease mortality rate. Furthermore, in the context of the severe pandemic currently being experienced worldwide, the present study summarized the experience and implications in pandemic prevention and control in Hubei province from the perspective of medical resource integration as follows: First, hospitals' internal medical resources were integrated, breaking interdepartmental barriers. Second, joint pandemic control was realized by integrating regional healthcare system resources. Finally, an external medical resource allocation system was developed.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
There are a few existing studies on whether domestic migration improves China's pension system's fiscal sustainability in the context of rapid urbanization and industrialization. In this paper, we ...systematically investigate the impact of migration on the solvency of the worker's old-age insurance for urban employees by constructing actuarial and econometric models. We use panel data from 2002 to 2018, collected from 31 provinces in China. The results show that the association between migration and the solvency of pensions is an inverted-U shape along the urbanization process. Further regional comparison showed that the above-stated inverted-U curve is more pronounced in the central and western regions. We also established that the number of participants and the contribution base are the main contributors to these results. Our conclusions are important for future population policies and public pension systems in China.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Coastal blue carbon refers to the carbon taken from atmospheric CO
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; fixed by advanced plants (including salt marsh, mangrove, and seagrass), phytoplankton, macroalgae, and marine calcifiers via ...the interaction of plants and microbes; and stored in nearshore sediments and soils; as well as the carbon transported from the coast to the ocean and ocean floor. The carbon sequestration capacity per unit area of coastal blue carbon is far greater than that of the terrestrial carbon pool. The mechanisms and controls of the carbon sink from salt marshes, mangroves, seagrasses, the aquaculture of shellfish and macroalgae, and the microbial carbon pump need to be further studied. The methods to quantify coastal blue carbon include carbon flux measurements, carbon pool measurements, manipulative experiments, and modeling. Restoring, conserving, and enhancing blue carbon will increase carbon sinks and produce carbon credits, which could be traded on the carbon market. The need to tackle climate change and implement China’s commitment to cut carbon emissions requires us to improve studies on coastal blue carbon science and policy. The knowledge learned from coastal blue carbon improves the conservation and restoration of salt marshes, mangroves, and seagrasses; enhances the function of the microbial carbon pump; and promotes sustainable aquaculture, such as ocean ranching.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Although several demographic studies have proposed that the relationship between gender egalitarian attitudes and fertility may depend on gender context of a region, to our knowledge, the interaction ...between contextual- and micro-level egalitarian attitudes has yet to be empirically tested. Using data from the Chinese General Social Survey carried out in 2015, we undertake the Multilevel Logistic Regression Analysis of 130 counties across China to investigate the association between egalitarian attitudes and fertility desires at the individual and county level. The results show that gender egalitarian attitudes are associated with lower fertility desires for both men and women at the individual and county level, and the negative effect is stronger for women than for men. Furthermore, the county-level egalitarian norm shows a positive cross-level interaction effect on desires among women but not among men. In counties with stronger egalitarian norms, women holding egalitarian attitudes have higher fertility desires than others, while in counties with weaker egalitarian norms, the situation is the opposite. Overall, our findings suggest that China is still in the early stages of the transition from a traditional to a gender egalitarian, and thus the actual and desired fertility in China may continue to fall in coming years. However, the positive cross-level interaction effect means that institutional support for promoting gender equality in all areas of life can improve the low fertility trend.
While informal caregiving is crucial for improving and maintaining health of the elderly, there is limited evidence of its potential effect on caregivers' wellbeing. Understanding this effect is ...important for policy makers to design effective long-term care policies. This longitudinal study aims to investigate the impact of informal caregiving on caregivers' subjective wellbeing in China.
Three waves (2016, 2018, 2020) of data from the China Family Panel Studies (CFPS) are constructed for empirical analysis. Ordered logit model is first used to estimate the effect. Fixed effects ordered logit model and mixed effects ordered logit model are further employed to control for the possible bias from unobserved individual heterogeneity.
Informal caregiving significantly reduces caregivers' subjective wellbeing and the negative effect is stronger for high-frequency caregivers. Subgroup analysis reveals that informal caregiving imposed greater negative impacts on women, those living in rural areas, being married, working, and living separately from parents. Further analysis of mechanism indicates that decrease in wage income, leisure and sleep time were channels through which informal caregiving affects caregivers' well-being.
When policy makers formulate sustainable long-term care policies and home support services, interventions to improve caregivers' stress-coping skills and ensure their engagement in leisure and social activities could be adopted to mitigate the negative effects on caregivers' subjective well-being.
The economy system is a complex system, and the complex network is a powerful tool to study its complexity. Here we calculate the economic distance matrices based on annual GDP of nine economic ...sectors from 1995–2010 in 31 Chinese provinces and autonomous regions,11In this paper, we just study the economy structure in Chinese mainland, and Taiwan, Hong Kong and Macao are not involved. In the following parts, we use ‘region’ to represent a province or autonomous region. The relevant economic data contains the annual GDP of nine economic sectors, and are downloaded from http://219.235.129.58/welcome.do, and we introduce the 31 regions in Appendix A simply. then build several spatial economic networks through the threshold method and the Minimal Spanning Tree method. After the analysis on the structure of the networks and the influence of geographic distance, some conclusions are drawn. First, connectivity distribution of a spatial economic network does not follow the power law. Second, according to the network structure, nine economic sectors could be divided into two groups, and there is significant discrepancy of network structure between these two groups. Moreover, the influence of the geographic distance plays an important role on the structure of a spatial economic network, network parameters are changed with the influence of the geographic distance. At last, 2000 km is the critical value for geographic distance: for real estate and finance, the spearman’s rho with l<2000 is bigger than that with l>2000, and the case is opposite for other economic sectors.
•We first study the spatial economic structure from the network perspective.•Connectivity distribution of a spatial economic network does not follow the power law.•There is a significant discrepancy of network structure between different economic sectors.•The extent of the influence of the geographic distance plays an important role on the structure of a spatial economic network.•2000 km is the critical value of geographic distance for its influence on the economic connection in China.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Summary
With the increase in urbanization in China, people's neighborhood has an important influence on their well-being. This study aims to explore the impact of neighborhood mutual support on ...well-being from the perspective of social work. A total of 13,486 samples from the 2016 China Labor-force Dynamics Survey were utilized. The data were analyzed by the ordered logit model and propensity score matching while controlling for individual, family, and socioeconomic features.
Findings
(1) The more the neighborhood mutual support, the higher individuals' degree of well-being; this conclusion is robust. 2) Neighborhood mutual support has a larger improvement effect on the well-being of groups with low social status. (3) Neighborhood mutual support improves well-being through two mechanisms: it can grow an individual's support network, helping them obtain more material support, and it enhances individuals' integration into society, improving their well-being through increased feelings of community security. (4) The influence of neighborhood mutual support is weakened when a community has formal social support (full-time social workers) because individuals can resolve their problems through formal social support, reducing their reliance on neighbors.
Applications
Based on the perspective of community development, understanding the influence of neighborhood mutual support on well-being is important. Social workers should adopt different intervention approaches according to characteristics of different groups to improve residents' level of neighborhood mutual support. Moreover, to promote community development, the government should consider arranging social work for less-developed communities.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
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