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Karst regions are exceptionally responsive to global change with their harsh natural environment, fragile ecology, and acute human-land conflicts. The reconstruction of cropland spatial pattern in karst areas during the historical period is typical for studying human-land relations in karst areas and has important practical significance for climate study. The ecological environment changes at regional and global scales, primarily to provide essential data and a theoretical basis for studying the inverse evolution of rock desertification in karst areas. Guizhou province, a typical karst area, was selected as the research area in 1820. Based on the correction of historical population data and cropland data, a reconstruction model of cropland spatial pattern in karst areas during the historical period was constructed by selecting factors such as elevation, slope, soil types, organic matter content, climatic productivity potential, distance to river and distance from settlements to reconstruct the spatial pattern distribution of cropland in 1820 of Guizhou. The results show that the data on cropland recorded in Guizhou during the Qing dynasty is too low, mainly due to Yin-Ni and the policy of Tu-Di-Mian-Ke. In 1820, the total area of revised cropland in Guizhou was 1,851,792 hm2, with the highest proportion of 14.32% in Dading Fu and the lowest in Songtao Ting at 1.6%. Only 30% of the grid in Guizhou has a cropland distribution. It is mainly concentrated in the central part of Qianzhong District (Anshun and Guiyang Fu), the southern part of Qianbei District (Pingyue Fu and southern Zunyi Fu), the western part of Qiandongnan District, the central and eastern parts of the Qiandongbei District. The overall average reclamation rate of land in Guizhou is 10.93%, the highest reclamation intensity in Qianzhong District, with 8.5% of grids ≥ 50%, and the smallest in Qianxinan District, with only 1.65% of grids ≥ 50%. The analysis is validated by comparing the reconstruction model and the reconstruction results. It can be seen that the reconstruction model and research results of this paper can more objectively reflect the distribution of cropland in karst areas during the historical period, and the reconstruction model is suitable for karst areas with low productivity levels. [ABSTRACT FROM AUTHOR]

Both runoff and rainfall do not happen at the same time and there is a certain lag in time. The length of lag time and lagged intensity are greatly affected by watershed storage capacity, which is related to the occurrence of droughts. To analyze the spatio-temporal evolution characteristics of rainfall-runoff in this study, lagged index (LI) is to be established based on 11 hydrological stations and 56 rainfall stations during the period 1965–2016 in the Central Guizhou of China (CGC). The results show that (1) the lagged response of runoff to rainfall in the CGC mainly shows the lag-3 period (lag-3 month), with the lagged area accounting for greater than 80%; (2) the spatio-temporal distribution difference of lagged intensity at different lagged periods is the lag-2 period/month (Cv = 0.62) < lag-1 period/month (Cv = 0.78) < lag-3 period/month (Cv = 0.82) = current period/month (Cv = 0.82); and (3) the lagged frequency mainly showed the medium frequency in the 1960s–1980s, with the lagged area 29.8–46.7%, and the medium–high frequency (49–59.4%) in the 1990s–2010s. These mean that the watershed lagged effect is the coupling result of four factors (i.e., rainfall, basin water storage, human activities, and lagged period). Thus, this study is to provide the theoretical basis for the drought monitoring and prediction in Karst drainage basin. [ABSTRACT FROM AUTHOR]

Carbonate rock chemical weathering carbon sinks reduce the rate of increase of the atmospheric CO2 concentration and global warming. However, uncertainty still exists in the estimation results of carbonate rock chemical weathering carbon sink fluxes (CCSF), and the contributions of climate change and ecological restoration to the CCSF are not clear. To this end, we compiled published site data on ion concentrations in different watersheds in China and used a classical thermodynamic dissolution model to reassess the potential and spatial and temporal patterns of the CCSF in China from 1991 to 2020. We quantified the contributions of temperature (MAT), precipitation (MAP), evapotranspiration (ET), soil water (SM), and the normalized difference vegetation index (NDVI) to the CCSF. The results revealed that (1) China's CCSF was 22.76 t CO2 km−2 yr−1, which was higher than the global average (15.771CO2 km−2 yr−1). The total carbonate rock chemical weathering carbon sink (CCS) was 4772.67×104 t CO2, contributing 14.91% of the global CCS through a carbonate rock area of 252.98×104 km−2. (2) China's CCSF decreased gradually from southeast to northwest, with values of 33.14, 12.93, and 7.27 t CO2 km−2 yr−1 in the southern karst, Qinghai-Tibetan karst, and northern karst regions, respectively. (3) The overall CCSF in China exhibited an increasing trend from 1991 to 2020, with a rate of increase of 0.16 t CO2 km−2 yr−1. (4) The contributions of the MAP, MAT, ET, SM, and NDVI to the CCSF were 63.3%, 3.02%, 27.5%, 3.1%, and 3.05%, respectively. Among them, the increase in precipitation was the main contributor to the increase in the CCSF in China over the last 30 years, while the enhancement of ET offset part of the positive contribution of the increase in precipitation to the CCSF. In conclusion, the results of this study provide a systematic quantification of the magnitude, the patterns, and the influencing factors of CCS over a long time series in China. The results are of great significance and provide a reference for the diagnosis and gap analysis of the national and global carbon neutrality capacities. [ABSTRACT FROM AUTHOR]

• Average start of the photosynthetic period in China was on the 123rd day of the year. • The average start of the photosynthetic period advances at a rate of 4.3 d (10 a)−1. • 64% of the region is temperature controlled, others are precipitation controlled. • Importance of temperature and precipitation determined by pre-season precipitation. • Climate change increases NPP by advancing the start of the photosynthetic period. In the context of global warming, the advancement of spring phenology in northern and temperate regions due to increased temperatures has been widely reported. Early and delayed start of the photosynthetic period (SOP) directly affects the vegetation net primary productivity (NPP). However, the interrelationship between climate change, the SOP, and the NPP is unclear. In this paper, we use the dynamics of decadal daily solar-induced chlorophyll fluorescence data to calculate the response of Chinese vegetation photosynthetic phenology to climate change and its impact on the NPP over the last 20 years. The results found that over the last 20 years, the average SOP in China was on the 123rd day of the year, and the SOP has advanced at an average rate of 4.3 d (10 a)−1, with a faster trend of SOP advancement in highland and high-altitude areas. 64% of SOP in China is controlled by temperature; 36% of the SOP in China is controlled by precipitation, and the relative importance of temperature and precipitation was reversed as the precipitation gradient decreased, with SOP dominated by temperature when pre-season precipitation ≧300 mm, and SOP dominated by precipitation when pre-season precipitation ≦300 mm. Finally, we find that climate change indirectly increases vegetation NPP by advancing SOP. Our study emphasizes the importance of precipitation on phenology. It provides a scientific basis for understanding and predicting the response of spring photosynthetic phenology to climate change and the contribution of spring phenology to carbon estimation in terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

• The CUE in karst areas is higher than in non-karst areas, and the WUE is slightly lower than in non-karst areas. • The CUE exhibited an increasing trend, and grassland (7.2 × 10−3 yr−1) increase was the most obvious. • The WUE exhibited a downward trend, shrub land (−8.4 × 10−3 g C kg−1 H 2 O yr−1) decreased most significantly. • Precipitation contributed 57.21% of the increase of CUE and 33.1% of the decrease in the WUE. It is crucial to determine the factors affecting the carbon use efficiency (CUE) and water use efficiency (WUE) of vegetation in ecosystems. However, the relationships between climate changes and CUE and WUE by karst vegetation in China are still unclear. The response of the CUE and WUE to regional climate change was studied by using trend analysis and partial derivative method. In addition, the distribution characteristics of the CUE and WUE of different land use types were analyzed. The following results were found. (1). From 2000 to 2018, the average of CUE in karst areas of China was 0.557, and the average value of WUE was 1.237g C kg−1 H 2 O. (2) The CUE of grassland was higher than that of forest land (0.051), whereas the WUE value of grassland was far lower than that of forest land (1.415 g C kg−1 H 2 O). (3) CUE was affected by precipitation (P), exhibiting an increasing trend (5.5 × 10−3 yr−1), and the most obvious increase occurred in the grassland (7.2 × 10−3 yr−1). Under the influence of solar radiation (SR), the WUE decreased (−1.5 × 10−3 g C kg−1 H 2 O yr−1), and the largest decrease occurred in the shrub land (−8.4 × 10−3 g C kg−1 H 2 O yr−1). (4) 90.31 % CUE increase depended on P and SR, while 78.32 % of the decrease in the WUE was due to P and SR. This study makes important contributions to clarifying the responses of the CUE and WUE of ecosystems to climate changes in karst areas, optimizing the management of regional water and soil resources, and promoting healthy development of the ecological environment. [ABSTRACT FROM AUTHOR]

Ecosystem services (ESs) synergies have been broadly studied, whose synergy control areas and driving mechanisms were still not fully understood. Here, We analyzed soil conservation (SC), water yield (WY), net primary productivity (NPP) and food supply (FS) on the basis of geospatial analysis techniques from 1992 to 2015. The results showed that the SW karst areas contributed 23.7% of SC and 14.56% of NPP with only 8.4% of China's continent. 49.28% of China's land was synergy control areas, while accounted for 82.23% in the SW karst areas. The cause of this phenomenon was twofold, one was the significant increase in NDVI was mainly due to human activities (HA), and the coincidence rates between the HA dominated areas and the synergies control areas up to 90.7%. These results emphasized that ecological engineering was a key factor of the synergy among multi-ESs, the synergy control areas should be priority for ecological restoration. [ABSTRACT FROM AUTHOR]

The global climate change situation partly depends on the climate change policies of countries around the world, including China. Therefore, it is necessary to reasonably reduce carbon emissions (CEs) and increase carbon sink in order to progressively achieve the carbon neutral (CN) goal. However, the capacity and the potential to achieve carbon neutral with the support of its ecosystem, that is to say the carbon neutral capacity (CNC) and potential, are still unclear. To this end, based on China's energy emissions data, meteorological and hydrological data, lithology data, and vegetation data, we used the GEM-CO 2 model, soil respiration model, spatial autocorrelation analysis method and other methods to establish the spatial information map of China city-scale CNC from 1997 to 2017. Furthermore, based on the future climate, vegetation data, CEs data and their influencing factors in 2025–2060, the Back Propagation neural network model was used to predict the CN potential of China's provinces. This study found during the study period, annual CEs of 5.63 Pg CO 2 were not absorbed, which is about 90% of the average annual CEs. And the carbon surplus regions were mainly concentrated in the less developed northeastern and southwestern border regions. Moreover, the change in the CNC in China from 1997 to 2017 was −13.37 Tg/yr, indicating that the CNC of China's terrestrial ecosystems overall reduced. It should be noted that most provinces are not highly polarized, that is, there is no significant differences in CNC between cities in the provinces. Moreover, the scenario simulation's method of IPCC provides a reference for this manuscript, so we set up two future scenarios (A2 and B1 scenarios). In the future, China is expected to achieve a carbon emission peak before 2030 under the B1 scenario while it will continue to grow under the A2 scenario. From 2017 to 2060, the CNC under the two scenarios (A2/B1) will decrease by 44.58% and increase by 15.54%. It follows then that the road to CN in China will be difficult without corresponding policy intervention. In short, this study has clarified China's CNC from the past to the future, as well as CNC's spatial distribution and changing trends. This provided theoretical and data support for China to introduce corresponding zero-carbon solutions based on its understanding of CNC. • The spatial information map of China city-scale carbon neutral capacity (CNC) was established. • Annual CEs of 5.63 Pg CO 2 were not absorbed, which is about 90% of the average annual CEs. • The carbon surplus regions were mainly concentrated in the less developed border regions. • From 2017 to 2060, the CNC under the two scenarios (A2/B1) will decrease by 44.58% and increase by 15.54%. [ABSTRACT FROM AUTHOR]

As part of a study initiating the development of an analytically validated Dietary Supplement Ingredient Database (DSID) in the United States (US), a selection of dietary supplement products were analyzed for their caffeine content. Products sold as tablets, caplets, or capsules and listing at least one caffeine-containing ingredient (including botanicals such as guarana, yerba mate, kola nut, and green tea extract) on the label were selected for analysis based on market share information. Two or three lots of each product were purchased and analyzed using high-pressure liquid chromatography (HPLC). Each analytical run included one or two National Institute of Standards and Technology (NIST) Standard Reference Materials (SRMs) and two products in duplicate. Caffeine intake per serving and per day was calculated using the maximum recommendations on each product label. Laboratory analysis for 53 products showed product means ranging from 1 to 829 mg caffeine/day. For products with a label amount for comparison ( n = 28), 89% ( n = 25) of the products had analytically based caffeine levels/day of between −16% and +16% of the claimed levels. Lot-to-lot variability ( n = 2 or 3) for caffeine in most products (72%) was less than 10%. [ABSTRACT FROM AUTHOR]

To establish an evaluation method for the ecological benefits of rocky desertification control in karst areas, data reference was provided for the benefits of the national comprehensive control project of rocky desertification. This article analyzed the spatiotemporal variation characteristics of soil conservation, water yield, and net primary productivity (NPP) of southwestern China using GIS spatial analysis technology and INVEST Model, the trade-offs and synergistic relationship between ecosystem services and its influencing factors were discussed. The results showed that: (1) During the 15 years, the average value of ecosystem services showed an increasing trend. NPP, water yield, and soil conservation were increased by 43.04 gC/m2, 4.37 mm, and 15.4 t·ha−1, respectively. (2) There was a synergistic relationship between NPP and soil conservation. Increased NPP could improve soil erosion, while water yield exhibited trade-off relationship with NPP and soil conservation. (3) Over the past 15 years, the average comprehensive score of the ecological condition in the study area has increased from 0.30 to 0.31, meanwhile the ecological situation of the study area is gradually improved. (4) Through the analysis of hotspots, we found that more than half of the regions had no hotspots for ecosystem services, meanwhile this region was mainly karst area. Through this study, the trade-offs and synergies between ecosystem services were understood. The ecological benefits of rocky desertification control were evaluated based on the background of ecosystem services, which also provided a reference for the subsequent research on rocky desertification control. [ABSTRACT FROM AUTHOR]

Abstract This work identifies the vegetation communities, landform types and seasons in which vegetation is most sensitive to water imbalance in the karst area of southwestern China. The normalized difference vegetation index (NDVI) and standardized precipitation and evapotranspiration index (SPEI) were used to evaluate the effects of water balance conditions on vegetation in different seasons and at different time scales. During the growing seasons from 1982 to 2013, the vegetation growth in 79% of the study area was statistically significantly sensitive to the water balance condition (p < 0.05). The vegetation in the spring and autumn responded more visibly to water imbalances. The SPEI over the last 6 months was statistically significantly correlated with the monthly maximum NDVI during the growing season over the larger areas compared with the SPEI over other time periods. Therefore, the vegetation was most likely sensitive to six months of water imbalance in this area. Among the selected vegetation types, the shrubland and sparse woodland were the most sensitive to water imbalances, whereas grasslands and forests were less sensitive. The maximum correlation coefficient between the NDVI and SPEI for each karst landform type was statistically significantly different (p < 0.01). The vegetation in the peak-cluster depressions was the most sensitive to water imbalances, whereas the vegetation in the middle and high karst mountains was the least sensitive to water imbalances. Overall, although the climate of the karst region of southwestern China is humid and subtropical, the vegetation is still vulnerable to water imbalances in particular regions and soils. Graphical abstract Unlabelled Image Highlights • Standardized Precipitation and Evapotranspiration Index (SPEI) were applied in karst area. • Water imbalance impacts on vegetation were analyzed. • The vegetation communities and landform types where vegetation growth is most sensitive to water imbalance were identified. [ABSTRACT FROM AUTHOR]

This article illustrates the importance of having analytical data on the vitamin and mineral contents of dietary supplements in nutrition studies, and describes efforts to develop an analytically validated dietary supplement ingredient database (DSID) by a consortium of federal agencies in the USA. Preliminary studies of multivitamin mineral supplements marketed in the USA that were analyzed as candidates for the DSID are summarized. Challenges are summarized, possible future directions are outlined, and some related programs at the Office of Dietary Supplements, National Institutes of Health are described. The DSID should be helpful to researchers in assessing relationships between intakes of vitamins and minerals and health outcomes. [ABSTRACT FROM AUTHOR]

Susceptibilities to fourteen antimicrobial agents important in clinical medicine and agriculture were determined for 752 Escherichia coli isolates of serotypes O26, O103, O111, O128, and O145. Strains of these serotypes may cause urinary tract and enteric infections in humans and have been implicated in infections with Shiga toxin-producing E. coli (STEC). Approximately 50% of the 137 isolates from humans were resistant to ampicillin, sulfamethoxazole, cephalothin, tetracycline, or streptomycin, and approximately 25% were resistant to chloramphenicol, trimethoprim-sulfamethoxazole, or amoxicillin-clavulanic acid. Approximately 50% of the 534 isolates from food animals were resistant to sulfamethoxazole, tetracycline, or streptomycin. Of 195 isolates with STEC-related virulence genes, approximately 40% were resistant to sulfamethoxazole, tetracycline, or streptomycin. Findings from this study suggest antimicrobial resistance is widespread among E. coli O26, O103, O111, O128, and O145 inhabiting humans and food animals. [ABSTRACT FROM AUTHOR]

Abstract: Although an estimated 50% of adults in the United States consume dietary supplements, analytically substantiated data on their bioactive constituents are sparse. Several programs funded by the Office of Dietary Supplements (ODS) at the National Institutes of Health enhance dietary supplement database development and help to better describe the quantitative and qualitative contributions of dietary supplements to total dietary intakes. ODS, in collaboration with the United States Department of Agriculture, is developing a Dietary Supplement Ingredient Database (DSID) verified by chemical analysis. The products chosen initially for analytical verification are adult multivitamin-mineral supplements (MVMs). These products are widely used, analytical methods are available for determining key constituents, and a certified reference material is in development. Also MVMs have no standard scientific, regulatory, or marketplace definitions and have widely varying compositions, characteristics, and bioavailability. Furthermore, the extent to which actual amounts of vitamins and minerals in a product deviate from label values is not known. Ultimately, DSID will prove useful to professionals in permitting more accurate estimation of the contribution of dietary supplements to total dietary intakes of nutrients and better evaluation of the role of dietary supplements in promoting health and well-being. ODS is also collaborating with the National Center for Health Statistics to enhance the National Health and Nutrition Examination Survey dietary supplement label database. The newest ODS effort explores the feasibility and practicality of developing a database of all dietary supplement labels marketed in the US. This article describes these and supporting projects. [Copyright &y& Elsevier]

Abstract: The Nutrient Data Laboratory of the United States Department of Agriculture (USDA) is collaborating with the Office of Dietary Supplements (ODS), the National Center for Health Statistics (NCHS), and other government agencies to design and populate a dietary supplement ingredient database (DSID). This analytically based, publicly available database will provide reliable estimates of vitamin and mineral content of dietary supplement (DS) products. The DSID will initially be populated with multivitamin/mineral (MVM) products because they are the most commonly consumed supplements. Challenges associated with the analysis of MVMs were identified and investigated. A pilot study addressing the identification of appropriate analytical methods, sample preparation protocols, and experienced laboratories for the analysis of 12 vitamins and 11 minerals in adult MVM supplement products was completed. Preliminary studies support the development of additional analytical studies with results that can be applied to the DSID. Total intakes from foods and supplements are needed to evaluate the associations between dietary components and health. The DSID will provide better estimates of actual nutrient intake from supplements than databases that rely on label values alone. [Copyright &y& Elsevier]

Abstract: Several activities of the Office of Dietary Supplements (ODS) at the National Institutes of Health involve enhancement of dietary supplement databases. These include an initiative with US Department of Agriculture to develop an analytically substantiated dietary supplement ingredient database (DSID) and collaboration with the National Center for Health Statistics to enhance the dietary supplement label database in the National Health and Nutrition Examination Survey (NHANES). The many challenges that must be dealt with in developing an analytically supported DSID include categorizing product types in the database, identifying nutrients, and other components of public health interest in these products and prioritizing which will be entered in the database first. Additional tasks include developing methods and reference materials for quantifying the constituents, finding qualified laboratories to measure the constituents, developing appropriate sample handling procedures, and finally developing representative sampling plans. Developing the NHANES dietary supplement label database has other challenges such as collecting information on dietary supplement use from NHANES respondents, constant updating and refining of information obtained, developing default values that can be used if the respondent cannot supply the exact supplement or strength that was consumed, and developing a publicly available label database. Federal partners and the research community are assisting in making an analytically supported dietary supplement database a reality. [Copyright &y& Elsevier]