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Afforestation is a national policy in China, yet the impact of afforestation on the accumulation of organic matter within this ecosystem of the Yellow River Economic Zone (YREZ) remains somewhat elusive. This study, characterized by its comprehensiveness, included an array of data streams encompassing MODIS-derived gross primary productivity (GPP) data, meteorological insights, topographical particulars, land usage categorizations, population density metrics, and nocturnal luminosity records. The Theil-Sen median estimator, Mann–Kendall significance test, partial correlation coefficient analysis, and geodetector model were applied to assess the spatiotemporal characteristics of GPP and reveal the factors influencing the spatial heterogeneity of GPP within the YREZ and its provinces. The findings revealed a consistent ascending trajectory of GPP within the YREZ from 2000 to 2021. Shaanxi and Shanxi Provinces exhibited notably greater GPP increases, surpassing 80.00%, and outperformed Inner Mongolia and Henan. Spatial heterogeneity was chiefly driven by relative humidity and precipitation, except in Henan, where human factors had a greater influence. The land use category exerted a considerable impact on the spatial arrangement of GPP. The interplay between precipitation and land use type predominantly caused GPP heterogeneity in the economic sphere, while other factors played pivotal roles within the provinces. Precipitation and temperature had predominantly positive effects on GPP variation, with Inner Mongolia and Shanxi experiencing discernible positive effects fueled by precipitation. Overall, this study unravels the trajectory of GPP evolution, engendering an exhaustive understanding of the propelling forces engendering its variegated spatial disparities in the YREZ. • A substantial 97.49% of the YREZ witnessed an increase in GPP. • Human factors dominated the spatial heterogeneity of GPP in Henan. • The interaction between land use type and climate factors took precedence in the YREZ. • GPP in the YREZ exhibited positive correlations with precipitation and temperature. • Urbanization expansion, at the expense of farmland land and forest land, inhibited GPP growth. [ABSTRACT FROM AUTHOR]

The Jiawula Ag–Pb–Zn deposit lies in the renowned Ag–polymetallic metallogenic province of northern China. The origin of this structurally controlled ore body is linked to fluid migration and mineralization along cogenetic fault systems. Sulphur isotopic compositions suggest that the ore-forming aqueous solutions were derived mainly from deep magmatic fluids. Hydrogen and oxygen isotopic compositions indicate that these fluids were magmatic during early stages of ore formation and meteoric during late-stage mineralization. Lead isotopic compositions indicate that this metal was derived mainly from a mantle source, and to a lesser extent from a crustal source. Collectively, the isotopic data indicate that formation of the Jiawula Ag–Pb–Zn deposit was ultimately a reflection of late Yanshanian (140–120 Ma) volcanic–subvolcanic hydrothermal activity. The addition of meteoric water to these magmatic hydrothermal fluids created favourable conditions for mineralization. During ore formation, metallogenesis took place in a relatively open, non-equilibrium system under conditions of low δ34S∑S and an intermediate oxidation state. Microthermometric study of fluid inclusions indicates homogenization temperatures of 180–260°C. Salinities, densities, pressure, and depth of ore-forming fluids ranged from 0.18 to 12.62 wt.% NaCl eqv., 0.637 to 0.976 g/cm3, 3.44 to 162.05 bar, and 0.5 to 1.5 km, respectively. Laser Raman studies of single-phase fluid inclusions show that the ore-forming fluids belong to the H2O–NaCl system. Analysis of bulk chemical compositions of fluid inclusions indicates that the ore-forming fluid can be classified as the Na+–Ca2+– –Cl− fluid type. All obtained geochemical data demonstrate that the ore-forming fluids of the Jiawula Ag–Pb–Zn deposit are medium- to low-temperature, medium- to low-pressure, medium- to low-salinity, and low-density fluids. Based on their compositions, they can be classified into two end-members: magmatic hydrothermal fluid and meteoric water. The key factors allowing for metal transport and precipitation during ore formation include the sourcing of magmatic fluids with high contents of metallogenic elements and the mixing of these hydrothermal fluids with meteoric waters resulting in the formation of a large Ag–Pb–Zn deposit. In terms of genetic type, the Jiawula deposit can be regarded as a volcanic–subvolcanic hydrothermal vein Pb–Zn–Ag ore deposit. [ABSTRACT FROM PUBLISHER]