Tree-Ring Width, Stable Carbon and Nitrogen Isotopes, and Carbon-to-Nitrogen Ratio of Broadleaved and Coniferous Trees in the Qinling Mountains

The dataset includes tree-ring width (BAI) series, along with stable carbon isotopes (δ¹³Ccor), nitrogen isotopes (δ¹⁵N), and carbon-to-nitrogen ratio (C-N ratio), collected from chestnut (Castanea mollissima), oak (Quercus aliena), and Chinese pine (Pinus tabulaeformis) in the Qinling Mountains.