Seasonal dynamics of vegetation over the past 100 years inferred from tree rings and climate in Hulunbei'er steppe, northern China

► Monthly NDVI for the semi-arid steppe were extended back more than 100 years. ► It is the easternmost seasonal tree-ring and climate based vegetation variables in China. ► It enriches the climate and environmental research for the region of Northeast Asia. ► It captures local vegetation dense/sparse signals and revealed long-term vegetation variability. ► As a proxy, it has some unique functions and worth to do further researches.