Centennial-Scale Relative Humidity Reconstruction and Trend Prediction from Pinus massoniana Ring-Widths in the middle Dabie Mountains

Situated in China’s north–south climatic transition belt, the Dabie Mountains are characterized by high climatic variability and a paucity of long-term meteorological records, severely limiting regional climate change research. Here we present the tree-ring width reconstruction of relative humidity (RH) for the Dabie Mountains spanning the past 100 years. Multi-taper spectral analysis and CLM ERA-interim 10 cm soil-moisture data were used to examine the periodicity and spatial representativeness of the RH series, while HadISST1 sea-surface temperature data were employed to identify the teleconnection mechanisms driving moisture variability. On this basis, the SSA-based Caterpillar-SSA v3.40 software was applied to project future RH trends, quantitatively providing the expected range and turning points of regional humidity over the next 15 years. The resulting high-resolution information offers a robust scientific basis for forest management, water-resource allocation, and climate-adaptation strategies in the Dabie Mountains.