Tree-ring-based reconstruction of summer minimum temperature in the Mangui area, Northern Greater Khingan range (1758–2019 CE)

Boreal coniferous forests in the northern Greater Khingan Range of northeastern China are highly sensitive to climate change, and reconstructing long-term climatic records in this region is essential for understanding carbon cycles and ecological carrying capacity. Based on the standardized tree-ring width chronology (STD) of Larix gmelinii from Mangui in the Greater Khingan Range, the responses of tree radial growth to Genhe Meteorological Station (GHS) and Climatic Research Unit (CRU) gridded data were comparatively analyzed. The results show high consistency between GHS and CRU temperature data, but significant discrepancies in precipitation data. Larch growth is limited by annual temperature and exhibits a nonlinear response to August precipitation and Standardized Precipitation Evapotranspiration Index (SPEI) of both the previous and current years. The STD chronology was strongly negatively correlated with the previous-year May–July minimum temperature in both datasets (GHS: r = −0.765; CRU: r = −0.689), with the GHS data showing a stronger climate-growth relationship. Based on this relationship, May–July minimum temperature variations in the study region were reconstructed for 1758–2019 CE. Spatial analysis indicates broad regional coherence between the reconstructed series and temperature variations across Mongolia, southern Siberia, and northern China. The reconstruction identifies major warm and cold periods that are generally consistent with regional proxy records and historical evidence. Periodicity analysis reveals variability at 3–8 years, 9.4–10.1 years, 15.2–19.6 years, and 46.3–51–years timescales, which may be associated with El Niño-Southern Oscillation (ENSO), solar activity, (Pacific Decadal Oscillation) PDO, and Atlantic Multidecadal Oscillation (AMO), respectively. This study enriches high-resolution climatic records for high-latitude East Asia and provides an important historical and scientific basis for assessing the stability and carbon balance of coniferous forest ecosystems under global warming.