Climate-Growth Relationships of Chinese Pine (Pinus tabulaeformis Carr.) at Mt. Shiren in Climatic Transition Zone, Central China.

Tree ring data from the southern boundary of Chinese Pine (Pinus tabulaeformis Carr.) distribution where is the southern warm temperate margin, the paper analyzes the response of climate factors along north-south direction to tree growth. The results show that temperature and precipitation in May-June and relative moisture from March to June are main limiting factors on trees growth; however, the temperature in the south of the mountains and the moisture in the north of the mountains have relatively greater influence on trees' growth. Additionally, we also found that the regional scPDSI(MJ) (that is scPDSI in May-June) was the most significant and stable factor limiting tree growth to be used for reconstruction. The reconstructed scPDSI(MJ) revealed that there were 29 extremely dry years and 30 extremely wet years during 1801-2016, and it could represent the drought variation in central and eastern monsoon region. The variation exists in good agreement with the reconstructed PDSI for Mt. Shennong and the drought/wetness series in Zhengzhou. Further research found that the droughts of May-June in central China were mainly impacted by local temperature and moisture (including precipitation, soil moisture, potential evaporation and water pressure), and then by the northern Pacific Ocean and the northern Atlantic Ocean. These results may provide better understanding of May-June drought variation and service for agricultural production in central China.