Response of Pinus taiwanensis growth to climate changes at its southern limit of Daiyun Mountain,mainland China Fujian Province

The Pinus taiwanensis trees of a Chinese endemic species form pure forests at infertile sites in humid subtropical China, which can aid soil reservation and ecological resiliency at such sites. Herein, we used dendrochronological methods to investigate the growth patterns and their relationship with climate by analyzing 158 cores of 79 P. taiwanensis trees at 4 sites in their southernmost distribution in mainland China at Daiyun Mountain in Fujian Province. Tree growths at sites with favorable conditions generally showed an age-related growth trend, which decreased from approximately 5 mm to 0.5 mm in about a century. Trees in moderately stressed environments established high growth in their juvenile periods but were highly susceptible to environmental stresses such as a sharp growth decline in the 1990s. The temperature in February and the moisture in July are the major limiting factors for most of the tree growths, except for a few extremely stressed P. taiwanensis trees. The growth of the dwarf P. taiwanensis trees, with all ring diameters of the first 20 years less than 4 mm, is mainly limited by the dry climate in May. Under the potential future warming trend, drought stress can be particularly threatening to these dwarf P. taiwanensis trees, which are likely to be the germplasm resources for this species in this region.