*2.3. Sample Prepartion and Ring-Width Measurement*

Before mounting, the collected increment cores were dried in air to avoid their shrinkage in the mount. When the dried cores were mounted on wooden sticks, the direction of the tracheids was kept vertical. The cross plans of the mounted cores were sanded using a belt sander unless the ring boundaries were clearly visible. The sanding was started with #80 through #120 and #360 up to #600. The ring boundaries were observed under a stereo microscope (Nikon SMZ, Japan), and the annual ring width was measured to the nearest 0.01 mm using the LINTAB (Rinntech, Germany) measurement system.
