Fig. 1

Appearance of a the experimental warming study site using b infrared heaters in an open-field planted with Q. variabilis (Q) and P. densiflora (P) seedlings, and c the experimental design. In April 2010, a total of 16 experimental plots (1 × 1 m with a 2-m buffer between the plots) were established. The soil temperature at a depth of 5 cm and the volumetric soil moisture content at depths from 0 to 10 cm were monitored in the center of each experimental plot using soil temperature sensors (108-LC, Campbell Inc., USA) and soil moisture sensors (CS616, Campbell Inc., USA) (n = 16), respectively