Figure legends
FIGURE 1 (a ) Location of the study site in Jianfengling Nature Reserve (18°53′N, 108°43′E) on Hainan Island, China. (b ) Field experiment set up showing an open-top chamber (OTC) and the treatment layout within an OTC. The experimental unit consisted of two columns of six 40×40 cm quadrats. One column was randomly selected to spray pesticides (Celest Gold and Ridomil Gold) for inhibiting soil-borne pathogens that cause seedling damping-off. The other column was sprayed with the same volume of distilled water. Tree species marked with “**” were the two focal species, Ormosia semicastrata f. litchiifolia and Cyclobalanopsis patelliormis . Their respective congeneric species, O. pinnataand C. hui , were used to test the host specificity of soil-borne pathogens. (c ) Warming magnitude of the OTCs (monthly mean temperatures with 95% bootstrapped confidence intervals), indicating the difference between the soil temperature in the OTCs and the soil temperature in the paired control plots. The horizontal dotted line denotes mean value of the OTC warming magnitude over the three-year field experiment (0.89 °C).
FIGURE 2 Hazard ratios (relative risk) of seedling mortality ofOrmosia semicastrata f. litchiifolia (a ) andCyclobalanopsis patelliformis (b ). The effects of three factors (distance to the parent tree, with pesticides versuswithout pesticides, and OTC warming versus control) on seedling mortality were based on hazard models for modelling seedling survival times by the end of the three-year field experiment. A hazard ratio larger than one indicates an increased hazard of seedling mortality under a treatment versus control (i.e., the baseline reference).n is the number of seedlings per treatment.