Sensitivity of Fruiting for Pinus koraiensis to Climate Change and Mechanisms of Masting in the Original Broad-leaved Korean Pine Forest in North Xiaoxing' an Mountain,China
To find out sensitivity of fruiting for Korean pine (Pinus koraiensis) to climate change and mechanisms of masting,we studied Korean pine in the original broad-leaved Korean pine forest which has high stand stability and the yields of Korean pine seeds in nearly 16 years. We decomposed the yields of Korean pine seeds into trend yields and climatic fluctuant yields by resouce switching theory, resource matching theory and the suggestion of Nicholls. Then, we analyzed the influence of weather on climatic fluctuant yields. The results reveal: (1) The current year yields of Korean pine seeds significantly negative correlated with the combined yields of the last 2 years and showed exponential relationship with it,which supports the resource switching hypothesis. And resource switching probably acts as Korean pine cone maturating inhibition among the reproductive processes in a mast year. (2) The temperature difference between the two previous Junes(AT_6) better predicts the yields of Korean pine seeds. (3)The period of bud meristerms development for Korean pine fruiting was the most key climate-sensitive phase. Negative temperature and sunshine duration, coupled with positive precipitation in the period significantly correlated with climatic fluctuant yields of Korean pine. (4) Positive temperature anomaly in some years was beyond the optimum temperature range of the development of bud meristerms and caused reproduction of Korean pine to fall. (5) The yields of Korean pine seeds in many periods of reproductive development was sensitive to climate change, indicating that resource switching and resource matching may be exhibited by a single masting. These findings suggest Korean pine reproduction are vulnerability to climate warms and may be an increasingly important bottleneck for future Korean pine regeneration,especially in areas with greater increases in temperature.