关键词: 光照强度, 荧光特征, 光合特征, 谢君魔芋, 能量分配

Abstract: It is necessary to accurately assess the geographic distribution of Larix gmelinii natural forest and its climatic suitability for forest management. There were eight potential climatic factors influencing L. gmelinii forest’s geographic distribution, including mean temperature of the coldest month (T_c), mean temperature of the warmest month (T_w), annual range of monthly mean temperature (DTY), accumulated temperature no less than 5 ℃ (GDD₅), annual precipitation (P), precipitation in autumn and winter (P_a&w), moisture index (MI) and solar radiation(RAD). We confirmed the dominant climatic factors using the MaxEnt model and Jackknife analysis method. The results showed that T_c, DTY, RAD and GDD₅ were the dominant climatic factors for the distribution of L. gmelinii natural forest, and the cumulative contribution rate of these factors reached 87.8%. This indicated that thermal factors (temperature and solar radiation) were the key factors rather than water conditions. The relationship between the distribution of L. gmelinii forest and the dominant climatic factors was developed by the MaxEnt model, whose accuracy reached the “excellent” level with an AUC value of 0.956. Furthermore, the distribution of L. gmelinii natural forest in China mainly located in low and moderate climatic suitability zones. The thresholds of the four dominant climatic factors were given by their relationship with the geographic distribution probability of L. gmelinii, i.e., -28.8 ℃≤T_c ≤-19.5 ℃; 39.0 ℃≤DTY≤46.2 ℃; 2871.7 MJ·m^-2≤RAD≤3519.8 MJ·m^-2; 1000.0 ℃·d≤GDD₅≤ 2100.0 ℃·d.

Key words: Amorphophallus xiei, fluorescence characteristics, light intensity, photosynthetic characteristics., energy partitioning