小兴安岭北部原始阔叶红松林红松结实气候敏感性及其种子年机制探讨

选取林分较为稳定的原始阔叶红松林作为研究地点，分析近16年的红松结实动态，研究红松（Pinus koraiensis）结实的气候敏感性及其种子年机制。首先按资源限制理论分析了红松结实的资源限制性，再根据资源匹配（气候假说）理论和Nicholls关于产量研究的建议将红松种子产量分解为趋势产量和气候产量，利用红松气候产量与前3年的气象数据进行气候影响分析，并且结合前期的物候观测，找出了红松结实的气候敏感阶段及其敏感的气象指标。结果显示：（1）红松当年种子产量与去年和前年产量和呈显著负相关，二者呈指数关系，表明了红松结实中资源限制机制的存在。并且资源限制可能是球果成熟对同年其它生殖发育的单向自我营养限制关系。（2）去年与前年6月平均气温的差值（ΔT₆）对当年红松种子产量具有很好的预测性。（3）花原基形成期是红松结实最为关键的气候敏感期，红松气候产量与此阶段气温和日照呈极显著负相关，与降水呈极显著正相关。（4）部分年份异常高温已经超出了花原基形成的最适温度范围，导致了红松产量的下降。（5）红松结实在生殖发育期内不同阶段都对气候变化表现敏感，红松种子年现象受到了资源限制机制和资源匹配机制的共同作用。本研究结果预示了温度升高，尤其是在气温升高过快的地区，红松结实对气候变暖具有一定的脆弱性并可能成为未来红松天然更新的重要瓶颈。

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(ΔT₆) 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.