【目的】研究树木的生长机制能够为树木年轮学以及重建高分辨率环境演变历史提供重要途径和基础,在高分辨率的基础上分析不同林龄树木径向生长对气候的响应特征,能更好地规划被监测树种在不同林龄的生存策略。【方法】利用带状树干径向测量仪于2017年7月—2018年7月对福建省将乐国有林场不同林龄的杉木(Cunninghamia lanceolata)进行监测,以最大值法提取日径向生长量,用Gompertz模型对累积径向变化值进行模拟,利用偏相关分析研究不同林龄杉木的年内径向变化特征及其对气象因子的响应。【结果】在生长季,不同林龄杉木的日径向变化都呈现相似的周期性(包括收缩期、膨胀恢复期和生长期3个阶段)。不同林龄的日径向变化程度不同,日振幅随着林龄增加而增大。杉木的年生长期较长,且不同林龄的年生长期随林龄增加逐渐缩短,生长季开始的时间却随着林龄增大而向后推移。幼龄林、中龄林、近熟林生长期分别为:2月初—10月末、2月末—9月末、3月初—7月末,且分别在5月末、5月初、4月末达到生长速率最大值。不同林龄杉木径向生长对于气象因子的敏感性呈下降趋势:幼龄林杉木生长主要受到降水、最低温度、平均温度、平均相对湿度的影响;中龄林杉木生长主要受到降水、最小相对湿度的影响;而在近熟林和成熟林中,气象因子与杉木生长没有显著的相关关系。【结论】在未来气候变化的背景下,气象因子的变化可能会逐渐影响到林龄较小的林分,因此对将乐杉木人工林进行经营时要因地制宜,针对不同林龄的杉木林应采取不同的营林措施。

【Objective】The study of tree growth mechanisms can provide an important foundation for dendrophology and reconstruction of high-resolution environmental evolution history. By analyzing the response characteristics of radial growth of trees in different ages to climate on an hourly basis,superior survival strategies can be developed for trees monitored at different ages.【Method】In the Jiangle National Forest Farm of Fujian Province, a band-dendrometer was used to monitor Cunninghamia lanceolata within forests of different ages from July 2017 to July 2018. The maximum radial growth was extracted using the maximum method, and the cumulative radial variation was simulated using the Gompertz model to analyze the annual radial variation characteristics of C. lanceolata and its response to meteorological factors.【Result】During the growing season, the daily radial changes at different ages of C. lanceolata showed similar periodicity, including systolic period, expansion recovery period and increase period. The daily radial variation of different forest ages was diverse and the daily amplitude increased with the increase in forest age. The annual growth period of C. lanceolata is relatively long, and the growth period of different ages of C. lanceolata increased gradually with the increase in forest age, but at the beginning of the growing season an opposite effect was observed. The growing seasons were as follows: early February to late October (young forest); late February to September (middle-aged forest); early March to late July (near-mature forest); and C. lanceolata did not grow in mature forests. The growth rate reached the maximum at the end of May, the beginning of May, and the end of April, respectively, in each growing season. The sensitivity of the radial growth of C. lanceolata to meteorological factors at different forest ages showed a downward trend. The growth of C. lanceolata in young forests was mainly affected by precipitation, minimum temperature, average temperature, and average relative humidity. The growth of C. lanceolata in middle-aged forests is mainly affected by precipitation and minimum relative humidity. There was no significant correlation between meteorological factors and the radial growth of C. lanceolata in near-mature and mature forests.【Conclusion】In the context of future climate change, alterations in meteorological factors may gradually affect stands in younger forests. Therefore, the management strategies used for C. lanceolata plantations in Jianle County should be adjusted to local conditions, and forest management measures should be adopted for C. lanceolata forests based on the age of the forest.