关键词: 杉木, 径向生长, 生长季, 林龄, 气候因子, 福建将乐

Abstract:

【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.

Key words: Cunninghamia lanceolate, stem radial variations, growing season, forest age, meteorological factor, Jiangle Fujian Province