雪松年内径向生长节律研究

Intra-annual Radial Growth Rhythm of Cedrus deodara

研究树木年内径向生长规律(intra-annual radial growth)可以为树木生长对气候变化响应研究提供高分辨率基础数据。以雪松为研究对象,采用微树芯技术通过室内制作石蜡切片的方法观察雪松形成层和木质部细胞在生长季期间的活动过程,运用Gompertz函数模拟雪松径向生长的过程,探讨分析洛阳地区针叶树雪松树木年内径向生长节律,并结合气象数据,分析温度、降水量与年内径向生长的关系。结果表明:1)在生长季期间,形成层和扩大加厚期细胞活动呈现双峰分布,木质部细胞积累过程呈现“S”型曲线。2)通过Gompertz函数模拟雪松生长过程,发现在第162天,径向生长细胞个数和长度均出现最大值,分别为1.15个/d、36.7μm/d。年内平均累计生长细胞个数达到178.3个,年内平均累计生长量达到5276.7μm。3)年内径向生长的进程受日均气温和日均降水量的共同影响,温度在生长季不同时期表现为不同的相关性,降水量在生长季期间表现为正相关。

Studies on the intra-annual radial growth can provide high-resolution basic data for the understanding of the tree growth response to climate changes.In this study,living cedar(Cedrus deodara)trees growing in Luoyang were taken as the research objects.The micro tree core technology was adopted to collected samples,from which the paraffin sections were prepared.The cedar cambium and xylem cell activity processes during the growing season were observed.The process of radial growth was simulated by using Gompertz function.The annul radial growth rhythm of the cedar trees were analyzed.Combined with meteorological data,the relationships between annual radial growth and temperature&precipitation were analyzed.The results showed that 1)during the growth season,the cambium and the cell activity in the thickening phase showed bimodal distribution,and the accumulation process of xylem cells presented an S-shaped curve.2)The simulation of growth process by Gompertz function revealed the maximum number(1.15/d)and length of radial growth cells(36.7μm/d)at about the 162th day.The average number of cells growing in a year was 178.3,and the average number of cells grown in a year was 5276.7μm.3)The radial growth process in a year was affected by the daily average temperature and the daily average precipitation.The temperature showed different correlations in different periods of the growing season,while the precipitation showed a positive correlation in the growing season.The results of this study can provide data support for further prediction of the growth trend of trees under global climate change.