• 论文 •

### 天目山柳杉树轮δ13C方位变化及成因探讨

1. 1. 南京师范大学地理科学学院,南京210008;
2. 中国科学院南京地理与湖泊研究所湖泊沉积与环境开放实验室 南京210097;
3. 临沂师范学院地理与旅游系,山东临沂276005
• 收稿日期:2005-06-22 修回日期:2005-11-03 出版日期:2006-04-15 发布日期:2006-04-15
• 作者简介:王建(1962-),男,南京师范大学教授,副校长,博士生导师。主要研究方向为地貌演变与地貌过程。 E-mail:jwang@njnu.edu.cn
• 基金资助:

国家重点基础研究发展计划(2003CB415201);国家自然科学基金资助项目(49771001)

### An investigation into the causes of the azimuth variations of δ13C in Cryptomeria fortunei tree rings at Tianmu Mountain

WANG Jian1, ZHAO Xing-yun1,2, QIAN Jun-long3

1. 1. College of Geographical Science,Nanjing Normal University,Nanjing 210097,China;
2. Geography and Tourism Department of Linyi Teachers' College,Linyi,Shandong 276005,China;
3. Lake Sediment and Environment Laboratory,Nanjing Institute of Geography and Limnology,CAS,Nanjing 210008,China
• Received:2005-06-22 Revised:2005-11-03 Online:2006-04-15 Published:2006-04-15

Abstract:

The δ13C annual series in different azimuths of two Cryptomeria fortunei Hooibrenk ex Otto et Dietr（for short CF-1 and CF-3,respectively） tree discs collected from west Tianmu Mountain,Zhejiang Province were determined based on cross-dated tree ring age.The analysis of variance shows that the δ13C values in Cryptomeria fortunei tree rings varied along with azimuths significantly.At the same time,we found the differences of the average δ13C values among azimuths were up to 0.56‰（for CF-3）1.34‰（for CF-1） and the inter-annual variations in each azimuth were up to 0.9‰1.63‰（for CF-1） and 0.6‰1.1‰（for CF-3）.The δ13C variability in space was the same as to the inter-annual.This indicates the study on the azimuth variation of δ13C in tree rings has the same significance to that on the inter-annual variation.The statistical analysis proved that correlation coefficients are highly correlated,ranging from 0.4 to 0.87 for CF-1 and from 0.59 to 0.89 for CF-3 at significance level of α = 0.001 among different azimuths,respectively,as well as from 0.48 to 0.89 for the same azimuths between CF-1 and CF-3 tree discs at significance level of α = 0.001.This indicates that local environmental factors resulting in the δ13C values varying along with azimuths significantly were similar for the two tree rings.In our study,we mainly analyzed the causes that resulted in the differences in the δ13C values at the same azimuths for CF-1 and CF-3 as well as between the different azimuths for both CF-1 and CF-3.The differences of the solar radiation on different tilted surfaces and of the radiant condition（such as radiant intensity and efficient sunlight hours） at the different azimuths on crown of a tree were the most important factors leading to the δ13C variations along with azimuths.The site conditions where the trees stand including latitude,longitude and altitude as well as gradient and slope orientation can affect the variations of the sunlight,microenvironment temperature,humidity and soil nutrient along the different radials and thus affect the variations of δ13C values of tree rings along the azimuths.So the site conditions where the trees were collected are important factors leading to the azimuth variations of the δ13C values in tree rings.