植物生态学报 ›› 2010, Vol. 34 ›› Issue (5): 517-525.DOI: 10.3773/j.issn.1005-264x.2010.05.005

• 研究论文 • 上一篇    下一篇

坡向对海拔梯度上祁连圆柏树木生长的影响

彭剑峰1, 勾晓华2,*(), 陈发虎2, 方克艳2, 张芬2   

  1. 1河南大学资源与环境研究所, 河南开封 475004
    2兰州大学西部环境教育部重点实验室, 中-德干旱环境联合研究中心, 兰州 730000
  • 收稿日期:2009-09-08 接受日期:2009-12-03 出版日期:2010-09-08 发布日期:2010-05-01
  • 通讯作者: 勾晓华
  • 作者简介:* E-mail: xhgou@lzu.edu.cn

Influences of slope aspect on the growth of Sabina przewalskii along an elevation gradient in China’s Qinghai Province

PENG Jian-Feng1, GOU Xiao-Hua2,*(), CHEN Fa-Hu2, FANG Ke-Yan2, ZHANG Fen2   

  1. 1Institute of Resource and Environment, Henan University, Kaifeng, Henan 475004, China
    2Center for Arid Environment and Paleoclimate Research (CAEP), and Key Laboratory of Western China’s Environment Systems of the Ministry of Education, Lanzhou University, Lanzhou 730000, China
  • Received:2009-09-08 Accepted:2009-12-03 Online:2010-09-08 Published:2010-05-01
  • Contact: GOU Xiao-Hua

摘要:

选择青海省同德县南部河北林场的一个连续坡面, 根据不同海拔和坡向设置4个采样点, 采集祁连圆柏(Sabina przewalskii)树轮数据, 分析不同海拔和坡向对树木生长的影响。结果表明: 坡面上部3个采样点的树轮年表特征值均呈一定的变化规律——平均敏感值(MS)和标准差(SD)随海拔升高而增大, 一阶自相关(AC)随海拔升高而递减, 下限年表特征值均表现出与其他3点的不同, 都是最值(MSSD均最大, AC最小); 年表间相关和主成分分析结果都显示出海拔梯度上的变化规律, 但下限差异显著; 树轮指数与当年6-8月平均气温的相关系数呈增强趋势, 森林上限受当年7、8月平均气温影响较大, 下限树轮指数不仅与当年6月和前一年11月的气温显著负相关, 而且受前一年8月和当年5月的月降水量影响显著。与通常情况“下限树木生长受降水制约”比较, 这里的温度作用增强而降水限制减弱。显然, 坡向扭转是海拔梯度上影响祁连圆柏生长变化的重要因子。

关键词: 海拔梯度, 气候响应, 祁连圆柏, 坡向, 树轮指数

Abstract:

Aims Our objective was to collect tree-ring data of Sabina przewalskii and analyze the effects of elevation and aspect on tree growth.

Methods We collected tree ring samples from four sample sites that differed by elevation and slope aspect on a continuous mountain slope of Hebei Forest Farm in southern Tongde County, eastern Anymaqen Mountains, Qinghai Province. We analyzed relationships among the four tree ring-width chronologies using correlation and Principal Component Analysis (PCA) and made simple correlation function analysis between tree-ring width index and climate factors by Dendro2002 software.

Important findings Tree-ring chronological eigenvalues indicated the upper three sites had similar variation, but differed from the low-elevation chronology. Correlations among chronologies and results of PCA showed there was change along the altitude gradient. Correlations between tree-ring index and mean temperature in current June-August trended to increase, and the upper treeline was mainly determined by mean temperature of current July and August. There were significantly negative correlations between tree-ring index of the low sampling sites and temperature of prior November and current June and significant positive correlations between tree-ring index of the low sampling sites and precipitations of prior August and current May. Compared to the usual situation of tree-growth at lower elevation limits being constrained by precipitation results indicated an enhanced role of temperature and a reduced role of precipitation. Slope aspect played an important role in the growth of S. przewalskii along the elevation gradient.

Key words: elevation gradient, response to climate, Sabina przewalskii, slope aspect, tree-ring index