Acta Geographica Sinica ›› 2007, Vol. 62 ›› Issue (7): 742-752.doi: 10.11821/xb200707007

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Hor izontal Var iations of Climatic Response of Qilian Juniper (Juniperus przewalskii) in the Anyemaqen Mountains

PENG Jianfeng1,2, GOU Xiaohua1, CHEN Fahu1, ZHANG Yongxian3, LIU Puxing1,4, ZHANG Yong1, FANG Keyan1   

  1. 1. Center for Arid Environment and Paleoclimate Research (CAEP), Key Laboratory of Western China's Environment Systems MOE, Lanzhou University, Lanzhou 730000, China;
    2. College of Environment and Planning, Henan University, Kaifeng, 475004, China
    3. Institute of Tibetan Plateau Research, CAS, Beijing 100085, China;
    4. College of Geography and Environment Sciences, Northwest Normal University, Lanzhou 730070, China
  • Received:2006-11-16 Revised:2007-04-20 Online:2007-07-25 Published:2007-07-25
  • Supported by:

    National Natural Science Foundation of China, No.40671191,No.40421101; Chinese NSFC Innovation Team Project (No.40421101), Program for New Century Excellent Talents in University (No.NCET-05-0888), Chinese 111 Project (No.B06026)

Abstract:

A spatiotemporal patterns analysis of a network with 20 Qilian juniper (Juniperus przewalskii) tree ring-width chronologies from 5 slopes along a west-east gradient in the Anyemaqen Mountains on the northeastern Qinghai-Tibetn Plateau was performed by means of chronology statistics. Higher SNR and EPS values implied the more climatic information in these chronologies. Most correlations among standard chronologies taken in pairs are significant, with the mean correlation coefficient for all sites being 0.35, indicating that environment condition was consistency. The result of Hierarchical Cluster Analysis showed two well-defined groups at large, corresponding to the two groups, the eastern and the western. Scatter plots of component loadings indicated that stands growing in a similar climate environment are most important on variability of radial growth. The first component of chronologies in east-west regions implied that the center of Qilian juniper (Juniperus przewalskii) growing transplants eastwards along the Anyemaqen Mountains and the eigenvalues (narrow years) tree-growth in the western and the eastern Anyemaqen were synchronous. Correlation between the first principal component (PC1) and the second principal component (PC2) and the climatic factors revealed similarity and differences in radial growth along the west-east gradient in the study area, nevertheless the difference of PC2 is more prominent. Temperature was the main limiting factor to tree growth PC1 in the western Anyemaqen, especially the impact of current late spring and early summer the most significant , and Precipitation was very importance to tree growth, but precipitation was mainly limiting factor of tree growth PC2. Temperature and precipitation held definite commutative.

Key words: Qilian juniper, ring-width chronology, cluster analysis, principal component analysis, climatic response