Chin J Plan Ecolo ›› 2015, Vol. 39 ›› Issue (5): 442-452.DOI: 10.17521/cjpe.2015.0043

• Orginal Article • Previous Articles     Next Articles

Relationship of tree growth and climatic factors at treeline of Picea likiangensis var. balfouriana forest in Basu County, Xizang

LIU Juan1,2, DENG Xu1,2, LÜ Li-Xin1,*()   

  1. 1State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    and 2University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2015-01-05 Accepted:2015-03-31 Online:2015-05-01 Published:2015-05-26
  • Contact: Li-Xin LÜ
  • About author:

    # Co-first authors

Abstract: Aims

Temperature is usually hypothesized to be the primary climate factor limiting tree growth at high elevation. We test this hypothesis by investigating the tree growth and climate factors at treeline ecotone on the southeastern Xizang Plateau.

Methods

Tree-ring samples of Picea likiangensis var. balfouriana were collected at treeline ecotone in Kese Village, Bangda Town, Basu County, Xizang. These samples were polished, measured, crossdated, and detrended to produce sequences of tree-ring width indices for each individual sample. Pearson correlation coefficients were calculated among each pair of the individual samples. Correlation between tree-ring sequences and climatic factors (air temperature and precipitation) were also calculated to examine tree-ring responses to air temperature, precipitation.

Important findings

At the treeline ecotone of P. likiangensis var. balfouriana, air temperature had little effect on tree-ring growth. Precipitation in growing season had a strong effect on tree growth with large variation among individual trees. Our results suggest that temperature sensitivity of tree growth might be over-estimated at treeline ecotone on the southeastern Xizang Plateau.

Key words: timberline, growing season precipitation, winter temperature, individual difference, cluster analysis