Xiaoming Wang, Xiuhai Zhao, Lushuang Gao
Climatic response of Betula ermanii along an altitudinal gradient in the northern slope of Changbai Mountain, China
Dendrobiology 2013, vol. 70: 99-107
http://dx.doi.org/10.12657/denbio.070.011
Abstract: The sensitivity of Betula ermanii tree-ring growth to climate variation over an altitudinal gradient was assessed. Betula ermanii forest grows in the northern slope of Changbai Mountain from approximately 1,700m above sea level (a.s.l.), and forms the upper tree line at nearly 2,100ma.s.l.. Six study sites were constructed along the altitudinal gradient (1,670 to 2,010 m a.s.l.) and ring-width chronologies of Betula ermanii were built. The mean tree-ring series intercorrelation (RBAR) increased with elevation. In principal component analysis, the first unrotated principle component explained 77.1% of the total variance, indicating the tree-ring growth of Beutla ermanii over the altitudinal gradient was governed by regional climate. Correlation function analysis revealed that the radial growth of Betula ermanii was significantly similar in response to climatic conditions. Overall, the low temperatures during previous June, July and during the dormant period (previous October to current May) and the high temperatures during current June, July and August would benefit the radial growth of Betula ermanii. Abundant precipitation during growing season (previous June, July, September and current August), previous November and current May, would also facilitate the tree-ring growth. The reason for this uniform growth behavior in Betula ermanii remained unclear. Betula ermanii in Changbai Mountain formed relatively pure stands with an open canopy, which might be partly contributing to the common growth response to climatic signals along the altitudinal gradient, but further work was required for testing this assumption.
Additional key words: temperature, precipitation, dendroclimatology, tree line, tree ring