Chinese Journal of Plant Ecology (植物生态学报) 2013/37:12 PP.1142-1152
Aims The radial growth in Picea meyeri is reportedly limited by different climatic factors at different elevations. Our objectives were to investigate the variations in the responses of radial growth to climate warming, and to determine the distribution pattern along elevational gradient in P. meyeri. Methods We selected four sites representing a range of elevations on the southern slope of Luya Mountain in Shanxi Province, and took increment core samples from trees on each site for establishing tree-ring width chro-nologies along the elevational gradient. Statistical characteristics were computed in order to assess the reliability of the chronologies. Inter-chronology correlation was conducted to determine the growth trends during 1958–1983 and 1984–2007. Person’s correlation was also performed to investigate the relationships between tree growth and climate. At last, the dynamics of growth-climate relationship were analyzed with the moving correlation method to examine the variations of dendroclimatic in response to climate warming. Important findings At the lower elevations, there was a stronger influence of climate on tree growth in P. meyeri during the period 1984–2007 with increasing temperature than during 1958–1983 with decreasing tem-perature; whereas the growth of trees displayed reversed patterns of climate effect between the two periods at higher elevations. The growth and climate relationship in P. meyeri varied with elevations. At 2 060 m a.s.l., the significance level of the relationship between tree growth and July precipitation increased from p < 0.05 during 1958–1983 to p < 0.01 during 1984–2007; a significant negative correlation (p < 0.05) was found between the tree growth and the monthly mean temperature in May–July. At 2 330 m a.s.l., the tree growth showed a highly sig-nificant positive correlation (p < 0.01) with July precipitation during 1958–1983, but was not significantly related to any of the climate factors during 1984–2007. In contrast, the growth of trees did not show any significant rela-tionship with climate during 1958–1983 at 2 440 m a.s.l., but it was found to be significantly (p < 0.05) and nega-tively correlated with monthly mean temperature in October of the previous season during 1984–2007. At 2 540 m a.s.l., there was a highly significant (p < 0.01) negative correlation between the tree growth in P. meyeri and the mean temperature in November of the previous season during 1958–1983, and significant (p < 0.05) negative cor-relations were found between the tree growth and monthly mean temperatures in October of the previous season and January of the current season, as well as between the tree growth and the monthly precipitation in June during 1984–2007. According to the moving correlation analysis, with increasing temperature, the influence of main cli-mate factors on growth enhanced at lower elevations whereas weakened at higher elevations, which probably ex-plain the reduced sensitivity of growth response to climate warming at higher elevations in P. meyeri. Our study suggests that climate warming would alter the difference in the relationship between and climate factors caused by elevation gradient in P. meyeri.