[Variations of Picea crassifolia tree-ring cell structure and their implications to past climate in eastern margin of Qaidam Basin, Northwest China].
Tree-ring samples of Picea crassifolia were collected from the upper tree-line in the eastern mountainous area of Qaidam Basin in Qinghai Province. The tree-ring width and the cell number and size of the tree-ring were measured, and the standard chronologies for the early-wood cell number, late-wood cell number, total cell number of tree-rings, maximum cell size, and minimum cell size were constructed. By using correlation analysis and the response functions between cell characteristic indices and 1970-2000 climate factors at Chaka meteorological station which was close to the sampling site, the relationships between P. crassifolia growth at cell scale and climate factors were discussed. The results showed that the early-wood cell number was positively correlated to the wintertime temperature from previous October to current March, while the late-wood cell number was positively correlated to the minimum temperature in previous November and December and to the mean temperature in current July and August. Both the early-wood and the late-wood cell numbers were negatively correlated to the precipitation in July, and the early-wood cell number was positively correlated to the precipitation in May. The chronology of maximum cell size of early-wood was positively related to the precipitation in February, while that of minimum cell size of late-wood was positivelyrelated to the precipitation in August. It was concluded that the cell number and cell size could not only reveal the information of temperature change, which was recorded by tree ring width as well, but also provide additional information of precipitation. Since different types of tree-ring indices contained different climate information, multiple aspects of climate change information could be extracted from different tree-ring indices of the same species at the same site, and the cell level tree ring characteristics had great potential to supply the information regarding past climate.
Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China. liy04@126.com
Yan
Y
Li
Er-Yuan
EY
Liang
Xue-mei
XM
Shao
D002681:China; D004463:Ecology / Q000379:methods; D028222:Picea / Q000033:anatomy & histology* / Q000166:cytology; D018547:Plant Stems / Q000033:anatomy & histology* / Q000166:cytology; D011891:Rain; D012621:Seasons; D013997:Time Factors; D014887:Weather