The Relationship Between The Growth Of Larix Gmelinii In The North Alpine Of Great Khingan And The Climate Change

This paper builds chronology of Larix gmelinii Rupr. ex Kuzen. tree-ring width at different altitudes of Aokelidui mountains in the north alpine of Great Khingan, analyzes the changes of climate indices such as average temperature, average maximum temperature, average minimum temperature accumulated temperature and precipitation in study region, use correlation analysis method studies the relationship between radial growth at different altitudes and climate factors, and reveals the influences of climatic change to the growth of Larix gmelinii Rupr. ex Kuzen. in north Great Khingan. The primary results are:(1) Between1960～2008, the rise of temperature in these region is very obvious. The change rate is greater than the national average and the three northeastern provinces of China; meanwhile, the average annual temperature, average annual maximum temperature and average annual minimum temperature are increasing significantly. There is larger increase in winter and spring, a smaller in summer and autumn with the least in autumn.0℃,5℃,10℃,15℃accumulated temperature increased significantly, Rise between50.68～55.2℃·d·10a)-1, The lower boundary temperature standards, the greater the accumulated temperature rise. Accumulated temperature variation much the same over time under different boundary temperature. The precipitation in study region shows a not significantly downward trend. Precipitation changes show seasonal variations. The precipitation remains unchanged in winter, slightly decrease in spring and autumn, and with3.32mm decrease rate per10a, the largest decreases in summer.(2) The Larix gmelinii Rupr. ex Kuzen. in north alpine of Great Khingan is suitable for dendroclimatology studies, and the standard chronologies of ring width is better than residual chronology. Through computing the variation tendency of standard chronologies of ring width, we find that there is a increasing trend in tree-ring width between1960to2010, the largest and the most sensible to climatic change in the middle of slope. The sensibility of larch radial growth to climate is the strongest in the middle of slope, which dues to the growth environment of the trees in sampling spot. In addition, larch ring at different altitude may generate consistent narrow rings or wide rings in some years.(3) Temperature is the main factor that affects the growth of Larix gmelinii Rupr. ex Kuzen. in Aokelidui moutain. Temperature of the previous year’s months7,8,9,10have important impacts on high-altitude larch radial growth, however, this effect weakens with reducing altitude. The temperature of July and August also affect the growth of larch. Temperature changes have different effects on Larix gmelinii Rupr. ex Kuzen. at different altitudes, which mainly dues to the different kinds of climatic conditions at different altitudes, and larches at different altitude will not show the same changes with temperature. The relationship with accumulated temperature and radial growth of mid-elevation larch is closely related. And it is not reach significant levels with other elevation larchs. The effect of precipitation on Larix gmelinii is smaller than temperature, and it is not main limit factor of larch growth in this region. This is determined by the biological characteristics of Larix gmelinii Rupr. ex Kuzen. and climatic characteristics of this region.