[Response differences of radial growth of Larix gmelinii and Pinus sylvestris var. mongolica to climate change in Daxing'an Mountains, Northeast China]

Abstract

Daxing'an Mountains is one of regions in China with the most significant climate change. Larix gmelinii and Pinus sylvestris var. mongolica are the most important species in this area. The study of their radial growth response to climate change would provide a scientific basis for predicting the dynamics of boreal forests under climate change. A total of 451 tree-ring cores of L. gmelinii and P. sylvestris var. mongolica were collected from six sites in the Daxing'an region, and 12 standard chronologies were established. We compared the tree growth trend since 1900, and analyzed their response to the climate factor in each site using Pearson correlation analysis. Effects of temperature and precipitation on the annual radial growth of L. gmelinii and P. sylvestris var. mongolica were investigated by linear mixed models. The time stability of the relationship between two species growth-climate was compared by moving correlation. The results showed that the radial growth of L. gmelinii was negatively correlated with mean temperature in March and positively correlated with precipitation in the previous winter and July of current year. The radial growth of P. sylvestris var. mongolica was positively correlated with temperature in August and precipitation in the growing season (from May to September) of current year. Snow in winter played an important role in promoting the radial growth of L. gmelinii, whereas precipitation in summer limited the radial growth of P. sylvestris var. mongolica. The responses of L. gmelinii and P. sylvestris var. mongolica to climate change were significantly different, which affected tree growth, species composition, and spatial distribution in the boreal forests.

Keywords: Daxing'an Mountains; Larix gmelinii; Pinus sylvestris var. mongolica.; climate change; tree ring.