Study of the difference in climate response of Dahurian Larch and Pinus sylvestris growth in the north Great Higgnan Mountains of permafrost regions, Northeast China
Based on the Dahurian Larch and Pinus sylvestris tree-ring samples taken from Genhe, Hanma and Huzhong permafrost regions in the north Great Higgnan Mountains, five tree-ring width chronologies were established, and then the basal area increment (BAI) was calculated for the five sites. The response analysis showed that temperature was the dominant factor affecting the tree growth in these regions, with distinct difference between the two species. BAI of Dahurian Larch was significantly and negatively correlated with the monthly average temperature in March. BAI of Pinus sylvestris was significantly and negatively correlated with the monthly averaged temperature from previous December to current April. The climate limiting factor on the radial growth of Dahurian Larch had transformed from a significant negatively correlation with SPEI index in Janurary from 1957 to 1990 into a significant correlation with SPEI index from Janurary to April and temperature in March from 1991 to 2013, and the climate limiting factor for Pinus sylvestris had changed from a significant negative correlation with February and August temperatures from 1957 to 1990 to a significant correlation with precipitation in July and SPEI index from June to July from 1991 to 2013. These results indicated that the two species responding to climate change,especially,to temperature change,was different under the background of global warming,even the climate limiting factor on radial growth would change in different periods for the same species.