Assessing the adaptability of alien (Larix kaempferi) and native (Pinus armandii) tree species at the Baiyunshan Mountain, central China

The tree-ring samples of alien Japanese larch (Larix kaempferi, BYL) and native Chinese white pine (Pinus armandii, MSY) were collected from the Baiyunshan National Nature Reserve, central China. Linear fitting reveals reduced growth of the two tree-species, in particular a sharp reduction in 2004 yr for BYL. The growth pattern indicates that they hold high homogeneity of forest stands and regional environment, and we developed three standard chronologies of BYL, MSY and RC (regional multi-species tree-rings). Correlation results demonstrate varied correlations between RC, BYL, MSY and different climatic factors, but all chronologies are limited by temperature and the restriction of temperature on Japanese larch (BYL) is far greater than that of Chinese white pine (MSY). This may be related to the fact that Japanese larch is an alien species and not adapted to the local hygrothermal climatic conditions. However, as for scPDSI and SPEI, there are negative and insignificant correlations with BYL while positive and significant correlations with MSY in the early or end of the growing season. Finally, we analyzed a sharp reduction of BYL ring-width in 2004 yr, and found that tree growth was limited by February-April high temperature and March-April RH and March SPEI, indicating the BYL growth decline during high temperatures-induced drought.