Growth responses of Larix olgensis forests to climatic drying-warming trend in the northern mountainous region of Jilin Province, northeastern China

ObjectiveLarix olgensis forest in northeastern China has been threatened by significant climatic drying-warming trend. So we need to figure out how stand factors (i.e. forest age, density, volume, etc.) and climatic conditions affect forest growth-climate relationship together.

MethodOur study area was located in Jilin Province, between the northern part of Changbai Mountain and Laoyeling Mountain of northeastern China. We analyzed the relative effects of climatic conditions and stand factors on the growth-climate relationship of Larix olgensis forests with dendrochronological method, in order to study the mechanism regulating the response of L. olgensis forests to climate change.

ResultThe results showed that, in the past 30 years, it had a clear drying-warming trend in the study area, and the growth of L. olgensis forests was significantly affected by changing climate. The growth-climate relationship was affected both by climatic and stand factors, but the influence of climate factors was much stronger. Palmer drought severity index (PDSI) explained 50.72% of variations in growth-climate relationship in PCA 1, indicating that the effects of water were more important than temperature. Stand age also showed a significant effect, stands with older age were more susceptible to growth limitation caused by increased temperature. Other stand factors (e.g. density and volume) did not show significant effects in this study.

ConclusionUnder a drier and warmer future climate, the growth of young L. olgensis forests may be promoted. But the growth of older stands might be limited by the water deficit caused by climate warming. Thus it is necessary to use examined forest management methods to alleviate the vulnerability to climate change, so as to ensure the sustainable development of the L. olgensis forests.