Abstract: Treeline is an ideal ecotone to monitor the responses of forests to climate change. However, it is still unclear how treeline respond and adapt to climate change, which is one of key topics in evaluating relationships between climate and alpine forests. We reviewed current understanding of the responses of treeline position and regeneration to climate change. Since the 20th century, treelines showed diverse responses to climatic change in the Northern Hemisphere. However, tree regeneration at treelines showed an overall increasing trend. Simultaneously, tree morality occurred due to warminginduced drought in some regions. In Europe and North America, about 56% studied treelines showed upward shifts, while 44% were stable. In Asia, 64% studied treelines moved upward significantly, while 36% showed little change in treeline elevation or kept stable. We discussed the driving factors for the diverse responses of treeline shifts in the Northern Hemisphere. As indicated by recent studies, treeline shifts in different areas were driven by various climatic and non-climatic factors. Such an understanding is crucial to predict spatio-temporal dynamics of treelines in response to future climate change.

Key words: ecosystem service value, main ecosystem service, dynamic evaluation, driving force