Tree-ring researches over the northwest China: a review

Located in the central Eurasian continent and far from oceans, northwestern China is characterized as an extremely dry environment with much higher evaporation than the available precipitation. This area is one of the most severe, unique and typical arid regions in the world. Therefore, this area is not only sensitive to regional climate changes, but may also be closely linked to global change. Climate studies of this region are representative and have a typical significance. However, it is hard to get a comprehensive understanding of the regional climate change because of the lack of meteorological records. Because of its accuracy, continuity, high-resolution, variable measurement accuracy, sensitivity to climatic factors, wide distribution, easy sampling and ease of obtaining a large volume of copies, dendro-science may be the perfect high-resolution climate index. Currently, dendrochronology is widely used in various fields of past environment change. A lot of researches have been developed around the Tianshan and Qilian Mountains. Dendroclimatology, dendroecology and dendrohydrology are applied in these areas. With ring width and density, as well as isotope data, we can reconstruct past environment changes. Long-term chronologies that developed from the middle Qilian Mountains and Qaidam Basin are important for learning paleo-climate change. Through the dendro-science achievements in northwest China as the text introduced, we can see that dendro-science still has a long way to go. This paper summarizes the tree-ring related studies since the early part of the last century in northwest China, which may help give an overview of the dendrochronology studies in this area.