第七届青年地学论坛

Xinjiang Uyghur Autonomous Region, the largest provincial division of China with an area over 1.6 million km², is located in the continental Asia and extends between 73°40′–96°23′E and 34°25′–49°10′N. The general topographic structure of Xinjiang consists of three mountain ranges with two basins in between. From north to south, the mountain ranges and basins are the Altay Mountains, the Junngar Basin, the Tienshan Mountains, the Tarim Basin, and the Kunlun Mountains. The complex topography and inland locations receives little water vapor in the ocean, where the Pacific, the Atlantic and Arctic Ocean water hardly reach. Therefore, climate change on multiple timescales in Xinjiang is vital to be investigated under the global warming context. Instrumental meteorological observation is too short for trying to estimate climate change and variability. To access information about the climate system predating instrumental observations, reliable proxy records (natural archives) are necessary. Tree rings is one of the most widely used proxy for high-resolution climate reconstructions during the past time in terms of its precise dating and duplication. The widely distributed Siberian larch (Larix sibirica Ledb.) and schrenk spruce (Picea schrenkiana Fisch. et Mey) favored the dendroclimatogy study in Xinjiang and have made considerable progress. The main advances included a significant increase in the spatial coverage of tree-ring chronologies developed for climate reconstruction. New tree-ring sampling sites have been established across the Tienshan Mountains, the Altay Mountains, and the inland river basins. Tree-ring chronologies longer than 600 years are mostly found in western Tienshan Mountains, while records around 200 years are commonly derived in the east ranges. Tree growth is sensitive to growing season temperature in upper treeline along Altay Mountains, and chronologies spanning 400 years have been collected. Hydroclimatic variations in the main inland river basin, including the Yili, Urumuqi, and Manasi River, were developed over the past 300 years. Tree-ring width is the most commonly studied parameter, although stable isotope ratios and wood density data have also been obtained for specific sites. Stable oxygen isotope data frequently shares a common hydroclimate signal, and density data respond to temperature variability. In general, tree-ring width-based temperature reconstructions originate from higher elevation sites compared to hydroclimate reconstructions. Most of the tree ring reconstructions are based on individual site or local-scale chronologies, although a limited number of regional-scale and field reconstructions have been developed. Climate dynamics aiming at exploring the linkage between local climate variability and the large atmospheric circulation are implied by tree rings. Future dendroclimatological study in Xinjiang shall focus on multiple tree ring index combination, the tree growth/climate mechanism and response to extreme climate events.

tree ring; tree growth; climate change; climate variation; climate reconstruction; temperature; hydroclimate; Xinjiang