On the morning of August 22, the 9th China Dendrochronology Conference was grandly opened at Lanzhou University. As an important academic event in the field of dendrochronology in China, the conference brought together experts, scholars, and young students from universities and research institutes across the country. Centering on the theme "Tree Rings—Western Environment and Sustainable Development", participants jointly discussed the latest advances, frontier directions, and scientific value of dendrochronology in global change, ecological security, and regional sustainable development.
At the opening ceremony, Ge Quansheng, President of the Geographical Society of China (GSC) and Researcher at the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences; Wang Wei, Vice President of Lanzhou University; Liu Yu, Chair of the Tree-Ring Research Committee of the GSC and Researcher at the Institute of Earth Environment, Chinese Academy of Sciences (IEE, CAS); and Li Yu, Dean of the School of Earth and Environmental Sciences, Lanzhou University, delivered speeches in turn. They introduced relevant situations from the perspectives of the development and future of dendrochronology in China, Lanzhou University's disciplinary accumulation rooted in western China, the scientific value of tree-ring records, and the heritage of tree-ring research in the School of Earth and Environmental Sciences. They expressed expectations that this conference would serve as an opportunity to further strengthen academic exchange and collaborative innovation, and to promote dendrochronology in serving national ecological security and sustainable development in western China. The opening ceremony was moderated by Professor Gou Xiaohua from the School of Earth and Environmental Sciences, Lanzhou University.
Gathering Wisdom to Open New Horizons: Six Invited Plenary Talks Offering Insights into the Future of Tree-Ring Science
After the opening remarks, the conference moved to the invited plenary session. The invited plenary reports were co-moderated by Researcher Liang Eryuan and Researcher Shao Xuemei.
Six experts delivered invited plenary reports on topics including the development of dendrochronology in China, integration of multiple proxy records, regional climate change, forest ecological processes, and large-scale circulation reconstruction, providing participants with a rich and diverse academic exchange.
Researcher Liu Yu from IEE, CAS, presented a report entitled "China in Tree Rings". Starting from ancient Chinese literature's understanding of tree rings, he systematically reviewed the introduction of modern dendrochronology into China, the application of cross-dating methods, and the continuous expansion of research fields. He pointed out that rigorous dating is the foundation of tree-ring research, and that data sharing and international cooperation should be further strengthened, so as to improve the ability to predict the future on the basis of reconstructing the past and understanding the present.
Professor Cheng Hai from Xi'an Jiaotong University delivered a report entitled "Tree Rings and Stalagmites". From the perspectives of scientific innovation, chronology, and integration of multiple proxy records, he explained the complementary value of tree-ring and stalagmite research. Stalagmite records can extend the time scale of research, while tree rings have advantages such as high resolution and precise dating; combining the two can help improve radiocarbon calibration and paleoclimate time series. He advocated developing independent research tools, focusing on pioneering scientific questions, and using past environmental records to identify early warning signals of abrupt climate change.
Professor Gou Xiaohua from Lanzhou University delivered a report entitled "Climate Change and Forest Ecological Responses in the Qilian Mountains". She introduced the scientific significance of the Qilian Mountains as a national ecological security barrier, an important water conservation area, and a region sensitive to climate change. Based on tree-ring reconstructions of Qilian juniper and stable isotope studies, she reviewed millennial-scale drought and temperature changes in the region, as well as characteristics of recent decades such as warming, changes in precipitation patterns, and an increase in extreme events. She pointed out that climate and forest responses in the Qilian Mountains show significant spatiotemporal differences, and that related research can provide scientific support for ecological protection and water resource security.
Professor Yang Bao from Nanjing University delivered a report entitled "Research Progress on Climate Change over the Tibetan Plateau over the Past Millennium". He systematically introduced the application progress of high-resolution proxies such as tree rings in reconstructing temperature and moisture changes over the Tibetan Plateau, identifying regional differences, and analyzing driving mechanisms. He explained the importance of long-term climate records for understanding environmental evolution of the plateau and its global connections.
Researcher Liang Eryuan from the Institute of Tibetan Plateau Research, Chinese Academy of Sciences, delivered a report entitled "Dendroecology: Deciphering Patterns, Processes, and Driving Mechanisms of Forests and Shrublands". Combining long-term plot surveys along alpine treelines and shrubland zones, transplantation experiments, and model analyses, he pointed out that the impacts of climate warming on forest patterns are regulated by multiple processes, including phenological changes, interspecific and intraspecific competition, nutrient limitation, and long-term adaptation. Related research has advanced dendroecology from individual growth responses to comprehensive quantification of forest–shrub interactions and ecosystem dynamics.
Professor Xu Guobao from Northwest University delivered a report entitled "Large-Scale Circulation Reconstructions Based on Tree Rings and Their Impacts on Extreme Events". Combining tree-ring chronologies with historical documents, he introduced reconstruction results of changes in the position of the westerly jet stream over the past approximately 700 years, revealing differential impacts of the jet's north–south shifts on temperature, precipitation, and extreme events in different regions of Europe. He also presented progress in research on atmospheric wave train changes in the Northern Hemisphere. The report pointed out that future changes in the position and amplitude of circulation may further exacerbate extreme climate risks in some regions.
The invited plenary reports by the six experts were rich in content and broad in perspective, covering multiple frontier directions including the development of dendrochronology in China, integration of multiple proxy records, climate and environmental changes in the Qilian Mountains and the Tibetan Plateau, ecological processes of forests and shrublands, large-scale circulation, and extreme events. They not only demonstrated the academic accumulation and innovative vitality of tree-ring research in China, but also brought an academic exchange of both breadth and depth to the participants, laying a good foundation for subsequent thematic discussions of the conference.
Thematic Sessions: Six Directions Converge to Expand the Boundaries of Tree-Ring Science
From the afternoon of August 22 to the afternoon of August 23, the conference set up six thematic sessions in the Lecture Hall of the Yifu Science Building and the Guochang Lecture Hall of the Biology Building. These sessions systematically covered tree-ring dating and dendroclimatology, tree physiology and dendroecology, tree-ring stable isotopes, multi-indicator methods of tree rings and hydrological, glacial, and geomorphological applications, tree-ring data integration and remote sensing simulation and large AI models, as well as the integration of tree rings with multiple types of records such as stalagmites, ice cores, lake sediments, historical documents, and the rise and fall of civilizations. Different research directions converged here, and diverse technical methods inspired one another, jointly outlining a new picture of cross-scale and interdisciplinary development in tree-ring science.
The thematic exchanges showed three distinct trends: a shift from single ring-width indicators to the integrated use of multiple indicators including density, anatomical structure, stable isotopes, and blue intensity parameters; a deepening from statistical correlations to process-based mechanisms such as tree growth, water use, and forest resilience; and a transformation from traditional measurement and reconstruction to intelligent research driven by satellite remote sensing, ecosystem models, machine learning, and artificial intelligence. At the same time, cross-validation between tree rings and lake sediments, stalagmites, ice cores, and historical documents has further extended the temporal depth of environmental change research, providing a more complete chain of evidence for understanding extreme climates, mountain hazards, and the interactions between the natural environment and human societies.
Young scholars also became a highlight of the conference. The Young Scholars Forum featured 22 presentations, focusing on the elevation dependence of hydrothermal conditions, responses to extreme heat and precipitation, and tree resistance and resilience under compound stresses such as drought and fire. Young researchers organically combined tree-ring observations, satellite remote sensing, and ecosystem models, showing vigorous innovative vitality in multi-source data fusion and the analysis of ecological process mechanisms, injecting inexhaustible momentum into the sustainable development of tree-ring science.
The two-day exchange further consolidated academic consensus: future tree-ring research should continue to strengthen long-term observations, sample preservation, and baseline data accumulation; promote the sharing and integration of multi-indicator, multi-regional, and multi-archive data; deepen interdisciplinary cooperation with ecology, climatology, hydrology, geomorphology, archaeology, and artificial intelligence; and, on the basis of rigorous dating and reliable reconstruction, place greater emphasis on process interpretation and predictive capacity building, so as to advance tree-ring science from "recording the past" to "explaining processes, understanding the present, and predicting the future".
Summary and Outlook: Always on the Road
The closing ceremony was moderated by Researcher Liu Yu, Chair of the Tree-Ring Research Committee of the GSC and Researcher at the Institute of Earth Environment, Chinese Academy of Sciences. Professor Chen Zhenju from Shenyang Agricultural University, as the summarizer for Thematic Session 1; Researcher Fan Zexin from the Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences (XTBG, CAS), for Thematic Session 2; Professor Li Qiang from Xi'an Jiaotong University for Thematic Session 3; Professor Wang Xiaochun from Northeast Forestry University for Thematic Session 4; Professor Duan Jianping from Beijing Normal University for Thematic Session 5; and Researcher Lan Jianghu from the Institute of Earth Environment, Chinese Academy of Sciences, for Thematic Session 6, delivered summaries in turn. Professor Wu Xiuchen from Xi'an Jiaotong-Liverpool University delivered the summary for the Young Scholars Forum. They systematically reviewed the major progress and future directions in each field, and expressed gratitude to the speakers, session conveners, staff, and volunteers who worked hard for the successful convening of the conference.
After deliberation by the Tree-Ring Research Committee of the GSC, the 10th China Dendrochronology Conference will be hosted by Xinjiang Normal University and is planned to be held in Urumqi in late August 2028. At the closing ceremony, Professor Ye Mao, Dean of the School of Geography and Tourism of Xinjiang Normal University, presented the proposal to host the 10th China Dendrochronology Conference. The next conference will build on Xinjiang's tree-ring research foundation in cold and arid regions and its geographical advantage in connecting with Central Asia, further deepening domestic and international academic exchange and expanding the regional and international influence of tree-ring science research in China.
One ring records the passage of time; one gathering unites academic strength. Although the 9th China Dendrochronology Conference has drawn to a close, the exploration of tree-ring science continues. In the face of global change and sustainable development in western China, we look forward to tree-ring scholars across the country continuing to work hand in hand, using tree rings as a bond, western China as a window, and global change as the backdrop, to jointly promote new progress in theoretical innovation, methodological breakthroughs, data integration, and international cooperation in China's dendrochronology.
