关键词: 树木年轮, 干扰历史, 气候变化, 老龄树

Abstract: Aims Old trees not only record the climate and environment change information, but also witness the history of social changes. Understanding the history of growth change and disturbance of old trees is useful to accurately assess the health of old trees in the context of global warming and to develop conservation plans. Methods We used tree-ring ecology methods to analyze the disturbance history of the old tree (Pinus tabulaeformis) in the Xishan mountain of Beijing. Important findings There were five major growth suppression (1830–1837, 1855–1869, 1881–1891, 1920–1930 and 1960–2000) and release events (1820–1830, 1869–1881, 1909–1918, 1947–1959, 1960–1970 and 1980–1986). The response analysis of tree growth to climate factors and the historical data showed that drought events and subsequent climatic improvement were the main reasons for growth suppression and release events. Further studies showed that the average growth rate of old trees was 2.70 mm·a–1 before 1840, and then the growth gradually decreased. After 1980, there was an obvious growth suppression, and the annual average growth rate decreased to 0.38 mm·a–1. A stronger negative correlation between tree growth and temperature emerged after 1965, and a significant positive correlation emerged for Palmer Drought Severity Index (PDSI). These results suggest that the warming and drying trend in Beijing in recent years may further negatively affect old trees in the urban area. These results are helpful for further understanding the regularity of forest disturbance in Beijing area during historical period, and are of great significance for accurately assessing the health status of elderly trees under the background of climate change.

Key words: tree-ring, climate change, disturbance history, old trees