普达措国家公园四种针叶树径向生长对气候因子的响应

运用树木年代学的原理和方法,对普达措国家公园大果红杉、长苞冷杉、高山松和麦吊云杉4个优势针叶树种的年轮宽度进行测量,建立年轮宽度差值年表。分析年表与香格里拉气象站的日、月气候数据的相关性,研究4个优势针叶树种的径向生长对气候因子的响应。结果表明: 大果红杉的年生长速率最高,长苞冷杉的年生长速率最低;4种针叶树径向生长对气候因子的响应存在物种特异性,大果红杉与气候因子的相关性最强,麦吊云杉的径向生长对气候因子的响应不敏感;长苞冷杉树轮宽度年表与上年冬季(11、12月)和当年夏季(7月)的平均温度呈显著正相关;大果红杉树轮宽度年表与生长季早期(6月)温度呈显著正相关,与同期降水量和相对湿度呈显著负相关;而高山松树轮宽度年表与生长季早期(5月)的降水量和相对湿度呈显著正相关,与同期最高温度呈显著负相关,表明高山松的径向生长主要受生长季早期水分可利用性的影响。

Radial growth responses of four coniferous species to climate change in the Potatso National Park,China

Using the principles and methods of dendrochronology, we measured tree-ring width of four dominant coniferous species, i.e., Larix potaninii var. macrocarpa, Picea brachytyla, Pinus densata, and Abies georgei, in the Potatso National Park, and established the tree-ring width resi-dual chronologies. We analyzed the correlation of tree-ring width residual chronologies with daily and monthly climate data from the Shangrila meteorological station to analyze the response of radial growth to climate factors. The results showed that L. potaninii var. macrocarpa had the highest annual growth rate, and A. georgei had the lowest. Radial growth showed species-specific responses to climate changes, with the highest sensitivity of L. potaninii var. macrocarpa and the lowest sensitivity of P. brachytyla. Ring-width chronology of A. georgei correlated positively with mean temperature during previous winter (November and December) and current summer (July). Ring-width chronology of L. potaninii var. macrocarpa correlated positively with temperature during the early-growing season (June), but negatively with precipitation and relative humidity. Ring-width chronology of P. densata correlated positively with precipitation and humidity but negatively with maximum temperature during the early-growing season (May), indicating that its radial growth was primarily influenced by water availability during the early-growing season.