| 摘要: |
| 【目的】分析色季拉山急尖长苞冷杉群落对气候变化的响应，探讨不同海拔急尖长苞冷杉林适应全球气候变暖的异同。【方法】以色季拉山优势树种急尖长苞冷杉种群为研究对象，利用树木年代学的方法，结合TASP-Win及ARSTAN程序建立4个海拔梯度（3 700，3 900，4 100和4 300 m）急尖长苞冷杉的树轮宽度标准年表，采用回归分析和Pearson相关分析探究气温突变前后树木径向生长的变化趋势及其与气温和降水量的相关性。【结果】色季拉山气温突变的分界点为1985年，急尖长苞冷杉径向生长趋势对气温突变的响应存在明显分异现象，即不同海拔地区树木的径向生长对气温的响应发生了变化。气温突变前，各海拔梯度的树木径向生长主要受最低气温限制，3 700 m区域与当年7月最低气温呈极显著负相关，4 100 m区域与前一年8月最低气温呈显著负相关；气温突变后，急尖长苞冷杉径向生长受最高气温的促进作用明显，较低海拔（3 700和3 900 m）区域与前一年和当年7-8月最高气温呈显著正相关，较高海拔中4 300 m区域与前一年10月和12月最高气温呈极显著正相关，4 100 m区域虽然仅与当年5月最高气温显著负相关，但却不再受到最低气温的限制。气温突变前，3 700和3 900 m区域急尖长苞冷杉径向生长不受降水限制，4 100 m区域与当年4月降水量呈正相关，4 300 m区域与当年7月降水量呈正相关；气温突变后，3 700 m 区域与当年8月及前一年8月和10月降水量呈负相关，4 100 m区域与降水量不相关。【结论】气温升高可促进高海拔区域急尖长苞冷杉的生长，并提高其生长适应区海拔高度；同时，气候变化导致急尖长苞冷杉径向生长出现分异现象。 |
| 关键词: 升温突变 径向生长 海拔梯度 急尖长苞冷杉 色季拉山 |
| DOI：10.13207/j.jnwafu.2026.01.009 |
| 分类号: |
| 基金项目:国家自然科学基金项目（32371651）；西藏高原森林生态教育部重点实验室研究生创新计划项目（XZAJYBSYS-202412） |
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| Divergent response of radial growth to temperature and precipitation in a population of Abies georgei var.smithii in the Sygera Mountains |
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JIA Yuqi,YU Deshui,REN Yihua,ZHAO Guoqing,ZHOU Penghao,ZHAO Yingxia
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1.Institute of Xizang Plateau Ecology,Xizang Agricultural and Animal Husbandry University,Nyingchi,Xizang 860000,China;2.Key Laboratory of Forest Ecology in Xizang Plateau,Ministry of Education,Nyingchi,Xizang 860000,China;3.Baishan City Academy of Forestry Sciences,Baishan,Jilin 134300,China;4.Linzhi National Forest Ecosystem Observation & Research Station of Xizang,Nyingchi,Xizang 860000,China;5.College of Research and Environment,Xizang Agricultural and Animal Husbandry University,Nyingchi,Xizang 860000,China;6.Key Laboratory of Alpine Vegetation Ecological Security in Xizang,Nyingchi,Xizang 860000,China;7.Linzhi National Forest Ecosystem Observation & Research Station of Xizang,Nyingchi,Xizang 860000,China
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| Abstract: |
| 【Objective】The study aimed to analyze the response of Abies georgei var.smithii (Smith fir) communities in the Sygera Mountains to climate change and to explore the similarities and differences in their adaptation strategies to global warming at different altitudes.【Method】Dendrochronological methods were applied to A.georgei var.smithii communities across four altitudinal gradients (3 700,3 900,4 100,and 4 300 m) in the Sygera Mountains.Standardized tree ring width chronologies for the four altitudinal gradients were developed through the integrated application of TASP-Win and ARSTAN software.Regression analysis and Pearson correlation analysis were adopted to investigate the trends in tree radial growth before and after the abrupt temperature change,and assess the correlations of the tree-ring width index with temperature and precipitation.【Result】The abrupt temperature change in Sygera Mountain was identified with a threshold year of 1985.The radial growth response of A.georgei var.smithii to this climatic shift exhibited significant altitudinal divergence,reflecting altered temperature-growth relationships across altitudes.Before the abrupt temperature change,the radial growth across all elevations exhibited primary constraints from minimum temperatures:the 3 700 m site displayed a highly significant negative correlation with July minimum temperatures of the current year,while the 4 100 m site showed a significant negative correlation with August minimum temperatures of the preceding year.After the abrupt temperature change,radial growth of A.georgei var.smithii was enhanced by maximum temperatures.At lower elevations (3 700 m and 3 900 m),radial growth demonstrated significant positive correlations with maximum temperatures during July-August of both the current and the preceding years.The higher elevation site (4 300 m) exhibited highly significant positive correlations with October and December maximum temperatures of the preceding year.Notably,the 4 100 m site transitioned to a significant negative correlation with May maximum temperatures of the current year,no longer showing minimum temperature limitations.Prior to the abrupt temperature change,radial growth at 3 700 m and 3 900 m was not enhanced by precipitation,whereas the 4 100 m and 4 300 m sites correlated positively with April and July precipitation of the current year,respectively.After the abrupt temperature change,the 3 700 m area was negatively correlated with August precipitation of the current year and August and October precipitation of the previous year,while the 4 100 m area was not correlated with the precipitation.【Conclusion】Climate warming enhances radial growth of A.georgei var.smithii at higher elevations,driving an upward shift in its growth acclimatization zone. Concurrently,climate change has induced elevational divergence in the radial growth of A.georgei var.smithii. |
| Key words: abrupt warming radial growth altitudinal gradient Abies georgei var.smithii Sygera Mountains |
