摘要
为研究川西米亚罗林区不同海拔梯度下树木径向生长对干旱事件的响应规律,采集该林区低(海拔3100 m)、中(海拔3300 m)、高(海拔3500 m)海拔紫果云杉树木年轮样芯(共计90根),建立低、中、高海拔树木年轮宽度年表。将3个海拔树木年轮宽度年表分别与上一年9月至当年9月各气候因子[最高气温,平均气温,最低气温,帕默尔干旱指数(PDSI),月降水量]做相关性分析,评估树木在3次干旱事件中的抵抗力、恢复力和生态韧性及受旱后树木恢复比例和恢复时间。结果表明:3次干旱事件分别发生在1986、1997—1998、2002—2003年,PDSI分别为-1.7、-2.1、-2.5,第1次干旱事件达到轻旱(PDSI<-1.0),第2、3次干旱事件达到中旱(-2.0<PDSI<-3.0)。低、中、高海拔树木均受到3次干旱事件的影响,且普遍在干旱事件发生期间或之后呈现出较低的年轮宽度指数。低海拔树木径向生长与当年3月的平均气温、最低气温、最高气温呈显著负相关(P<0.05);中海拔树木径向生长与各月气候因子均无显著相关;高海拔树木径向生长与上一年12月的平均气温、最低气温呈显著、极显著正相关(P<0.05、P<0.01),与上一年10月的降水呈显著负相关(P<0.05),与当年1月的降水呈显著正相关(P<0.05)。高海拔树木对干旱事件的抵抗力、恢复力、生态韧性普遍高于中、低海拔树木。中、高海拔树木干旱后恢复速度最快,仅4 a完成恢复,而低海拔树木则需6 a。
To investigate the response patterns of the radial growth of Picea purpurea to drought events across different altitudinal gradients in the Miyaluo forest area of western Sichuan,this study collected a total of 90 tree-ring cores at altitudes of 3100 mlow altitude,3300 mmid altitude,and 3500 mhigh altitude within the area and established tree-ring width chronologies for the low,mid,and high-altitude zones,respectively.Correlation analyses were then conducted between the tree-ring width chronologies of the three altitudes and monthly climatic factors[maximum temperature,mean temperature,minimum temperature,Palmer Drought Severity IndexPDSI,and monthly precipitation]from September of the previous year to September of the current year.Meanwhile,the resistance,recovery,and resilience of trees during three drought events,as well as the recovery ratio and recovery time of trees after drought stress,were assessed.The results showed that the three drought events occurred in 1986,1997—1998,and 2002—2003,with PDSI values of-1.7,-2.1,and-2.5,respectively.The first drought event reached the level of mild droughtPDSI<-1.0,and the second and third drought events were classified as moderate drought-2.0<PDSI<-3.0.Trees at low,mid,and high altitudes were all affected by the three drought events,and generally exhibited lower ring width indices during or after the occurrence of these drought events.Specifically,tree radial growth at the low altitude was negatively correlatedP<0.05 with the mean temperature,minimum temperature,and maximum temperature in March of the current year.No significant correlation was found between tree radial growth at mid altitude and any monthly climatic factor.Tree radial growth at the high altitude showed positive correlations with the mean temperature and minimum temperature in December of the previous yearP<0.05,P<0.01,respectively.Moreover,it exhibited a negative correlation with the precipitation in October of the previous yearP<0.05 and a positive correlation with the precipitation in January of the current yearP<0.05.In addition,trees at the high altitude showed higher resistance,recovery,and resilience to drought events than those at mid and low altitudes,with trees at mid and high altitudes having the fastest post-drought recoverycompleting recovery in only 4 years,while trees at the low altitude required 6 years to recover.
作者
张建伟
孙胜杰
郭明明
ZHANG Jianwei;SUN Shengjie;GUO Mingming(College of Forestry,Hebei Agriculture University,Baoding,Hebei 071000,China)
出处
《森林与环境学报》
北大核心
2026年第2期141-149,共9页
Journal of Forest and Environment
基金
国家自然科学基金项目“基于碳氧同位素的青藏高原东缘云杉和冷杉对干旱的径向生长响应及其机制”(32301584)。
关键词
川西
米亚罗林区
树木年轮
径向生长
生态韧性
干旱
western Sichuan
Miyaluo forest area
tree ring
radial growth
resilience
drought
