摘要
【目的】探究天山中部地区不同海拔雪岭云杉径向生长变化趋势、对气候因子的响应以及应对干旱胁迫的生态弹性,为预测气候变化下天山雪岭云杉林沿海拔梯度的群落发展趋势提供理论参考。【方法】在天山北坡中段雪岭云杉森林的下林线、林带中部、上林线处采集雪岭云杉树芯样品,建立3个树轮标准年表,计算胸高断面积增量,分析雪岭云杉径向生长与气候因子的关系,采用抵抗力、恢复力和恢复弹力分析雪岭云杉对干旱胁迫的响应。【结果】在过去61年,研究区各海拔雪岭云杉径向生长均受到明显抑制,受抑制程度表现为下林线处最重,林带中部次之,上林线处较轻;不同海拔影响雪岭云杉径向生长的主控气候因子存在差异,下林线主要与当年4—7月气温显著负相关(P<0.05),与上一年6月和当年4、6月降水量及上一年8月至当年9月自校准帕默尔干旱指数(scPDSI)显著正相关(P<0.05);林带中部主要与上一年6—8月和当年3—4、6—7月气温显著负相关(P<0.05);上林线主要与当年2和6—7月气温显著正相关(P<0.05),与上一年8月和当年4月降水及上一年6月至当年5月scPDSI显著正相关(P<0.05);雪岭云杉径向生长对气候因子的响应在海拔梯度和时间梯度上均有差异,由下林线至上林线,与气温的负相关性及与降水和scPDSI的正相关性均依次减弱。在时间梯度上,与气温的相关性逐渐减弱,与降水和scPDSI的正相关性逐渐加强。不同海拔雪岭云杉应对干旱胁迫的生态弹性具有差异,抵抗力和恢复弹力表现为上林线>林带中部>下林线,恢复力表现为下林线>林带中部>上林线;下林线雪岭云杉对干旱较敏感,遭受干旱胁迫时生长下降明显;在抵抗力与恢复力反向平衡关系未打破时,下林线雪岭云杉不受干旱遗留效应影响。【结论】因研究区升温迅速而降水增加缓慢,各海拔雪岭云杉遭受干旱胁迫越来越严重,其中下林线雪岭云杉径向生长降幅最大,抵抗力最小,生长衰退风险最高。
【Objective】To study the trend of radial growth change,response to climatic factors and ecological resilience to drought stress of Picea schrenkiana at different altitudes in the central Tianshan Mountains,and to provide theoretical references for predicting the community development trend of P.schrenkiana forests along the altitudinal gradient in the Tianshan Mountains under climate change.【Method】The core samples of P.schrenkiana were collected at the lower,middle and upper forest line of P.schrenkiana forest in the middle section of the northern slope of Tianshan Mountains.Three tree-ring standard chronologies were established,and the basal area increment was calculated.The relationship between the radial growth of P.schrenkiana and climatic factors was analyzed.The resistance,recovery and resilience were used to analyze the response of P.schrenkiana to drought.【Result】In the past 61 years,the radial growth of P.schrenkiana at all altitudes in the study area was significantly inhibited.The degree of inhibition was the highest at the lower forest line,followed by the middle forest belt,and the upper forest line was lighter.There are differences in the main climatic factors affecting the radial growth of P.schrenkiana at different altitudes.The radial growth of P.schrenkiana at the lower forest line is mainly negatively correlated with the temperature from April to July of the current year,and is significantly positively correlated with the precipitation in June of the previous year(P<0.05),April and June of the current year,and the self-calibrated Palmer drought index(scPDSI)from August to September of the current year(P<0.05).The radial growth of P.schrenkiana at the middle forest belt is mainly negatively correlated with the temperature from June to August of the previous year,from March to April and June to July of the current year(P<0.05).The radial growth of P.schrenkiana at the upper forest line is mainly positively correlated with the temperature from February to July of the current year,and is significantly positively correlated with August of the previous year(P<0.05).There was a significant positive correlation between the precipitation in April and scPDSI from June of last year to May of this year(P<0.05).The response of radial growth of P.schrenkiana to climatic factors was different in altitudinal gradient and temporal gradient.The negative correlation with air temperature decreased successively and the positive correlation with precipitation and scPDSI decreased successively from underline to overline.The correlation with air temperature decreased gradually and the positive correlation with precipitation and scPDSI increased gradually in temporal gradient.The ecological resilience of P.schrenkiana to drought at different altitudes is different.The resistance and resilience are shown as upper forest line>middle forest belt>lower forest line,and the recovery is shown as lower forest line>middle forest belt>upper forest line.P.schrenkiana is more sensitive to drought,and its growth decreases significantly under drought stress.When the reverse balance between resistance and resilience is not broken,P.schrenkiana is not affected by the residual effect of drought.【Conclusion】Due to the rapid increase of temperature and slow increase of precipitation in the study area,P.schrenkiana at different altitudes is more and more seriously affected by drought stress.Among them,the radial growth of P.schrenkiana in the lower forest line decreased the most,the resistance was the smallest,and the risk of growth decline was the highest.
作者
周小东
常顺利
王冠正
孙雪娇
张毓涛
李翔
Zhou Xiaodong;Chang Shunli;Wang Guanzheng;Sun Xuejiao;Zhang Yutao;Li Xiang(Key Laboratory of Oasis Ecology under the Ministry of Education College of Ecology and Environment,Xinjiang University,Urumqi 830046;Xinjiang Tianshan Forest Ecosystem National Positional Observation Research Station,Urumqi 830063;Institute of Forest Ecology,Xinjiang Academy of Forestry,Urumqi 830063)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2024年第3期45-56,共12页
Scientia Silvae Sinicae
基金
国家自然科学基金项目(U1503187)
2023年新疆天然林保护修复典型区域生态效益监测与价值评估
2024年新疆天山森林生态系统观测项目。
关键词
树木年轮
径向生长
林线
云杉森林
生态弹性
tree rings
radial growth
forest lines
spruce forest
ecological resilience
作者简介
通讯作者:常顺利。
