亚洲树轮稳定氧同位素研究进展

Advances in tree-ring stable oxygen isotope study in Asia

树轮稳定氧同位素作为一种高精度的古气候代用指标,在亚洲地区的发展起步晚进步快。树轮稳定氧同位素比率(δ^(18)O)对区域气候信息有较强的记录能力,且与水汽循环关系密切,对于理解复杂的亚洲气候起着重要作用。亚洲地区树轮δ^(18)O对温度的响应主要出现在高纬度地区,中低纬度树轮δ^(18)O主要记录与水分(降水、相对湿度、PDSI等)有关的信号。对亚洲地区已发表的树轮δ^(18)O与气候要素(温度、降水、相对湿度)的相关分析显著性统计显示,生长季气候对树轮δ^(18)O至关重要,树轮δ^(18)O与温度的显著相关关系呈正相关,与降水和相对湿度的呈负相关,温度和降水通过降水δ^(18)O影响树轮δ^(18)O,但各自的信号强度存在区域差异,而相对湿度信号则广泛记录在不同区域不同树种之中。亚洲树轮稳定氧同位素研究集中于中低纬度地区,因而对大气水文循环的响应主要侧重于对亚洲夏季风和ENSO的研究,对季风降水的记录反映了季风活动的变化特征以及与之有关的环流信息;季节分辨率的树轮稳定氧同位素研究限于低纬热带亚热带区域,但对于理解区域气候和季风活动的年内变化、挖掘年轮不清晰树种的树轮学研究潜力具有重要的意义。

The oxygen isotope in tree ring,as a proxy of paleoclimatology with high resolution,is develop late but fast in Asia.Stable oxygen isotope ratio（δ^（18）O） of tree ring records strong environment information,and related to moisture cycle closely,which makes it important in studying complex Asian climate.Tree ring δ^（18）O responses to temperature mainly in high latitude region,for middle to low latitude,it records moisture change like precipitation,relative humidity（RH） and PDSI.This study statistics the published correlation analysis results of tree ring δ^（18）O with temperature,precipitation and RH in Asia,it appears that the environment of growing season is crucial to tree ring δ^（18）O,the significant relationship of tree ring δ^（18）O with temperature,precipitation and RH is positive,negative and negative respectively.Temperature and precipitation influence rainfall δ^（18）O thus tree ring δ^（18）O,but their effects varies at difference region; RH is widely recorded in the tree ring δ^（18）O.As the majority of study regions located in middle to low latitude region,most tree ring δ^（18）O series are used to study Asian summer monsoon and ENSO through its relationship with monsoon rainfall; Seasonal resolved tree ringδ18 O studies only carry out in tropical and subtropics area now,but they are meaningful to understand intraannual climate change and monsoon activity,and make it possible to study species without distinct annual rings.