Different hydraulic strategies under drought stress between Fraxinus mandshurica and Larix gmelinii seedlings  

作　　者：Dandan Luo Chuankuan Wang Ying Jin Zhimin Li Zhaoguo Wang 

机构地区：[1]Center for Ecological Research,Northeast Forestry University,26 Hexing Road,Harbin 150040,People’s Republic of China [2]Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education,Northeast Forestry University,Harbin 150040,People’s Republic of China

出　　处：《Journal of Forestry Research》2023年第1期99-111,共13页林业研究（英文版）

基　　金：the National Science and Technology Support Program of China(2011BAD37B01);the Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R09);the National Key Research and Development Program of China(2016YFD0600201);the Fundamental Research Funds for the Central Universities(2572018AA07)。

摘　　要：Persistent and severe drought induced by global climate change causes tree mortality mainly due to the hydraulic imbalance of conduit systems,but the magnitude of injury may be species dependent.A water-exclusion experiment was carried out on seedlings of two tree species with distinct characteristics,i.e.,Fraxinus mandshurica and Larix gmelinii to examine hydraulic responses of leaf,stem,and root to drought stress.The two species displayed different hydraulic strategies and related traits in response to drought stress.L.gmelinii reduced its leaf hydraulic conductance by quick stomatal closure and a slow decline in leaf water potential,with a more isohydric stomatal regulation to maintain its water status.In contrast,F.mandshurica was more anisohydric with a negative stomatal safety margin,exhibiting strong resistance to embolism in stem and leafstem segmentation of hydraulic vulnerability to preserve the hydraulic integrity of stem.These differences in hydraulic behaviors and traits between the two species in response to drought stress provide a potential mechanism for their coexistence in temperate forests,including which in the forest modeling would improve our prediction of tree growth and distribution under future climate change.

关 键 词：Embolism resistance Hydraulic vulnerability Stomatal safety margin Stomatal regulation Temperate species Drought stress 

分 类 号：S792.41[农业科学—林木遗传育种]