Response of plant physiological parameters to soil water availability during prolonged drought is affected by soil texture  

作　　者：HUANG Laiming ZHAO Wen SHAO Ming'an 

机构地区：[1]Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China [2]College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Arid Land》2021年第7期688-698,共11页干旱区科学（英文版）

基　　金：This study was financially supported by the National Natural Science Foundation of China(41601221);the Ministry of Science and Technology of China(2016YFC0501605);the Youth Innovation Promotion Association of Chinese Academy of Sciences(2019052);the Bingwei Outstanding Young Talent Project from the Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences(2017RC203);the Scientific Research Program from the State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources(A314021402-2010)。

摘　　要：Soil water deficit is increasingly threatening the sustainable vegetation restoration and ecological construction on the Loess Plateau of China due to the climate warming and human activities.To determine the response thresholds of Amygdalus pedunculata(AP)and Salix psammophila(SP)to soil water availability under different textural soils,we measured the changes in net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO2 concentration(Ci),leaf water potential(ψw),water use efficiency(WUE)and daily transpiration rate(Td)of the two plant species during soil water content(SWC)decreased from 100%field capacity(FC)to 20%FC in the sandy and loamy soils on the Loess Plateau in the growing season from June to August in 2018.Results showed that Pn,Gs,WUE and Td of AP and SP remained relatively constant at the beginning of soil water deficit but decreased rapidly as plant available soil water content(PASWC)fell below the threshold values in both the sandy and loamy soils.The PASWC thresholds corresponding to Pn,Gs and Ci of AP in the loamy soil(0.61,0.62 and 0.70,respectively)were lower than those in the sandy soil(0.70,0.63 and 0.75,respectively),whereas the PASWC thresholds corresponding to Pn,Gs and Ci of SP in the loamy soil(0.63,0.68 and 0.78,respectively)were higher than those in the sandy soil(0.58,0.62 and 0.66,respectively).In addition,the PASWC thresholds in relation to Td and WUE of AP(0.60 and 0.58,respectively)and SP(0.62 and 0.60,respectively)in the loamy soil were higher than the corresponding PASWC thresholds of AP(0.58 and 0.52,respectively)and SP(0.55 and 0.56,respectively)in the sandy soil.Furthermore,the PASWC thresholds for the instantaneous gas exchange parameters(e.g.,Pn and Gs)at the transient scale were higher than the thresholds for the parameters(e.g.,Td)at the daily scale.Our study demonstrates that different plant species and/or different physiological parameters exhibit different thresholds of PASWC and that the thresholds are affected by soil texture.The result can provide guida

关 键 词：plant available soil water content drought stress soil water deficit sustainable vegetation restoration sandy soil loamy soil Loess Plateau 

分 类 号：S152.75[农业科学—土壤学]