摘要
采用盆栽控水试验,研究了3个水分处理,即田间持水量(FC)的(75±5)%、(55±5)%和(35±5)%,对丁香、黄刺梅、连翘的叶、茎、极细根(0~1 mm)、细根(1~2 mm)和粗根(>2 mm)化学计量特征的影响。结果表明:3种灌木相同器官间氮(N)和磷(P)含量以及C∶N、C∶P、N∶P均存在显著差异。随着干旱胁迫的加剧,3种灌木各器官C含量总体上无显著变化;叶片N含量呈增加趋势,茎N含量逐渐下降,极细根和细根N含量均呈先上升后下降的趋势;叶片、茎P含量呈降低趋势,极细根和细根P含量呈先增加后下降的趋势。3种灌木在干旱胁迫下叶C∶N呈降低趋势,叶和茎C∶P、N∶P均呈增加趋势。干旱胁迫对极细根C∶N和叶C∶P、N∶P影响最大,而对粗根C∶N、N∶P以及极细根C∶P的影响最小。土壤C、N含量与灌木各器官中C、N、P含量无显著相关性,但土壤P含量与叶和根系C、N、P含量均显著相关。土壤中相对缺乏的P是影响灌木器官化学计量特征的最重要因素。干旱对不同灌木不同器官化学计量的影响不同,叶和极细根的化学计量较其他器官对干旱胁迫更加敏感。干旱可能主要通过影响灌木对土壤中养分P的吸收和在不同器官中的分配,进而影响灌木不同器官的化学计量特征,尤其是与P相关的化学计量特征。
In order to explore how water stress affects the stoichiometric characteristics in leaves,stems,very fine roots(0-1 mm),fine roots(1-2 mm)and thick roots(>2 mm)of three shrub species,we studied the effects of three water treatments[(75±5)%,(55±5)%and(35±5)%of field water capacity(FC)]on the stoichiometric characteristics of different organs of Syringa oblata,Rosa xanthina and Forsythia suspensa in a pot experiment.The results showed that there were significant differences in nitrogen(N)and phosphorus(P)contents,C:N,C:P and N:P of the same organ among the three species.With the intensification of drought stress,there was no significant change of C content in all organs of the three species.The N content increased in leaves,but decreased gradually in stems.The N content in very fine roots and fine roots increased first and then decreased.The P content decreased in leaves and stems,while increased first and then decreased in very fine roots and fine roots.Under drought stress,leaf C:N decreased,C:P and N:P of leaf and stem increased.There was the strongest effect of drought stress on the C:N of very fine roots and C:P and N:P of leaves.There was the least effect of drought stress on C:N,N:P of thick roots and C:P of very fine roots.There was no significant correlation between the contents of C,N in soil and the contents of C,N and P in shrub organs,but soil P content was significantly correlated with the contents of C,N and P in leaves and roots.It was concluded that the relative P limitation in soil was the most important factor affecting the stoichiometric characteristics of shrub organs.Drought had different effects on the stoichiometry of different organs in different shrub species.The stoichio-metry of leaves and very fine roots was more sensitive to drought stress than that of other organs.Drought might affect the stoichiometric characteristics especially related to P in different organs of shrubs,mainly by affecting plant absorption of soil P and its distribution in different organs.
作者
陈佳瑞
王国梁
孟敏
王润超
CHEN Jia-rui;WANG Guo-liang;MENG Min;WANG Run-chao(Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,Shannxi,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resource,Yangling 712100,Shannxi,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2021年第1期73-81,共9页
Chinese Journal of Applied Ecology
基金
国家重点研发计划项目(2017YFC0504601)
国家科技支撑计划项目(2015BAC01B03)资助。
关键词
干旱胁迫
器官
化学计量特征
drought stress
organ
stoichiometric characteristics
