Soil moisture control of sap-flow response to biophysical factors in a desert-shrub species, Artemisia ordosica
Soil moisture control of sap-flow response to biophysical factors in a desert-shrub species, Artemisia ordosica
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沙漠灌木油蒿树液流对生物物理因素响应的土壤湿度控制
DOI：
10.5194/bg-14-4533-2017
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发表时间：
2016-11
期刊：
影响因子：
4.9
通讯作者：
Peltola Heli
中科院分区：
文献类型：
--
作者：
Zha Tianshan;Qian Duo;Jia Xin;Bai Yujie;Tian Yun;Bourque Charles P-A;Ma Jingyong;Feng Wei;Wu Bin;Peltola Heli
抽象。目前对荒漠灌木物种适应干旱胁迫过程的认识还不完全。在这项研究中，我们测量了油蒿液流和相关的环境变量在整个生长季节的2013年和2014年（每年5月至9月期间），以更好地了解环境控制的液流的时间动态。我们发现，在2013年干旱年份的展叶期和展叶期发生干旱，导致每叶面积的液流（Js）显著下降，导致2013年的蒸腾量比2014年低34%。当土壤体积含水量（VWC）大于0.10 m3 m−3时，单位叶面积的液流与辐射（Rs）、气温（T）和水汽压亏缺（VPD）呈正相关。 日间Js一般比Rs早6小时。然而，这一时滞随着VWC的增加而减小。Js对环境变量的相对响应（即，Rs，T，和VPD）变化与VWC，Js被更强烈地控制植物生理过程在干旱期间表示的低解耦系数和低敏感性的环境变量。根据这项研究，土壤水分控制油蒿的树干液流（因此，植物蒸腾）响应的生物物理因子的日变化。该物种通过调节气孔导度和提高Js峰值时间的节水策略来逃避（适应）水分限制，表现为滞后效应。这项研究的结果增加了沙漠灌木物种在干旱胁迫下的适应过程的知识。这方面的知识是必不可少的模拟沙漠灌木生态系统功能在不断变化的气候条件下。
Abstract. The current understanding of acclimation processes in desert-shrub species to drought stress in dryland ecosystems is still incomplete. In this study, we measured sap flow in Artemisia ordosica and associated environmental variables throughout the growing seasons of 2013 and 2014 (May–September period of each year) to better understand the environmental controls on the temporal dynamics of sap flow. We found that the occurrence of drought in the dry year of 2013 during the leaf-expansion and leaf-expanded periods caused sap flow per leaf area (Js) to decline significantly, resulting in transpiration being 34 % lower in 2013 than in 2014. Sap flow per leaf area correlated positively with radiation (Rs), air temperature (T), and water vapor pressure deficit (VPD) when volumetric soil water content (VWC) was greater than 0.10 m3 m−3. Diurnal Js was generally ahead of Rs by as much as 6 hours. This time lag, however, decreased with increasing VWC. The relative response of Js to the environmental variables (i.e., Rs, T, and VPD) varied with VWC, Js being more strongly controlled by plant-physiological processes during periods of dryness indicated by a low decoupling coefficient and low sensitivity to the environmental variables. According to this study, soil moisture is shown to control sap-flow (and, therefore, plant-transpiration) response in Artemisia ordosica to diurnal variations in biophysical factors. This species escaped (acclimated to) water limitations by invoking a water-conservation strategy with the regulation of stomatal conductance and advancement of Js peaking time, manifesting in a hysteresis effect. The findings of this study add to the knowledge of acclimation processes in desert-shrub species under drought-associated stress. This knowledge is essential in modeling desert-shrub-ecosystem functioning under changing climatic conditions.
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中国荒漠地区灌木液流对降雨脉冲的响应
影响因子：
6.2
作者：
Zhao W. Z., Liu B.
通讯作者：
Zhao W. Z., Liu B.
影响因子：
2.6
作者：
Chaolei Zheng;Quan Wang
通讯作者：
Chaolei Zheng;Quan Wang
影响因子：
3.5
作者：
F. Razzaghi;S. H. Ahmadi;V. I. Adolf;C. R. Jensen;S. Jacobsen;M. Andersen
通讯作者：
F. Razzaghi;S. H. Ahmadi;V. I. Adolf;C. R. Jensen;S. Jacobsen;M. Andersen
影响因子：
6.2
作者：
Jia, Xin;Zha, Tianshan;Peltola, Hell
通讯作者：
Peltola, Hell
DOI：
10.1007/3-540-26599-6_7
发表时间：
2005
期刊：
--
影响因子：
--
作者：
D. Baldocchi
通讯作者：
D. Baldocchi