The response of sap flow in shrubs to rainfall pulses in the desert region of China
The response of sap flow in shrubs to rainfall pulses in the desert region of China
复制标题
中国荒漠地区灌木液流对降雨脉冲的响应
DOI：
10.1016/j.agrformet.2010.05.012
复制
发表时间：
2010-08
影响因子：
6.2
通讯作者：
Zhao W. Z., Liu B.
中科院分区：
文献类型：
--
作者：
Zhao W. Z., Liu B.
降雨脉冲可以显著地驱动荒漠生态系统结构和功能的演化，理解荒漠植物对降雨响应的机制是理解荒漠生态系统对全球气候变化响应的关键。本研究是在中国黑河流域中部的荒漠-绿洲交错带进行的。采用液流仪测定了沙生灌木（白刺和沙枣）枝条和茎段的液流，并采用“阈值-延迟”模型研究了液流速率对降雨脉冲的响应。结果表明，降雨后1h左右，树干液流开始响应，液流速度比降雨前增加2 ~ 3倍。随着降雨量的增加，树干液流速度先显著增加后逐渐降低。在脉冲持续时间内，降雨量、树种、种内部位对树干液流的响应存在显著差异，且交互作用也存在显著差异（P<0.0001）。其响应模式遵循阈值延迟模型，茎和枝的阈值分别为≤5.2和1 mm，表明小降雨事件（<5 mm）对荒漠地区植物生长和存活的重要性。
Rainfall pulses can significantly drive the evolution of the structure and function of desert ecosystems, and understanding the mechanisms that underlie the response of desert plants to rainfall is the key to understanding the responses of desert ecosystems to global climatic change. The present study was carried out at the desert-oasis ecotone in the middle of China's Heihe River Basin. We measured sap flow in the branches and stems of desert shrubs (Nitraria sphaerocarpa and Elaeagnus angustifolia) using sap flow gauges, and studied the response of sap velocity to rainfall pulses using the “threshold-delay” model. The results showed that the response of sap flow began about 1h earlier after rainfall, and that sap velocity increased two to threefold, compared to its pre-rainfall value. The sap velocity increased significantly, then decreased gradually, with increasing rainfall. The response of sap flow differed significantly between rainfall, species, position within species during pulse duration, and the interactive effects also differed significantly (P<0.0001). The response pattern followed the threshold-delay model, with lower thresholds of ≤5.2 and 1mm of rainfall for the stems and branches, respectively, demonstrating the importance of small rainfall events (<5mm) for plant growth and survival in desert regions.
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DOI：
--
发表时间：
1999
期刊：
--
影响因子：
--
作者：
F. Pugnaire;F. Valladares
通讯作者：
F. Pugnaire;F. Valladares
三种中亚沙漠灌木的水分利用策略及其对降雨脉冲事件的响应
影响因子：
4.9
作者：
通讯作者：
--
影响因子：
11.6
作者：
R. Sponseller
通讯作者：
R. Sponseller
影响因子：
5.4
作者：
Eltahir, EAB
通讯作者：
Eltahir, EAB
影响因子：
5.5
作者：
H. Walter
通讯作者：
H. Walter