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在干旱,恢复和重复干旱期间的树木功能和木质栓塞之间的关系在阿勒松树干旱期间的恢复和重复干旱

Yael Wagner¹, Mila Volkov¹, Daniel Nadal-Sala^2,3

¹Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel.

Physiologia plantarum

|October 26, 2023

概括

树木可以从干旱中幸存下来,但这种损害会阻碍恢复. 然而,先前的干旱暴露提供了对未来干旱事件的一些保护.

科学领域:

植物生理学植物生理学
森林生态森林生态
干旱压力生理学干旱压力生理学

背景情况:

树木可以在干旱期间承受大量的树栓塞.
无法逆转的栓塞影响干旱后的恢复和重复干旱压力下的功能.
阿勒松 (Pinus halepensis) 适应地中海气候,非常适合研究干旱应对.

研究的目的:

为了研究不同程度的干旱诱导的西栓塞如何影响阿勒松树干旱后的恢复.
确定第一次干旱造成的液压损坏对随后干旱期间树木表现的后果.
了解栓塞对树木生存和功能的长期影响.

主要方法:

盆栽的阿勒松树苗经过脱水,以达到目标水位潜力 (-3.5, -5.2, -9.5 MPa),诱导不同的栓塞水平 (~6%, ~41%, ~76%).
在8个月的恢复期间,监测了血栓塞,叶子气交换和水潜力 (Ψx).
一个单独的实验测试了反复出现的干旱的影响,通过将树木暴露在 -6.0 MPa 上或没有先前脱水 (-5.2 MPa).

主要成果:

树木达到 -9.5 MPa 水位的树木经历了死亡率,致命栓塞水平平均为76% (最低62%).
口腔恢复与水力损坏的程度相反,持续至少一个月的干旱后.
与首次干旱的树木相比,遭受第二次干旱事件的树木需要更长时间才能达到致命的水潜力.

结论:

体栓塞的程度显著损害了干旱后的口腔恢复,作为"干旱遗产".
虽然有害,但这种减少的口腔导电性可能在连续的干旱事件中作为保护机制.
了解栓塞的影响对于预测干旱和半干旱地区森林弹性至关重要,这些地区面临越来越多的干旱频率.

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