Hydraulic failure
noun phrasePronunciation: /haɪˈdrɔːlɪk ˈfeɪljər/
The disruption of water transport through the xylem system when air bubbles (cavitation) form and block water column continuity, preventing water movement from roots to shoots. This critical physiological threshold determines plant survival during extreme drought stress.
Plain English
When air bubbles block water movement through plant vessels, preventing water from reaching leaves during severe drought.
Etymology & History
Usage
"Hydraulic failure occurred when water potential reached the cavitation threshold, causing irreversible xylem dysfunction and plant mortality."
Style guide notes: Specify cavitation threshold (P50 or P88) values when discussing hydraulic failure vulnerability; distinguish from temporary versus permanent failure states.
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Contrasted with
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Frequently Asked Questions
What causes hydraulic failure in plants?
Hydraulic failure results from increasing water stress causing air to enter xylem vessels through pit membranes, forming embolisms that block water transport.
Can plants recover from hydraulic failure?
Once cavitation occurs in xylem vessels, recovery requires embolism refilling through vascular parenchyma, which is metabolically costly and often incomplete.
Why Test Candidates on This?
Hydraulic failure is critical for understanding plant survival strategies and drought-induced mortality in forest ecology and climate change contexts.
Required skill level: Senior