Phloem Catastrophe: Using Bifurcation Analysis to Predict Plant Tipping Points
Year: 2025
Type: article
Abstract: This is an accepted article with a DOI pre-assigned that is not yet published.A mathematical framework is developed to analyze phloem failure in plants using bifurcation analysis and catastrophe theory. The framework balances sucrose production from leaf photosynthesis modeled using stomatal optimality theory with sucrose transport through the much studied pressure-driven M\"unch mechanism. The model also integrated xylem water potential, osmotic gradients, and sucrose sink strength along the phloem. Systematic variation of key control variables, including xylem water potential and sucrose removal rate, reveals the emergence of multiple equilibria and identifies thresholds beyond which phloem transport becomes dynamically unstable to small perturbations. Phloem failure is shown to arise through an imperfect super-critical pitchfork bifurcation, characterized by two stable sucrose loading concentration states separated by an unstable intermediate one. The lower concentration stable state was within the range of sucrose loading values reported in the literature. Such phloem catastrophe was mathematically analogous to critical transitions in other eco-hydrological systems including xylem cavitation in plants. The analysis provides a mechanistic basis for quantifying phloem vulnerability and indicates that vascular stability requires coordination and balance between photosynthetic demand and phloem hydraulic capacity.
Source: ARC Geophysical Research
DOI: 10.5149/arc-gr.2526
Authors: Louis Youssef, Mazen Nakad, jean-christophe domec, Sanna Sevanto, Gabriel George Katul
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7108477631
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