Mechanistic Feedbacks and Early-Warning Signals of Regime Shifts in the Soil–Water–Vegetation Nexus

The stability of terrestrial ecosystems rests upon the intricate Soil–Water–Vegetation (SWV) nexus. Historically, these systems have been studied through linear or gradual frameworks; however, emerging evidence suggests that the combination of intensifying land degradation and climate extremes creates synergistic pressures that far exceed the sum of their individual impacts. When soil health is compromised, its capacity to regulate moisture is diminished, which in turn stresses vegetation and alters local energy balances. This feedback loop can push the hydrological cycle toward critical thresholds at which the system undergoes a rapid, non-linear transition to a new stable state, such as the conversion of a perennial river basin into an ephemeral system or the aridification of formerly humid landscapes. Understanding these non-linearities is essential as we enter an era of unprecedented climatic volatility.

The primary objective of this Research Topic is to move beyond conceptual or descriptive treatments of tipping points toward the mechanistic quantification of SWV feedbacks and the operational identification of early-warning signals that precede regime shifts. Current hydro-climatic modelling often fails to resolve the bidirectional couplings between soil moisture, vegetation dynamics and microclimate that govern where manageable alteration ends and permanent regime change begins.

To preserve a clearly delimited scope and avoid duplication with currently active Research Topics in Frontiers in Water — including those on tipping points and water accounting, the Critical Zone under climate change, vegetation-restoration scaling, compound hydro-climatic extremes, nature-based solutions, and ecodynamic recovery — contributions must satisfy two scope conditions:
• Mechanistic SWV feedback evidence. Submissions must provide quantitative, mechanistic evidence of bidirectional couplings within the soil–water–vegetation nexus (e.g., vegetation loss → soil-moisture depletion → microclimatic alteration → further vegetation stress), rather than describing land-use or climate impacts on water in isolation.
• Early-warning relevance with cross-scale validation. Submissions must engage the detection or anticipation of regime shifts — for example through critical slowing down, rising variance or autocorrelation, spatial-pattern indicators, or hysteresis diagnostics — and demonstrate cross-scale consistency from pedon or plot through catchment to regional or basin scale.
We invite high-quality original research, comprehensive reviews, and innovative case studies that meet both conditions and combine field and remote-sensing data with advanced non-linear modelling. Themes of interest include, but are not limited to:
• Mechanistic quantification of vegetation–soil-moisture–microclimate feedbacks under combined land-degradation and climate-extreme stressors.
• Identification and validation of early-warning indicators (critical slowing down, variance and autocorrelation rises, spatial-pattern metrics, hysteresis) for SWV regime shifts in real landscapes.
• Cross-scale evidence linking pedon- and plot-scale soil–water–vegetation dynamics to catchment- and regional-scale hydrological regime shifts.
• Data–model integration combining in-situ observations, satellite eco-hydrology and non-linear or process-based models to constrain SWV feedbacks and threshold behaviour.
• Mechanistic case studies of documented or incipient regime shifts (e.g., perennial-to-ephemeral basin transitions, aridification of humid landscapes, vegetation-cover collapse) where SWV feedbacks and early-warning signals can be diagnosed.
• Mitigation and management interventions evaluated specifically for their effect on SWV feedback strength, threshold proximity, or early-warning indicators in near-threshold systems.

Stand-alone conceptual work on tipping points, stand-alone Critical Zone, vegetation-restoration scaling, compound-extreme, nature-based solution, or ecosystem-restoration contributions that do not deliver mechanistic SWV-feedback evidence with early-warning relevance fall outside the scope of this Research Topic.

Article types and fees

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Brief Research Report
• Community Case Study
• Conceptual Analysis
• Data Report
• Editorial
• FAIR² Data
• FAIR² DATA Direct Submission
• General Commentary
• Hypothesis and Theory
• ... View all formats

Articles that are accepted for publication by our external editors following rigorous peer review incur a publishing fee charged to Authors, institutions, or funders.

Article types

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Brief Research Report
• Community Case Study
• Conceptual Analysis
• Data Report
• Editorial
• FAIR² Data
• FAIR² DATA Direct Submission
• General Commentary
• Hypothesis and Theory
• Methods
• Mini Review
• Opinion
• Original Research
• Perspective
• Policy and Practice Reviews
• Policy Brief
• Review
• Systematic Review
• Technology and Code

Keywords: Land Use Change, Climate Variability, Hydrological Cycle, Water Yield, Attribution Analysis

Important note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.