Landscapes are frequently positioned as amenities or co-benefits to engineered infrastructure, despite their critical role in regulating disturbance, recovery dynamics, and baseline conditions across coupled human–natural systems. This paper reframes landscape function as preventive infrastructure and introduces a conceptual framework capable of bridging ecological organization with infrastructure-grade performance criteria. Drawing on landscape ecology and systems perspectives, we argue that commonly used “green” proxies often measure presence rather than the functional organization necessary for disturbance regulation under variability. Building upon established concepts of ecological integrity in conservation and landscape ecology, we articulate a landscape-scale formulation - Landscape Ecosystem Integrity, defined as a system condition and dynamic state characterized by the completeness and connectivity of ecological relationships within a landscape, enabling effective self-regulation of key processes, moderation of disturbance impacts, and long-term systemic stability, while retaining capacity for improvement or degradation over time. Two integrity mechanisms are emphasized as especially decisive at landscape scales: trophic completeness (internal regulatory architecture) and connectivity (spatial conditions enabling regulation, recolonization, and adaptive response across landscape mosaics). The paper advances the hypothesis that ecosystem integrity functions as preventive infrastructure by reducing disturbance amplification and downstream burden. A staged validation pathway is outlined to operationalize integrity components, test integrity-oriented interventions, and evaluate system-level outcomes, providing a foundation for the subsequent development of integrity capacity indicators and metric logic for comparative assessment and longitudinal tracking. This work does not introduce new terminology, but rather consolidates and extends existing ecological concepts into a coherent landscape-scale framework suitable for design, governance, and long-term performance assessment. This work is part of the ongoing research and design practice of LASD Studio (www.lasdstudio.com).