As population aging accelerates, the mounting burden on informal family caregivers in areas lacking formal care systems threatens the sustainability of elder care. This study aims at evaluating how the rural living environment and external connectivity jointly alleviate caregiver burden and exploring whether regional accessibility serves as a substitute for local infrastructure deficits. Guided by Ecological Systems Theory, we analyzed a cross-sectional dataset of 327 matched caregiver-recipient dyads from rural China using multivariate regression and mediation models. Results indicate that a favorable local environment reduces burden both directly and indirectly through improved recipient health. Crucially, county-level accessibility moderates this relationship via a substitution effect, where the marginal relief from local environmental improvements is most potent in isolated areas but diminishes where external access is convenient. Dimension-specific analyses show that developmental and physical strains are particularly sensitive to these factors. We conclude that sustaining informal care requires a dual-pathway strategy: prioritizing local “soft” assets like community safety and cultural activities while enhancing regional connectivity to service hubs. Ultimately, this research provides empirical evidence and a theoretical framework for enhancing rural informal care sustainability through environmental optimization, thereby advancing Sustainable Development Goals regarding health, reduced inequalities, and sustainable communities.
Jiang et al. (Sat,) studied this question.