What is the role of AI for sustainability? Research finds that AI can support sustainable development in some cases but may exacerbate the problems in other cases. This controversy, we argue, may be resolved by adding a technical dimension to the concept of sustainability and broadening the ecosystem concept to include people, technology, and nature. From this ecological perspective, we conducted a discourse analysis of 15-year academic publications (2010-2024) from multiple disciplines and found that various AI techniques and tools have been developed and used to affect the environmental, socioeconomic, and technical sustainability of ecosystems. Once completed, the study is expected to demonstrate the utilities of our ecological view in helping (1) account for both the benefits and costs of AI for a sustainable future, (2) break disciplinary silos and promote collaborative and interdisciplinary approaches to sustainability, and (3) enrich digital sustainability research and practice.