The assertion that ‘ecosystems are infrastructure’ is now common in conservation science and ecosystem management. This article interrogates this infrastructural ontology, which we argue underpins diverse practices of conservation investment and ecosystem management focused on the strategic management of ecosystem functions to sustain and secure human life. We trace the genealogies and geographies of infrastructural nature as an ontology and paradigm of investment that coexists (sometimes in tension) with extractivist commodity regimes. We draw links between literatures on the political economy of ecosystem services and infrastructure and highlight three themes that hold promise for future research: labor, territory, and finance.