["Environmental Policy and Governance, EarlyView. ", "\nABSTRACT\nSince the 1990s, environmental policy has shifted toward ecosystem protection and biodiversity conservation, a development often described as an ecological turn. This article argues that in practice this turn has taken the form of an ecological “U‐turn,” as environmental ambitions are subordinated to production‐oriented objectives. While earlier research has documented tensions between production and environmental protection in forest governance, less attention has been paid to how ecological measurements and indicators become central sites of political struggle. Drawing on expert interviews and policy documents from Norway and Sweden, the article analyses how ecological goals were translated into forestry through new forms of measurement, monitoring, and assessment, and how these instruments became contested. Combining insights from Peter Hall's theory of policy change, the Advocacy Coalition Framework, and research on policy instrumentation, we show that the ecological turn reconfigured forest governance by introducing new environmental goals, instruments, and forms of expertise, and by temporarily rebalancing relations between competing coalitions within the forest‐policy subsystem. Over time, however, this more collaborative dynamic gave way to a more adversarial subsystem, in which measurement practices shifted from supporting the identification and protection of ecological values to defining thresholds for acceptable degradation and legitimizing trade‐offs. The article shows how technical measurements do not simply inform policy learning but also reshape environmental conflict. Though rooted in forest governance, these findings speak to broader cross‐cutting tensions in environmental policymaking, where technical measurements may obscure political choices embedded in ecological turns and other sustainability transformations.\n"]