Even as new elements of a research infrastructure are added, older parts continue to exert persistent and consequential influence. We introduce the concept of sedimentary legacy to describe the relationship between infrastructure and research objects. Contrary to common accounts of legacy infrastructure that underscore lock-in, static, or constraining outcomes, sedimentary legacy emphasizes how researchers adapt infrastructure to support the investigation of new research objects, even while operating under constraining legacies. To illustrate the implications of sedimentary legacy, we track shifting objects of investigation across the history of the Long-Term Ecological Research (LTER) Network, focusing especially on recurrent ecological investigations of 'human disturbance' as researchers shift to study socioecological objects. We examine the relationship between scientific objects and the resources collected and preserved to render such objects tractable to scientific investigations, and show how the resources of a long-term research infrastructure support the assembly of certain objects of investigation, even while foreclosing others.
Keywords: Long-Term Ecological Research Network (LTER); adaptation; ecological science; knowledge infrastructures; scientific objects.