ABSTRACT
This chapter focuses on the fieldwork and the related intellectual discourses through which the Paul Duvigneaud-group engaged the spaces of their city as objects of knowledge, and through which they redefined what these spaces were and how they should be dealt with in planning practice. It provides insights into what historians of urban technology Michael Hard and Thomas Misa have described as the complementary processes of circulation and appropriation. Appropriation is always a selective process through which circulating concepts and objects get mixed with locally existing traditions. The chapter traces how Duvigneaud shifted his focus from forest ecosystems to the city and how this was mediated by local political circumstances. It also focuses on three parallel strands of ecological knowledge-making in Brussels: the articulation of a theoretical concept of urban ecosystems, the quantitative accounting of the urban "metabolism", and the ecological survey of urban spaces.
