ABSTRACT
This chapter explores the role that the co-production of knowledge and ‘contingent knowledge-making’ (De Munck and Lachmund) by activist citizens, scientific experts, and governmental officials played in the protection, care and management of street trees in West Berlin in the 1970s and 1980s. Since the 1960s, drought, soil pollution by de-icing salts, air pollution resulting from industry and motorised traffic, and dog urine had increasingly been affecting the health of West Berlin's street trees. Withering and dying trees incited citizen protest and environmental activism. The chapter shows how this protest both built upon and led to scientific research into trees’ vulnerability and resilience. It elucidates how environmental activism motivated the use of aerial photography and the experimentation with different cartographic and recording techniques for urban tree surveys. Illustrating the different techno-scientific methods and representations used by various urban actors to save street trees and improve their health, the chapter also draws attention to how they were conceived of as both ‘bureaucratic trees’, understood as cultivated, planted and controlled by humans, and ‘real trees’, imagined as lying beyond human control. Revealing the close entanglement of emotional citizen activism, purportedly objective scientific research and pragmatic urban tree management, the chapter posits that their contingent knowledge-making was a fundamental step in re-establishing West Berlin's pre-war image as a model tree city.
