Abstract
This paper documents research taking place in the midst of a series of shifts in biodiversity policy in the UK. It examines recent attempts to enrol volunteer naturalists and lay citizens into biodiversity action planning, suggesting that such attempts can be seen as a nascent form of environmental citizenship, which is based on the exchange of knowledge of nature among the different communities involved (policy makers, volunteer naturalists and lay citizens). By focusing on a range of knowledge practices, the paper explores the selective appropriation of some ways of knowing over others. It documents ways in which some actors involved are beginning to reflect on what it might mean for biodiversity policy to accommodate each others' knowledge and practices. The paper suggests that an increased sensitivity to the range of practices and knowledges embodied within these different domains may result in a redefinition and expansion of the category of citizen, and may in turn have implications for the way in which ‘biodiversity’ comes to be defined.