On the normative roles of biodiversity and naturalness in conservation.

Nature is an opaque concept. Consequently, the term biodiversity conservation has replaced nature conservation in most conservation contexts. We review the conceptual indeterminacies that plague the terms nature and natural but then show that comparable difficulties plague biodiversity. Then, we provide a new theory that sorts out the respective normative roles of naturalness and biodiversity within the ecocentric-intrinsic school of conservation. This is an elaboration on the conservation philosophy presented by Saltz and Cohen (2023). They presented a 3-tiered normative scheme: ultimate value, midlevel principles, and lower level case-specific judgments. The ultimate value is naturalness, which exists on a gradient. Ethical judgment is needed to choose the most adequate midlevel principle or principles among autonomy, integrity, and resilience based on case-specific parameters and the goal of maximizing naturalness in a given area. Saltz and Cohen (2023) do not specify the role of biodiversity, however. We fill in that crucial gap by explaining that the midlevel principles refer to structural and functional biodiversity. The principles prioritized are those that will contribute the most to naturalness, depending on the biodiversity attributes and management options in a given area. In this scheme, biodiversity represents the lower tier, case-specific metrics for assessing naturalness. However, because biodiversity can only be quantified by proxies that cannot be projected onto a unified scale, biodiversity acts as an umbrella term for the measures that are the metrics for assessing naturalness. As such, biodiversity is a salient parameter to be measured for maximizing naturalness in conservation and is analogous to measures of homeostasis for safeguarding health in medicine.