The natural imperative for biological conservation

To contribute significantly to environmental policy of the next century, conservationists will need to reach a consensus on their fundamental values and goals and to persuade society to adopt them. Resolution of the debate over the continued role of naturalness as a guiding concept has important implications for how conservation is practiced and the future of the discipline. I examine five aspects of naturalness in the context of biological conservation: (1) its utility, (2) its assessment, (3) its relation to values and ethics, (4) alternative imperatives, and (5) implications of adopting it as a guiding concept. Naturalness can be viewed as a continuous gradient with completely natural and completely artificial extremes. Human actions are unnatural to the extent that they rely on technology to transform natural ecosystems. The ecological consequences of technological transformation often overwhelm the capacity of other biota to adapt and are a root cause of biodiversity loss. The naturalness of most ecosystems or ecosystem alterations can be assessed objectively despite imperfect knowledge if evolutionary limits and natural ranges of variability are carefully considered. Most conservationists value naturally evolved biotic elements such as genomes and communities over artificial elements. This judgment, which is not shared by society at large, is based on intrinsic and instrumental values, including respect for nature and recognition that many ecosystem amenities stem from natural processes. Given the wide accessibility of ecologically destructive technology, fundamental shifts in societal values and approaches to ecosystem alteration are needed to achieve conservation. Respect for nature must supplant the prevailing world view of human superiority. Although sometimes difficult to assess, naturalness is a more reasonable guide for conservation than are other ecosystem features such as diversity, productivity, or evolution, and naturalness is the foundation for several current conservation concepts such as ecological integrity and ecological restoration. Conservation biologists can help develop conservation practices and ethics that emphasize the importance of natural ecosystems. Key roles include refining distinctions between natural and anthropogenic conditions, devising ways to use ecosystems without losing biotic diversity, and facilitating shifts in societal values toward more respect for nature.