Why Wilderness?

Why is it important that we keep our last remaining wilderness? If this an ethical question, a practical one, or both? I would argue it is both. I believe in the intrinsic value of nature, that nature is not just for human use, but has a right to exist for itself. In that case, the most natural areas have a right to survive.  Large natural areas are the original and best of planet Earth - this is essentially what the IUCN defines wilderness as. So yes it is an ethical question. It is also a practical one however. Human society relies on ecosystem services to survive. These rely on native biodiversity to maintain ecological processes. Wilderness areas are a major bastion of wild nature and thus native biodiversity. Biogeography tells us that the number of species an area can support is related to the fourth root of the land area, thus the bigger the area the more species survive in the long term. Certainly it is not everything we need to do to protect biodiversity, but keeping our last large natural areas (wilderness) is certainly a key part of long term viability. Of course we need connectivity also to link them together. So keeping wilderness means keeping more native species in the long term, stopping extinctions and thus maintaining the ecosystem services that society relies on. It is thus a very practical thing to keep wilderness as well as being ethical! what do you think?