Under the provisions of the EU Habitats Directive, conservation means a series of measures required to maintain or restore the natural habitats and the populations of species of wild fauna and flora at a favourable status. In the case of habitats, habitats of concern are: (i) are in danger of disappearance in their natural range; or (ii) have a small natural range following their regression or by reason of their intrinsically restricted area; or (iii) present outstanding examples of typical characteristics of one or more of the five following biogeographical regions: Alpine, Atlantic, Continental, Macaronesian and Mediterranean.
In the case of species, conservation status means the sum of the influences acting on the species concerned that may affect the long-term distribution and abundance of its populations within its territory. The conservation status will be taken as 'favourable' when: (i) population dynamics data on the species concerned indicate that it is maintaining itself on a long-term basis as a viable component of its natural habitats, and (ii) the natural range of the species is neither being reduced nor is likely to be reduced for the foreseeable future, and (iii) there is, and will probably continue to be, a sufficiently large habitat to maintain its populations on a long-term basis.
The reasons to preserve nature are ethical more often than they are economic. There is no credible argument, moreover, that all or even most of the species we are concerned to protect are essential to the functioning of the ecological systems on which we depend. The species most likely to be endangered are those the biosphere is least likely to miss. Many of these species were never common or ecologically influential; by no stretch of the imagination can we make them out to be vital cogs in the ecological machine. In defending old-growth forests, wetlands, or species we make our best arguments when we think of nature chiefly in aesthetic and moral terms.
Conservation is not only a concern for the rich, as the economic burden of environmental degradation falls most heavily on the poor of the developing world. The view that it is only a concern for the rich is tragically short sighted.
There is a tendency to protect unviable life forms in artificial ways, retarding the evolutionary process.