Gaston K.J. and Fuller R.A. (2008) Commonness, population depletion and conservation biology. Trends in Ecology and Evolution 23: 14-19. doi: 10.1016/j.tree.2007.11.001
This opinion paper claims that the study of common species deserves more attention from a conservation perspective. There are several key points that make important any potential depletion of common/widely-distributed species: commonness is itself rare, common species may drive spatial variation in species richness and they are fundamental to the structure of most assemblages and ecosystems. In addition to the conservation and study of threatened species, the authors propose a categorization of common species based on their level of population depletion. The aim is to avoid dramatic impacts on ecosystem function that may follow from depletions of common species even without threatening their persistence. The authors are more vague about how to implement such monitoring in practice but they suggest an additional approach to the current design of nature reserves. Their proposal is to focus on a wider landscape matrix, where the human activity (e.g. habitat destruction) is taking place, and monitor/manage the use of the landscape using the state of common species populations as indicator. One principal challenge to implement such strategy is that, with the exception of commercially harvested species, very few data exist about the temporal trajectories of common species’ populations.

