Table 1. Factors likely to cause over- or under-estimation of the extent of species’ distributions, with the application of SDMs to future climate scenarios. These conclusions assume that a basic SDM approach (i.e., correlation of distribution data with environmental data) has been applied, and no special efforts have been made to counter these factors. See text for an explanation of the reasoning.


  Systematic under-estimation of distribution (“false pessimism”):
 
  • Interspecific interactions
  •  
  • Incomplete sampling of niche
  •  
  • Adaptation and evolution
  •      
      Systematic over-estimation of distribution (“false optimism”):
     
  • Non-inclusion of mobility data
  •      
      Non-systematic errors:
     
  • Lack of equilibria
  •  
  • Unprecedented environments
  •  
  • Scale mismatch
  •  
  • Non-inclusion of land-use change
  •  
  • Failure to distinguish cause and correlation