Matching species with reserves -: uncertainties from using data at different resolutions

I address the problem of the mismatch between the spatial resolution of data for species and reserves. Such mismatch may help to recognise variability in species recording in reserves. Using distribution data from 10 x 10 km grid cells for angiosperms, bryophytes, pteridophytes in Portugal, I investigate how mapping rules used to assign reserve coverages to grid cells would affect estimates of species representation in reserves. It was found that the estimated representation of species would be greatly affected by variation in the mapping rules used. The range of expected representation of species in reserves would vary from a minimum of 30% for bryophytes to a maximum of 63% for angiosperms. Current reserve networks would always represent fewer angiosperms than expected by chance; depending on the rules, more or fewer bryophytes than expected by chance; and slightly more, or just as many, pteridophytes as expected by chance. These results call for the need to assess sensitivity of reserve selection and evaluation procedures to data and decision-rules, without which it may be difficult to assess the effectiveness of reserves to represent biodiversity. (C) 2003 Elsevier Ltd. All rights reserved.