Ecology and Development Series No. 10, 2003 - ZEF

Conservation of the wild Coffea arabica populations in situinspected and viewed for consistency, agreement of general trends with knownenvironmental gradients, and distribution patterns; second, the predicted results werecompared with the known data from the 57 sample plots. To compare the predicted valueswith the measured values from the sample plots, the predicted values at the plot locationswere extracted from the map. The difference between the predicted and the measured valueswere tested using the paired t-test.6.2.4 Input criteria and pre-processingThe criteria mapsThree criteria, i.e., one physical and two biological criteria, and a constraint, were used toevaluate reserve area suitability in this study. These criteria were the spatial patterns of theabundance of coffee, species diversity index, and elevation. The first two are biologicalcriteria, and were used to address the conservation of coffee and other plant species diversityin the decision. Elevation was used to incorporate the topographic position in the decisionmaking.All criteria are continuous variables. In addition to the input criteria for evaluation, aconstraint criterion of land-use right was also used to incorporate qualitative data concerningsocial suitability.The coffee criterion map is the most important map, since the major objective is toconserve the wild coffee populations occurring in the forest. The diversity of other plantspecies as the evaluation criterion was accounted for by using the map layer of the Shannondiversity index. Beside conservation of biodiversity, conservation of the landscape,especially of the riverine vegetation on steep slopes at low elevation, can also be consideredimportant part of forest conservation. Areas at lower and mid elevation in the study sites arealso more valuable for conservation, since they represent areas that are less disturbed bypeople and have a diverse plant species. This was accounted for using the elevation maplayer as a physical input criterion.Standardization of criteria mapsMulti-criteria evaluation involves different techniques of combining various criterion maplayers. The different map layers may have different units and ranges of scales. In such case,the input map layers should be transformed to a common scale or comparable unit104