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Some areas, of course, have extensive information, perhaps 

 including records of species no longer present, and other areas 

 have very little data but are still of great value. Therefore, 

 the system is designed to be highly flexible with regular updating 

 and change of ratings possible. For this reason, no data on sites 

 with low ratings are destroyed since data may accumulate to 

 increase the ratings. Also, areas with high ratings may be 

 lowered with loss or destruction of ecological features. 



Several versions of the ranking system were tried out in this 

 survey. One of the early systems used gave equal weighting to 

 each of the criteria but it was only partially successful in 

 establishing what the project staff judged to be valid priorities. 

 With the acquisition of more detailed data from each area a 

 reevaluation was required and the present evaluation system was 

 used. [SEE TABLE 4] 



A separate but related procedure in the rating process was 

 the use of mapping techniques. When all of the ecologically 

 significant data on plants, animals, unique communities and habitats, 

 wetlands and other features have been mapped and printed on trans- 

 parent overlays, the data are then visually available. A base map 

 of the areas presently protected, transparent ecological data 

 overlays, and an overlay of the proposed natural area sites 

 permit visual evaluation of the value of each proposed site and 

 shows the need for additional specific natural area sites to protect 

 concentrations of important fauna, flora, and ecosystems. Overlays 



