conducting the statewide biological inventories, and this fact points to the 

 overall good environmental health that is evident in most of the State's 

 waters. As will be described below, German Gulch would appear to fall into 

 this same "good-health" category. 



With regard to the German Gulch periphyton collections, diatom taxa 

 numbers and diversities as summarized in Table 15 were found to be typically 

 above or near the state averages, and they were observed to be well above the 

 diagnostically critical 25 and 2.00 or 3.00 levels. These juxtapositions 

 thereby are indicative of a generally good biological health along the gulch 

 with absence of any significant environmental degradations. In relation to 

 the lower German Gulch site near its mouth, taxa numbers and diversities were 

 calculated to be somewhat lower than those upstream, but they remain adequate- 

 ly high so as to be also suggestive of a fairly good biological condition. 

 For the most part, therefore, German Gulch can be readily distinguished from 

 those few Montana streams that demonstrated relatively low diversity values 

 and that demonstrated the potential for facing adverse environmental stress. 



Nevertheless, the fact that the taxa numbers and diversities of the lower 

 gulch site fell into the 25 to 40 and 3.00 to 4.00 ranges points to the 

 possible occurrence of some very mild environmental problems in the bottom 

 section of the waterway. Thus, another statistical evaluation was performed 

 leading to the calculation of equitability indices in order to shed additional 

 light on the environmental status of the lower gulch station. 



Along with diversity, equitability is another community index that can 

 be used as a check to further assess the ecological shape of a periphyton 

 collection. This equitability index (e) basically compares the number of taxa 

 that were actually retrieved from a sampling site with a theoretical taxa 

 number that should have been obtained in response to the sample's diversity on 



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