Figure 11. (Con ) 



Relative Resistance of Different Habitat 

 Types 



A one-way analysis of variance was used to examine 

 the significance of differences in relative cover resulting 

 from differences in the resistance of the six habitat 

 types. Duncan's multiple range test (a = 0.05) was used 

 again to identify significant differences between types. 

 Table 4 displays the relative resistance of these types 

 after different numbers of passes. 



After as few as 25 passes, some of the more fragile 

 forested types had lost significantly more cover than the 

 FESC-FEID grassland had. Above 75 passes, FESC- 

 FEID was significantly more resistant than all of the 

 forested types, and the most resistant of the forested 

 types, ABLA/XETE, had significantly more cover than 



ABLA/CLUN, the least resistant habitat type. After 200 

 passes, ABLA/XETE generally retained significantly 

 more cover than all of the other forested types. Differ- 

 ences between the four least resistant habitat types were 

 most pronounced between 300 and 900 passes. Above 

 900 passes, cover loss was so great on these four latter 

 types that differentiation diminished. 



As indicated in the discussion of previous studies, 

 there are many possible ways of ranking habitat types 

 according to their relative resistance. The number of 

 passes it takes to eliminate more than 50 percent cover 

 was more than 1,600 for FESC-FEID; 400 to 800, depend- 

 ing upon local differences in species composition, for 

 ABLA/XETE; 200 for ABLA/VACA and ABLA/CLUN- 

 VACA; 100 for PSME/SYAL; and 75 for ABLA/CLUN. 



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