these patterns using DCCA (Appendix Figure HI) demonstrates that 

 conditions relating to soil disturbance and slope instability 

 (e.g., "badlands" and "blov;out" sites) are primary gradients 

 affecting compositional patterns among all plots. 



Forest Plots 



The four forest communities segregate distinctly within the 

 DCA ordination (Figure 3c) . The first two axes appear to reflect 

 complex moisture/landf orm gradients (Appendix Figure H2). 

 PINPON/JUNSCO occurs on relatively xeric sites on sedimentary 

 soils (mostly in breaks) and PINPON/PSESPI and PSEMEN/SCHSCO 

 occupy more mesic sites at higher elevations in mountains. 

 JUNSCO/ORYMIC was found in a moderately mesic draw v/ithin sedi- 

 mentary breaks. 



Shrubland Plots 



DCA ordination of all 53 shrubland plots indicates that 38 

 of the plots lie near the origin of axes 1 and 2 and that the 

 ARTLON/ORYHYM and SARVER/ATRGAR "badlands" types and the JUNHOR/ 

 SCHSCO "blowout" type are outliers (Figure 3d) . This is the same 

 situation as described above for the first three axes of the DCA 

 ordination of all 125 study plots. When axes 1 and 3 are shown 

 (Figure 3e) the ARTTRI/FESCTUI type characteristic of the highest 

 elevations of shrubland occurrence in the study area appears as 

 an outlier (on the third axis) . 



Removing all "badlands" and related communities (i.e., 

 JUNHOR/SCHSCO, ATRCON-ARTTRI , SARVER/PASSMI , SARVER-ATRGAR, and 

 ARTLON/ORYHYM) and the ARTTRI/FESCAM high elevation type produces 

 the DCA ordination shov;n in Figure 3f. Plots within the 

 remaining seven communities group together, for the most part, 

 within the ordination space defined by axes 1 and 2. 



DCCA interpretation of the overall patterns of vegetation 

 and environment within the shrublands is presented in Appendix 

 Figure H3 . Axis 1 is strongly correlated to soil disturbance and 

 slope instability with "badlands" communities having positive 

 scores and communities typically on relatively stable surfaces 

 with little erosion having negative scores. Axis 2 is charac- 

 terized by a complex radiation/moisture/disturbance gradient with 

 communities on sunny, xeric sites having higher scores than rela- 

 tively shady, mesic sites. Also, the JUNHOR/SCHSCO "blowout" 

 type has a low score on DCCA axis 2. 



Grassland Plots 



DCA ordination of all 56 grassland plots is presented in 

 Figure 3g (axis 1 vs. axis 2) . Most of the plots cluster near 

 the origin. The SCHSCO-I-IUHCUS and CALLON-CARINO community types 

 are outliers along the first axis. Both of these types are 



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