IV, RESULTS AND DISCUSSION 



This section provides an update to interpretation of the 

 significance of the Alzada Oak stand, its conservation status and 

 needs. Approximately 12 acres with Ouercus macrocarpa were found 

 among the 3 60 acres of BLM tracts evaluated, representing ca. 1% 

 of the stand. It was spread across four of the six wooded or 

 partially wooded tracts evaluated. 



The Alzada Oak stand is the only population of Quercus macrocarpa 

 (G5S1) in the state, and a singular plant community fPinus 

 ponder osa / Quercus macrocarpa ; G2S1) . It has state significance 

 in both respects, and potential rangewide significance as a plant 

 community. This plant community or closely related plant 

 communities are also known from Nebraska, South Dakota and 

 Wyoming. The G2 rank (globally threatened) is to be considered 

 preliminary. 



The Alzada Oak stand warrants some level of protection. It is 

 recommended that Quercus macrocarpa remain on the BLM state list 

 of sensitive species to avert species threats where it is found 

 on lands administered by the BLM, even though these lands 

 represent less than 1% of the stand, and do not include many 

 individuals. Subsurface rights administered by BLM below the 

 stand may be more extensive. 



The long history of grazing by sheep and horses and the harsh 

 environment at the site favor high numbers of introduced species 

 and a relatively impoverished native flora. Further fieldwork is 

 recommended early in the season to make assessments of overall 

 species diversity, successional status and recovery potential. 



Two other plant species of state significance grow at the site, 

 penstemon anaustifolius (G5S1) and Linaria canadensis var. texana 

 (G4G5S1) . Both are localized within the stand and have fewer 

 than five other records in the state. They were not found on 

 BLM tracts in the stand. 



Bentonite mining has developed within the center of the stand, in 

 at least three sections. Quercus macrocarpa trees have been 

 excavated in these sections, including trees at the edge of a 

 grove on BLM stand 4 (Figure 1) . Accompanying the mining activity 

 are areas of surface disturbance, major road developments, and 

 spoil piles. 



While Quercus macrocarpa has been tested for mine revegetation in 

 the eastern part of the country, mitigation by revegetation in 

 general or with eastern genotypes in particular does not restore 

 stand integrity. 



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