HERPETOLOGY OF ZUNI MOUNTAINS — GEHLBACH 251 



sition Zone in addition to the woodland biome of Castetter (1956), 

 pinyon-cedar woodland and petran chaparral of Clements (1920, pp. 

 183-187, 197-199), and pmyon-jimiper and lower ponderosa pine 

 zones of Pearson (1931). 



Two species, Diadophis punctatus and Salvadora gmhamiae, pres- 

 ently are known only from this life belt but probably are more 

 widely distributed. Ambystoma tigrinum, Scaphiopus hammondi, 

 Bufo woodhousei, Rana pipiens, Hyla arenicolor, Phrynosoma douglassi, 

 Sceloporus undulatus, Urosaurus ornatus, Eumeces multivirgatus, 

 Cnemidophorus velox, and Thamnophis elegans reach then* gi-eatest 

 abundance here. Other, rarer species, such as Hypsiglena torquata 

 and Crotalus molossus, may be centered in the Roughlands Life Belt. 



Dominated by pinyons, one-seed junipers, alligator junipers (Juni- 

 perus deppeana), and Rocky Mountams junipers (J. scopulorum) , the 

 pinyon-juniper association is the most widespread vegetational type 

 (pi. IB). Shrub cover is relatively sparse but consists of aspect 

 dominants similar to those of the oak-mahogany association de- 

 scribed below. Amphibians and reptiles such as Scaphiopus ham- 

 mondi, Phrynosoma douglassi, and Cnemidophorus velox are more 

 abundant where the pinyon-juniper resembles a rocky savanna. 

 Openings in the savanna often are occupied by saltbush and occa- 

 sionally extensive stands of big sagebrush. If large boulders are 

 present, as on hillsides and mesa edges, Crotaphytus collaris and 

 Urosaurus ornatus are typically present. 



The oak-mahogany association is composed largely of Gambel oak 

 (Quercus gambeli) and mountain mahogany. Below approximately 

 7000 feet, wavyleaf oak (Q. undulata) may replace Gambel oak. 

 Shrubs like gooseberry {Ribes sp.), skunkbush (Rhus trilobata), and 

 datil (Yucca baccata) are present in varying numbers. This associa- 

 tion occupies canyon sides and may replace the pinyon-juniper or 

 ponderosa pine where timber is cut. Marked by heavier, more mesic 

 cover, it shelters Bufo woodhousei, Eumeces midtivirgatus, and some 

 adults of Ambystoma tigrinum. It is distinct from the riparian associ- 

 ation of canyon bottoms that is dominated by the narrowleaf cotton- 

 wood (Populus angustijolia) and various willows (Salix spp.) (pi. IB). 

 Hyla arenicolor, Rana pipiens, and Thamnophis elegans are more or 

 less limited to the vicinity of streams and ephemeral ponds resulting 

 from stream subsidence in the riparian association. 



Transition from pinyon-juniper woodland into the Alontane Life 

 Belt often is gi-adual, especially on the north side of the Zuni Moun- 

 tains and on Mount Taylor. Ponderosa pine (Pinus ponderosa) 

 occurs in a few, relatively pure stands as low as 7200 feet. In the 

 ponderosa pine association, mountain muhly (Muhlenbergia montana) 

 may be the predominant ground cover. Pituophis melanoleucus and 



