252 PROCEEDINGS OF THE NATIONAL MUSEUM vol. hg 



Crotalus viridis were collected here as were representatives of all 

 species found to be more abundant in pinyoji-juniper, oak-niohagany, 

 and riparian associations. 



Montane Life Belt 



The heavy cover characteristic of this uppermost life belt prevails 

 above approximately 7800 feet; lower limits may be found in sheltered 

 canyons and on north-facing slopes, where exposure is a restricting 

 factor. The ponderosa pine association marks the lower boundary 

 and may include Douglas fir (Pseudotsuga menziesi) in cooler situa- 

 tions. Upper limits are best developed on the higher peaks, where 

 the spruce-fir association includes Engelmann spruce {Picea engel- 

 manni) and Douglas fir along with alpine fir (Abies lasiocarpa) and 

 other conifers (pi. IC). With the exception of parks and the limited 

 alpine tundra association on Mount Taylor, vegetation is usually too 

 thick to permit much heating of the substrate. The soil is composed 

 of humus covered by conifer needles. Bailey's (1913, pp. 41-51) 

 Transition, Canadian, and Hudsonian Life Zones are included in this 

 belt as are the coniferous forest and petran alpine biomes of Castetter 

 (1956), petran montane and subalpine forests of Clements (1920, pp. 

 207-210, 224-226), and Pearson's (1931) ponderosa pine, Douglas 

 fir, and Englemann spruce zones. 



No reptiles or amphibians are restricted to this belt and none appear 

 to reach their maximum abundance here. While 14 species were 

 collected in montane associations, all of the reptiles except Thamnophis 

 elegans came from logged-off areas or rocky openings in ponderosa 

 pine and spruce-fu' associations. Rana pipiens, Bi/fo woodhousei, 

 and Hyla arenicolor, among others, follow the riparian association 

 that also penetrates the Montane Life Belt. Ambystoma tigrinum, 

 Pseudacris triseriata, Eumeces multivirgatus, Phrynosoma douglassi, 

 and T. elegans were fouiid in parks or stands of quaking aspen 

 {Populus tremuloides) (pi. IC). Only P. douglassi was taken in the 

 alpine tundra association, which has no arboreal vegetation. 



Recent Environmental Changes 



There is little doubt that the Zuni region has suffered considerable 

 modification within the past hundred years. The impact of man is 

 superimposed on a record of continuous climatic change. Drought 

 reduced the water supply and, coupled with grazing pressure, has 

 eliminated much of the original grassland (Castetter, 1956, pp. 269, 

 272). Statements on the former abundance of grass were made by 

 Bigelow (1856, p. 6), Whipple (1856, p. 62), and many others. Eoth- 

 rock (1875, p. 120) described open parklike stands of ponderosa pine 



