The Use of Natural and Modified Pinyon Pine-Juniper Woodlands by Deer and Elk

Abstract

Pinyon pine (Pinus edulis)-juniper (Juniperus spp.) woodlands are important deer and elk habitats and occupy about 243,000 km2 of the western United States. In the study area at Fort Bayard, New Mexico, mule deer (Odocoileus hemionus) and elk (Cervus canadensis) ate evergreen browse exten- sively during winter. Mule deer ate more forbs during spring and summer, less browse during spring and less grass at all seasons than did elk. When woodland canopy was dense, production of midstory browse and understory herbage was reduced and deer and elk use diminished. Small clearings within the wood- lands (-0.5 km) were readily used by both deer and elk. Extensive clearing of pinyon pines and junipers increased herbage production but may have been sufficiently detrimental to wildlife to negate any addi- tional grazing values for range cattle. Although small patch-cuttings within woodlands increased useful- ness for deer and elk, large cuttings in themselves and those that isolated undisturbed woodland from contiguous protective cover were unacceptable wildlife habitat. J. WILDL. MANAGE. 41(3):543-559 Pinyon pine-juniper woodlands occupy about 243,000 km2 of the western United States and provide valuable wildlife habitat, rangeland, watersheds and recreational areas. These woodlands occupy fairly dry sites (33-51 cm precipitation/year) at ele- vations of 1,460-2,550 m, the zone below that usually occupied by ponderosa pine (P. ponderosa). A rich shrub midstory is maintained where pinyon pines and juni- pers invade brushlands but there is no mid- story where they invade grasslands. Livestock interests have frequently been concerned where increased density of these woodlands reduced herbage understory and range carrying capacity. Over 4,050 km2 in Arizona and New Mexico were recently cleared to reclaim grasslands for livestock. Conflicts arose because indigenous wildlife such as deer, elk, rabbits, coyotes, quail, tur- keys, songbirds and rodents have different habitat requirements than livestock. The