Browsing Journals and Magazines by Authors
Grazing influences on watering point vegetation in the Chihuahuan desertFusco, M.; Holechek, J.; Tembo, A.; Daniel, A.; Cardenas, M. (Society for Range Management, 1995-01-01)Long-term influences of livestock grazing on vegetation around watering points was studied on 2 upland Chihuahuan desert ranges in southcentral New Mexico using regression analysis. One range had been conservatives stocked since the 1950's while the other was more heavily stocked. About 45% of the climax vegetation occurred on the heavily stocked range compared to 70% on the conservatively stocked range. During 3 years of study, both ranges were stocked conservatively so annual utilization of the key forage grasses was 30-35%. Regression analyses showed black grama (Boueteloua eriopoda Torr.), mesa dropseed (Sporobolus flexuosus Thurb, Rybd.), threeawn (Aristida sp.), and total perennial grass standing crop increased as distance from water increased on the good condition range (P < 0.05). However, black grama and threeawn standing crop showed no association with distance from water on the fair condition range. Broom snakeweed (Xanthocephalum sarothrae Pursh.), the primary poisonous plant found on both ranges, was associated (r2 = 0.35) with distance from water only on the good condition range in April. Poisonous plants other than broom snakeweed decreased as distance from water increased with the exception of the fair condition range in October. No livestock losses from poisonous plants were noted on either range over the 3 years. We attribute this to the present conservative stocking rates. Our study supports the recommendation that downward stocking rate adjustments be made for the zone more than 1,600 m from water.
Jackrabbit densities on fair and good condition Chihuahuan desert rangeDaniel, A.; Holechek, J.; Valdez, R.; Tembo, A.; Saiwana, L.; Fusco, M.; Cardenas, M. (Society for Range Management, 1993-11-01)This study was conducted on Chihuahuan desert range near Las Cruces, in southcentral New Mexico, to determine the relationship of blacktailed jackrabbit (Lepus californicus) densities to good (GC) and fair (FC) range condition. The Soil Conservation Service procedure was used to classify ecological range condition. Line transect procedures were used to estimate jackrabbit populations from July 1988 to December 1990. Concurrently vegetation cover and mean plant height were determined with the line intercept procedure. Jackrabbit densities on the fair condition range were higher (P < 0.10) than those on the good condition range. This difference is attributed to the fair condition range containing more protective cover and preferred forage than good condition range. Jackrabbit abundance showed no season (P < 0.10) or year differences (P < 0.10). Jackrabbits preferred grass-shrub mosaic habitats more than shrubland and grassland habitats. The need for diverse food sources and protective cover were apparently major determinants of habitat selection by jackrabbits. The good condition range contained greater (P < 0.10) grass cover and less (P < 0.10) shrub cover than the fair condition range. Our results indicated that maintaining Chihuahuan desert ranges in good to excellent condition is the best means of achieving lower abundance of jackrabbit populations.