Journal of Range Management, Volume 53, Number 6 (November 2000)http://hdl.handle.net/10150/6354692024-03-28T17:23:37Z2024-03-28T17:23:37ZJournal of Range Management, Volume 53, Number 6 (November 2000)http://hdl.handle.net/10150/6505832020-12-23T01:29:41Z2000-11-01T00:00:00ZJournal of Range Management, Volume 53, Number 6 (November 2000)
Complete digitized issue.
2000-11-01T00:00:00ZTracked vehicle effects on vegetation and soil characteristicsProsser, C. W.Sedivec, K. K.Barker, W. T.http://hdl.handle.net/10150/6438242020-09-24T01:22:15Z2000-11-01T00:00:00ZTracked vehicle effects on vegetation and soil characteristics
Prosser, C. W.; Sedivec, K. K.; Barker, W. T.
A 3-year experiment to evaluate tracked vehicle effects on vegetation and soil characteristics was established on the Gilbert C.Grafton South State Military Reservation (CGS) in North Dakota. Study objectives were to evaluate the effects of 3 tracked vehicle use intensity treatments on plant species cover and frequency, and soil compaction. The 3 treatments evaluated include heavy use (74 passes), moderate use (37 passes) and no use. The moderate use treatment represents a typical use of 1 battalion unit at CGS with the heavy use treatment classified as 2 battalion units. This land area comprised a 50 by 150 meter block subdivided into three, 50 by 50 meter blocks. Each 50 by 50 meter block was subdivided into three, 16.7 by 50 meter blocks with each block treated with 1 of the 3 treatments. Soil bulk density increased (P < 0.05) on the moderate and heavy use treatments in the 0 to 15, 30 to 45, and 45 to 60 cm soil depths. Kentucky blue-grass (Poa pratensis L.) cover (P < 0.05) decreased in 1996 on both the moderate and heavy use treatments but was not (P >0.05) different among all treatments in 1997. The tracked vehicle use on the heavy and moderate treatments did not change species composition or litter amounts after 2 years; however, bulk density and bare ground increased on both treatments in 1996 and 1997.
2000-11-01T00:00:00ZFire history of the Rochelle Hills Thunder Basin National GrasslandsPerryman, B. L.Laycock, W. A.http://hdl.handle.net/10150/6438232020-09-24T01:22:01Z2000-11-01T00:00:00ZFire history of the Rochelle Hills Thunder Basin National Grasslands
Perryman, B. L.; Laycock, W. A.
A fire scar chronology was constructed from ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and Rocky Mountain juniper (Juniperus scopulorum Sarg.) trees within the 70 km2 Rochelle Hills Area of the Thunder Basin National Grasslands, in north-east Wyoming. A total of 65 fire scars occurred in 48 crossdated samples, and a master fire chronology was constructed for the period 1565 to 1988. No trees recorded more than 3 fires and most (26 of 42) recorded only one. For this reason, fire frequency intervals were considered as fire-free intervals in the Rochelle Hills Area. The Weibull Median Probability Interval (WMPI) for the entire period of record was 7.4; 7.9 for the non-suppression period (1565 to 1939); and 6.7 for the suppression period (1940 to 1988). Infrequent occurrence of multiple scars, rough topography, and low potential substrates suggest that understory fuel loads were limited in amount and spatial consistency during most fire years. Position of scars within annual growth rings suggests that most fires (80%) occurred during the latter stages of the growing season or during the dormant period.
2000-11-01T00:00:00ZFood aversion learning to eliminate cattle consumption of pine needlesPfister, J. A.http://hdl.handle.net/10150/6438222020-09-24T01:21:48Z2000-11-01T00:00:00ZFood aversion learning to eliminate cattle consumption of pine needles
Pfister, J. A.
Conditioned food aversions are a potentially useful tool to eliminate consumption of some toxic plants by livestock. This study examined consumption of pine needles (Pinus ponderosa Lawson) in South Dakota and Oregon by pregnant cattle. Averted cattle were conditioned to avoid green pine needles using a gastrointestinal emetic, lithium chloride; control (non-averted) animals were not treated. Averted and non-averted cattle were offered green pine needles during pen trials, and they were also grazed in pastures with abundant pine needles in 2 winter trials during 1997 and 1998. Averted cattle ate no green needles in pen trials in Oregon and South Dakota in either year; whereas, control cattle always ate some green needles during those tests. The 1997 South Dakota field trial was inconclusive: the averted cattle ate no needles and the control cattle ate almost no needles while grazing. In the 1998 Oregon field study, the averted cows began eating pine litter after 4 days in the pasture, and the aversion to green needles extinguished rapidly thereafter. In Oregon, controls ate more than 50% of their diet as pine needles, and particularly selected green needles from recently cut trees or branches. When the trial ended after 16 days, the controls and averted cattle were both eating about the same amount of green pine needles and dry needle litter even though they grazed in different pastures. Although averted to green needles, cattle did not appear to generalize the aversion from green needles to dry needle litter. Conditioning permanent aversions may require averting cattle to all forms of pine needles (i.e., green and dry) likely to be encountered in a pasture.
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