Resource managers in the western United States have long assumed that water was a key limiting factor on wildlife populations in arid habitats. Beginning in the 1940s-1950s, state and federal resource management agencies initiated water development programs intended to benefit game species and other wildlife. At least 5,859 such developments have been built in 11 western states. Most state wildlife management agencies in the western United States have ongoing wildlife water development programs that vary greatly in extent. Ranchers and range managers also have developed water sources for livestock, many of which also are used by wildlife. Recently, critics have suggested that wildlife water developments have not yielded expected benefits, and may negatively impact wildlife by increasing predation, competition, and disease transmission. Based upon a comprehensive review of scientific literature, we conclude that wildlife water developments have likely benefitted many game and non-game species, but not all water development projects have yielded expected increases in animal distribution and abundance. Hypothesized negative impacts of water developments on wildlife are not supported by data and remain largely speculative. However, our understanding of both positive and negative effects of wildlife water developments is incomplete, because of design limitations of previous research. Long-term, experimental studies are needed to address unanswered questions concerning the efficacy and ecological effects of water developments. We also recommend that resource managers apply more rigorous planning criteria to new developments, and expand monitoring efforts associated with water development programs.

Winterfat [Krascheninnikovia lanata (Gueldenstaedt) syn. Ceratoides lanata (Pursh) J.T. Howell, syn. Eurotia lanata (Pursh) Moq.] is a native shrub of mixed prairie of North America. A large portion of hydrated seeds and seedlings can be killed when exposed to seedbed desiccation. Winterfat seeds and young seedlings subjected to varying levels of desiccation were studied to measure the influence of this stress. Germination was unaffected (P > 0.05) when seeds were exposed for 0 to 10 hydration-desiccation cycles (2 hours hydration and 22 hours desiccation cycle(-1) at 20 to 30% relative humidity and 20 degrees C). Linear increases in germination rate (0.6% day(-1) hydration-desiccation cycle(-1)), seedling length (0.1 mm hydration-desiccation cycle(-1)), and seed decay (1.5% hydration-desiccation cycle(-1) occurred with an increasing number of hydration-desiccation cycles. Seedling survival following desiccation decreased 10.4% mm(-1) as seedling length increased from < 2 mm to 10-15 mm. Seedling survival was positively correlated with relative humidity and negatively correlated with duration of desiccation. The difference (P < or = 0.05) in survival between 0 and 90% relative humidity was 62% for seedlings 4-6-mm in length and 70% for seedlings 9-11-mm in length. Seedlings from seeds that germinated rapidly were more tolerant of desiccation than those from seeds germinating slowly. After desiccation in 30% relative humidity, survival of seedlings from seeds germinating on the first day of incubation was 40% greater than those from seeds germinating on the third day of incubation. Electrolyte leakage indicated that desiccation damaged cells. Establishment of winterfat seedlings will be favored by seedbed conditions that protect seedlings from severe and prolonged desiccation and allow fast entry of the radicle into soil.

Russian knapweed [Acroptilon repens (L.) DC.] is a creeping, perennial, unpalatable, noxious weed that infests thousands of rangeland and pasture hectares in the western U.S. often forming monocultures. Chemical or mechanical control of Russian knapweed usually is temporary allowing re-invasion or the weed over time. Our objective was to determine whether combining chemical or mechanical methods with seeding of perennial grasses would reclaim Russian knapweed infested areas more effectively than any of the treatments applied alone. Five suppression treatments combined with 5 seeded perennial grasses were evaluated to reclaim Russian knapweed infested site. Two years after suppression treatments were done, clopyralid + 2,4-D + seeded grasses controlled 66 to 93% or Russian knapweed whereas clopyralid + 2,4-D applied alone controlled only 7% of Russian knapweed. Glyphosate + 'Critana' thickspike wheatgrass [Elymus lanceolatus (Scribn. & Sm.) Gould] controlled 36% of Russian knapweed 2 years after treatment (YAT) while glyphosate + 'Hycrest' crested wheatgrass [Agropyron cristatum (L.) Gaertn.], 'Bozoisky' Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski], or 'Sodar' streambank wheatgrass [Elymus lanceolatus (Scribn. &Sm.)] increased Russian knapweed growth 1.5, 2, and 1.6-fold, respectively. Glyphosate applied alone tripled Russian knapweed growth. Metsulfuron + streambank wheatgrass controlled 61% of Russian knapweed 2 years after treatments were applied while metsulfuron applied alone controlled 40% of Russian knapweed. Mowing was ineffective and mowing + crested wheatgrass increased Russian knapweed growth about 2-fold. Clopyralid + 2,4-D + streambank wheatgrass yielded 6, 48, and 18 times more seeded grass than metsulfuron treated, mowed, or non-treated control plots seeded with streambank wheatgrass. Clopyralid + 2,4-D + stream-bank wheatgrass, while expensive (262 ha(-1)), was the best treatment combination because it controlled Russian knapweed effectively while the sod-forming grass established well and helped to prevent re-invasion by the weed.

Livestock-guarding dogs are an effective way of protecting rangeland sheep from predators. However, open mountain/forest range and widely ranging sheep are factors that may make adaptation to Norwegian conditions difficult. This paper focuses on the dogs' working patterns and effectiveness under different working regimes. A 3,500 ha. unfenced forest/mountain range pasture in bear habitat comprised the research area in which 624 sheep from 2 herds grazed. The field trial lasted 3 months, and a total of 10 Great Pyrenees participated for various time intervals. Three different working regimes were evaluated. 1) loose dogs without the command of a dog handler (Method A); 2) loose dogs under the command of a dog handler (Method B); and 3) loose dogs guarding sheep inside a fenced, 1 km(2) forest pasture (Method C). Nocturnal behavioural activity patterns and data on predation were recorded. Method A proved too uncontrolled for Norwegian conditions, because sheep dispersed too widely and dogs ranged too far, causing conflicts in nearby settlements with wildlife, and with livestock. Pasture dogs (C) were > 3 times less active and were engaged in guarding activities < 50% as often as patrol dogs (B). However, they barked > 15 times more frequently, and no sheep carcasses were found inside the fence. Therefore, Method C probably had the best preventive effect.

Two trials were conducted in 1994, 1995, and 1996 to determine the first limiting nutrient for summer calving cows grazing Sandhills range. In Trial 1, 48 lactating summer calving cows grazing native range during the breeding season were assigned to 1 of 4 supplement treatments: 1) control-no supplement, 2) energy, 3) degradable intake protein (DIP), and 4) DIP + undegraded intake protein (UIP). Cows were group-fed supplements in 8 pastures (2 pastures/treatment). The trial began 4 September and ended 4 November each year. Diet samples from esophageally fistulated cows averaged 7.5% crude protein and 54.5% in vitro organic matter digestibility. Supplemented cows lost less body condition compared to control cows (P = 0.04). Cow and calf weight gains were increased by supplemental DIP or DIP + UIP combination compared to energy supplement (P = 0.09 and 0.08, respectively). Forage intake and digestibility were not different among treatments (P > 0.20). Milk production was lower for non-supplemented than supplemented cows (P = 0.10). Trial 2 began 5 November and ended 10 January in 1994-1995, 1995-1996, and 1996-1997. Treatments and pastures were the same as described in Trial 1, however, only 40 cows were used. In Trial 2, diet samples from esophageally fistulated cows averaged 6.2% crude protein and 52.3% in vitro organic matter digestibility. No differences (P > 0.10) in body condition score were detected. Total organic matter intake was lower for control compared to supplemented treatments (13.5 vs.15.5 kg day(-1); P < 0.10). We concluded that DIP was the first limiting nutrient for summer calving cows during the breeding season and during autumn-winter lactation after the breeding season.

Japanese brome (Bromus japonicus Thunb.) has invaded many northern mixed prairie communities. Understanding how defoliation affects the life cycle or this species is critical for proper grazing management of communities infested with this annual. The objective of this study was to determine the effect of defoliation on growth of Japanese brome. Treatments included no clipping or clipping to 75- or 150-mm stubble height weekly or biweekly for 65 to 70 days in a greenhouse. Response of Japanese brome tiller numbers, leaf height, and above- and below-ground biomass were measured in 1991, 1992, and 1997. Clipping vegetative plants in 1991 reduced tiller numbers and leaf heights, whereas clipping plants with reproductive shoots in 1992 and 1997 increased tiller numbers and reduced leaf heights. Herbage accumulated during clipping, above-ground and total biomass were similar in 1991 and 1997, but lower in 1992. Accumulated herbage was reduced by reducing stubble height from 150 mm to 75 mm on a biweekly frequency and increasing the frequency of clipping from biweekly to weekly at either the 150-mm or 75-mm stubble height. Reducing the stubble height also reduced above-ground and total biomass. Increasing frequency of clipping did not generally affect total biomass. Some inflorescences were produced with even the most severe clipping treatment.

Characterization of relationships between grazing and vegetation responses is difficult. Rapid and accurate measurement of pasture canopy characteristics would help clarify these relationships if canopy changes are directly related to grazing variables. The objectives of this study were (1) to evaluate use of the LI-COR LAI-2000 for quantification of changes in canopy density and architecture in response to defoliation by cattle, (2) to determine if changes in leaf area index (LAI) measured with the LAI-2000 are related to stocking rate, and (3) to determine advantages and drawbacks of the LAI-2000 for monitoring grazing impacts on canopy density and architecture. Leaf area index and mean foliage tilt angle were measured before and after defoliation by cattle (Bos taurus L.) in June, July, and August under 9 grazing treatments on Nebraska Sandhills range. Differences in LAI could be attributed to certain grazing treatments at various points throughout the season. Grazing treatment had little impact on mean foliage tilt angle. Change in LAI (delta LAI) had a significant negative relationship with stocking rate (P < or = 0.0001). The relationship detected for delta LAI versus stocking rate predicted LAI reductions of between 0.14 and 0.40 for the range of stocking rates studied; stocking rate accounted for 62% of the decrease in LAI caused by grazing. When configured for the Sandhills canopy, the LAI-2000 provided a rapid and precise method for quantification of the degree of defoliation associated with grazing.