This study investigated vegetation strategies for a fly ash landfill in a semi-arid environment. Ten plant species adapted to the local climate were initially evaluated for their germination characteristics in various mixtures of Tivoli fine sand, fly ash, and cattle manure. Alkali sacaton (native, Sporobolus airoides (Torr.) Torr.), blue grama (native, Bouteloua gracilis (H.B.K.) Lag. Ex Griffiths), a forage sorghum (variety Canex, Sorghum bicolor (L.) Moench), sand bluestem (variety Woodward, Andropogon hallii Hack.), and sideoats grama variety El Reno, Bouteloua curtipendula (michx.) Torr.) were selected for further evaluation. Concurrently, mixtures were evaluated to determine the effects of the soil amendments on soil saturated paste electrical conductivity (EC) and pH. The addition of even 50 g kg-1 fly ash increased EC values above 4.0 dS m-1, indicating salt tolerant species may be needed. Six mixtures were selected for use in a greenhouse study and for further study of moisture retention characteristics. Using an X/Y format, where X is fly ash content and Y is manure content (g kg-1) and the balance of the mixture was Tivoli fine sand, those mixtures were 0/0, 200/0, 200/100, 200/200, 100/100, and 300/100. The addition of manure provided ample quantities of plant nutrients. Alkali sacaton was the only plant specie not adversely affected by the addition of fly ash. For biomass production, height, vigor and leaf tip burn, all remaining species had significantly better growth or ratings with 0/0 as compared to any other mixture. Soil moisture retention characteristics of the Tivoli fine sand can be significantly changed through amendment with fly ash or manure. Sixty cm of Tivoli sand was estimated to have the same available water holding capacity as 45 cm of 200/0, 39 cm of 200/100, 34 cm of 200/200, 47 cm of 100/100, and 33 cm of 300/100.

Many range managers have suggested that clubmoss (Selaginella densa Rydb.) negatively alters the composition of seed banks and inhibits the establishment of plant species that decrease under improper grazing management. Alternatively it is possible that soil seed banks contain few seeds of decreaser species and composition of the seed bank is independent of clubmoss. The purpose of this study was to determine the composition and diversity of the soil seed bank in relation to the clubmoss cover and compositional characteristics of plant communities in the Northern Mixed Prairie of southwestern Saskatchewan. Cover of vascular plants was determined and soil seed bank samples were collected in 100 grazed plant communities. Soil seed bank samples were incubated in the laboratory with emerging seedlings being identified to species. Eight percent (SE ± 1.9) of emerging seedlings in the seed bank were decreasers, 73% (SE ± 2.8) were increasers, and 19% (SE ± 2.3) were invaders, indicating regeneration of decreaser species might be limited by low numbers of seeds in seed banks. Clubmoss cover was not correlated (P = 0.32 to 0.98) with species richness, species diversity, density of decreasers, density of increasers, density of invaders, and total seedling densities in the seed banks. Seed banks and plant communities shared few species as indicated by a low similarity index (x̄ = 0.31, SE ± 0.02). Species richness (x̄ = 3.6 species per 102 cm2, SE ± 0.18) and diversity (x̄ = 1.00, SE ± 0.05) of seed banks were poorly correlated with characteristics of the plant communities. Range condition score was positively correlated (r = 0.17, P = 0.09) with total seedling densities in the soil seed bank, indicating more seedlings can potentially develop from the seed bank with increasing range condition of plant communities. We reject the hypothesis that clubmoss negatively affects the composition of seed banks. Mechanically disturbing plant communities to control clubmoss is predicted to lead to plant communities that are dominated by increasers and/or invaders. Managing for production of seeds by desired species should be a priority in promoting establishment of desired species.

Fertilizer application enable producers to influence pasture production. The effect of N fertilization on grass production and leguminous plant content of pasture and strategic N application has received much attention. Changing agricultural policies suggest that chemical fertilizer inputs may be diminished and that alternative sources of nutrients are desired. The aim of this study was to evaluate the effect of N and K fertilization on production, botanical composition, and forage mineral composition to gain some insight into what influence changing fertilization practices would have on pasture productivity. Three K and 3 N application rates were applied in a factorial design on a white clover (Trifolium repens L.)—perennial ryegrass (Lolium perenne L.) sward. Potassium and nitrogen application increased herbage production and had differential influences on botanical composition. Nitrogen decreased clover content in the pasture, whereas K increased the proportion and production of white clover. The effects of K application appeared later in the experiment than those associated with N. We concluded that K is very important for development and maintenance of white clover in pasture, which increases herbage and protein production. Nitrogen was associated with lesser amounts of N, P, K, and Mg in pasture, because of lesser amounts of clover in the sward. Changing fertilization practices will have definite influences on sward composition and pasture productivity. Any interpretation of pasture mineral content should take botanical composition changes into account.

Revegetation and sustainable cattle grazing are major objectives in the reclamation of mine tailings at the Highland Valley Copper mine in British Columbia, Canada. A total of 84 cow-calf pairs grazed forage extremely high in molybdenum (Mo) for 11 weeks in the summer and fall for 3 consecutive years (1999-2001). The average stocking rate was 0.63 ha AUM-1. The animals' diet consisted primarily of alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.) containing 100-400 ppm Mo. Both cows and calves showed adequate daily gains of 0.78 kg head-1 day-1 and 1.33 kg head-1 day-1, respectively. Uptake of Mo was demonstrated by elevated levels of Mo in rumen contents and feces. Clinical signs of Mo toxicity were observed in less than half of the cows and in only a few calves. Clinical signs included a stiff shuffling gait, watery diarrhea, and a rough hair coat. Lameness, the primary sign, was resolved in all animals by the end of each trial. Diarrhea was also resolved by the end of the trial and hair coats returned to normal by the following spring. The onset and severity of the affliction appeared to be related to prevailing moisture conditions, which may have affected Mo availability in forage. Some affected animals were treated with Cu injections to no avail. Liver biopsies and serum samples showed marginal to adequate copper (Cu) levels but potentially toxic levels of Mo. In the third year of the trial, Cu-containing boluses were employed but they did not prevent the onset of clinical signs.

Management of feral horses grazing on Atlantic and Gulf coast barrier islands requires information on seasonal habitat preferences and distribution of important forage species to maintain stable populations and prevent destruction of fragile island ecosystems, particularly as coastal development further restricts free range. Counts from seasonal aerial surveys of Currituck Banks, N.C. were used to determine whether particular habitats were used more or less than would be expected by chance. On-ground observations were used to determine the relative intensity of grazing on vegetation by habitat and season. Feral horses showed seasonal preferences for particular forage species and habitat types. Horses grazed upon at least 16 graminoid and 5 forb species across 6 identified habitat types covering 4,619 ha. In late winter, Maritime Forest was used significantly more than expected while Tidal Freshwater Marsh was used less than expected. In spring, all habitats were used in the proportion expected based on availability. In early summer, Wet Grassland was preferentially used while Dry Grassland was preferentially avoided. The relative degree of exposure from wind may explain why horses spent less time than expected in exposed marshes during winter and more time than expected in forest. The availability of fresh water and hydrophytes may explain why horses spent more time than expected in Wet Grassland in summer and less time than expected in Dry Grassland. Seasonal habitat preferences should be considered when managing for ecosystem sustainability of feral horses on barrier islands.

Mourning dove (Zenaida macroura L.) densities were determined using strip census techniques over a 2-year period (spring 1996 to winter 1998) on pastures in early-, mid-, and late-seral ecological condition. This study was conducted on the Chihuahuan Desert Rangeland Research Center and adjacent Bureau of Land Management rangelands in south-central New Mexico on 6 adjoining pastures that were similar in terrain and shape. Mourning dove densities pooled across sampling periods (8) were different (P < 0.10) on pastures in mid- and early-seral condition. They averaged 10.3, 33.9, and 7.2 birds km-2 on pastures in late-, mid- and early-seral condition, respectively. Leatherleaf croton (Croton pottsii Lam.), the primary mourning dove food on all study pastures, was more abundant (P 0.10) on late- and mid-seral pastures than on early-seral pastures. Therefore, heavy livestock grazing may adversely affect mourning dove populations in the Chihuahuan Desert by depleting leatherleaf croton. Autumn perennial grass cover and standing biomass differed (P < 0.10) among seral stages. More optimal interspersion of bare ground and perennial grasses may further explain why mid-seral rangelands tend to favor mourning doves. Our study shows mourning doves in the Chihuahuan Desert prefer moderately grazed, mid-seral rangelands over heavily grazed, early-seral rangelands.

Because most of Texas consists of privately owned land and the amount of brush cover on rangelands may affect off-site water yields, there has been increasing interest in publicly funded brush clearing programs aimed at increasing water yield. The Pedernales River was selected as 1 of 8 watersheds to determine the feasibility of implementing such a program. A survey questionnaire was mailed to 720 landowners in Blanco and Gillespie County (containing most of the Pedernales watershed) in June 2000 to identify factors that influence their interest in participating in a brush reduction program. The sample consisted of equal numbers of landowners with 4-20, 21-202, and > 202 ha of land. Fifty eight percent of the survey participants responded, 82% of whom answered questions about their willingness to enroll at least part of their land in a brush reduction program. Property size and income from wildlife were found to be significant positive determinants and level of satisfaction with brush a significant negative determinant of respondents' willingness to enroll. To optimize public investments, it may be preferable to maximize the area enrolled in a brush removal program by targeting larger landowners who appear to be willing to enroll larger portions of their land without requiring compensation that exceeds their net cost of enrollment. Because land in the Edwards Plateau is being subdivided and purchased by people who do not depend on land-based income and who may be more tolerant of brush, public funds required to encourage landowner participation may increase over time.