Switchgrass and Giant Miscanthus Biomass and Theoretical Ethanol Production from Reclaimed Mine Lands

Switchgrass (Panicum virgatum L.) and giant miscanthus (Miscanthus x giganteus Greef & Deuter ex Hodkinson & Renvoize) are productive on marginal lands in the eastern USA, but their productivity and composition have not been compared on mine lands. Our objectives were to compare biomass production, composition, and theoretical ethanol yield (TEY) and production (TEP) of these grasses on a reclaimed mined site. Following 25 years of herbaceous cover, vegetation was killed and plots of switchgrass cultivars Kanlow and BoMaster and miscanthus lines Illinois and MBX-002 were planted in five replications. Annual switchgrass and miscanthus yields averaged 5.8 and 8.9 Mg dry matter ha^?1, respectively, during 2011 to 2015. Cell wall carbohydrate composition was analyzed via near-infrared reflectance spectroscopy with models based on switchgrass or mixed herbaceous samples including switchgrass and miscanthus. Concentrations were higher for glucan and lower for xylan in miscanthus than in switchgrass but TEY did not differ (453 and 450 L Mg^?1, respectively). In response to biomass production, total ethanol production was greater for miscanthus than for switchgrass (5594 vs 3699 L ha^?1), did not differ between Kanlow and BoMaster switchgrass (3880 and 3517 L ha^?1, respectively), and was higher for MBX-002 than for Illinois miscanthus (6496 vs 4692 L ha^?1). Relative to the mixed feedstocks model, the switchgrass model slightly underpredicted glucan and slightly overpredicted xylan concentrations. Estimated TEY was slightly lower from the switchgrass model but both models distinguished genotype, year, and interaction effects similarly. Biomass productivity and TEP were similar to those from agricultural sites with marginal soils.     

Microbial and Phosphate Dynamics in a Restored Shrub Steppe in Southwestern Wyoming

Soil microbial activity and soil nutrients were monitored on a revegetated coal surface mine in southwestern Wyoming from the initial planting in 1982 through 1987. Total soil nitrogen (N) and organic matter did not change during this period. However, despite no changes in available phosphorus (P) concentrations, the total P declined over 50% during the five-year period, with no apparent reduction in the loss rates. The greatest loss was in the bound inorganic P pool. Moisture appeared not to limit microbial mass-C. Microbial mass-C was higher under shrubs than in interspaces and increased with time. Total organic matter did not increase. Thus, the ratio of microbial mass-C to organic matter-C increased during the study period. This suggests that the input of readily decomposable substrate may limit microbial activity. During the study period, all above-ground litter was removed by wind. Root production in the surface soils was low and highly variable and, in this habitat, probably did not contribute largely to the organic matter status. These data suggest that despite an apparent recovery of many parameters used to indicate reclamation or restoration success, the soil-bound P pools could be undergoing a loss. Microbial-C and organic matter changes indicate a system that is not approaching equilibrium within the required monitoring period of most restoration efforts. These parameters could eventually reduce the recovery potential of restored sites.     

Physiological Performance of Andropogon gerardii, Panicum virgatum, and Sorghastrum nutans on Reclaimed Mine Spoil

Physiological and vegetative performances of three prairie grasses were investigated to assess their adaptation to soil conditions at two strip mine sites and a nearby railroad prairie. Additionally, rhizomes of the species were transplanted to a pot experiment and grown in both field soil and greenhouse potting medium to investigate the extent to which plants are limited under field conditions. Field measurements of photosynthetic rate and stomatal conductance to water vapor were made on the three species monthly from May to late August. Gas exchange measurements on potted plants were made biweekly from early May to mid-July. In September, vegetative and flowering characteristics were measured on both field and potted plants. Field gas exchange rates were highest at one of the mines. Sorghastrum nutans had the highest rates at the mine sites, whereas Panicum virgatum had the highest rates at the prairie site. Potted plants from the prairie site usually exhibited the highest gas exchange rates, and Sorghastrum nutans had higher rates than Panicum virgatum and Andropogon gerardii. Potted plants in field soil generally had higher gas-exchange rates than plants growing in greenhouse potting medium, and potted plants had higher gas-exchange rates than field-grown plants. Vegetative and reproductive performance of field plants was highest at one of the mine sites. Potted plants in greenhouse medium had up to twice the vegetative and reproductive output as potted plants in field soil or plants growing in the field. The physiological and vegetative performance of these species indicates that they are well adapted to the soil conditions at these strip mine sites, and that they are a viable alternative to nonnative plantings for restoration.     

Impact of an oil field effluent on microbial activities in a Wyoming river

The survival, functions, and physiological diversity of autochthonous sediment microbiota were examined in situ at five stations along the Little Popo Agie River, WY; one station above, one at, and three below a discharge point for oil wastewater from Union Oil Company's Dallas Field. Below the oil wastewater discharge point there were increases in electron-transport activity, carbon dioxide production, and microbial populations of heterotrophs, ammonifiers, hexadecane degraders, starch hydrolyzers, protein hydrolyzers, and sulfate reducers. At a station 1420 m below the discharge point, however, overall sediment microbial activities and all of the physiological groups of bacteria, except hexadecane-degrading microbiota, were at levels comparable with those at the control station above the discharge point. Similarly, mineralization of glucose, amino acids, hexanoic acid, and hexadecane was elevated at stations directly below the discharge point, but appeared to subside rapidly. Xenobiotic biodegradation potential of the sediments varied with the chemical and the sample location and was not directly related to oil residue levels in the sediment. Microorganisms thus appeared to maintain physiological diversity and increased in numbers and activity in a riverine environment that contained petroleum hydrocarbon concentrations known to be deleterious to freshwater fish and macrobenthic communities.     

Restoration of Tropical Moist Forests on Bauxite-Mined Lands in the Brazilian Amazon

We evaluated forest structure and composition in 9- to 13-year-old stands established on a bauxite-mined site at Trombetas (Pará), Brazil, using four different reforestation techniques following initial site preparation and topsoil replacement. These techniques included reliance on natural forest regeneration, mixed commercial species plantings of mostly exotic timber trees, direct seeding with mostly native early successional tree species, and mixed native species plantings of more than 70 tree species (the current operational restoration treatment at this site). Replicated fixed-radius plots in each treatment and in undisturbed primary forest were used to quantify the canopy and understory structure and the abundance and diversity of all vascular plant species. Treatment comparisons considered regeneration density, species richness and diversity for all floristic categories, and, for trees and shrubs, the relative contribution of initial planting and subsequent regeneration from soil seed banks and seed inputs from nearby primary forests. With the possible exception of the stands of mixed commercial species, which were superior to all others in terms of tree basal-area development but relatively poor in species richness, all treatments were structurally and floristically diverse, with a high probability of long-term restoration success. Of these, the mixed native species plantings appeared to be at least risk of arrested succession due to the dominance of a broader range of tree species of different successional stages or expected life spans. In all treatments, several locally important families of primary forest trees (Annonaceae, Chrysobalanaceae, Lauraceae, Palmae and Sapotaceae) were markedly underrepresented due to a combination of poor survival of initial plantings and limitations on seed dispersal from the surrounding primary forest.     

The History of Dinosaur Footprint Discoveries in Wyoming with Emphasis on the Bighorn Basin

Dinosaur traces are well known from the western United States in the Colorado Plateau region (Utah, Colorado, New Mexico, and Arizona). Utah contains the greatest abundance of known and documented dinosaur footprints and trackways. Far less well known, however, is the occurrence and distribution of dinosaur footprint-bearing horizons in Wyoming. Scientific studies over the past 10 years have shown that three of the four Middle and Upper Jurassic formations in northern Wyoming contain dinosaur footprints. Two of the footprint-bearing horizons are located in geologic intervals that were once thought to have been deposited in offshore to nearshore marine settings and represent rare North American examples of Middle Jurassic (Bajocian and Bathonian) dinosaur remains. Some of these new Wyoming sites can be correlated to known dinosaur footprint-bearing horizons or intervals in Utah. Wyoming has a great potential for additional discoveries of new dinosaur footprint-bearing horizons, and further prospecting and study is warranted and will ultimately lead to a much better understanding of the geographic distribution and behavior of the potential footprint-makers.     

Long-Term Effects of Fire on Vegetation Structure and Predicted Fire Behavior in Wyoming Big Sagebrush Ecosystems

Ecosystems - Fire historically occurred across the sagebrush steppe, but little is known about how patterns of post-fire fuel accumulation influence future fire in Wyoming big sagebrush (Artemisia...     

Effect of Soil Type on Population Densities of Nematodes in Soybean Rotation Fields

The effect of soil type on population densities of plant parasitic nematode species in 17 field blocks of four different soil types rotated to corn, soybeans, wheat, and forage mixtures was investigated during a generally droughty 5-year period. High densities of Helicotylenchus pseudorobustus were found in dark silty clay loams. Highest densities of Tylenchorhynchus acutus were also in one of the dark-colored silty clay loams. Light-colored silt loams favored development of Paratylenchus projectus, which developed poorly in the darker soils. Comparable densities of Xiphinema americanum were found in all soils and on all crops, regardless of soil type. Tylenchorhynchus martini, although present, did not build up in any of the soils. Populations of Pratylenchus species were generally low in the rotated blocks of all soil types.     

冻融交替对科尔沁沙地不同土地利用方式土壤呼吸的影响

在中高纬度和高海拔地区,冻融作用影响土壤的理化性质和微生物性状,进而影响土壤呼吸过程。研究冻融作用下土壤呼吸的变化,对准确估算全球碳循环具有重要意义。以科尔沁沙地沙质草地、樟子松疏林草地和农田为研究对象,通过冻融实验比较不同土地利用方式和冻融循环对土壤呼吸的影响。结果表明:土地利用方式对土壤呼吸有显著影响,在未发生冻融作用时沙质草地土壤呼吸速率显著大于樟子松疏林草地和农田(P0.05),3种土地利用方式的土壤呼吸平均速率分别为0.339、0.258和0.234μmolCO2.m-2.s-1;不同冻融循环对沙质草地和樟子松疏林草地土壤呼吸影响显著(P0.05)。其中,一次冻融循环条件下沙质草地、樟子松疏林草地和农田土壤呼吸平均速率分别为0.276、0.243和0.233μmolCO2.m-2.s-1,多次冻融循环条件下分别为0.314、0.274和0.259μmolCO2.m-2.s-1;沙质草地、樟子松疏林草地和农田的Q10值分别为116.0、26.2和16.4,表明冬季低温条件下土地利用方式强烈影响土壤呼吸对温度的敏感性。     

Septicemic pasteurellosis in elk (Cervus elaphus) on the United States National Elk Refuge, Wyoming

Septicemic pasteurellosis caused by Pasteurella multocida is believed responsible for the deaths of 48 elk (Cervus elaphus) on the National Elk Refuge near Jackson, Wyoming (USA) during 1986 and 1987. Clinical signs included depression and salivation; necropsy findings included congestion and petechial and ecchymotic hemorrhages in lymph nodes, diaphragm, lungs and endocardium. Pasteurella multocida was isolated from femur marrow of eight carcasses and a variety of tissues from eight others.     

福建永定桫椤群落内主要灌木种群的种间联结性研究

采用X^2检验、联结系数（AC）和种间共同出现百分率（PC）等指标,分析了福建省永定桫椤群落内主要灌木树种的种间联结性,结果表明：除少数种对外,绝大多数种群间的联结性不显著;在联结性显著的种对中,下述4个种对之间有较高的正联结性;赤楠-杜茎山、蔷薇属一种=细齿叶柃、沿海紫金牛-杜茎山,青冈-冬青,表明这4个种对间的生态习性和对环境的需求较一致。     

Nest Predation Risk on Ground and Shrub Nests in Forest Margin Areas of Sulawesi, Indonesia

Forest loss and fragmentation in Indonesia may seriously affect the survivorship of forest birds and lead to local extinction of bird populations. We used 786 artificial nests baited with quail eggs to examine the effect of habitat alteration on nest predation in Lore Lindu National Park, Sulawesi. Natural forest and four habitats of forest margin areas: forest edge, forest gardens, coffee plantations, and secondary forest, were studied. Two types of artificial nests, ground and shrub nests were placed in these habitats at two different locations for a period of 8 days. In addition, we used automatic cameras and cage-traps to identify the predators. Nests in shrubs experienced significantly higher predation rates in forest margin areas than in natural forest. Predation on ground nests did not differ significantly between these habitat types, but was significantly higher than that on shrub nests in each habitat except forest edge. Rodents were the most common predators of both nests, but shrub nests were also susceptible to Dwarf cuscus (Strigocuscus celebensis), squirrels, and tree snakes. The nest predation rates we found were among the highest found in tropical rainforests, probably a consequence of the unique predator assemblages of Sulawesi. These results suggest that egg survival is negatively affected by human intervention and that human-induced habitats might have only limited importance for the conservation of Sulawesi's largely endemic understorey avifauna. These considerations might be important since forest margins comprise significant proportions of protected areas on Sulawesi and play an important role in future Park zoning concepts as well as in conservation-oriented land use management.     

Pre- and postsynaptic effects of dopamine antagonists on dopaminergic synaptic transmission in Helix pomatia

The rate of transmitter mobilization in identified dopaminergic synapses was decreased by the dopamine antagonists pimozide, chlorpromazine, haloperidol, cis-flupenthixol, curare, clozapine and high concentrations of ergometrine. The depolarizing postsynaptic potential was inhibited by pimozide, chlorpromazine, haloperidol, cis-flupenthixol, curare, clozapine, (+)-butaclamol and high concentrations of ergometrine. The hyperpolarizing synaptic potential was inhibited by naloxone, methysergide, (+)-butaclamol, haloperidol, 6-hydroxydopamine and low concentrations of ergometrine, while pimozide, cis-flupenthixol, trans-flupenthixol, curare, clozapine, promethazine, chlorpromazine and (-)-butaclamol had no clear effect. The presynaptic receptors involved in modulation of the mobilization rate showed similarities with the dopamine receptors mediating depolarizations. The dopamine antagonists changed dynamics of synaptic transmission.     

Interactive Effects of Black-Tailed Prairie Dogs and Cattle on Shrub Encroachment in a Desert Grassland Ecosystem

The widespread encroachment of woody plants throughout the semi-arid grasslands in North America has largely resulted from overgrazing by domestic livestock, fire suppression, and loss of native large and small mammalian herbivores. Burrowing-herbivorous mammals, such as prairie dogs (Cynomys spp.), help control shrub encroachment through clipping of shrubs and consumption of their seedlings, but little is known about how this important ecological role interacts with and may be influenced by co-existing large herbivores, especially domestic livestock. Here, we established a long-term manipulative experiment using a 2 × 2 factorial design to assess the independent and interactive effects of black-tailed prairie dogs (Cynomys ludovicianus) and cattle (Bos taurus) on honey mesquite (Prosopis glandulosa) abundance and structure. We found that, after five years, mesquite abundance was three to five times greater in plots where prairie dogs were removed compared to plots where they occurred together or alone, respectively. While both prairie dogs and cattle reduced mesquite cover, the effect of prairie dogs on reducing mesquite abundance, cover, and height was significantly greater than that by cattle. Surprisingly, cattle grazing enhanced prairie dog abundance, which, in turn, magnified the effects of prairie dogs on mesquite shrubs. Mesquite canopy cover per hectare was three to five times greater where prairie dogs and cattle were absent compared to where they occurred together or by themselves; whereas, cumulative mesquite height was two times lower on sites where prairie dog and cattle occurred together compared to where they occurred alone or where neither occurred. Data from our experimental study demonstrate that prairie dogs and moderate grazing by cattle can suppress mesquite growth, and, when their populations are properly managed, they may interact synergistically to significantly limit mesquite encroachment in desert grasslands.     

Effects of Microwave Exposure at Various Power Densities on Mitochondrial Marker Enzymes in Mouse Brains

Four groups of C₅₇BL mice were irradiated with 3 GHz pulse (PW) microwaves for 3 hours at incident power densities of 0.1, 0.5, 1 and 5 mW/cm² respectively. The amount of mitochondria1 marker enzymes succinate dehydrogenase (SDH) and monoamine oxidase (MAO) in the hypothalamus and hippocampus were determined by microspectrophotometry. SDH and MA0 in the irradiated groups (except 0.1 mW/cm²) were significantly lower compared to the control group (p < 0.01). The lowest level occurred in the 5 mW/cm² group. The threshold level was 0.5 mW/cm². To compare the effects of PW with continuous wave (CW) exposure, two experimental groups were exosed to 2.45 GHz, using CW; the enzymes were decreased only in the 5 mW/cm² group. The results show that PW radiation is more effective then CW radiation in decreasing SDH and MA0 levels.     

Influence of Population Densities of Heterodera schachtii on Sugar Beets Grown in Microplots

High initial population densities of Heterodera schachtii larvae (36 and 108/gm of soil) greatly retarded the seedling emergence of sugar beet ''Monogerm CSF 1971'' in Vineland fine sandy loam. In comparison with controls, initial population densities (P_i''s) of 1.7, 3.0, 6.2, and 14.4 larvae/gm of soil respectively reduced the weight of storage roots by 38, 56, 64, and 92%. Weights of tops also decreased with increases in P_i; weights of tap and small feeder roots tended to be higher at all P_i''s except the highest. Sucrose percentage was not affected by any initial nematode density. The populations were lower at midseason than at seeding, and at harvest had increased greatly, with respective populations of 339, 402, 222, and 140 larvae/gm of soil. At harvest, cysts/gm of soil and cysts/gm of root were respectively 4.4 and 72, 6.1 and 99, 6.1 and 191, and 5.8 and 140. The maximum rate of multiplication was 150-200. and maximum density was 400 larvae/gm of soil. The high pathogenicity and multiplication rate of the nematode was attributed to optimum temperature conditions and soil type.     

Colonization of Claviceps purpurea sclerotia on Triticale by Fusaria in 1985

During 1985 60% of Claviceps purpurea sclerotia collected from Triticale heads were colonized by Fusarium acuminatum Ell. et Ev. and F. heterosporum Nees.     

Effects of eimerian (Apicomplexa: Eimeriidae) infections on nutrient assimilation in the Wyoming ground squirrel.

Effects of infection with mixed species of Eimeria (E. callospermophili, E. morainensis, and E. beecheyi) on the digestive physiology of Wyoming ground squirrels (Spermophilus elegans) are described. Infected and uninfected squirrels were administered arginine and methionine in saturated glucose solution. Blood was drawn at time 0 and 30 min postadministration. Significant differences were not found between infected and uninfected squirrels in plasma glucose, arginine, or methionine assimilation. In a second experiment, infected and uninfected squirrels were fed a food slurry of known caloric value. All feces were collected for 24 hr postfeeding. Differences were not detected in fecal caloric content or digestive efficiency. These results in conjunction with results reported in the literature suggest a reassessment of the "parasitic" nature of these squirrel symbionts. We propose that associations of some Eimeria species and hosts that evolve under natural conditions are examples of parasite-host interactions that often evolve toward commensalism.