Reclaimed Mine Lands Research Articles

THRESHOLD LIMITS FOR SELENIUM IN THE COAL MINING AREAS OF NEW MEXICO

The concerns for selenium (Se) toxicity problems became a major issue to the coal mining industry in the western United States during the 1970s. Problems with Se toxicity in aquatic ecosystems led to a great amount of speculation with regard to Se levels found in backfill and soil materials at surface coal mines. Regulatory agencies quickly established standards to deal with the potential calamity based on limited databases which were conservative in the context of today's knowledge of the Se toxicity issue. The economic impact of these standards has been substantial as a result of regulatory mitigation requirements. Analysis of data collected in the western United States demonstrates that Se levels corresponding to near maximum threshold limits do not usually result in toxic levels of Se in the vetation. For example, at the San Juan Mine, New Mexico, the mean hot-water soluble Se for backfill materials was 0.122 ppm which is above the suitability limit of 0.10 ppm previously used as the maximum by the New Mexico Mining and Minerals Division. Corresponding levels of Se found in four wing saltbush were about 0.84 ppm Se. Therefore, near maximum threshold levels of hot-water soluble Se found in the backfill material results in Se levels of four wing saltbush that are much lower than the 5.0 ppm chronic toxicity level for vegetation. At the Navajo Mine, cattle grazing reclaimed lands exhibited a deficiency in blood Se levels as opposed to a toxicity. There is clear evidence that chronic Se toxicity to limestock and wildlife is unlikely on grazing rangeland or reclaimed mine land and is only problematic on three sites that provide limited alternatives to high Se vegetation. 41 refs., 2 figs., 1 tab.

ANTECEDENT SOIL WATER FOR MANAGED LANDSCAPES IN CENTRAL ALBERTA

Land management practices are known to influence runoff through alteration of the antecedent soil water. For accurate estimation of runoff, direct measurement of antecedent soil water would be necessary. This study investigated antecedent soil water and the potential for summer storm runoff under different land management practices. The two-year study was conducted on five sites: three sites under forage (one on reclaimed mine lands), and two sites under pasture. Treatments included haying, mowing, fallow, and moderate and heavy livestock grazing. Soil water was measured with a neutron probe and was generally less than 50% of water holding capacity (dry conditions). During recharge periods, water increased to near field capacity, but soil water was close to wilting point for some measurement dates. Pasture sites were generally wetter than forage sites, with the difference being most pronounced on fallow treatments. The reclaimed site had generally lower total soil water than the unmined ones.

Shrub Densities on Pre‐1985 Reclaimed Mine Lands in Wyoming

AbstractThe reestablishment of native shrubs is part of the mandate under which mining companies extract mineral resources in Wyoming and other western states. Post‐mining shrub density and species mixtures have been topics debated by various mine reclamation stake holders. By law, coal‐mined lands in Wyoming must now meet a post‐mining shrub density of 1 shrub/m2 on 20% of the affected area. To better understand the long‐term results of shrub reclamation methods, we measured shrub density by species in 14 pre‐1985 seedings at eight mines in three geographic regions of Wyoming. The sites studied were selected as Atriplex canescens (Pursh) Nutt. (fourwing saltbush) and grass or as Artemisia tridentata Nutt. ssp. wyomingensis (Beetle and Young) (Wyoming big sagebrush), fourwing saltbush, and grass post‐mining communities. Shrub density and composition varied by site but typically reflected the seed mixtures used. Seedings that used a diversity of shrub species generally had greater 1994 shrub densities. Seeding rates between 60 and 1000 shrub seeds/m2 had a positive, linear relationship with shrub density up to 0.6 shrubs/m2 when sagebrush was part of the shrub seed mixture. We conclude that the likelihood of meeting the shrub standard can be enhanced by seeding diverse shrub mixtures at high seeding rates.

99/01371 Optimization of an integrated gas turbine—geothermal power plant : Bidini, G. et al. Energy Convers. Manage., 1998, 39, (16–18), 1945–1956

Dedicated bioenergy crops grown on marginal lands such as reclaimed mine lands and other non-arable lands are auspicious cellulosic sources for sustainable bioenergy production. In this study, characterization of pyrolysis products were documented for two dedicated bioenergy crops grown on reclaimed coal-mine lands in West Virginia. Two clonal varieties (Private and Public varieties) of Miscanthus (Miscanthus x giganteus) and two varieties (Bomaster and Kanlow varieties) of Switchgrass (Panicum virgatum L) were used in this study. The oven-dried samples were pyrolyzed in a fixed-bed batch reactor under an inert condition and at a temperature of 500 °C to produce biochar and bio-oil (vapor condensate). The pyrolysis product, energy and carbon conversion yields were calculated. Additionally, biochar and bio-oil were characterized for elemental composition, volatile, ash and calorific values. Results showed that there was no significant difference in the biochar yields (about 30.00% yield) obtained from the clonal varieties of Switchgrass and Miscanthus. The bio-oil yields were in the range of 45.00–51.00% with the Miscanthus (Private variety) having the highest bio-oil yield of 50.61%. The carbon content of the biomass, biochar and bio-oil were found to be 46.80–48.02%, 77.72–80.23% and 54.68–59.68%, respectively. Average calorific values were found to be 19.49 MJ/kg, 29.01 MJ/kg and 24.98 MJ/kg for the biomass, biochar and bio-oil, respectively. Results for the surface chemistry of the biochars showed carbon and oxygen to be the major chemical constituents of the surfaces of the biochars. Carbon dioxide (CO2), nitrogen (N2) and carbon monoxide (CO) were found to be the major components of the non-condensable gas and the CO:CO2 ratio showed that the non-condensable gas cannot be used as a fluidizing medium.

Eroded Aggregate Size Distributions from Disturbed Lands

A characterization of eroded soil properties, especially size, is required for proper usage of modern process-based soil erosion models. In a study addressing reclaimed mine land erodibility, over 350 measured eroded aggregate size distributions were collected from erosion plots created on reclaimed and nearby unmined soils at three separate strip mine sites. The experimental design allowed for a comparison of eroded aggregate size distributions as a function of land slope, run sequence, and reclamation treatment. No influence of slope was apparent, as distributions collected from plots constructed at 6% slope were coarser than those collected from 18% slope, but finer than those collected from 12%. Samples collected during extra inflow runs, in which runoff rates, flow velocity, and rill erosion were greatest, had coarser distributions than samples collected during rainfall only runs, which tended to have similar distributions. Distributions from reclaimed topsoil treatments were similar to nearby unmined soils and were distinct from subsoil reclamation treatments. At two sites, topsoil treatments had coarser distributions, while the converse was true at the third.

Shrub Preference and Utilization by Big Game on New Mexico Reclaimed Mine Land

Mined lands are reclaimed so the land can be used for other purposes after mining. At the La Plata Mine in New Mexico, post-mining land uses include livestock grazing and providing wildlife habitat. The objective of this research was to evaluate use of seeded and volunteer shrubs by mule deer (Odocoileus hemionus) and elk (Cervus canadensis) during the first opportune season, which occurred 7 years following reclamation. Twelve species of shrubs (10 planted and 2 volunteer) were found on 4 different topdressing treatments. Five branches of shrubs for each species were marked and lengths measured prior to and following the winter wildlife grazing season to determine amount of use. Greatest use by both deer and elk was on curlleaf mountain mahogany (Cercocarpus ledifolius Nutt.), followed in decreasing order by fourwing saltbush (Atriplex canescens [Pursh] Nutt.), rubber rabbitbrush (Chrysothamnus nauseosus [Pall.] Britton), common winterfat (Ceratoides lanata [Pursh] Moq.), shadscale (A triplex confertifolia [Torr. and Frem.] Wats.) , antelope bit terbrush (Pursia tridentata [Pursh] DC.), big sagebrush (Artemisia tridentata Nutt.), skunk bush sumac (Rhus trilobata Nutt.), Utah juniper (Juniperus osteosperma [Torr.]Little), fringed sagebrush (Artemisia frigida Willd.), service berry (Amelanchier alnifolia Nutt.), and pinyon pine (Pinus edulis Engelm.). The greatest shrub utilization was on the Jocity topdressing treatment, which is the name of the soil series from which the topdressing was obtained. The Jocity soil series was found on a flood plain site dominated by greasewood (Sarcobatus vermiculatus [Hook.] Torr.). Other shrub utilization, in decreasing order of use, was on topdressing that was a mixture of Jocity and Atrac topdressing, spoil topdressing, and Atrac topdressing, which is a soil series found on an upland site dominated by big sagebrush.

Ten-Year Results from Bactericide Treated and Reclaimed Mine Land

Ten-Year Results from Bactericide Treated and Reclaimed Mine Land

Evaluation of procedures to estimate biomass on surface coal mine lands reclaimed under the Surface Mining Control and Reclamation Act of 1977

Current surface mine regulations as ascribed under the Surface Mining Control and Reclamation Act of 1977 require that mine lands be returned to the approximate original contours (AOC) with an area coverage of at least 70% and to biological productivity equal to or greater than that which existed prior to mining. Six different procedures were evaluated on nine mine sites in northwestern Pennsylvania as to their suitability to estimate aboveground biomass on mines reclaimed as hayland and pastures. Biomass estimates determined by different procedures were compared to those obtained by random clip plots and with landowner estimates of the annual yield from each site. Biomass estimates determined from a disk meter and landowner interviews varied approximately ±10% from those obtained from random clip plots compared to a variation of ±8%–37% for the other procedures. The number of samples required to obtain reliable estimates within ±10% of the mean at 95% confidence intervals varied among the different sampling procedures according to the variance in biomass on the site. Although all procedures may be used either singly or in combination to estimate above ground biomass on reclaimed mine lands, the combination of the disk meter, profile board, and vegetation height is recommended because of their ease of measurement compared to the other procedures.

Ten-Year Results from Bactericide Treated and Reclaimed Mine Land

Ten-Year Results from Bactericide Treated and Reclaimed Mine Land

Influence of Seeding Level upon Plant Community Dynamics on Reclaimed Mined Lands in Pennsylvania

Influence of Seeding Level upon Plant Community Dynamics on Reclaimed Mined Lands in Pennsylvania

Establishment of Four Species of Native Hardwoods on Reclaimed Mine Lands in Pennsylvania

Establishment of Four Species of Native Hardwoods on Reclaimed Mine Lands in Pennsylvania

Growth and selenium uptake of range plants propagated in uranium mine soils

Abstract High soil selenium (Se) levels have been found in association with uranium deposits in Texas. A concern that high Se concentrations may be found in forages grown on reclaimed mine lands prompted this investigation. A native soil sampled near the mining area, and overburden materials sampled from two Se enriched uranium mine spoil sites were compared in a plant growth study in the greenhouse. Shoot yields and shoot Se concentration in each of ten grasses common to the region were determined from plants harvested three weeks after germination and from shoot regrowth harvested four weeks after the first harvest. Shoot weights were reduced for 5 of the 10 species growing in soils with medium and high Se status. Total shoot weights of Cynodon dactylon and Panicum coloratum from two harvests were consistently highest in all soil materials and are highly recommended for use as a stabilizing cover crop for lands disturbed from uranium mining. Generally, no correlation was observed between shoot weight an...

Forest Productivity of Reclaimed Mined Land: A Landowner's Perspective

Forest Productivity of Reclaimed Mined Land: A Landowner's Perspective

Sharp-Tailed Grouse Use of Reclaimed Mine Land in Eastern Montana

Sharp-Tailed Grouse Use of Reclaimed Mine Land in Eastern Montana

The effect of Acacia albida on tin-mine spoil and their possible use in reclamation

From a number of studies in Africa, Acacia albida has been shown to have some extremely beneficial effects on the soil lying within the confines of its canopy shadow. On the Jos Plateau of Nigeria, Acacia albida is a natural colonizer of spoil mounds created as a result of opencast tin mining. Observation of the ground vegetation growing in the vicinity of a number of isolated Acacia albida indicated that the ground vegetation growing below the canopy was taller, more lush and a darker green than that growing outside the influence of the canopy, thus suggesting that the beneficial effect of Acacia albida on soils reported from elsewhere in Africa was operating at these sites. Analyses of soil samples collected from sites beneath and outside the canopy of a single tree confirmed this tentative hypothesis. Organic carbon, total nitrogen, pH, percentage base saturation and exchangeable calcium, magnesium, sodium and potassium were all significantly higher in soils from beneath the canopy than in those from outside. The soil beneath the tree also had a better-developed and stronger structure and a more active population of soil fauna. Having established that the Acacia albida did indeed have a beneficial effect on the spoil soils, the study was extended to compare the effect of Acacia albida on the spoil soil with that of the eucalypt plantations established on areas of reclaimed mine land. The sites under Acacia albida were found to have significantly higher levels of exchangeable calcium, pH and base saturation than those under the eucalypts. This difference is of some importance, since it has recently been shown that the eucalypt plantations are causing a gradual degradation of the soils rather than the amelioration hoped for by the unit that established the plantation policy in the 1960s. Having established that Acacia albida has a more beneficial effect on the spoil soils than the eucalypts, consideration is given to the possibility of using the native Acacia albida as an alternative to the exotic eucalypts. It is concluded, however, that a more detailed study is required into the effect that Acacia albida has on the spoil soils before any firm recommendation can be made, particularly as the eucalypts have much greater economic value than Acacia.

Institutional Constraints to Production of Reclaimed Mine Lands Suitable for Development in Central Appalachia

Institutional Constraints to Production of Reclaimed Mine Lands Suitable for Development in Central Appalachia

Spatial Variability for One Type of Phosphate Mine Land in Central Florida

AbstractSoil‐plant interaction problems are frequently encountered in the reclaimed phosphate minelands of central Florida. To solve some of these problems, a knowledge of the soil properties and their spatial variability must be acquired. An optimum sampling design for reclaimed mine lands can only be constructed after this information is known. Therefore, selected soil properties of one type of reclaimed phosphate mine land (overburden over sandtailings) in central Florida were investigated. A 6 × 21 sampling grid with 10‐m interval sampling points was constructed and soil samples (0–25 cm) were taken in four directions along selected transects. The results indicated that mean values were very high for total P (8.3 g/kg), extractable P (0.9 g/kg), and extractable Ca (2.3 g/kg) by the double acid method. The double acid method of extracting Ca, Mg, K, and Na yielded higher mean contents than the procedure using NH4OAc at pH 7. Correlation coefficients were highly significant between both extractable Ca and Mg and total extractable bases. Higher r values were obtained using KCl‐pH than H2O‐pH in studying the relationships of pH to the other soil properties except for total P. Semivariograms were calculated for the different soil properties studied in the four sampling directions. A composite semivariogram of all four directions was also constructed. Except for CEC and relative elevation, spatial correlation of all properties was encountered at sampling distances < 2.6 to 7.1 m. At a lag distance of six peak values occurred in several sampling directions for many of the soil properties studied. This indicates similar optimum sampling distances for the soil properties of interest.