Soil quality recovery

Nitrate fluxes from mined watersheds were 1-2 orders of magnitude higher than an adjacent forested watershed, impacting regional water quality.  Nitrate export declined after the cessation of active mining but persisted above reference levels for decades post-mining.  The persistence of mining-associated N export suggests N sources are linked to deeper flow paths within constructed valley fills.

Globally intensive agriculture has both increased nitrogen pollution in adjacent waterways and decreased availability of terrestrially derived carbon frequently used by stream heterotrophs in nitrogen cycling. We tested the potential for carbon additions via leaf litter from riparian restoration plantings to act as a tool for enhancing denitrification in agricultural streams with relatively high concentrations of nitrate (1.3-8.1 mg/L) in Canterbury, New Zealand. Experimental additions of leaf packs (N = 200, mass = 350 g each) were carried out in 200-m reaches of three randomly selected treatment streams and compared to three control streams receiving no additional leaf carbon. Litter additions increased ecosystem respiration in treatment streams compared to control streams but did not affect gross primary production, indicating the carbon addition boosted heterotrophic activity, a useful gauge of the activities of microbes involved in denitrification. Bench-top assays with denitrifying enzymes using acetylene inhibition techniques also suggested that the coarse particulate organic matter added from leaf packs would have provided substrates suitable for high rates of denitrification. Quantifying denitrification directly in experimental reaches by open-channel methods based on membrane inlet mass spectrophotometry indicated that denitrification was around three times higher in treatment streams where litter was added compared to control streams. We further assessed the potential for riparian plantings to reduce large-scale downstream nitrogen losses through increasing in-stream denitrification by modeling the effects of increasing riparian vegetation cover on nitrogen fluxes. Here, we combined estimates of in-stream ecosystem processes derived from our experiment with a network model of catchment-scale nitrogen retention and removal based on empirical measurements of nitrogen flux in this typical agricultural catchment. Our model indicated leaf inputs associated with increased riparian cover had the potential to double the catchment level rate of denitrification, offering a promising way to mitigate nitrate pollution in agricultural streams. Altogether, our study indicates that overcoming carbon limitation and boosting heterotrophic processes will be important for reducing nitrogen pollution in agricultural streams and that combining empirical approaches for predictions suggests there are large potential benefits from riparian re-vegetation efforts at catchment scales.

S .................................................................................................................................. i ACKNOWLEDGMENTS ............................................................................................................. iii LIST OF TABLES ......................................................................................................................... vi LIST OF FIGURES ....................................................................................................................... vii CHAPTER 1 ...................................................................................................................................

This study analyzed the interactions among a set of ecosystem services (ES) and derived ES bundles in the Headwaters of Coal River West Virginia (WV), in the Central Appalachians, an area historically characterized by surface mining and coal extraction. ES were modeled using the InVEST system, while a custom model was used to link water quality to freshwater ES, deriving information at two different spatial scales based on hydrologic units. High-resolution remote sensing data (1–2 m resolution) were used to incorporate historical information from land-cover (LC) transitions since 1976 to differentiate reclamation processes and characterize the forest class. Consistent ES tradeoffs were confirmed in areas characterized by surface mining processes that reported significant losses of carbon sequestration, habitat quality , and freshwater ES. The interaction of complex anthropogenic processes within the specific landscape led to the definition of different ES bundles, characterized not only by coal mining processes but also by the distribution of settlements and developed areas. The utilization of relatively small hydrologic catchments (1–25 km2), the comparison with a more extensive set of spatial units, and the inclusion of high-resolution data with multiple LC classes that included historical information, allowed the authors to infer knowledge about the interactions between ES changes and their drivers in the study area. The results can be used to implement conservation, as well as development-restoration strategies, by including ES assessments to promote a more sustainable land management approach in the rural-mining region of Central Appalachians and support future alternatives to extractive economies.

Mountaintop removal coal mining (MTM) is a form of surface mining where ridges and mountain tops are removed with explosives to access underlying coal seams. The crushed rock material is subsequently deposited in headwater valley fills (VF). We examined how this added water storage potential affects streamflow using a paired watershed approach consisting of two sets of mined and unmined watersheds in West Virginia. The mined watersheds exported 7−11% more water than the reference watersheds, primarily due to higher and more sustained baseflows. The mined watersheds exported only~1/3 of their streamflow during storms, while the reference watersheds exported~2/3 of their annual water yield during runoff events. Mined watersheds with valley fills appear to store precipitation for considerable periods of time and steadily export this alkaline and saline water even during the dry periods of the year. As a result, MTMVFs in a mixed mined/unmined watershed contributed disproportionately to streamflow during baseflow periods (up to >90% of flow). Because MTMVFs have both elevated summer baseflows and continuously high concentrations of total dissolved solids, their regional impact on water quantity and quality will be most extreme and most widespread during low flow periods.

Mountaintop removal and valley fill (MTR/VF) coal mining has altered the landscape of the Central Appalachian region in the USA. Among the changes are large-scale topographic recontouring, burial of headwater streams, and degradation of downstream water quality. The goals of our study were to: 1) compare the structure and function of natural and constructed stream channels in forested and MTR/VF catchments across ephemeral, intermittent, and perennial flow regimes and 2) assess the relationship between leaf litter breakdown and structural measures, such as the habitat assessments currently used by regulatory agencies. Specific conductance of stream water was, on average, 36 to 57× higher at perennial reaches below valley fills than at perennial reaches in forested catchments, whereas pH was circumneutral in both catchment types. Channel habitat and invertebrate assemblages in litter bags differed between forested streams and constructed channels in VF catchments. Invertebrate densit...

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Land use impacts are commonly quantified and compared using 2D maps, limiting the scale of their reported impacts to surface area estimates. Yet, nearly all land use involves disturbances below the land surface. Incorporating this third dimension into our estimates of land use impact is especially important when examining the impacts of mining. Mountaintop mining is the most common form of coal mining in the Central Appalachian ecoregion. Previous estimates suggest that active, reclaimed or abandoned mountaintop mines cover ~7% of Central Appalachia. While this is double the areal extent of development in the ecoregion (estimated to occupy <3% of the land area), the impacts are far more extensive than areal estimates alone can convey as the impacts of mines extend 10s to 100s of meters below the current land surface. Here, we provide the first estimates for the total volumetric and topographic disturbance associated with mining in a 11,500 km2 region of southern West Virginia. We...

Appalachian forests are threatened by a number of factors, especially introduced pests and pathogens. Among these is Phytophthora cinnamomi, a soil-borne oomycete pathogen known to cause root rot in American chestnut, shortleaf pine, and other native tree species. This study was initiated to characterize the incidence of P. cinnamomi on surface mined lands in eastern Kentucky, USA, representing a range of time since reclamation (10, 12, 15, and 20 years since reclamation). Incidence of P. cinnamomi was correlated to soil properties including overall soil development, as indicated by a variety of measured soil physical and chemical parameters, especially the accumulation of soil organic carbon. P. cinnamomi was detected in only two of the four sites studied, aged 15 and 20 years since reclamation. These sites were generally characterized by higher organic matter accumulation than the younger sites in which P. cinnamomi was not detected. These results demonstrate that P. cinnamomi is capable of colonizing reclaimed mine sites in Appalachia; additional research is necessary to determine the impact of P. cinnamomi on susceptible tree species at these sites.

Previous studies have made some progress with the use of microbial community properties as assessment criteria for rehabilitation success of postmining areas. Currently, there is a need for reference ranges of specific properties in rehabilitated postmining sites to make this approach more practical. The aim of this investigation was to compare assessment parameters indicative of microbial community function (enzymatic assays) and structure (phospholipid fatty acid (PLFA) analysis) in rehabilitated asbestos and coal discard sites and to establish ranges of minimum and maximum values for these parameters in both types of sites. The range established for dehydrogenase activity in coal discard sites was 24.3-339.5 μg INF g −1 2 h −1 and for asbestos 44.5-544.6 μg INF g −1 2 h −1 . Ranges were also established for β-glucosidase, urease, acid phosphatase and alkaline phosphatase. Complete PLFA profiles were determined and ranges established for major PLFA groups and ratios in both types of discard. From the PLFA profiles, viable microbial biomass was determined as 6,080-29,851 and 8,128-47,242 pmol g −1 dry weight for the coal and asbestos discard sites, respectively. While similar ranges were observed for both types of discard, a canonical correspondence analysis that accounts for functional and structural characteristics showed that sites clustered according to the origin of the samples.

Durant près de 75 ans, du milieu de XIXe siècle à la fin des annes 1920, le massif oriental des Picos de Europa fut lieu d'une exploitation minière de gisements de zinc. Les conditions difficiles liées à l'isolement et à l'altitude incitèrent à l'enrichissement in situ des minerais extraits, par une calcination à l'air libre. Cet article propose une aproche de l'incidence de telles calcinations sur l'environnement. Il tente dèvaluer la quantité de bois consommée et l'ampleur des conflits avec les agriculteurs et les collectivités locales mettant en cause les fumées des calcinations.

We measured C and N cycling indicators in Appalachian watersheds impacted by mountaintop removal and valley fill (MTR/VF) coal mining, and in nearby forested watersheds. These watersheds include ephemeral, intermittent, and perennial stream reaches, and the length of time since disturbance in the MTR/VF watersheds was 5 to 11 years. In forest soils compared to VF soils, both denitrification enzyme activity (DEA) and basal respiration (BR) were elevated (factor of 6 for DEA and factor of 1.8 for BR expressed on a weight basis) and bulk density was lower. Organic matter (OM) and moisture
were higher in the forest soils, which likely contributed to the elevated DEA and BR levels. Evaluation of soils data from our intermittent watersheds as a chronosequence provides some evidence of soil quality (DEA, BR, and soil moisture) improvement over the course of a decade, at least in the top 5 cm. Across the hydrological permanence gradient, sediment DEA was significantly higher (factor of 1.6) and sediment OM was significantly lower in forested than inVFwatersheds, whereas sediment BR did not differ between forested and VF watersheds.Dissolved organic carbon (DOC) concentrations were not different in mining-impacted and forested streams, whereas dissolved inorganic carbon (DIC) concentrations and DOC and DIC stable carbon isotopic compositions (δ13C) were significantly elevated in VF streams. The δ13C-DIC values indicate that carbonate dissolution was a dominant source of dissolved carbon in MTR/VF mining-impacted streams. The disturbance associated with MTR/VF mining significantly impacts C and N processing in soils, stream sediments, and stream water although our data suggests some improvement of
soil quality during the first decade of reclamation.

The United States' use of coal results in many environmental alterations. In the Appalachian coal belt region, one widespread alteration is conversion of forest to reclaimed mineland. The goal of this study was to quantify the changes to ecosystem structure and function associated with a conversion from forest to reclaimed mine grassland by comparing a small watershed containing a 15-year-old reclaimed mine with a forested, reference watershed in western Maryland.