Surface-mined Land Research Articles

Sowing of low and high diversity seed mixtures in ecological restoration of surface mined‐land

AbstractQuestionsWhat are the differences in speed and pathway of vegetation development on nutrient‐poor, unvegetated slopes sown with low‐diversity seed mixtures of cultivars and high‐diversity seed mixtures of regional species? And how is the susceptibility of the different sowing treatments to immigration events via seed rain? We compared differences in using a low‐diversity seed mixture in comparison with a high‐diversity seed mixture, both sown on nutrient‐deficient raw soil. We assessed differences of speed and pathway of vegetation development of different variants as well as their susceptibility to immigration events via seed rain.LocationCentralGerman Lignite Mining District.MethodsIn December 2004, the trial was established in complete block design with four variants: sowing of a low‐diversity seed mixture with three grass cultivars and sowing of a high‐diversity seed mixture with 40 herbs and 11 grasses of local provenance, both with and without an additional mulch layer. Vegetation surveys were made between 2005 and 2010. Using generalized linear models (GLM), we tested for treatment effects on species diversity, above‐ground biomass, total coverage of vegetation as well as number and coverage of target grassland species. In addition, we estimatedBray‐Curtis distances between treatments using non‐metric‐multidimensional scaling.ResultsSowing of a high‐diversity seed mixture clearly accelerated the vegetation development and led to a significantly higher biomass production in the 1st year. On both variants, the additional mulch layer facilitated the establishment of sown species and led to a higher coverage of the herb layer in the 1st year. After 6 yr, the influence of the mulch layer decreased for the benefit of the seed mixture. Despite species exchange between sites, sites sown with different seed mixtures were still dominated by different sets of species in the final year of our study. Whereas high‐diversity mixtures sped up vegetation development in the direction of highly diverse semi‐natural grasslands, low‐diversity mixtures considerably delayed the successional progress.ConclusionsIn grassland restoration in surface‐mined land, high‐diversity mixtures performed similar or even better than low‐diversity mixtures of grass cultivars with respect to ecosystem services such as biomass production and ground cover (erosion control). An additional mulch layer considerably accelerated the vegetation development in the 1st years on both sowing variants. In contrast to sowing of low‐diversity seed mixtures of grass cultivars, the use of high‐diversity seed mixtures of local provenance contributes to the enhancement of local biodiversity. Although target grassland species were able to migrate into the low‐diversity sites, this process is slow and only possible when appropriate seed sources are nearby.

English

The Appalachian region of USA hosts diverse forests and abundant high-quality coal reserves. Surface mining methods are often used for coal extraction. Because common reclamation methods in past years have not restored forest vegetation, surface mining has created a diverse land base. Although some mined lands have been placed into managed uses, most have not. Little is known about the extent and nature of the land resource base created by surface coal mining in Appalachia. Here, we report on development of methods for interpreting imagery acquired by the Landsat satellites since the early 1980s to identify surface-mine land disturbances by date of mining, and to estimate current woody canopy on those mined areas. We have conducted these analyses working within a study area in southwestern Virginias coalf ield. The mined-area identification algorithm, when applied to an independent dataset, was found to identify mined/non-mined areas correctly with an overall accuracy of 89.1%, with 87.4% of mined areas within the independent dataset were classified correctly as mines. Incorrectly classified mines were often areas with low levels of vegetative cover nested within correctly classified mine areas. Preliminary results show that woody canopy cover on mined and reclaimed areas can be estimated successfully using Landsat (0.80 R 2 ). Future work will further develop these procedures and apply them over a test area.

Twelve years of succession on sandy substrates in a post‐mining landscape: a Markov chain analysis

Knowledge of succession rates and pathways is crucial for devising restoration strategies for highly disturbed ecosystems such as surface-mined land. As these processes have often only been described in qualitative terms, we used Markov models to quantify transitions between successional stages. However, Markov models are often considered not attractive for some reasons, such as model assumptions (e.g., stationarity in space and time, or the high expenditure of time required to estimate successional transitions in the field). Here we present a solution for converting multivariate ecological time series into transition matrices and demonstrate the applicability of this approach for a data set that resulted from monitoring the succession of sandy dry grassland in a post-mining landscape. We analyzed five transition matrices, four one-step matrices referring to specific periods of transition (1995-1998, 1998-2001, 2001-2004, 2004-2007), and one matrix for the whole study period (stationary model, 1995-2007). Finally, the stationary model was enhanced to a partly time-variable model. Applying the stationary and the time-variable models, we started a prediction well outside our calibration period, beginning with 100% bare soil in 1974 as the known start of the succession, and generated the coverage of 12 predefined vegetation types in three-year intervals. Transitions among vegetation types changed significantly in space and over time. While the probability of colonization was almost constant over time, the replacement rate tended to increase, indicating that the speed of succession accelerated with time or fluctuations became stronger. The predictions of both models agreed surprisingly well with the vegetation data observed more than two decades later. This shows that our dry grassland succession in a post-mining landscape can be adequately described by comparably simple types of Markov models, although some model assumptions have not been fulfilled and within-plot transitions have not been observed with point exactness. The major achievement of our proposed way to convert vegetation time series into transition matrices is the estimation of probability of events--a strength not provided by other frequently used statistical methods in vegetation science.

Range Size, Habitat use, and Dial Activity of Feral Hogs on Reclaimed Surface-Mined lands in East Texas

During the last decade, surface lignite mines in eastern Texas have experienced damage by feral hogs (Sus scrofa) to reclaimed areas. Specifi cally, feral hogs have caused damage to plants used in reclamation. In addition to vegetative losses, erosion control problems and water quality impacts have been noted. Big Brown Lignite Mine in Freestone County, Texas, had tried to control feral hogs through year-long trapping, which proved expensive. We hypothesized that hogs were using reclaimed areas only at night and seasonally. If so, knowledge of travel lanes into the mine and seasonal use would help concentrate trapping efforts and reduce costs. To determine travel lanes and season use, we radio-monitored 6 male and 10 female feral hogs from January 1998 to January 1999 at Big Brown Mine. We determined annual range size and habitat selection using a geographic information system. Contrary to our hypothesis, we found feral hogs remained on reclaimed lands. We observed that male feral hogs had a signifi cantly (P < 0.02) larger mean annual range (15.8 km 2 ) than did female hogs (6.5 km 2 ), and hogs of both sexes preferred reclaimed wildlife areas and non-mined riparian corridors on the mine site, which had higher screening cover than other vegetation types. We found free water to be another important landscape feature that infl uenced hog movements. We observed that feral hogs moved greater distances from free water and screening cover during night hours. Feral hogs also traveled greater distances from both free water and screen cover during winter and spring than during summer or fall (P < 0.001). Based on the information obtained from our study, we recommend vegetation management (mowing of tall grass areas where hogs hide during daylight hours) be implemented to reduce hog impacts that occur mostly during night at the mine site. Reducing vegetative cover around water sources may also reduce hog impacts.

English

The ultimate goal of mineland reclamation is reestablishment of a productive, functional, and sustainable ecosystem suitable for postmining land use. Evaluation of reclamation success for bond release, however, is limited to examination of the reestablished plant community with emphasis also placed on soil erosion protection and landscape hydrologic function. Most ecosystem components and processes of the reclaimed site are not examined but are crucial to ecosystem function and sustainability. The objective of this paper is to present data from our work on recovery of ecosystem structure (e.g. organisms, soils, mycorrhiza) and function (e.g. biomass production, carbon cycling, nitrogen cycling) on reclaimed surface coal mines in Wyoming. Our studies of chronosequences of reclaimed sites indicate increasing productivity through time in all groups of organisms monitored (plants, bacteria, fungi, nematodes and arthropods) as well as increasing concentrations of soil organic matter, rapid incorporation of organic carbon into soil aggregates, redevelopment of mycorrhizae, and reformation of carbon and nitrogen pools. Although the precise trajectory of the restored ecosystems are very difficult to predict because of changing control variables such as potential biota (invasive species) and climate, our data indicates ecosystem structure and function is recovering on reclaimed surface minelands.

Topsoil Seed Bank of an Oak-Hickory Forest in Eastern Kentucky as a Restoration Tool on Surface Mines

Typical reclamation practices in the central Appalachian coal region often use compacted spoils as a topsoil replacement, and these soils are revegetated with aggressive grasses and legumes. This restoration approach results in an herbaceous-dominated landscape with limited natural succession by native flora. An alternative restoration method is to save topsoil prior to mining, stockpile it during mining, and then replace it on uncompacted spoils to “inoculate” the site with native plant species. In an effort to test this approach, vegetation assessments were performed at a relatively undisturbed forested site in Clay County, Kentucky, U.S.A. Eight 15 × 15–m plots were established, and soils from individual plots were used in seed bank studies both in the greenhouse and on loose-dumped mine spoils. Bulk soil samples were removed from the plots and subjected to cold stratification for 13 weeks, after which seeds were allowed to germinate under greenhouse conditions for 1 year. Additional topsoil (approximately 1.5 m3 from the upper 0–20 cm) was removed from the plots and replaced on fresh spoil in eight 2 × 5–m plots. Controls consisted of uncompacted spoil material substrate only. A total of 105 species emerged in the greenhouse from the seed bank. On the relocated topsoil, 69 species were recorded of which 39 were also observed in pre-mine vegetation surveys. Ten of the 17 most important pre-mine forested site species emerged from the relocated topsoil treatments on the mine site. Our results indicate that application of topsoil could enhance plant diversity and native species reestablishment on surface-mined lands.

Field-level spatial factors, associated edges, and dickcissel nesting ecology on reclaimed lands in Texas

Surface-mined land reclamation creates grass and shrub lands that provide important wildlife habitat, particularly for disturbance-dependent birds. Declines in disturbance-dependent birds have been observed for 30 years, emphasizing the importance of proper reclamation strategies. Understanding the influence of spatial factors on nesting ecology of avian populations can improve restoration strategies on reclaimed mines. We evaluated the influence of spatial factors on nest site selection, nest success, and nest parasitism of dickcissels ( Spiza americana) on two sites reclaimed as wildlife habitat on the Big Brown Mine, Freestone County, Texas, in 2002–2003. We found 119 nests, 14 of which were parasitized by the brown-headed cowbird ( Molothrus ater). Dickcissels were more likely to select nest sites farther from riparian areas and closer to brush-encroached areas. Nest success was not clearly explained by one or few variables. Parasitism was more likely to occur near riparian areas and roads. For these reasons, we suggest the establishment of larger wildlife habitat blocks, which would provide more field-interior habitat for dickcissels and similar species.

Thinning Response of a White Pine Stand on a Reclaimed Surface Mine in Southwestern Virginia

Abstract White pine (Pinus strobus L.) is planted extensively following reclamation of surface-mined land in the eastern coalfields. Little information exists on the productive potential of forests growing on reclaimed mined land and the response of these forests to intermediate stand treatments such as thinning. A thinning study was established in a 17-year-old white pine stand growing on a reclaimed surface mine in Wise County in southwest Virginia. A random complete block design was used to evaluate the growth response 9 growing seasons after thinning, when the stand was 26 years old. Stand parameters were projected to age 30 using a stand table projection. Site index of the stand was found to be 105 ft at a base age of 50 years. Thinning increased the diameter growth of the residual trees to 0.3 in. year−1 compared with 0.2 in. year−1 for the unthinned treatment; however, at age 26, there was no difference in volume or value per acre. When projected to age 30, the unthinned treatment had a volume of 6,530 ft3 ac−1 but was only worth $3,564 ac−1, whereas the thinned treatment was projected to have 6,654 ft3 ac−1, which was worth $4,559 ac−1 due to a larger percentage of the volume in sawtimber size classes. These results indicate that commercial forestry is a viable alternative for reclamation of surface-mined lands and that stands growing on reclaimed mined land can respond well to intermediate stand treatments.

English

Evaluation of mine reclamation success is based on examination of aboveground ecosystem components. Recovery of belowground constituents and processes, such as soil structure and nutrient cycling, is crucial to successful reclamation of disturbed lands. Inadequate recovery of belowground ecosystem structure and function during reclamation can lead to future site degradation. Our objective in this study was to test the hypothesis that recovery of plant community properties on reclaimed surface mine land accurately reflect recovery of soil structure, more specifically aggregate size distribution. In this study, above- and belowground constituents were sampled on reclaimed mine sites representing various ages (native rangeland, a 4 month old topsoil stockpile, 14, 26, and 29 year old reclamation) located in northeastern Wyoming. Cool-season grass (native and reclaimed) communities were sampled for aboveground biomass production, cover and species diversity according to Wyoming Department of Environmental Quality standards. Soil samples were analyzed for water stable aggregate size distribution with wet sieving. Soil structure appears to be recovering through time. An increase in macroaggregates (250-2000µm) on a weight basis and a decrease in free microaggregates (53-250 µm) and free silt and clay (<53 µm) on reclaimed sites with time was observed, indicating incorporation of free silt and clay and free microaggregates into macroaggregates. Aboveground biomass production and macroaggregate formation showed a significant relationship (R 2 = 0.457); however, no relationship was evident for microaggregate formation. No significant relationship existed among total cover and species diversity with respect to macro- and microaggregate formation. These preliminary results suggest that soil structural recovery is most closely related to plant biomass production, while other plant community properties do not necessarily reflect this recovery.

Stand Characteristics and Productivity Potential of Indiana Surface Mines Reclaimed Under SMCRA

Abstract The Surface Mining Control and Reclamation Act of 1977 (SMCRA) addresses a wide range of environmental concerns. However, its impacts on forest stand development and productive potential have only recently been investigated. We surveyed the vegetation and forest productivity on 22 surfacemine sites throughout the coal-bearing region of Indiana that were reclaimed to forest cover under the provisions of SMCRA 7–14 years prior to sampling. Black locust (Robinia pseudoacacia) and green ash (Fraxinus pennsylvanica) were the most widely occurring tree species.Tall fescue and goldenrod were the most widely occurring nonarborescent species. Median site index (base age 50 for black oak) was 30 ft. Although satisfying forest cover stocking requirements for bond release, these reclaimed surface mines almost always displayed a level of productivity farbelow those of native forests typical of this region. Reclamation techniques differing from those used on these study sites are needed to restore forest productivity to surface-mined lands while still complying with SMCRA.

English

The Appalachian coalfields occur largely under rugged mountains covered by native hardwood forests. These forests, soils, and bedrock are removed by the surface mining process. Surface mines are not typically reclaimed to a managed forest land-use, but are often seeded with non-native grasses and legumes, or with pines, black locust, and shrubs for unmanaged forest land. Surface mining and reclamation techniques since the passage of the Surface Mining Control and Reclamation Act of 1977 (SMCRA) create highly compacted mine soils with high coarse fragment content, low organic matter, and high pH, which inhibits native forest reestablishment. The purpose of this study was to develop a forest site quality classification model to advise landowners on the production potential and feasibility of reforesting their mined lands with white pine (Pinus strobus L.). Ten selected physical, chemical, and site properties were assessed and a model was developed using variables that were the most highly correlated with the growth of 10- to 18-year-old white pines established on post- SMCRA surface-mined sites. A model with soil pH, texture, density, and rooting depth variables yielded a coefficient of determination of 0.71. Sufficiency curves were used in a productivity index (PI) model to classify reclaimed surface-mined land into one of five forest site quality classes (FSQC). A site index (SI50 = dominant tree height at age 50) for white pine was estimated for each class, and this measure of productivity may be used to aid in management decisions regarding reforestation of surface mines in the Appalachian coalfields.

A Natural Channel Design Approach to Stream Restoration on Reclaimed Surface Mine Lands

Natural channel design methods are being considered for the purpose of re-establishing stable stream channels and valleys on reclaimed surface mine lands. Natural channel design is the process of applying fluvial geomorphic principles to transform unstable stream corridors into stable channels that maintain their dimension, pattern, and profile over time. Additional goals include improving aquatic habitats and restoring native riparian vegetation. Natural channel design concepts are reviewed in the context of their application to reclaimed mine lands. A tributary to the Mitchell River in the Blue Ridge Mountains of North Carolina is used as a case study demonstrating techniques that may be applied to reclaimed surface mine land sites. Additional

Modeling Regional Carbon Dynamics and Soil Erosion in Disturbed and Rehabilitated Ecosystems as Affected by Land Use and Climate

The quantification of carbon (C) and nitrogen (N) cycling inecosystems is important for (a) understanding changes inecosystem structure and function with changes in land use, (b)determining the sustainability of ecosystems, and (c) balancingthe global C budget as it relates to global climate change.A meso-scale study was conducted to determine regional effectsof climate change on C and N cycling within disturbedecosystems. Objectives of the research were to quantify (a)sediment yield, (b) current C storage in vegetation and soils,and (c) soil C efflux from both abandoned and rehabilitatedcoal surface-mined lands in Ohio. A dynamic model was developedto simulate sediment yield, grassland production, and C and Ncycling on surface-mined lands. Evaluation of plant productionand soil erosion submodels with data sets from surface-minedlands in the mid-western U.S. resulted in r2 values of 0.99 and0.97, respectively. Depending on the initial values of soil organic carbon (SOC),model simulations estimated that unvegetated surface-mined landsin Ohio yield approximately 441,325 Mg yr-1 of sediment andemit between 2,000–20,000 Mg yr-1 of C to the atmosphere fromdecomposition of SOC. While rehabilitated lands had a higher Cefflux rate than barren lands, a positive C sequestration rateof 18.4 Mg km-2 yr -1 was estimated as a result oforganic matter additions. This sequestion rate increasedconsiderably under projected climate change scenarios, while itdecreased when simulated rehabilitated grasslands were harvestedfor hay. Changes in land use and cover can cause surface-minedlands to be either a net sink or source for C. Successful rehabilitation of mined lands can decrease erosion and promotesoil C sequestration, while at the same time providingadditional lands for the management of natural resources.

Growth of Three Pine Species after Eleven Years on Reclaimed Minesoils In Virginia

Abstract A reforestation experiment was established to test the growth of three pine species on two different surface-mined sites in the Appalachian coalfields of southwest Virginia. One site was mined just prior to enactment of the 1977 Surface Mining Control and Reclamation Act (SMCRA), and one site was mined and reclaimed to its approximate original contour in accordance with post-SMCRA regulations. Three pine species (Pinus taeda, P. virginiana, and P. strobus) were planted on each site in 1981. A fertilization and an herbaceous weed control treatment were tested. Half the plots were fertilized with a 21 g fertilizer tablet at time of planting and a broadcast application of 50 kg/ha N as ammonium nitrate prior to the fourth growing season. Each plot was split to accommodate an herbaceous weed control treatment during the first 3 yr. After 11 yr, all three tree species grew very well on the prelaw bench site, but were less productive on the postlaw AOC site. The fastest growing species was loblolly pine, which averaged 22 ft tall. Aggressive herbaceous ground covers commonly established on surface-mined land to reduce erosion were successfully controlled by herbicides, resulting in a significant improvement in survival and growth for all tree species. Fertilization as used in this study had little effect on growth and was not as beneficial for tree establishment as the herbicide treatment. The performance of these commercial tree species in this study demonstrates that good forest management opportunities exist for the owners of surface-mined land. North. J. Appl. For. 17(3):95–99.

A model for estimating sediment yield from surface-mined lands

ABSTRACT A soil erosion submodel (SES) was developed to estimate sediment yield from disturbed lands with steep slopes and a high content of rock fragments. The model is based on the Revised Universal Soil Loss Equation (RUSLE) and was developed to interact with a biogeochemical model that determines above- and below-ground biomass. Following the simulation of 15 surface-mined plots on three sites in Ohio and Kentucky, SES appeared to more accurately predict sediment yield than both RUSLE and the Water Erosion Prediction Project model (WEPP). The coefficient of determination (r2) and standard error for the three sites were 39%, 81%, 97% and 33, 308, and 20 for WEPP, RUSLE, and SES respectively. The improved accuracy of SES over other models is attributed to its ability to simulate rock fragments and steep slopes in addition to the changes made to the support-practice factor (P) used in RUSLE. The process-based construction of SES enables it to be integrated with a biogeochemical model making it useful for research in ecosystem rehabilitation over large spatial and temporal scales.

Relationship of mycorrhizal activity to time following reclamation of surface mine land in western Kentucky. II. Mycorrhizal fungal communities

Over a period of 2.5 years, mycorrhizal fungal communities in soils of five abandoned surface coal mine sites in western Kentucky were studied in relation to time following reclamation. These sites were reclaimed at different times and were in varying stages of revegetation. At the seeding stage of reclamation, low populations of mycorrhizal fungal spores of only a few species, notably Glomus microcarpum Tul. &amp; Tul., Glomus aggregatum Schenck &amp; Smith emend. Koske, and Glomus fasciculatum (Thaxter) Gerdemann &amp; Trappe emend. Walker &amp; Koske, were present. Populations of spores of these species increased rapidly during the first 1 or 2 years after reclamation. Other species, notably those with larger spores, appeared with time. Spores of one group of species were a high proportion of the total early after reclamation, then declined in relation to populations of other species. A second group appeared soon after reclamation and maintained a relatively constant proportion of the total population. A third group was inconspicuous for a few years after reclamation but increased in proportion to the total population of spores with time. Species richness was low soon after reclamation, rose slowly and erratically over 5 years, then stabilized at about 10 species. Species dominance, diversity, and evenness were relatively constant after the first 2 years of reclamation.Key words: Glomales mycorrhizal fungi, arbuscular mycorrhizal fungi, abandoned minespoil, succession, community relations.

Relationship of mycorrhizal activity to time following reclamation of surface mine land in western Kentucky. II. Mycorrhizal fungal communities

Relationship of mycorrhizal activity to time following reclamation of surface mine land in western Kentucky. II. Mycorrhizal fungal communities

Relationship of mycorrhizal activity to time following reclamation of surface mine land in western Kentucky. I. Propagule and spore population densities

The relationships between estimates of mycorrhizal activity, time following reclamation, and soil edaphic factors were investigated over a period of 2.5 years during reclamation of five abandoned surface mine sites in western Kentucky. These sites were reclaimed at different times and were in varying stages of revegetation. At the seeding stage of reclamation and soon thereafter, propagule and spore population densities were low but invariably present. Roots recovered from minespoil during this period were not colonized, and colonization was not observed until a full year following reclamation. During the first 2 years following reclamation, colonization of roots, population densities of propagules and spores, and total spore volume increased rapidly. Thereafter, vegetative and mycorrhizal parameters appeared to stabilize. Each estimate of mycorrhizal activity in minespoil was highly correlated with time following reclamation and all other mycorrhizal parameters. Edaphic factors with positive relationships to mycorrhizal propagule and spore population densities included soil organic matter and calcium. Keywords: Glomales mycorrhizal fungi, reclamation, abandoned minespoil, most probable number, propagule population density.

Deep tillage effects on compacted surface-mined land : R. E. Dunker, C. L. Hooks, S. L. Vance & R. G. Darmody, Soil Science Society of America Journal, 59(1), 1995, pp 192–199

Deep tillage effects on compacted surface-mined land : R. E. Dunker, C. L. Hooks, S. L. Vance & R. G. Darmody, Soil Science Society of America Journal, 59(1), 1995, pp 192–199

Establishment of six tree species on deep-tilled minesoil during reclamation

Compaction of replaced soil during reclamation of surface-mined land can limit trees. Growth, survival, and water relations of bare-root seedlings of six tree species were followed on deep-tilled and untilled minesoil for 2 years after planting. Trees were planted in rows deep-tilled to 0.7 m and in untilled soil; mowing and herbicides controlled competing vegetation. Leaf area, shoot elongation, and diameter increment were measured in both years, and predawn and midday water potential, and midday stomatal conductance, were measured in the second year. Survival was 16–98% after the first season, varying more among species than between tillage treatments. Rainfall was 50% less in the second season, resulting in a progressive decline in predawn water potential in all treatments and a decrease in survival for several species on untilled soil. Similarly, trees on deep-tilled soil grew slightly more than those on untilled soil in the second season. Tillage effects on survival and growth were not consistently detectable between years, however, and 3 years after planting there were no further changes in survival. Differences in survival and growth among species were large. Survival of black locust was approximately double that of any other species, and its growth was several orders of magnitude greater than that of other species, whereas all of the tulip poplars died by the end of the second season. Over 2 years it appeared that most species had not grown enough either to exploit fully the deep-tilled soil or to be impeded on the untilled soil such that differences in establishment could be detected. The full impact of deep tillage on reclamation with trees must be assessed, however, by following growth and survival over a longer time period.