Reclaimed Mine Lands Research Articles

The Potential and Models of Agricultural Utilization of Reclaimed Mine Land

This study delves into the potential and models of agricultural utilization of reclaimed mine land, analyzing its significant role in environmental restoration, economic development, and social stability. The research indicates that through scientific planning and management, reclaimed mine land can be transformed into highly productive agricultural land, while also promoting the recovery of the ecological environment and the sustainable development of the socio-economy. The paper proposes agricultural utilization models that integrate the characteristics of reclaimed mine land, emphasizing the application of ecological agriculture concepts in land reclamation, and analyzes the positive impact of agricultural utilization on the socio-economic development of mining areas. The study also explores the relationship between agricultural utilization and the sustainable development of mining communities, highlighting the importance of policy support and community participation. Finally, the paper summarizes the innovative points and practical significance of the research and points out future research directions.

Use of lidar for monitoring vegetation growth dynamics in reclaimed mine lands in Kentucky

Surface coal mining in the Appalachian region has led to a significant forest disturbance over time. Evaluating the effectiveness of current reclamation practices in promoting vegetation growth on reclaimed mine sites is a key to understanding how much vegetation has changed in those sites since reclamation. This study employed statewide airborne lidar data to assess changes in lidar vegetation structural metrics on reclaimed mine lands in the Lower Levisa Watershed of Eastern Kentucky between 2011 and 2019 and compare vegetation growth at various reclaimed sites reclaimed in different decades. Eighteen inactive surface mines were selected for the study and categorized into four groups based on the release of their reclamation bonds in different decades. Lidar point cloud data were processed in ArcGIS Pro using filtering and segmentation algorithms to calculate various vegetation attributes from the point clouds, including maximum vegetation height (Hmax), mean height (Hmean), standard deviation of height (HSD), canopy cover (CC), and height percentiles (10, 50 and 75), which were represented as lidar metrics. The process of generating the lidar metrics involved creating Digital Elevation Models (DEMs) and Digital Surface Models (DSMs), calculating Canopy Height Models (CHMs), creating LAS height metrics and generating point statistics rasters to derive these metrics. Change maps for each metric were visually assessed over time, and circular plots with a radius of 12 m were established within each site for further statistical analysis. Significant changes in lidar vegetation metrics were observed between 2011 and 2019 with significant differences among sites reclaimed at different time periods. There was an overall increase in Hmean from 2011 to 2019, with values ranging from 2.4 to 3.8 m. Sites reclaimed in the 1980s experienced an average decrease in canopy cover of −0.5%, while those from the 1990s, 2000s, and 2010s demonstrated increases of 4.9%, 10.1%, and 18.1%, respectively, suggesting that canopy growth rates are higher in younger sites compared to older ones. Vertical variability of the vegetation also increased over time, as indicated by increasing HSD values. Utilizing statewide airborne lidar data allowed for a comprehensive and detailed assessment of vegetation dynamics on reclaimed mine lands. The findings of this study serve as a foundation for future research endeavors focused on vegetation recovery assessment and success in reclaimed mine lands using lidar data.

Development of energy plants from hybrids between Miscanthus sacchariflorus and M. lutarioriparius grown on reclaimed mine land in the Loess Plateau of China.

Miscanthus, a promising bioenergy plant, has a high biomass yield with high cellulose content suitable for biofuel production. However, harsh climatic and poor soil conditions, such as barren lands or abandoned mines, pose a challenge to the survival and yield of Miscanthus feedstock on the marginal land. The selection from the interspecific hybrids of Miscanthus might combine high survival rates and high yield, which benefits energy crop development in multi-stressful environments. A total of 113 F1 hybrids between Miscanthus sacchariflorus and M. lutarioriparius together with the parents were planted and evaluated for multiple morphological and physiological traits on the mine land of the Loess Plateau of China. The majority of hybrids had higher establishment rates than M. sacchariflorus while M. lutarioriparius failed to survive for the first winter. Nearly all hybrid genotypes outperformed M. lutarioriparius for yield-related traits including plant height, tiller number, tiller diameter, and leaf area. The average biomass of the hybrids was 20 times higher than that of surviving parent, M. sacchariflorus. Furthermore, the photosynthetic rates and water use efficiency of the hybrids were both significantly higher than those of the parents, which might be partly responsible for their higher yield. A total of 29 hybrids with outstanding traits related to yield and stress tolerance were identified as candidates. The study investigated for the first time the hybrids between local individuals of M. sacchariflorus and high-biomass M. lutarioriparius, suggesting that this could be an effective approach for high-yield energy crop development on vast of marginal lands.

Estimating Ecological Responses to Climatic Variability on Reclaimed and Unmined Lands Using Enhanced Vegetation Index

Climatic impact on re-established ecosystems at reclaimed mined lands may have changed. However, little knowledge is available about the difference in vegetation–climate relationships between reclaimed and unmined lands. In this study, ecological responses to climatic variability on reclaimed and neighbouring unmined lands were estimated using remote-sensing data at the Pingshuo Mega coal mine, one of the largest coal mines with long-term reclamation history in China. Time-series MODIS enhanced vegetation index (EVI) data and meteorological data from 1997 to 2017 were collected. Results show significantly different vegetation–climate relationships between reclaimed and unmined lands. First, the accumulation periods of all climatic variables were much longer on reclaimed mining lands. Second, vegetation on reclaimed lands responded to variabilities in temperature, rainfall, air humidity, and wind speed, while undisturbed vegetation only responded to variabilities of temperature and air humidity. Third, climatic variability made a much higher contribution to EVI variation on reclaimed land (20.0–46.5%) than on unmined land (0.7–1.7%). These differences were primarily caused by limited ecosystem resilience, and changed site hydrology and microclimate on reclaimed land. Thus, this study demonstrates that the legacy effects of surface mining can critically change on-site vegetation–climate relationships, which impacts the structure, functions, and stability of reclaimed ecosystems. Vegetation–climate relationships of reclaimed ecosystems deserve further research, and remote-sensing vegetation data are an effective source for relevant studies.

Coupling the probability of connectivity and RUSLE reveals pathways of sediment transport and soil loss rates for forest and reclaimed mine landscapes

Coupling erosion formulae with sediment connectivity methods is one promising approach to better represent structural and functional variability of sediment processes. To advance this goal, the probability of connectivity approach is coupled with the revised universal soil loss equation (RUSLE) in a basin with forest and reclaimed mine landuses. Model evaluation showed unforeseen codependency between connectivity formulae and RUSLE. For example, the RUSLE P factor was codependent with the probability of downstream transport within the connectivity formula. Researchers should use feedback calibration schemes to resolve lack of model independence. Connectivity modelling advanced prediction of sediment processes because it simulated the unforeseen impact of legacy terracing on sediment connectivity and soil loss. Structural control dominates connectivity in this study, and soil loss and connectivity are self-similar. The structural control is contrary to recent suggestions that functional, dynamic processes control sediment connectivity in all landscapes. Self-similarity also remains an open topic because a number of studies show poor correlation between soil loss and connectivity. On average 12% of forested land and 47% of reclaimed mine land was connected for events studied. Predicted soil loss rates in the reclaimed mine were approximately 30 times greater than the forest land despite the fact that the reclamation is classified as phase 3. Spatially explicit results highlight pathways that should be targeted for remediation, and this study supports the idea of the Forestry Reclamation Approach for remediation of excess soil loss.

From the Ground Up: Prairies on Reclaimed Mine Land—Impacts on Soil and Vegetation

After strip mining, soils typically suffer from compaction, low nutrient availability, loss of soil organic carbon, and a compromised soil microbial community. Prairie restorations can improve ecosystem services on former agricultural lands, but prairie restorations on mine lands are relatively under-studied. This study investigated the impact of prairie restoration on mine lands, focusing on the plant community and soil properties. In southeast Ohio, 305 ha within a ~2000 ha area of former mine land was converted to native prairie through herbicide and planting between 1999–2016. Soil and vegetation sampling occurred from 2016–2018. Plant community composition shifted with prairie age, with highest native cover in the oldest prairie areas. Prairie plants were more abundant in older prairies. The oldest prairies had significantly more soil fungal biomass and higher soil microbial biomass. However, many soil properties (e.g., soil nutrients, β-glucosoidase activity, and soil organic carbon), as well as plant species diversity and richness trended higher in prairies, but were not significantly different from baseline cool-season grasslands. Overall, restoration with prairie plant communities slowly shifted soil properties, but mining disturbance was still the most significant driver in controlling soil properties. Prairie restoration on reclaimed mine land was effective in establishing a native plant community, with the associated ecosystem benefits.

Early growth and survival of shrub willow on newly reclaimed mine soil

Shrub willow (Salix spp.) has been a focus of international efforts to develop renewable alternatives for fossil fuels and to sequester carbon from earth’s atmosphere. In the central Appalachian region of the eastern U.S., short rotation willow could be grown on the significant amount of reclaimed mine land, which would promote economic opportunities for these lands. The objective of this study was to examine various establishment treatments designed to overcome common properties of mine soils: high rock fragment content that causes planting difficulties and reduced water- and nutrient-availability. Three shrub willow clones (Fish Creek, Preble, and SX61) were planted using six planting/fertilizer treatments. The planting treatments compared a horizontal planting method to traditional vertical planting of cuttings. Fertilizer treatments compared no fertilization to controlled release and traditional fertilizer at a rate of 140 kg N ha−1. After two growing seasons, Preble outperformed the others in both survival and production but the influence of fertilizer treatments was inconsistent and varied by clone. Survival and growth for horizontally-planted cuttings was 46% relative to vertically planted cuttings at 83%. Results of this study will be used to direct future establishment practices for willow on reclaimed mine soils in West Virginia.

Utilization of Leaves in Mine Reclamation Land as Organic Fertilizer with Effective Bioactivatory of Microorganism 4 (em4) and Molasses

Organic fertilizer as an alternative to reduce the scarcity of chemical fertilizers, otherwise it can improve soil fertility. PT. Semen Gresik - Semen Indonesia Persero (Tbk.) Has a lot of plants in the treatment period in ex-mining land that needs fertilizer to help plant growth. In addition, in post-mining land, there is a lot of organic waste in the form of dry leaves under the stands of reclamation trees. The organic waste has the potential to be processed and used as organic fertilizer. This study aims to determine the utilize leaf litter in the reclaimed mine land as organic fertilizer with EM 4 and Molasses bioactivators. This study used is a laboratory experimental method. The results showed the composition of solid material in the form of leaf litter, bran, cow dung and husk charcoal in a ratio of 2: 1: 1: 1 as well as looking material in the form of molasses and EM4 with a dose of 100ml per 100kg of solid material dissolved in enough water (fertilizer can be clenched and expanded slowly and not broken). Conclusion leaf litter in the former reclaimed land can be processed and used as organic fertilizer.

Predicting particle-size distribution using thermal infrared spectroscopy from reclaimed mine land in the semi-arid grassland of North China

Particle-size distribution is one of the vital properties of semi-arid and reclaimed soils that closely correlates with desertification. The thermal infrared (TIR) spectrum between 8 and 14 μm has the potential for particle-size monitoring in remote sensing. This study aims to investigate the characteristic TIR spectra of reclaimed mine soils and establish a particle-size prediction model. The characteristics of the reststrahlen band (8–9.5 μm) could be used to distinguish the coarse soil content that occurs in various land use and reclamation areas. A significant negative correlation was noted between the coarse sand content and the TIR spectrum (8–14 μm). The support vector machine calibration model exhibited a higher prediction accuracy for estimating the coarse sand content, with a cross-validated R2 of 0.95 and root mean square error (RMSE) of 3.01%, than the partial least squares regression model. These outcomes provide a theoretical basis and technical support for particle-size distribution estimations using TIR spectroscopy in semi-arid and reclamation areas. Hence, this study proposes that the spectral characteristics and model undergo further testing and optimization before wider application for the observation of semi-arid and reclaimed mine land ecosystems.

Bioenergy crop production on reclaimed mine land in the North Appalachian region, USA

There is a growing interest in converting marginal lands to bioenergy crop production instead of using high quality croplands which could jeopardize food security and soil quality. Miscanthus (Miscanthus x giganteus Greef & Deuter ex Hodkinson & Renvoize) is a promising feedstock due to its high biomass production under temperate climate and a wide range of soil properties. Appalachian region contains about 1.1 million hectares (Mha) of reclaimed minesoils (RMS) that can be used to produce bioenergy crops and spare arable lands for food production. This study was conducted on 27 years old RMS which was converted to corn and miscanthus land uses in 2013. We assessed the growth performance (plant populations, height, tillers), and aboveground dry biomass (AB) yields of miscanthus and corn (Zea mays L.) compared to antecedent meadow under reclaimed mined land (RML) as affected by different fertilization practices during the first three years of establishment of corn and miscanthus. Results show that the growth and AB yields did not significantly vary between source (synthetic and organic) and rate of nitrogen applications (0, 75, 150, 225 kg N h−1) within each land-use. For the first three years meadow and corn on average had a 30% higher cumulative potential AB harvest compared to miscanthus (12.2 Mg ha−1). Miscanthus generally takes about three years to establish good stand. However, miscanthus had the highest AB yields in the third year (19.6 Mg ha−1) and is expected to maintain higher yields than the meadow (8.0 Mg ha−1) and corn (8.3 Mg ha−1) land-uses, resulting in a greater harvestable AB yield potential in the long-term. Continued monitoring of AB yields is critical to determining whether sustained yields can be maintained with little or no inputs in RML.

Pyrolysis characteristics of Arundo donax harvested from a reclaimed mine land

Production of biomass crops is competing with food production in terms of arable land, therefore, attention is being given to the establishment of dedicated energy crops on marginal lands. While more attention has been given to C4 plants like Miscanthus and Switchgrass due to their high productivity and ability to withstand unfavorable soil conditions, Arundo donax (a C3 plant) has also been proven to thrive well on marginal lands and has high productivity. In this study, pyrolysis of Arundo donax harvested on a reclaimed mine land in West Virginia was carried out in a batch reactor at a temperature of 500 °C for 30 min and the pyrolysis products were collected and characterized. Pyrolysis products distribution was 30.12%, 45.62% and 24.26% for the biochar, bio-oil and non-condensable gases, respectively. Calorific values of the biomass and the biochar were found to be 18.96 and 29.51 MJ/kg, respectively. The pH of the biochar showed that it is alkaline in nature while the pH of the bio-oil showed that it is acidic in nature.

Changes of solute transport characteristics in soil profile after mining at an opencast coal mine site on the Loess Plateau, China

Dramatic changes in soil during opencast coal mine activities inevitably change soil water and solute movement. The objectives of this study were to assess the effects of mining on solute transport in different soil profiles and to find the relationships between solute transport parameters and soil physicochemical characteristics. After taking undisturbed soil columns from the different soil profiles of natural land (NLs) and reclaimed mine land (RLs), ammonium nitrate displacement studies were conducted, and the breakthrough curves (BTCs) of NO3− and NH4+ were obtained. Due to mining and reconstruction, soil texture became coarser, bulk density increased 2.77–15.15%, cation exchange capacity (CEC), soil organic matter (SOM), and total nitrogen (TN) content decreased 19.54–37.25%, 53.66–72.05%, and 42.58–58.55%, respectively. Additionally, the distributions of the physicochemical properties changed. The BTCs of NO3− for all soil columns can be well explained by both the convection-dispersion equation (CDE) and the two-region model (T-R). The transport parameters average pore water velocity (v), dispersion coefficient (D), and dispersivity (λ) were lower in RLs, which indicates that solutes became difficult to penetrate after mining. A significantly correlated relationship of bulk density and soil texture with the v, D, and λ parameters only occurred in the RLs samples. This result indicates that transport processes in NLs columns became more complicated and that soil texture and bulk density played an important role in the transport process of RLs columns. The two-site model could well describe NH4+ transport for both NLs and RLs and provided a slightly better fit in RLs. This finding also gave evidence that RLs became homogeneous after mining and reconstruction. The parameter retardation factor (R) was significantly correlated to CEC, bulk density and soil texture in RLs. These results suggest that soil becomes homogeneous after mining and reconstruction and that high bulk density and fine soil texture could decrease the risk of leaching of solutes.

Dung beetle activity improves herbaceous plant growth and soil properties on confinements simulating reclaimed mined land in South Africa

Mining activities contribute greatly to economic growth and development in South Africa. However, post-mining soils have limited land-use potential due to low fertility, deficiency in organic matter content and poor physical, chemical, and microbiological properties. Dung beetles could potentially improve several aspects of soil degradation, complementing current rehabilitation efforts. Studies in relatively undisturbed soils of agro-ecosystems have found that dung burial introduces essential nutrients in dung to the plant root zone, which would otherwise remain on the soil surface and mostly volatilize in the absence of dung beetles. Furthermore, dung beetles create tunnels under dung pats, improving water infiltration rates, bulk density, soil aeration and pasture yields. The aim of the study was to determine whether these effects could be maintained on soil simulating reclaimed mined land, where very high rates of compaction may prevent tunnelling altogether. Three experimental treatments of dung + beetles (D + B), dung only (D) and control/no dung, no dung beetles (X) were applied twice over 2 years on 1 m3 experimental confinements. Various soil and herbaceous plant properties were assessed one and six months after each application of dung and beetles. Results obtained showed that water infiltration rate and plant biomass was significantly higher for all confinements containing dung beetles. Penetration resistance (soil strength) was significantly reduced for confinements with dung beetles. Magnesium and potassium levels in the soil were significantly higher for D + B treatments when compared to D and X treatments. In conclusion, results showed that dung beetles were able to maintain their activities in soils typical of reclaimed mine land, significantly improving soil properties and herbaceous plant growth. Incorporating the application of dung beetles to the conventional approach to rehabilitation has the potential to improve the efficacy of coal mine reclamation. This biological approach may also prove to be cost-effective over time as it provides a seasonal source of bioturbation, which does not disturb plant growth and reduces the requirements for soil rejuvenating tillage practices.

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.

The Impacts of Native-Grassland Restoration on Raptors and their Prey on a Reclaimed Surface Mine in Kentucky

Abstract We evaluated the effects of native-grass restoration on the spatial distribution and density of raptors, vegetative characteristics, and small-mammal communities at Peabody Wildlife Management Area, a large reclaimed surface-coal mine in western Kentucky. We surveyed raptors from 2008 to 2012 via distance sampling at roadside points, and conducted vegetation and small-mammal surveys. We found no associations between total small-mammal relative abundance and native-grass restoration or vegetative characteristics. However, management for native grass positively affected the density of Circus cyaneus (Northern Harrier) and influenced the local distribution of Northern Harriers and Buteo jamaicensis (Red-Tailed Hawk). These results suggest that restoration and management of native grass on reclaimed mine lands can enhance habitat for grassland raptors, including the Northern Harrier, a species of conservation concern throughout its range.

Prospects of medicinal herbs management in reclaimed minelands of Ukraine

The rocks of Nikopol manganese ore basin are represented with Neogenic and Paleogenic sediments. After realization of the stage of mine-technical reclamation loess-like and red-brown loams appear on the dump surface. Taking into biological specialty of most species of medicinal herbs, it can be assuming, some of them need culture on the humus rich soil to form the feedstock of stable quality, others can be successfully grown on pour leached soils, generally known as loess-like loams coming on the surface. Numerous types of medicinal herbs were tested in situ on the reclaimed mine land. From the comparison of the results with the defined permissible concentration limits, it was concluded that the levels of trace element contents in the locally available medicinal plants under investigation fall around the permissible range except for German chamomile ( Matricaria chamomilla ) , Dwarf everlast ( Helichrysum arenarium ), Motherwort ( Leonurus cardiac ) and St John's-wort ( Hypericum perforatum ) with regard to its extremely high Cu and Mn content.

Distribution of soil organic carbon and glomalin related soil protein in reclaimed coal mine-land chronosequence under tropical condition

The revegetation on mine spoiled lands has potential to improve the status of reclaimed mine-soil quality. However, to date the temporal dynamics of labile and stable fractions of soil organic carbon (SOC) and glomalin related soil protein (GRSP) have not been satisfactorily demonstrated. We investigated SOC and GRSP fractions including labile particulate OC (POC) and easily extractable GRSP (EE-GRSP) and stable non-particulate OC (NPOC) and difficulty extractable GRSP (DE-GRSP) along with other important soil properties in six reclaimed mine lands chronosequence (1 to 26 years old) and a reference forest site in Raniganj Coalfield, India. Our results demonstrated that the accumulation of SOC and GRSP significantly increased with increasing age of the sites, with greater extent of increment after 26 years were seen in labile POC (6.6×) and EE-GRSP (11.5×) compared to stable NPOC (1.8×) and DE-GRSP (6.2×). The higher contribution of GRSP-C in NPOC compared to TOC across the sites, indicate the proximate role of GRSP in accumulation and stabilization of SOC during the pedogenesis. The multivariate analysis revealed strong association among arbuscular mycorrhizal fungi (AMF) spore density, microbial biomass carbon, SOCs and GRSPs, suggesting the factors involved in SOC accumulation likely contributed to AMF proliferation and GRSP enrichment during the reclamation process. Moreover, strong correlation of GRSP and SOC with soil's bulk density, pH, total N and C/N ratio, suggest increasing GRSP and SOC content resulted in multi-level improvement in soil properties. Our results highlight the importance of using GRSP and SOC as indicator during mine land reclamation.

Changes in ecosystem carbon pool and soil CO2 flux following post-mine reclamation in dry tropical environment, India.

Open strip mining of coal results in loss of natural carbon (C) sink and increased emission of CO2 into the atmosphere. A field study was carried out at five revegetated coal mine lands (7, 8, 9, 10 and 11years) to assess the impact of the reclamation on soil properties, accretion of soil organic C (SOC) and nitrogen (N) stock, changes in ecosystem C pool and soil CO2 flux. We estimated the presence of C in the tree biomass, soils, litter and microbial biomass to determine the total C sequestration potential of the post mining reclaimed land. To determine the C sequestration of the reclaimed ecosystem, soil CO2 flux was measured along with the CO2 sequestration. Reclaimed mine soil (RMS) fertility increased along the age of reclamation and decreases with the soil depths that may be attributed to the change in mine soils characteristics and plant growth. After 7 to 11years of reclamation, SOC and N stocks increased two times. SOC sequestration (1.71MgCha-1year-1) and total ecosystem C pool (3.72MgCha-1year-1) increased with the age of reclamation (CO2 equivalent: 13.63MgCO2ha-1year-1). After 11years of reclamation, soil CO2 flux (2.36±0.95μmolm-2s-1) was found four times higher than the natural forest soils (Shorea robusta Gaertn. F). The study shows that reclaimed mine land can act as a source/sink of CO2 in the terrestrial ecosystem and plays an important role to offset increased emission of CO2 in the atmosphere.

Vegetative Community Development Over 30 Years within Pine Plantations on Reclaimed Mine Land in East

Reclamation of surface mines to plantation forests is a management option that reestablishes both economic and ecological functions after mining. This study investigated vegetative community characteristics (composition, richness, importance) over time in loblolly pine (Pinus taeda L.) plantations established over a thirty-year period on reclaimed lignite coal surface mine land in East Texas, United States. The open landscape of newly planted loblolly pine plantations on reclaimed mine land was amenable to shade-intolerant herbaceous and grass species but, when the canopy closed, favored woody species (trees, shrubs, vines) within two decades after stand establishment. Given that these plantations were established on sites generally described as dry to mesic uplands, species composition was generally congruent with East Texas ecology. Community composition, species richness and species importance were discussed, and loblolly pine growth data and vegetative community characteristics of unmined loblolly pine plantation sites in East Texas were compared to reclaimed sites. Surface mined lands reclaimed to plantation forests are ideal locations to conduct further research on how biodiversity and other ecosystems services can be improved while maintaining intended economic and ecological purposes.

Pyrolysis of dedicated bioenergy crops grown on reclaimed mine land in West Virginia

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 19.49MJ/kg, 29.01MJ/kg and 24.98MJ/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.