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The re-vegetation of mining wastes with native plants is a comparatively low-cost solution for mine reclamation. However, re-vegetation fails when extreme pH values, low organic matter, or high concentrations of phytotoxic elements inhibit plant establishment and growth. Our aim was to determine whether the combined addition of municipal waste compost and diazotrophic endophytes (i.e., microorganisms that fix atmospheric N2 and live within plants) could improve plant growth, organic matter accumulation, and phytostabilization of trace element contaminants in two types of hard rock mine waste. We grew a widespread native perennial grass, Bouteloua curtipendula, for one month in alkaline waste rock (porphyry copper mine) and tailings (Ag-Pb-Au mine, amended with dolomite) sourced from southeastern Arizona, United States. B. curtipendula tolerated elevated concentrations of multiple phytotoxic trace elements in the tailings (Mn, Pb, Zn), stabilizing them in roots without foliar translocation. Adding compost and endophyte seed coats improved plant growth, microbial biomass, and organic matter accumulation despite stark differences in the geochemical and physical characteristics of the mining wastes. The widespread grass B. curtipendula is a potential candidate for re-vegetating mine wastes when seeded with soil additives to increase pH and with microbial and organic amendments to increase plant growth. This study quantifies improvements to plant growth, soil fertility, and trace element stabilization with a municipal waste compost topdressing and diazotrophic endophyte seed coating in two common hard rock mining wastes of the western United States. It establishes that a widespread perennial grass, Bouteloua curtipendula, can grow despite high concentrations of phytotoxic trace elements and minimal soil nutrients, and stabilizes trace elements on or in its roots, making it a suitable option for re-vegetation or phytostabilization of hard rock mining wastes. [ABSTRACT FROM AUTHOR]

Unconventional oil and gas (UOG) drilling has expanded rapidly across the United States, including in the Fayetteville Shale formation in north-central Arkansas where drilling began in 2004. As one of the oldest regions of UOG activity in the United States, this area has experienced significant land-use changes, specifically development of natural habitat and agricultural land for gas infrastructure. In recent years, drilling of new wells has stopped and production has declined. By 2017, 1038 wells had ceased production and been abandoned, which makes them eligible for land reclamation. However, most of these sites (80%) have not been reclaimed and continue to cause losses in ecosystem services. If reclamation was performed on lands associated with abandoned infrastructure, we estimate more than $2 million USD annually in agricultural, timber, and carbon sequestration values would be gained. These benefits far outweigh the costs of reclamation, especially since the benefits accrue over time and reclamation is a short-term cost. Our estimates indicate a 2–4 year break-even time period when cumulative ecosystem services benefits will outweigh reclamation costs. We predicted a well-abandonment rate of 155 per year until 2050 when 98% of wells will be abandoned, which indicates great potential for future ecosystem services restoration. Thus, we recommend that Arkansans at the government and citizen level work to restore lands impacted by UOG development in the Fayetteville Shale region so that their value to landowners and society can be recovered, which will enhance long-term economic and environmental benefits. [ABSTRACT FROM AUTHOR]

There is renewed interest in re-establishing trees on 0.6 million ha of mining-disturbed lands in the Appalachian mountains of Eastern United States. Many coal-mined lands reclaimed to meet requirements of US federal law have thick herbaceous vegetation and compacted soils which impede tree establishment. Mitigation practices were applied on three mine sites and evaluated for success in enabling planted trees to become established. Eastern white pine ( Pinus strobus), hybrid poplar ( Populus deltoids × Populus trichocarpa), and mixed Appalachian hardwoods were established using weed control only and weed control with subsoil ripping. Trees were measured in October of 2008 after 5 years of growth. Subsoil ripping increased mixed hardwood survival from 43 to 71 %, hybrid poplar biomass index from 1.51 to 8.97 Mg ha, and Eastern white pine biomass index from 0.10 to 0.32 Mg ha. When restoring trees to unused mined sites, subsoil ripping can aid survival and growth to an extent that will result in a valuable forest. [ABSTRACT FROM AUTHOR]

The application of poultry manure to crops to obtain higher yields is a widely used practice in many poultry-producing regions of the United States and other parts of the world. This practice often results in the enrichment of phosphorus (P) in soils, resulting in various environmental and ecological concerns. We evaluated several diverse cowpea (Vigna unguiculata Walp.) genotypes to explore their potential for the removal of P from poultry manure-enriched soils and the soils that had not received poultry manure applications. Cowpea genotypes, including Champion and White Acre, extracted higher amounts of P compared to other genotypes under field and greenhouse conditions in both types of soils. These genotypes could play an important role in P removal from poultry manure-enriched soils. [ABSTRACT FROM AUTHOR]

Microsite availability is crucial for recruitment success in natural populations as well as populations being established for restoration projects. Understanding the specific microsite requirements of a particular species targeted for restoration will increase the probability of success of any restoration project. Surface mining for coal represents one of the largest anthropogenic disturbances to the forests of the eastern United States. The original natural range of the American chestnut (Castanea dentata (Marsh.) Borkh.) overlaps the extent of the Appalachian Coal Basin. With American chestnut being readied for reintroduction trials, we sought here to determine some of the effects of microsite conditions on the establishment success of American chestnut on mine sites reclaimed using new, compaction-reducing techniques (i.e., "end-dump" reclamation) that create a series of loosely dumped mounds roughly 8-m diameter and 3-m tall to serve as 19 a planting substrate. Specifically, we examined the effects of distance from existing forest edge, amount of existing cover of vegetation, small-scale topographic Ij position, and a small set of soil variables on the growth and survival over three seasons of American chestnut seedlings planted on a reclaimed mine site in ·9 east-central Ohio. We found decreased tree survival adjacent to existing forest edges and greater annual growth rates at distances of 20 and 50mfrom the ·jrfl existing forest edge. Microtopographic position had a significant effect on seedling growth and survival--seedlings planted higher on mounds had increased mortality and lower growth than those on the side slopes of those mounds. The amount of existing vegetative cover also affected survival and growth; trees growing in plots with higher vegetative cover values showed increased growth and survival. The compaction-reducing reclamation approach used here is relatively new and novel. Promising results that have been observed to date using American chestnut and this method seem to indicate that the combination may be very effective at restoring functional forests on lands degraded by surface mining. [ABSTRACT FROM AUTHOR]

Economic activity can damage natural systems and reduce the flow of ecosystem services. The harms can be substantial, as our case studies vividly illustrate. Most degraded landscapes have at least some potential to be reclaimed. However, uncertainty plagues decision making regarding degradation and reclamation, in relation to the extent of the damage, the success of reclamation, and how exposure will change in the future. We examine how a range of observed decision biases can lead to far-from-optimal policies regarding how much degradation to allow and when, as well as how and how much, to reclaim degraded sites. Despite our focus on degraded landscapes, we believe these are generic biases present in a wide range of risk situations. Our three case studies show these biases at work. The first two studies are of mining operations in the United States and Canada, and the third is of climate change. [ABSTRACT FROM AUTHOR]

Much of the land reclaimed since enactment of the 1977 Surface Mining Control and Reclamation Act is over-compacted. Excessive compaction in replaced growth media is detrimental to establishment of trees. If trees are to be grown on reclaimed sites, excessive compaction must be alleviated. Dry bulk density and penetration resistance can be used to indicate the level of compaction in replaced growth media. The University of Kentucky has developed reclamation test cells at a surface mine to determine the impact of organic soil supplements on selected soil physical properties of reclaimed sites. The organic soil supplements being evaluated include hardwood bark and straw and manure. Data were collected at the test cells for dry bulk density, maximum penetration depth and penetration resistance. The data show no statistical evidence that applying organic supplements has a major effect on selected soil physical properties in replaced growth media. [ABSTRACT FROM AUTHOR]

Over 1500 wetlands have been created in northeast Wyoming as a result of bentonite mining. The potential for future creation is high and many groups are interested in modifying wetland creation during the construction/reclamation stage to improve habitat for waterfowl. We examined a sample of 92 bentonite wetlands for waterfowl use in 1991 and 1992. Our main objective was to relate waterfowl use with variables that could be modified during the construction phase. In general, waterfowl use wetlands that are >1.0 ha in size, located within complexes of >5 wetlands within a 1 km radius, and have abundant emergent and submersed vegetation. Wetlands created through bentonite mining tend to be small (<0.5 ha), shallow, and unvegetated, but no current guidelines exist for improving their design. Building on the concept of wetland complexes, biologists and engineers could improve this region''s wetland resources dramatically if aspects of waterfowl ecology and management were incorporated into the design of future sites. [Copyright &y& Elsevier]

The experimental application of municipal biosolids to degraded arid and semiarid rangelands has been practiced for many years and is becoming more common in the western United States. Previous studies have examined the effects of applying biosolids to land areas that have been degraded by one or more different factors including overgrazing, fire suppression, and increased drought frequency, duration, or intensity. However, few of these studies have measured the persistence of biosolids in the soil. This study is an attempt to recover information from an abandoned reclamation effort in which municipal biosolids were spread on a degraded rangeland on the Jornada Experimental Range in southern New Mexico. The biosolids were applied in 1979 and were still present in substantial amounts when soil samples were taken in 1997. An estimated 32% of the applied biosolids persisted as fragments greater than 2 mm in diameter for almost 20 years. There were no apparent benefits of biosolid application at this site in terms of vegetation establishment within the first four years, and there was no correlation between vegetation patterns and the concentration of biosolids remaining in the soil in 1997. It is hypothesized that much of the applied sludge remains in the soil because of the recalcitrant nature of digested biosolids combined with the environmental conditions of soil in arid systems. Long-term results from biosolid addition experiments in arid and semiarid rangelands should be considered before the practice is widely used for reclamation of degraded rangeland sites. [ABSTRACT FROM AUTHOR]

Land consolidation is widely used as a powerful tool for land use management in many countries. In order to objectively reveal the current research status in the field of land consolidation, this paper uses the Bibliometrix and Biblioshiny software packages, and VOSviewer to analyze the literature in the field of land consolidation in the last 20 years of the Web of Science Core Collection Database. The results show that: (1) In the past two decades, the annual publication of papers on land consolidation rose. It can be divided into three stages: 2000-2007 for the embryonic period, 2008-2012 for the long-term, and 2013-2020 for the high-yield period. (2) Land consolidation studies covered 68 countries or regions. The top three countries were China, Poland, and the United States. China and the United States played an important role in international cooperation in the field of land consolidation, and Turkey mainly conducted independent research in the field of land consolidation. (3) Land consolidation, reclamation, China, remote sensing, and land fragmentation were the high-frequency keywords in the field of land consolidation in recent years. (4) The research focusing on the field of land consolidation involved its development course, its impact on ecosystem services, and the evaluation of its benefits. (5) The theme of land consolidation studies was shunted and evolved over time, and nine evolution paths could be summarized in the studies of cultivated land fragmentation, development course of land consolidation, and impacts of land consolidation on soil. Finally, this paper predicted the future research directions of land consolidation: exploring new methods for evaluating the benefits of land consolidation, the scale effects of the impact of land consolidation on ecosystem services, research on the mechanism and comprehensive effects of land consolidation on soil, research on land consolidation and rural revitalization, and land consolidation theory research.

Research Highlights: We found promising success for black walnut (Juglans nigra L.) planted on a legacy surface mine. Our results indicate that direct seeding can be an effective restoration method, and that shelters may not be needed. Background and Objectives: Reforestation in the Appalachian coalfields has primarily relied on the planting of nursery stock late in the dormant season. This study examined the use of direct seeding during the fall, a practice that, if successful, could both reduce costs of planting and open up a new season for reforestation planting. Black walnut is of particular value for wildlife habitats, timber value, and even human nutrition. In addition, it normally occurs in diverse forests with rich soils of the region. Therefore, establishment on previously surface-mined lands may indicate a positive successional trajectory and resilience. Materials and Methods: This study took place in eastern Kentucky, USA, on a site that was surface mined from 1996 to 2000 and subsequently reclaimed as a wildlife habitat. In 2010, the site was decompacted according to the Forestry Reclamation Approach (FRA) by deep ripping with a bulldozer, and in November 2011, a 2 × 2 factorial experiment was initiated to compare the growth of walnut trees planted either by seed or as one-year seedlings, and either with or without tree shelters. Each treatment (four total: Unsheltered Seedling, Sheltered Seedling, Unsheltered Seed, and Sheltered Seed) had three replicate plots of 17 × 9 m, with 50 seeds or seedlings planted per plot. Measurements (survival, height, diameter, and volume) were made in 2012, 2013, and 2016. Effects of planting type and shelter presence, as well as their interaction, were analyzed using linear mixed models. Results: Planting type was significant for all measurements in the first two years (seedlings > seed), but this difference was largely diminished by 2016. There was a significant interaction of the two main effects, such that shelters benefited (or did not affect) those trees planted as seedlings, but hindered those planted from seed. [ABSTRACT FROM AUTHOR]