"Transparency- the ability to see into and understand the inner workings of a landscape- is an absolutely essential ingredient to sustainability" -Robert Thayer from "Green World, Green Heart" Current land filling practices that bury waste and debris below layers of earth and synthetic caps do not take into account the potential of reclamation of the site after the landfill debris has become stable. As development and consumerism increases, the need for land reclamation grows stronger, as earth will succumb to overabundance of human excessiveness. Can a space be created that not only reclaims land, but also exposes what is hidden- in order to educate the public on the importance of recycling and sustainability? Is it possible to design a space that addresses the issues and culture of the past, present and future, particular to a geographic site? Can landscape architects use landscape as an educational medium for self-discovery? / Master of Landscape Architecture

The present state of forestry post mining land uses has prompted concern among researchers, landowners, and the public. Surface mines reclaimed to forests under the provision of the Surface Mining Control and Reclamation Act (SMCRA) may not achieve site productivity levels required by the law. Anecdotal evidence suggests that many pre-law reforested mined sites are growing productive forests. The purpose of this study was to characterize these forests and the mine soils in which they are growing, and use them to benchmark forest development on mined land. Using 14 mined and 8 non-mined sites in the midwestern and eastern coalfields research to address the following objectives was undertaken: (i) characterize the development, composition, and diversity of woody species on pre-SMCRA, forested surface mined land; (ii) estimate forest and site productivity on surface mined land and determine the soil and site properties most influencing forest growth; (iii) estimate projected rotation-age timber product value; (iv) quantify current carbon sequestration pools associated with the developing woody plant biomass, the forest floor, and developing soil medium; (v) compare the diversity, forest and site productivity, commercial value, and carbon capture of reclaimed mined sites to that of regional non-mined forest systems. Species richness between non-mined and mined sites was about the same within each region with 14 to 15 tree species in the canopy. Canopy richness of eastern mined sites was less than that on midwestern mined sites (12 species compared to 17 species, respectively). Species richness of the understory and woody ground layer were similar between sites planted to pines versus hardwoods. White pine (Pinus strobus) monocultures, planted on many sites in the eastern region, caused species unevenness throughout all forest strata. Midwestern mined sites and eastern sites planted to hardwoods closely approximated non-mined sites in commercial species composition. Planted species represented the majority of canopy layer dominance and abundance (82% relative dominance and 56% relative abundance). Site productivity between non-mined sites and 12 of the 14 mined sites was similar. Regression analysis identified the five most influential soil properties affecting site quality, which included soil profile base saturation, total coarse fragments, total available water, C horizon total porosity, and soil profile electrical conductivity. These five properties explained 52 % of the variation in tree growth. Forest productivity of these mined sites was equal to or greater than that of non-mined forests, ranging between 3.3 m3ha-1yr-1 and 12.1 m3ha-1yr-1. Management activities such as planting pine and valuable hardwood species increased the stumpage value of forests on reclaimed mine sites. Rotation-age stumpage values on mined study sites ranged between $3,064 ha-1 and $19,528 ha-1 and were commonly greater than stumpage values on non-mined reference sites. After 20 to 55 years, total site carbon levels on mined study sites averaged 217 Mg ha-1, while total carbon amounts on natural sites averaged 285 Mg ha-1. The amounts of carbon captured within the plant biomass and litter layer were the same on mined and natural sites. However, the soil carbon content of mined sites averaged 39 % lower than natural soils. The amount of carbon captured across mined sites was largely a function of forest stand age. Pre-SMCRA forests growing on mined sites with productivity levels similar to non-mined sites are capable of developing forest attributes comparable to or greater than those found on non-mined land within a period of 60 years, the length of a commercial hardwood rotation. These mature forests can serve as benchmarks for forest development on mined lands being reclaimed under current state and federal regulations. / Master of Science

State highway agencies are searching for more cost-effective methods of rehabilitating roads. One sustainable solution is full-depth reclamation (FDR), a pavement rehabilitation technique that involves pulverizing and reusing materials from existing distressed pavements in place. There is, however, limited information on the long-term properties of these recycled materials. One important property, the elastic modulus, indicates the structural capacity of pavement materials and is highly recommended for design purposes by the Mechanistic Empirical Pavements Design Guide (MEPDG). The elastic modulus directly impacts selection of the overall pavement thickness, and an accurate estimation of the modulus is therefore key to a cost-effective pavement design. This thesis researched the modulus trends and functional properties of three in-service pavements rehabilitated with the FDR technique during the 2008 Virginia Department of Transportation (VDOT) construction season. Foamed asphalt (2.7% with 1% cement), asphalt emulsion (3.5%), and Portland cement (5%) were used as stabilizing agents for the FDR layers. Several deflection tests and distress surveys were conducted for the pavement sections before and after construction. An automated road analyzer (ARAN) was used to collect distress data over a period of 7 years. Deterioration models were developed to predict the durability of differently stabilized FDR pavements and compared to reference sections rehabilitated with traditional asphalt concrete (AC) overlays. The results of the moduli measured for the recycled base materials varied significantly over time. These changes were attributed to curing after construction, seasonal effects, and subgrade moisture. The structural capacity of the pavements improved irrespective of the stabilizing agent used. Rutting was higher for the foamed asphalt and emulsion sections. The International Roughness Index (IRI) was better for the cement stabilized sections compared asphalt stabilized sections. The Critical Condition Index (CCI) was similar for all treatments at the end of the evaluation period. The durability of the sections was comparable, with the cement stabilized FDR sections slightly outperforming the asphalt stabilized sections. / Master of Science / Replacing all roads in bad condition with new reconstruction or with traditional rehabilitation alternatives such as the mill and overlay will cost state highway agencies (SHAs) huge sums of funds. State departments of transportation are therefore seeking cost-effective ways to rehabilitate roads under their jurisdiction. An innovative technique being used by several SHAs today is full depth reclamation (FDR) which involves breaking down an existing roadway and immediately reusing the materials to construct a strengthened base layer for a new road. Despite the increasing use of FDR in recent years, several questions remain unanswered regarding the behavior of the strengthened base materials and their performance in the long-term under traffic loads. The elastic modulus is one material property that indicates the strength or structural capacity of pavement materials and usually impacts the selection of the overall thickness of the roadway. This thesis researched the modulus trends and functional properties of three in-service roadways rehabilitated with the FDR technique in 2008 by the Virginia Department of Transportation. Foamed asphalt (2.7% with 1% cement), asphalt emulsion (3.5%), and Portland cement (5%) were used to strengthen the FDR base layers. Several deflection tests and distress surveys were conducted for the pavement sections before and after construction. The moduli measured for the recycled base materials varied significantly over time. These changes were attributed to curing after construction, seasonal effects, and subgrade moisture. Long term performance monitoring of the projects showed that rutting was higher for the foamed asphalt and emulsion sections. The International Roughness Index (IRI), which gives an indication of the overall ride quality i.e. how smooth the pavement surface is, was better for the cement stabilized FDR sections compared to the asphalt stabilized counterparts. The structural capacity of the pavements improved irrespective of the stabilizing treatment used. The Critical Condition Index (CCI) was similar for all treatments at the end of the evaluation period. The durability of the sections was comparable, with the cement stabilized sections projected to last slightly longer than asphalt sections.

Natural soils in the Appalachian coal mining region occur on steep slopes and are often thin, rocky, acidic, and/or infertile. This often makes use of natural topsoil for surface coal mine reclamation impractical. Sandstone (SS) and siltstone (SiS) topsoil substitute materials in mixed and pure treatments were compared to ascertain their effects on soil genesis and tall fescue (Festuca arundinaceae Schrab.) growth in a rock mix study. A second surface amendment experiment with similar objectives was established and contained treatments of sawdust, topsoil, a control, and four rates of sewage sludge. Soil pH, extractable P, and coarse fragment contents decreased at the soil surface from 1982 to 1984. The CEC decreased from 1982 to 1983 due to leaching of cations solubilized from carbonates, but stabilized by 1984. Soil total-N and water availability increased from 1982 to 1984. Particle size distributions changed as sand and >2 mm sized materials weathered into silt and clay sized particles. As sand contents decreased over time, silt contents increased. Morphologically distinct A horizons developed in these soils rapidly and were formed primarily by plant rooting and organic matter additions. Treatment application, topsoil substitute placement, and grading also created morphologically distinct horizons. Fescue biomass production indicates topsoil substitutes support more vigorous vegetative growth than topsoil, especially when topsoils are mixtures of subsoil and A horizons. Biomass production was primarily limited by N, P, and water availability. Blended rock mixes consistently supported higher biomass production than pure SS and SiS treatments. Municipal sewage sludge applied at rates-56 Mg/ha equaled or exceeded inorganic fertilization for establishment and maintenance of tall fescue stands, and did not cause heavy metal phytotoxicity. / M.S.

State highway agencies are searching for more cost-effective methods of rehabilitating roads. One sustainable solution is full-depth reclamation (FDR), a pavement rehabilitation technique that involves pulverizing and reusing materials from existing distressed pavements in place. There is, however, limited information on the long-term properties of these recycled materials. One important property, the elastic modulus, indicates the structural capacity of pavement materials and is highly recommended for design purposes by the Mechanistic Empirical Pavements Design Guide (MEPDG). The elastic modulus directly impacts selection of the overall pavement thickness, and an accurate estimation of the modulus is therefore key to a cost-effective pavement design. This thesis researched the modulus trends and functional properties of three in-service pavements rehabilitated with the FDR technique during the 2008 Virginia Department of Transportation (VDOT) construction season. Foamed asphalt (2.7% with 1% cement), asphalt emulsion (3.5%), and Portland cement (5%) were used as stabilizing agents for the FDR layers. Several deflection tests and distress surveys were conducted for the pavement sections before and after construction. An automated road analyzer (ARAN) was used to collect distress data over a period of 7 years. Deterioration models were developed to predict the durability of differently stabilized FDR pavements and compared to reference sections rehabilitated with traditional asphalt concrete (AC) overlays. The results of the moduli measured for the recycled base materials varied significantly over time. These changes were attributed to curing after construction, seasonal effects, and subgrade moisture. The structural capacity of the pavements improved irrespective of the stabilizing agent used. Rutting was higher for the foamed asphalt and emulsion sections. The International Roughness Index (IRI) was better for the cement stabilized sections compared asphalt stabilized sections. The Critical Condition Index (CCI) was similar for all treatments at the end of the evaluation period. The durability of the sections was comparable, with the cement stabilized FDR sections slightly outperforming the asphalt stabilized sections. / Master of Science

Mine tailings result from surface mining coastal plain soils and sediments and are redeposited in a slurry form to the mined area. Mine tailing contains a low amount of organic matter, a low pH, and a high P fixation capacity. This research was carried out in the Atlantic Coastal Plain region to determine if mine tailings reclamation could be accomplished by utilization of yard waste compost and wood ash. Yard waste compost was used to increase the organic matter content and wood to increase pH of the mine tailings. Field research was conducted to determine the effect of yard waste compost and wood ash incorporation into mine tailings on (Zea mays L.) and peanut (Arachis hypogaea) yields. Levels of yard waste compost applied to the mine tailings were 1, 2, 4, 6, 8, and 12% by weight, and wood ash was applied twice at a rate of 2.4 t ha⁻¹. Increases in corn and peanut yields on the mine tailings were attributed to increased available water from the application of yard waste compost and to increased pH from the application of wood ash. Successful use of the yard waste compost and wood ashes for reclamation of the mine tailing is shown by the higher peanut yields on the tailings soils than adjacent natural soils. Although the corn grain yields were relatively high (up to 7830 kg ha⁻¹) where yard waste compost and wood ash were applied to the tailings, the overall corn grain yields were higher on the adjacent natural soil. Probable reasons for lower corn grain on the tailings were inadequate available water at times of maximum need and N and/or P deficiencies. Zinc deficiency was induced in corn plants by the high level of P fertilization required to overcome the high P fixation capacity of the mine tailings. The Zn deficiency could be corrected by either foliar or broadcast-disk in application of ZnSO₄. / Master of Science

M.S.

Recycling felled urban trees that are hazardous or unhealthy is increasingly viewed as a viable practice to control disposal costs, promote environmental practices, and support local commerce. Wide spread waste wood utilization is encumbered by numerous presumptions about wood quantity, quality, accessibility, and presence of foreign objects; yet there is almost no scientific literature about these presumptions. Without this knowledge, informed decisions cannot be made about the viability of waste wood utilization. In this study, we assessed the quality and quantity of timber in street trees scheduled for routine removal by the District of Columbia (the District) using a modified timber grading protocol adapted from the United States Forest Service. We developed a second protocol to assess the feasibility of timber salvage by identifying physical barriers commonly encountered in urban areas (e.g., high volume traffic, utilities around the tree, and infrastructure). The randomized sampling scheme was stratified by land-use zones and focused on the six most abundant tree species: Acer platanoides, Acer rubrum, Acer saccharum, Quercus palustris, Quercus phellos, Quercus rubra. Our findings suggest the majority of condemned street trees are of too poor quality to contain timber (58% cull rate); however, trees that contain merchantable logs are likely to be easily removed. A notable discovery that could prove problematic for wood salvage was that the majority of trees (88%) contained superficial metal items embedded in the trunk surface. Furthermore, presence or absence of a merchantable-sized log (p=0.0445) depended on the tree's species, as did the average volume observed (p<0.0001). Additionally, land-use zones had an effect on the removal feasibility scores (p=0.0257) but had no effect on log presence or log volume. Throughout the District, we estimated that 36,500 board feet of merchantable logs are generated from routine removals of our top six species annually. These findings provide empirical data pertaining to urban timber salvage, which might aid decisions on the investment worthiness of utilizing urban street trees. / Master of Science

Coal mining has had profound impacts in the Appalachian region, initiating a need to understand the implications of traditional and current reclamation practices on wildlife. I evaluated wildlife use of reclaimed sites of varying ages and cover types in southwestern Virginia. I compared reclaimed sites to another form of anthropogenic disturbance (clearcut) and relatively undisturbed mature forest. Birds were surveyed during early mornings throughout the breeding season in 2007 and 2008 using the point count method. Amphibians were surveyed using artificial cover, constrained-time night searches, and auditory pond surveys. Microhabitat data were collected at each sampling point and were combined with landscape-level GIS information to relate habitat characteristics and wildlife patterns. I observed 80 bird species using reclaimed areas, clearcuts, and mature forest. Pre-regulation sites (prior to the Surface Mining Control and Reclamation Act of 1977) supported the highest number of species overall. Cluster analysis identified 4 bird associations based on habitat characteristics. I developed site-specific, landscape-level, and mixed-scale logistic regression models to identify habitat characteristics that best predicted the presence of 27 species. For 18 species, mixed-scale models performed best, suggesting the importance of a multi-scale approach to habitat analysis. Salamanders were generally not detected on reclaimed areas, possibly due to the lack of soil moisture, leaf litter, and woody debris on young sites. Frogs were present in all water bodies surveyed, suggesting the importance of managing ponds and wetlands on reclaimed sites. Identifying and focusing on important habitat characteristics will help managers enhance post-mining land for wildlife. / Master of Science

Adequate supply and availability of nitrogen (N) is a major factor hindering successful revegetation of reclaimed surface mines. Because topsoils are often unrecoverable, “topsoil substitutes”, made up of overburden materials devoid of N, are often used on reclaimed surfaces. Four replications of seven surface treatments were applied to 12 m² plots of 2:1 sandstone:siltstone material on a reclaimed coal surface mine in Wise Co., VA: 1) fertilizer (168 kg/ha N, 147 kg/ha P, and 139 kg/ha K), 2) limed (7.8 Mg/ha), fertilized topsoil (30 cm deep), 3) 112 Mg/ha sawdust + fertilizer + 336 kg/ha slow-release N, and 4-7) lime-treated municipal sewage sludge at rates of 22, 56, 112, and 224 Mg/ha. Nitrogen availability after 40 mo (as determined by aerobic and anaerobic incubations) in sawdust- and sludge-amended soils was two to 20 times higher than in fertilized and topsoil-amended soils. Moisture holding capacity was nearly twice as high in sawdust-amended soils as in all other treatments. Soil nitrate (NO₃⁻) levels (0-20 cm layer) in excess of 75 μg/g were detected in the 112 and 224 Mg/ha sludge plots 28 mo after application. Stem volumes of three-year-old pitch X loblolly pines (<i>Pinus rigida</i> X <i>taeda</i>) were four times larger in soils amended with sawdust + slow-release N and were twice as large in soils amended with 22 and 56 Mg/ha sludge compared to fertilized-only seedlings. Increased seedling mortality was observed in the 112 and 224 Mg/ha sludge treatments, possibly due to high soluble salt levels and/or manganese deficiencies. The availability of N from sawdust + slow-release N or sludge (≤ 56 Mg/ha) is better than that of inorganic fertilizer for sustained tree growth. These amendments are recommended for reclamation to the extent that they are economically available. / M.S.