Research Experiences for Undergraduates In the Headwaters of Appalachian Kentucky

Detailed Research Description

Our general approach is to begin with classroom and field instruction in the first part of the summer, and then move students increasingly towards independent work in the second part--culminating in an independent research project designed, executed, and presented by the participants. Throughout the program they will have specific assignments designed to keep them focused and on track as they develop and execute their research.

Our undergraduate and teacher research experience focuses on two aspects of carbon budgeting as impacted by coal mining including: (1) assessing changes in the soil carbon reservoir by sampling and analyzing forest soils that have not been mined as compared to soils in various stages of reclamation, and (2) assessing changes in surface erosion induced by coal mining by sampling and analyzing eroded soils produced from various phases and types of mining including (a)"pre-law mine land" defined as mined sites reclaimed prior to the 1977 Surface Mining Control and Reclamation Act; (b) "post-law mine land" or land reclaimed after 1977, (c) land currently being mined, and (d) an undisturbed, old-growth forest site.

Assessing changes in soil carbon reservoirs: Figure 2 shows a map of eight sites in various stages of reclamation in Letcher County. These sites will be the focus for the soil carbon reservoir sampling. The sites were chosen after analysis of aerial photographs, land cover and soil data maps, roadways and mining maps, and discussion with mining experts. Final choices were picked based on access, data availability, and proximity to the Lilley Cornett Woods field camp. We chose a range of transitions in land-use (i.e., mining at different years and mining to forest and mining to grassland). Figure 3 shows one site (site D in Figure 3) and illustrates the land use transition that has occurred over the past nine years due to mining. The participants will use maps of the site to help see the changes occurring at the mining sites. In addition, forest cover maps and soil physical and chemical property maps will be analyzed.

Participants who focus on changes in soil carbon reservoirs will be required to formulate a hypothesis on the variability of carbon as impacted by mining. The overarching hypotheses will be that litter input and soil properties impacting soil carbon turnover are responsible for the variation of TOC and δ13C in the soil profile at the sites (Powers and Schlesinger, 2002). Participants will be required to formulate a more specific question and then a hypothesis based on the variability at the sites shown in Figure 2. Hypotheses will be formulated potentially based on variability due to: type of reclaimed land (grassland, pine-forest, barren); time since reclamation in a single reclaimed type (e.g., three sites with grassland reclamation in 1970, 1980, and 1990); un-mined forest type (i.e., old-growth hardwood, hardwood, pine-mixed); heterogeneity of TOC and δ13C at a single site; and variability due to soil physical and chemical properties (e.g., pH, texture). Each student's hypothesis will be tested based on composite soil samples from three or more 1 ha sites. For example, a student that compares three grassland reclaimed sites from 1970, 1980, and 1990 may hypothesize that accretion rates of carbon are dependent upon soil organic carbon stabilization with little influence from lignite breakdown in the microbial pool. Measurement of δ13C from different soil fractions at varying depths in the soil column will investigate this hypothesis.

2.2.2 Assessing changes in surface erosion: Figure 4 shows a map of four watersheds that have been targeted for the surface erosion studies. These watersheds are presently being monitored for sediment and fluid discharge. Two meteorological stations are located near the watersheds and are depicted in Figure 4. In addition, sediment traps are being used to collect samples for isotopic analysis. The four watersheds were chosen with the intent to represent a variety of mining conditions with similar soil, topographic and climatic conditions. The mining history of the watersheds includes pre-law mining, post-law mining, current mining, and an undisturbed site. Table 1 details the historical and present state of each watershed.

Site Name	Stream Name	Watershed Area (sq km)	Types of Mining	Years of Surface mining	Current status of mining
Whitaker	Whitaker Branch	3.8	Surface Area and Underground	1998-2003	reclaimed recently, no active mining
Island Branch	Island Branch	2.2	Surface (Auger) and Underground	1998-present	active mining
Pole	Un-named	1.9	Surface (Auger) and underground	1975-1994	reclaimed more than 10 years ago
Big Everidge	Un- named	0.6	None	None	No mining ("control site")

Participants who focus on changes in surface erosion will be required to formulate a hypothesis regarding how mining impacts erosion. The overarching hypotheses will be that hydrologic changes that are a result of mining are responsible for surface erosion and incision in the stream corridor indicated by TOC and δ13C and δ15N of eroded-soils. Participants will be asked to narrow the hypothesis by asking specific questions related to the watersheds and performing comparisons with the undisturbed Big Everage Watershed. Individual participant projects will be focused based on ideas including: temporal changes from different storms (in one watershed), contribution of δ13C and δ15N from surface soils as compared to sediments from the stream corridor (in one watershed); comparison of eroded-soil δ13C and δ15N signatures in multiple watersheds based on upland activities, comparison of total sediment and total carbon flux from multiple watersheds; and timing since mining stopped. For participants studying soil erosion, composite surface soil samples, streambank and floodplain soils, and streambed samples will be collected. Collection of eroded soils and sediments from the sediment traps and automated samplers and discharge measurements will also be collected by the participants; however, collection of these samples will also be performed by the staff at Lilley Cornett Woods during the spring and early summer months preceding the REU in order that sufficient eroded soil data is available for analyzing temporal and spatial erosion trends