The Philip M. Smith Graduate Research
Grant for Cave and Karst Research
2015 Grants
Justin N. Carlson ($2,500)
Ph.D. Candidate
Department of Anthropology
University of Kentucky
Assessing Human Activities, Sediment Deposition, and Pedogenesis at Crumps Cave Vestibule and Sink, Warren County, Kentucky
Abstract - Excavations in
Crumps Cave, Kentucky, to collect archaeological and geoarchaeological
data to refine the chronology of occupation, determine the range of
prehistoric activities, and assess the geomorphological and pedological
history of cave and sinkhole sites in the south-central Kentucky karst.
Document evidence of anthropogenic forest impacts by fire and its
timing in relation to intensive cave use in central Kentucky. The Late
Archaic-Early Woodland transition (ca. 3500-2500 BP) in central
Kentucky is a critical period for changes in land use, adoption of new
subsistence technologies, and socio-economic reorganization. The work
at Crumps Cave is significant to cave and karst studies in three ways:
(1) developing a model of hunter-gatherer and early horticultural
utilization of holokarst terrains; (2) contributing to contemporary
forest management literature by considering long-term history of
karstic barrens and cedar glades ecosystems; and (3) elucidating the
Holocene history of geogenic, biogenic, and anthropogenic sediment
deposition in Crumps Cave sink and vestibule, and the effects of
prehistoric human land use on cave systems.
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Mara L. Cashay ($2,500)
M.S. Student
Department of Biology
Appalachian State University
Impact of exogenous nutrients on Mn-oxidizing microbial consortia among caves of the southern Appalachian Mountains
Abstract- Manganese-oxidizing
microbes are common in a variety of environments, including cave and
karst systems, and can act as indicators of water quality and/or
bioremediators in their natural habitats. The microbial ecology of Mn
oxide deposits is not well understood and even less is known about the
factors that stimulate Mn-oxidizing microbes in situ. Previous studies
suggest that biological Mn oxidation is carbon limited. Preliminary
results from the proposed research however, have shown that fungal
growth can be stimulated without inducing biotic Mn oxidation the
addition of simple sugars (i.e. glucose and malt extract), as well as
complex carbohydrates (i.e. wood, cotton and cellulose). This lack of
simple correlation between Mn oxidation and additional exogenous carbon
suggests that other environmental factors need to be considered in
order to define the biotic role of Mn oxidation within cave systems.
The aim of this study is to identify the range of factors that
stimulate biotic Mn-oxidizing activity in situ and to identify how
anthropogenic impacts may alter biogeochemical cycling and contaminant
trapping within these ecosystems. This work has far reaching
implications for water quality within karst aquifers that house a
significant portion of the drinking water for the eastern United States.
________________________________________
Aaron Covey ($3000)
Ph.D. Candidate
Department of Earth and Environmental Sciences
Vanderbilt University
Quantifying Parameters of Climate
Variability on Soil and Speleothem Carbon Isotopes: Coupling Modern
Cave Monitoring with Multicomponent Reactive Transport Model
Abstract - Speleothem carbon
isotope values (δ13C) have potential to record past variability in
hydroclimate, vegetation, and soils. Yet, these data are often not
interpreted in a paleoclimate context due to the multiple and complex
environmental factors controlling δ13C. Radiocarbon (14C) can provide
insight into water-soil/rock interaction in the epikarst, but it is
also complicated by input from multiple subsurface carbon pools. By
using a reactive transport model that has been ground-truthed with
observations of modern systems, the factors controlling drip water
carbon isotope systematics can be constrained, providing the basis
needed to build an interpretive framework for speleothem δ13C and 14C
records. I propose to couple monitoring of a modern cave system with a
thermodynamically and kinetically driven multiphase reactive transport
model, CrunchFlow. Monitoring of surface temperature and precipitation,
soil temperature and moisture gradients, and cave temperature and pCO2
will set the initial boundary conditions for the model. Monthly δ13C
and seasonal 14C samples in soil (gas and water) and cave (air and drip
water) will constrain the factors controlling drip water δ13C and 14C,
providing data for a best-fit model of the soil-epikarst environment.
Once the model has been parameterized, I will conduct a series of
experiments to determine how changes in temperature, precipitation,
seasonality, vegetation, and soil thickness influence δ13C and 14C of
drip water over varying timescales. These model simulations will help
determine the fundamental factors that control δ13C in drip waters and
should thus provide an innovative and powerful tool for future
interpretations of speleothem δ13C records
________________________________________
Charles D. R. Stephen ($1,500)
Ph.D. Student
Department of Biological Sciences
Auburn University
Reassessment of the cave pseudoscorpion Hesperochernes mirabilis (Pseudoscorpiones: Chernetidae)
Abstract -The karst regions of
Tennessee, Alabama, and Georgia are well known as a biodiversity
hotspot for cave life. Pseudoscorpions represent some of the best
examples of this phenomenon, but their true diversity throughout the
Appalachian karst has likely been underestimated. Few people are
working on the group worldwide, and there are no active workers based
in North America. Our knowledge of Appalachian cave pseudoscorpions is
restricted to species lists, species descriptions, and unsupported
hypotheses of the genealogical relationships between species. In most
Appalachian troglobitic pseudoscorpions, the distribution of an entire
species is restricted to a single cave system. The biggest exception to
this pattern is Hesperochernes mirabilis. This species is known from at
least 145 caves located from Alabama to Ohio and on either side of
significant geographic barriers to dispersal. It may represent a
complex of several species, of which some may be rare and deserving of
protection. Alternatively, it may represent an extreme example of
phoresy (or "hitching rides"), in which it is tracking the distribution
of larger animals. Using phylogenetics, I will identify the boundaries
of populations and test their genetic connectivity. If analyses support
the hypothesis that H. mirabilis is a species complex, the species will
be redefined, and distinct lineages will be described as new species.
Results from this work will affect either the conservation status of
currently unprotected H. mirabilis populations and the caves they
inhabit, or provide compelling evidence for the impact that migrant
mammals have on the genetic diversity of cave-inhabiting arthropods.
________________________________________
Gilles Tagne ($2,500)
Ph.D. Student
Department of Geological Sciences
Ball State University
Using geochemical and isotopic data to partition sources of groundwater in epigenic karst aquifers
Abstract -This research
comprises two related objectives in the study of epigenic karst
aquifers: 1) to better constrain the flux of carbon through a detailed
study of inorganic and organic carbon, including the temporal
variation, reaction pathways, and relation to overlying land use; and
2) to examine the source and transport of sulfur and the impact of this
sulfur upon water-rock interactions.
• The focus is upon
the critical zone that extends from the land surface to the base of the
zone of active groundwater circulation and includes the soil, the
epikarst, and underlying conduits.
• The scope includes karst aquifers in Paleozoic
carbonates of southeast Kentucky with a record of prior investigation
and differing land use.
• The vision is to use results from this study to
contribute to a greater understanding of the critical zone, deeper
groundwater, and the impact of changing land use on karst aquifers.
This study juxtaposes two primary geochemical pathways for carbonate
dissolution in karst aquifers, carbonic acid conveyed by meteoric
recharge and the oxidation of reduced sulfur entrained into groundwater
flow. I will attempt to quantify the magnitude of each pathway and
additionally assess the influence of petroleum-associated brines from
deeper groundwater upon on the chemistry of these karst aquifers. This
study will contribute to a mixing model to partition contributions of
surface and deeper sources to nutrient and carbon flux in karst
aquifers. It will also provide new insights in the geochemistry of
karst waters in area impacted by agriculture and historic oil
exploration.
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last updated or validated on January 26, 2019