School of Environmental Studies

A pilot study for the qualitative detection of methamphetamine at sites within a sewage collection system adjacent to locations suspected to harbor illegal drug activities was investigated and preliminary findings are reported. Sewage samples were collected over a time interval of four weeks using a Polar Organic Chemical Integrative Sampler (POCIS) deployed directly into the sewer line. The POCIS sorbent was extracted and analyzed via high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Methamphetamine was found in sewage from one of three sampling sites at a concentration greater than the HPLC-MS/MS method detection limit (MDL) of 3 ng/mL. The goal of this research was to establish proof-of-concept of the feasibility for sampling and analysis using POCIS devices in the sewage collection system. The data encourage further testing and research. The ability to pinpoint the presence of methamphetamine in the sewer may in the future be used as a forensic tool in law enforcement.

The identification and quantitation of the non-ecstasy amphetamine-type stimulants (ATSs) amphetamine and methamphetamine in lakes, rivers, wastewater treatment plant influents, effluents, and biosolids are reviewed. Neither monitoring nor reporting is required of these ATSs, which are considered emerging pollutants, but they have been identified in the environment. Amphetamine and methamphetamine enter our water supply by human excretion after legal or illegal consumption and via manufacturing in clandestine laboratories. Analytical methodology for sampling, sample preparation, separation, and detection of ATSs is discussed. Reported occurrences of ATSs in the environment and their use in municipal sewage epidemiology are noted. Future research needs that challenge applications of analytical techniques are discussed. The review focuses on research reported from 2004 to 2009.

Karst aquifers that are dominated by conduit recharge are at high risk of contamination because there is little filtration or sorption of contaminants in the water. Identifying flow paths through conduit aquifers is required in order to delineate basin boundaries and potential areas at risk from groundwater contamination. In this study we report on the first continuous (~1 year) discharge and water quality data set ever collected from the Boils spring on the Highland Rim of middle Tennessee. The Boils drains the Roaring River-Spring Creek system, a State Scenic River and Wildlife Management Area. We also report on the results of a quantitative dye trace that was done to identify surface contributions to this spring. At the Boils, we measured discharge, temperature, and specific conductance for an approximate one-year period. The average annual discharge of the Boils during 2015 was 2.1 m3/s, with storm discharge reaching as much as 14 m3/s. Conductivity at the Boils spring ranged fr...

Students in the Environmental and Sustainability Studies Capstone Experience 1 and 2 courses have prepared recommendations for the Upper Cumberland Development District (UCDD) to address illegal dumping in the 14 counties of the Upper Cumberland. The purpose of this study was to compile the best available information and to characterize dumpsites for analysis and decision making. In Capstone 1, teams conducted literature reviews for the associated sociological, economic, and environmental issues and compiled a white paper discussing the motivations for illegal dumping, benefits and costs of abatement, environmental and health effects of dumping, best practices for educating and motivating children and adults, helpful data management and grant strategies, and best practices for discouraging and preventing dumping. Our Geographic Information System (GIS) team produced an ESRI ArcGIS map and evaluated dumpsites across counties to create a standardized form for collection of characteriz...

The Tennessee Central Heritage Rail Trail, completed in October 2016, is a 4.23 mile long mixed-use bike trail that is envisioned to run 19 miles from Baxter to Monterey. Currently, the trail starts at the Cookeville Train Depot Museum, passes through Tennessee Tech University, and ends at the Algood Community Library and Senior Citizen Center. After an initial exploratory examination of the trail, a selection of low-lying areas was visually identified as potential hazards during a storm event based on their estimated likelihood of flooding or sedimentation. Data was gathered manually in the form of geolocated ground photographs and GNSS GPS points during a walk of the trail by the researchers. Collected data was then analyzed in association with flow accumulation data derived from USGS 3DEP LiDAR data collected for the Upper Cumberland region in December 2015 and January 2016. However, since the LiDAR data was collected prior to the trail’s completion, the researchers used it to de...

The Calfkiller River in White County, TN, is part of the Caney Fork Watershed. Etheostoma akatulo (the Bluemask Darter) has been historically found in the Calfkiller River, but the last known sample was collected in 1968. Since then the Bluemask Darter has been extirpated from the Calfkiller River for unknown reasons. As a starting point for habitat assessment, we used available GIS elevation and land use data along with stream assessment data to create a model of potential habitat for the Bluemask Darter species in the Calfkiller River. Using this model, we have prioritized habitat areas and identified data gaps where future research on stream habitat is needed.

Restoring connections between rivers and floodplain wetlands can improve water quality downstream. The USDA Natural Resources Conservation Service’s Wetlands Reserve Program (WRP) has restored many wetlands in the Lower Mississippi River Valley by increasing floodplain-river connections. We are studying water quality changes over three years in a restored agricultural wetland in western Kentucky after reconnection with a large agricultural ditch via levee breaks. Floodwater quality is being measured over 24 h as stream water flows from the levee, through the forest, and into a remnant stream channel using 11 automated water samplers to monitor particulate and nutrient concentrations, and 23 water level loggers to estimate flow paths and discharge. Results from the first flood show nutrient and particulate concentrations were higher and more variable earlier in the flood and closer to levee breaks. Total suspended solids (TSS) concentration was a strong predictor for both total nitro...

Floodplain wetlands are vital ecotones that mitigate nutrient pollution from the surrounding watershed. Despite their valuable role in maintaining healthy streams, floodplain wetlands have been historically drained or degraded by intense agricultural practices. The U.S. Department of Agriculture’s Natural Resources Conservation Service (NRCS) manages the Wetlands Reserve Program (WRP), which allows cropland to transition back to wetlands. A key WRP restoration practice reestablishes natural hydrology regimes and connectedness with the river, which in turn should improve nutrient retention. This study is evaluating the effectiveness of hydrology restoration at increasing soil nitrogen and phosphorus uptake in 40 WRP wetland easements across western Tennessee and Kentucky. Thirty soil cores were collected from each of nine restored wetlands during the summer of 2019 (year one) and incubated in a laboratory system for 32 hours. Preliminary data suggest that both standing water and ease...

Restoration activities have been implemented in the lower Mississippi River basin through the Wetlands Reserve Program (WRP) to enhance essential functions by restoring wetlands. Soil can be a zone of significant nutrient retention in wetlands by providing an environment for microbial development and nutrient processing. The objective of this study was to assess soil microbe-based ecosystem function in three restored riparian wetlands in Western Kentucky, focusing on the relationship between microbial biomass and nutrient removal. We hypothesized that nutrient retention, and specifically denitrification is directly related to microbial biomass carbon (MBC). At each easement, thirty sediment cores were collected and used to measure a suite of soil processes and properties, including soil nitrogen (N) and phosphorus (P) uptake rates, denitrification potential, soil moisture, and MBC. MBC was significantly higher in undisturbed older habitat, followed by remnant forest, and lowest in the shallow water areas. Denitrification potential, and N and P uptake were strongly correlated with MBC and soil moisture. Our results suggest that increasing total soil microorganism biomass is an indicator for monitoring improvements in ecological functions in restored wetlands, with potentially important long-term consequences for denitrification and nutrient retention

The course of the bark beetle-vectored fungus, Leptographium terebrantis S. J. Barras and T. J. Perry, in stemwood growth loss of declining pines in the southeastern United States was assessed in a 13-year-old loblolly pine (Pinus taeda L.) plantation near Eufaula, Alabama, U.S.A. Using stem inoculation as a surrogate for root infection, we hypothesized that L. terebrantis infection impairs sapwood function and thus limits the tree leaf area (AL), new root production, and stemwood growth. Sterile toothpicks colonized by L. terebrantis at varying inoculum densities was used to elicit host growth responses. In the third year after inoculation, the root pathogen reduced the foliage moisture content, whole-tree leaf area (AL), the ratio of AL to tree sapwood area (AS), and stemwood growth in trees receiving the high inoculation treatment relative to those receiving the low or medium inoculation treatments, or the wound or control treatments after seven months of water deficit. The absen...

The definition of a species  has been argued extensively by philosophers and biologists resulting in the development of many different concepts which often contradict each other (Naomi, 2011). An integrative approach using multiple types of data (e.g, morphological, ecological, behavioral, genetic) may be the most successful at correctly assigning taxonomic levels (Pante et al., 2014). This approach may also be the best way to evaluate subspecific classifications (Makowsky et al., 2010). While many discount the existence of subspecies, the use of this level of classification is often vital in the conservation of populations (Haig et al., 2006).  Here, we use an integrative approach of ecological niche modeling and molecular genetics to investigate the taxonomy of a state imperiled gartersnake subspecies, Thamnophis sirtalis annectens, using ecological niche modeling and molecular phylogenetics analyses. The distribution, taxonomy, population biology, and natural history, in general, of the Texas gartersnake (Thamnophis sirtalis annectens) are poorly known.  It was described in the 1950’s as one of the 12 currently recognized subspecies of the common gartersnake (T. sirtalis) based solely on morphological data.  Since its initial description, its behavior, ecology, and systematics have not been examined and it remains one of the more enigmatic of the 12 subspecies.  Recently, it was given a conservation rank of S2 (imperiled) in the state of Texas and those that are familiar with it have suggested that its numbers are dwindling.  Using ecological niche modeling and mtDNA sequence data we begin to understand the natural and evolutionary history of T. s. annectens. The results of this study provided additional information on the ecology and potential habitat range of T. s. annectens as well as information on  the phylogenetic systematics of this subspecies. Our ecological niche model indicates areas where conservation efforts for T. s. annectens should be focused as well as important environmental variable such as landcover and geology that T. s. annectens prefers. When including T. s. annectens in a comparative niche model, this subspecies primarily occupies distinctly different habitat than the red-sided gartersnake, T. s. parietalis, which also occurs in Texas. Statistical analysis indicated that T. s. annectens occupies as significantly different ecological niche than T. s. parietalis. Similarly, the genetic data indicate that T. s. annectens can be differentiated from T. s. parietalis and T. s. sirtalis, however this difference is greatest between T. s. sirtalis.  While this work has told us much about T. s. annectens, more is left to be learned including ground-truthing our ecological niche model. Collecting additional genetic data to verify the phylogenetic relationships we have hypothesized here should also be done in the future.  Regardless, this work indicates T. s. annectens may be distinct both genetically and ecologically and provides conservation managers with niche models that will assist in locating the optimal habitat required by this subspecies.

We investigate the taxonomic status of the Texas garter snake, Thamnophis sirtalis annectens,a species of greatest conservation need in Texas. We broadly test the hypothesis that an integrative approach to species conservation has greater utility than using only a single data type (e.g., molecular, morphological, behavioral, or ecological) by demonstrating how ecological niche modeling and molecular genetics can be used synergistically to resolve taxonomic classifications. Using a phylogenetic analysis based on molecular data, we found that some putative T. s. annectens specimens actually represent a co-occurring subspecies (the redsided garter snake, Thamnophis sirtalis parietalis), which is not of conservation concern. However, both T. s. annectens and T. s. parietalis are genetically distinctive from another co-occurring subspecies, Thamnophis sirtalis sirtalis, and the ecological distinctness of T. s. annectens from T. s. parietalis suggests that T. s. annectens is, in fact, a distinct evolutionary subunit. Only when both genetic and ecological information were included was the distinctiveness of T. s. annectens apparent, thus highlighting the need for integrative approaches in conservation management regardless of the taxa in question.