Displaying items by tag: ecosystem

downloadDr. Brian MIller
 

MTSU researchers document hellbender's accelerating decline in Middle Tennessee

(Author’s note: I was aware of the hellbender before interviewing Brian Miller, but did not know the giant salamanders were present on the Highland Rim of Tennessee. Subsequent reading and interviews with other researchers, including Dr. Bill Sutton at Tennessee State University, Nashville, confirm Miller’s statements that hellbenders are vanishing from large portions of Tennessee, and Missouri. The healthy populations in portions of the Great Smoky Mountains and Cherokee National Forest may be an exception to a general trend toward extirpation and, ultimately, extinction).

Brian Miller has been researching hellbenders for decades. He serves on the faculty of Middle Tennessee State University where he teaches in the biology department and mentors younger researchers, many of whom publish their research.

He has even developed a digital "Guide to the Reptiles and Amphibians of Middle Tennessee." The guide began more than 30 years ago as a dichotomous key for students in his vertebrate zoology class and now includes hundreds of photographs and exceeds 400 pages.

Dr. Miller researches the hellbenders of the Highland Rim, the upland that surrounds Nashville and the Great Basin. Populations of hellbenders in streams of this region are perhaps Tennessee's most endangered.

QUESTION: I noticed that you specialize in herpetofauna. Most of the research listed on your faculty page is focused on amphibians, but with some papers on snakes. Can you comment about your research?

ANSWER: You are correct that amphibians are my primary research interest, particularly salamanders. However, I also have strong interests in reptiles, and my students and I have conducted research on various species of snakes and turtles.

When did you become interested in hellbenders?

Hellbenders have been of interest to me since I first encountered them while enrolled in a course on herpetology at the University of Missouri in 1977. I was fortunate that the professor of that course, Dean Metter, was involved with research on hellbenders and I began to assist with his research in 1978, in collaboration with Robert Wilkinson at Southwest Missouri State University in Springfield, Missouri.

Chris Petersen was working on his master's degree with Dr. Wilkinson at that time and he matriculated to the University of Missouri a couple of years later to start on his Ph.D, which was also with hellbenders. Chris and I spent time in the field gathering data for his Ph.D. project until I moved to Washington State to work on my Ph.D.

I was hired into the biology department at Middle Tennessee State University in 1989 and began working with hellbenders in this state in 1990. At that time, I was able to locate populations in several rivers in Middle Tennessee, including a large population in the Collins River. I decided to concentrate my efforts on this population and one in the Buffalo River.

Of note, the population I worked with in the Collins River was dominated by large adults, whereas the population in the Buffalo River consisted of many age classes, including young individuals.

The Collins River situation was like what I was familiar with in Missouri and Arkansas populations. Unfortunately, by the early 2000s the population I was working with in the Collins River was gone; however, populations remain in the Buffalo River. My research with hellbenders during the past decade has been concentrated in streams in the Western Highland Rim.

Do you work with both subspecies, the Ozark, and the Eastern hellbender?

I worked with both subspecies while a student at the University of Missouri when assisting with projects in the Metter lab, but since I moved to Tennessee, I have worked only with Tennessee populations.

What do you perceive as the greatest threats to hellbender populations?

I am not certain why most populations of hellbenders are in decline rangewide, but suspect that habitat alteration, including sedimentation, and disease are involved in many if not all areas where declines are occurring. Lack of recruitment of young is a common theme of populations that decline. 

Published in News
OLYMPUS DIGITAL CAMERA         Great Smoky Mountains National Park Air Resource Specialist is seen at the Look Rock air quality research station.   Courtesy National Park Service

The lack of regional and local vehicle traffic during the pandemic greatly reduced measurable pollution in Great Smoky Mountains National Park.

This is your Hellbender weekend read, and the first in an occasional Hellbender Press series about the effects of the Covid-19 pandemic on the natural world

Great Smoky Mountains National Park shut down for six weeks in 2020 during the Covid-19 pandemic. Recorded emissions reductions during that period in part illustrate the role motor vehicles play in the park's vexing air-quality issues. The full cascade of effects from the pollution reductions are still being studied.

Hellbender Press interviewed park air quality specialist Jim Renfro about the marked reduction of carbon dioxide and other pollutants documented during the park closure during the pandemic, and the special scientific opportunities it presents.  He responded to the following questions via email.

Hellbender Press: You cited “several hundred tons" in pollutant reductions during an interview with WBIR of Knoxville (in 2020). What types of air pollutants does this figure include? 

Answer: Carbon dioxide (CO2) would be most of the tons reduced from the lack of motor vehicles in the park during the park shutdown because of the pandemic.  Carbon monoxide (CO), nitrogen oxides (NOx),  volatile organic compounds (VOCs), and particulate matter are other emissions that were lower, but to a much lesser extent.  

HP: During what time frame?

A: It was based on when the primary park roads were closed, for about a six-week period from March 24 through May 9 (2020) 

HP: Was this based on data collected at the Look Rock air-quality monitoring station or monitoring sites throughout the park? 

A: No, it was estimated reductions in air emissions (tons) from using the park's emissions inventory for criteria air pollutants and greenhouse gases coupled with the reduction in park visitation data for the period of the park shutdown.

HP: Was this a result of reduced auto travel in the park? 

A: Yes. 

HP: A lot of emissions, of course, come from outside of the park. Was the improvement in air quality also a function of reduced pollutants coming from outside the park? 

A: The documented reduction was with emissions, not air quality. Air quality analysis is still under way to look at changes in air pollutants. 

HP: What do you think the primary reasons for the air quality improvements were?  

A: If there were reductions in air pollutants (and that is still being analyzed by EPA and NPS Air Resources Division), it was due primarily to the reduction in motor vehicle emissions in and near the park (and regionally).

HP: Did you purposefully set out to quantify the pandemic’s effect on air quality, or was this an “accidental” discovery? 

A: We did not purposefully set out to quantify the pandemic's effect on air quality. Monitoring efforts continued during the pandemic and provided a unique and unexpected opportunity to characterize the differences in air emissions (from park closures and limited motor vehicle emissions) and air pollutants (which will take longer to look at laboratory analysis after quality assured analysis).

Published in Air

img 2460State and local officials want to expand another 'road to nowhere' by way of the controversial $200 million Pellissippi Parkway extension in Blount County.   Lesli Bales-Sherrod/Hellbender Press

The newest road to nowhere

The former “missing link” of the Foothills Parkway. The “road to nowhere” in Bryson City, North Carolina. Blount County, Tennessee, has its own unfinished road project, without the catchy nickname: the Pellissippi Parkway Extension.This proposed 4.4-mile stretch of four-lane highway would lengthen State Route 162, known as Pellissippi Parkway, from where it ends at Old Knoxville Highway (State Route 33) to East Lamar Alexander Highway (State Route 73/U.S. 321) in Maryville.

The project, which would impact 56 properties and cost at least $60 million, is not without controversy. Citizens Against the Pellissippi Parkway Extension, “believe(s) this interstate highway is not needed, wastes state resources and will have negative impacts on the area along the route and on the quality of life in Blount County as a whole,” according to the group’s website, saveitdontpaveit.org. Besides loss of farmland, residences and businesses, CAPPE’s concerns include sprawl, traffic, water and air quality, noise, economic impact and the destruction of wildlife habitat and increased rates of roadkill.

State and local government officials, however, maintain the Pellissippi Parkway Extension will address needs such as “limited mobility options in Blount County and Maryville, poor local road network with substandard cross sections (with narrow lanes, sharp curves, and insufficient shoulders), lack of a northwest/east connection east of Alcoa and Maryville, safety issues on roadways in the area, and traffic congestion and poor levels of traffic operation on major arterial roads and intersections,” according to the Record of Decision signed by the Federal Highway Administration on Aug. 31, 2017.

The Pellissippi Parkway Extension has been part of the Knoxville regional transportation planning vision since 1977, according to a 2010 Draft Environmental Impact Statement, and has a long, storied history -- complete with a 2002 lawsuit from CAPPE, seeking to stop it. Nothing has happened publicly, however, since the Record of Decision selected a preferred route for the new stretch of road, which would cross Old Knoxville Highway, Wildwood Road, Brown School Road, Sevierville Road and Davis Ford Road before terminating near Morning Star Baptist Church in Maryville.  
Published in News

Color photograph shows the grassy herbaceous ground cover and the trees planted in straight rows; This walnut orchard was planted by the Tennessee Valley Authority as part of its early mission to promote the growth of economically useful trees in the Tennessee Valley.   Courtesy UT Tree Improvement Program

Part I of this three-part series examines how the development of civilizations and rapid population growth gave rise to forest tree domestication. Parts II and III will discuss the role that the University of Tennessee’s Tree Improvement Program has played in forest sustainability by contributing to the productivity and health of Tennessee’s present and future forests.

Wood and lumber figured prominently in ancient civilizations, ranging from everyday use for warmth, cooking, and shelter to specialty uses like veneers for furniture and construction with scented woods. 

No matter what continent or hemisphere, as human civilizations evolved from collections of nomad hunter-gatherers to the steel, brick, glass, and mortar cities of today, the impact on forested land proportionally increased. As villages became towns and, eventually, cities, forests were harvested in an ever-increasing radius around the population centers. Wild animals and plants were also harvested in the same manner, drastically altering ecosystems and causing massive erosion.

Nations that quickly exhausted the best trees in their limited forested lands, like ancient Egypt and Greece, met wood demands for construction or specialty products by importing wood from other nations. The then-rich forests of Lebanon and Cyprus were harvested to export timber to countries suffering from a timber famine.  

Published in Voices