Displaying items by tag: research

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
 

ORNL researchers receive 2021 Sustainability Science Award for mapping human influence on U.S. river and stream changes 

Researchers from Oak Ridge National Laboratory mapped and quantified hydrological changes throughout the country due to urban development, energy production and other human factors and won a prestigious award for their efforts.

The team’s analysis was published in the Proceedings of the National Academy of Sciences and received the 2021 Sustainability Science Award from the Ecological Society of America.

“The Sustainability Science Award recognizes the authors of a scholarly work that make a substantial contribution to the emerging science of ecosystem and regional sustainability through the integration of ecological and social sciences. The researchers will be recognized during the society’s annual meeting in August,” according to an ORNL release announcing the award.

The research coupled U.S. Geological Survey stream-flow records with geospatial modeling to quantify human impact on national water resources and concluded the 7 percent of affected aquatic systems hold 60 percent of North American freshwater fish, mussels and other species.

“This work exemplifies how ORNL’s interdisciplinary research in environmental and geospatial science helps equip decision makers with the tools needed to move our nation toward a more sustainable future,” Stan Wullschleger, associate laboratory director for ORNL’s Biological and Environmental Systems Science Directorate, said in the release.

Lead author Ryan McManamay, an aquatic ecologist and faculty member at Baylor University, was with ORNL’s Environmental Sciences Division at the time of publication. Co-authors include ORNL’s Sujithkumar Surendran Nair, Christopher DeRolph, the late April Morton, Robert Stewart, Matthew Troia and Budhendra Bhaduri; Northern Arizona University’s Benjamin Ruddell; and the University of Tennessee’s Liem Tran and Hyun Kim.

“It was a privilege to work with this team that spanned across multiple disciplines and institutions,” said Bhaduri, an ORNL Corporate Research Fellow and director of ORNL’s Geospatial Science and Human Security Division. “Given the impacts of climate change, there has never been a more pressing opportunity to address environmental sustainability. It’s a tremendous honor to make this scientific contribution and to be recognized for it.”

Published in News

124505910 10157221252975764 8815228407492920926 oThe Chattanooga Zoo will soon open an exhibit to hellbenders, such as the one seen here in a tank at the zoo.  Courtesy Chattanooga Zoo

New hellbender exhibit at Chattanooga Zoo will serve as a hub for cooperative research

Thanks to grants from two generous organizations, some oft-elusive hellbenders have a new home at the Chattanooga Zoo. The Hiwassee Education and Research Facility is nearly complete, and it features hellbender exhibits and a classroom. The exhibit includes juvenile hellbenders hatched from eggs collected from the Duck River in central Tennessee in 2015.  

The zoo is also fabricating a stream environment exhibit that will house nine larger sub-adult hellbenders, each about 10 years old and 14.5 inches long. Visitors can observe hellbenders feeding in the completed exhibit, but it will be open only during limited hours. After the project's completion, the zoo plans to partner with researchers who hope to learn more about hellbenders. 

"The Chattanooga Zoo is thrilled at the introduction of its new Hiwassee Hellbender Research Facility," zoo officials said in a statement to Hellbender Press. 

“We believe that this new facility will open rare opportunities for guests to be educated on this otherwise elusive native species, and that the project would lead to important strides made in hellbender research. 

“From all of this, our hope is for more conservation efforts made in our local waterways, also known as the eastern hellbender’s home.”

Published in Water

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