Annette Summers Engel
Donald H. Jones Professor of Aqueous Geochemistry
University of Tennessee at Knoxville
Department of Earth and Planetary Sciences
Engel Lab Research -
Biodiversity of caves and karst in the Valley and Ridge
Of the >50,000 caves reported in the United States, over 1,138 cave-restricted animals have been described. These troglobionts (terrestrial obligate cave species) and stygobionts (aquatic obligate cave species) possess traits uniquely associated with life in perpetual darkness and limited food resources. One of the richest karst areas in the United States is in TAG (Tennessee, Alabama and Georgia), with Tennessee currently ranking 2nd to Texas for the most obligate subterranean species. Tennessee currently has more mapped caves than any other state, at over 10,000. However, recent examinations of spatial patterns of cave biodiversity, species richness, and endemism in Tennessee identify that only 5% of Valley and Ridge caves (of ~500 caves) have fauna records. Almost nothing is known about the microbiology of caves in Tennessee. Moreover, several undersampled areas exist, including in northeast Tennessee extending from the more intensely inventoried southwestern Virginia karst. As such, it is possible that many TAG cave species await discovery and description. There is still much to be learned about the distribution of obligate cave fauna, their evolutionary histories, and ecosystem dynamics (including food web structures and microbial detrital loop).
 
We explored about 100 caves to address sampling gaps in TAG Valley and Ridge caves. Although this specific project is over, we are still conducting research. Our goals are to (1) conduct biological inventories, which include ecological and life history information for species, and (2) document species occurrences that define geographic extents and examine spatial patterns of biodiversity, endemism, and sampling effort. From these data, we developed  an educational outreach module that is promotin​g awareness and conservation of subterranean fauna throughout TAG. So far, we have discovered many new populations for spiders, beetles, mites, and aquatic invertebrates. Much more remains to be discovered!
 
 

Project website

Past support: Cave Conservancy of the Virginias (2014-2016); University of Tennessee, Jones Endowment
 
Collaborators: 
Dr. Matthew L. Niemiller, University of Illinois at Urbana-Champaign ( website )
 
Dr. Kirk Zigler, The University of the South
 
Dr. Dante Fenolio, San Antonio Zoo
 
Dr. K. Denise Kendall (University of Illinois, Champaign-Urbana) 

+ a host of others

Related Publications and Presentations from the Group

Nichols, H. (REU student), Paterson, A.T., Engel, A.S. (2018) Microbiology of anthropogenically impacted caves in the Appalachian Valley and Ridge region, Tennessee. National Speleological Society convention, Helena, Montana, July 30 – August 3. 

Niemiller, M.L., Zigler, K.S., Carter, E.T., Stephen, C.D.R., Engel, A.S., Shear, W.A. (2018) Influence of geological barriers on the phylogeography and dispersal of cave-adapted Scoterpes millipeded (Chordeumatida: Trichopetalidae) in the Interior Low Plateau and Appalachians karst regions. 24th International Conference on Subsurface Biology, Aveiro, Portugal, August 20-24, 2018. 

Engel, A.S., Niemiller, M.L., Zigler, K.S., Ayala, B.N., Hart, P.B., Kuhajda, B.R., Armbruster, J.W. (2018) Reconstructing Late Pliocene through Early Pleistocene ancestral river drainage basins in the Interior Low Plateau and Appalachians karst regions to understand the evolutionary history of Typhlichthys subterraneus (Percopsiformes: Amblyopsidae). Geological Society of America, Southeastern section meeting, Knoxville, TN, Abstracts with Programs. Vol. 50, No. 3, doi: 10.1130/abs/2018SE-313063 

Niemiller, M.L., Zigler, K.S., Carter, E.T., Stephen, C.D.R., Engel, A.S., Shear, W.A. (2018) Influence of geological barriers on the phylogeography and dispersal of cave-adapted Scoterpes millipeded (Chordeumatida: Trichopetalidae) in the Interior Low Plateau and Appalachians karst regions. Geological Society of America, Southeastern section meeting, Knoxville, TN, Abstracts with Programs. Vol. 50, No. 3, doi: 10.1130/abs/2018SE-312727. 
  
Niemiller, M.L., Zigler, K.S., Ober, K.A., Carter, E.T. Engel, A.S., Moni, G., Philips, T.K., Stephen, C.D.R. (2017) Rediscovery and conservation status of six  short-range endemic Pseudanophthalmus cave beetles (Carabidae: Trechini). Insect Conservation and Biodiversity. 10:495-501. doi:10.11/icad.12263.
  
Engel, A.S., Paterson, A.T., Niemiller, M.L. (2017) Biogeography of microbes from caves in the Interior Low Plateau and Appalachians karst regions. International Congress of Speleology, Australia. July, 2017. 

Engel, A.S., Niemiller, M.L., Zigler, K.S., Stephen, C.D.R., Carter, E.T., Paterson, A.T., Keenan, S.W., Taylor, S.J. (2017) Invertebrate and vertebrate cave fauna records for the Appalachian Valley and Ridge, in Moore K., White S. (eds). Proceedings of the 17th International Congress of Speleology, July, Sydney, Australia, Volume 1, Australian Speleological Federation Inc. Sydney, p. 82-86.

Keenan, S.W., Paterson, A.T., Niemiller, M.L., Slay, M.E., Clark, S.A., Engel, A.S. (2017) Observations of the first stygobiont snail (Hydrobiidae, Fontigens sp.) in Tennessee, in Moore K., White S. (eds). Proceedings of the 17th International Congress of Speleology, July, Sydney, Australia, Volume 1, Australian Speleological Federation Inc. Sydney. 

Niemiller, M.L., Zigler, K.S., Hart, P.B., Kuhajda, B.R., Armbruster, J.W., Ayala, B.N., Engel, A.S. (2016) First record of a stygobiotic fish (Percopsiformes: Amblyopsidae: Typhlichthys) from the Appalachians karst region in the eastern United States. Subterranean Biology. 20: 39-50. doi:10.3897/subtbiol.20.9693

Zigler, K.S., Kuhajda, B.R., Ayala, B.N., Niemiller, M.L., Engel, A.S. (2015) First observation of Southern Cavefish (Typhlichthys subterraneus) east of the Cumberland Plateau. Bulletin of the Georgia Speleological Society 2015: 9-11.

Keenan, S.W. Paterson, A.T., Niemiller, M.L., Slay, M., Engel, A.S. (2016) The first observations of a stygobiont snail (Hydrobiddae, Fontigens sp.) in Tennessee. National Speleological Society meeting, Ely, Nevada, July, 2016.

Engel, A.S. (2016) Prevalence of microbial taxonomic groups to specific subterranean habitats may shed light on ubiquity of microbial function in cave ecosystems. International Conference for Subterranean Biology, Fayetteville, Arkansas. June 12-17, 2016. p. 20. http://www.speleobiology.com/icsb2016/wp-content/uploads/bsk-pdf-manager/ICSB_2016_Abstracts_2.pdf 

Niemiller, M.L., Zigler, K.S., Stephen, C.D.R., Carter, E.T., Paterson, A.T., Taylor, S.J., Engel, A.S. (2016) Vertebrate fauna in caves of the east Tennessee Valley and Ridge region (USA). Journal of Cave and Karst Studies. 78:1-24. DOI:10.4311/2015LSC0109.
 
Niemiller, M.L., Zigler, K.S., Stephen, C.D.R., Carter, E.T., Paterson, A.T., Taylor, S.J., Fenolio, D.B., Kendall, K.D., Engel, A.S. (2015) Updated invertebrate and vertebrate cave fauna records for eastern Tennessee Appalachian Valley and Ridge. National Speleological Society convention, Waynesville, Missouri, July 13-17, 2015. (talk)
      
Kendall, K.D., Niemiller, M.L., Engel, A.S., Zigler, K.S., Fenolio, D.B. (2015) Cave biodiversity and conservation teaching and learning module for K-5 students in the Tennessee-Alabama-Georgia region. National Speleological Society convention, Waynesville, Missouri, July 13-17, 2015. (poster)
  

Field Photographs

Representative troglobionts observed in the Valley and Ridge caves during bioinventories in Year 1 of the project: A) a cave ant beetle (Batriasymmodes spelaeus) from Grainger Co., TN; B) a terrestrial cave isopod (Amerigoniscus nicholasi) from Roane Co., TN; C) a cave milliped (Scoterpes copei) from Meigs Co., TN; D) an undescribed aquatic cave snail (Antrorbis n. sp.) from Roane Co., TN; E) Tennessee Cave Beetle (Pseudanophthalmus tennesseensis) from Knox Co., TN; F) Appalachian Valley Cave Amphipod (Crangonyx antennatus) from Meigs Co., TN. All photographs by Dr. Matthew L. Niemiller. 
Geochemistry. Geomicrobiology. Geology. Ecology.

Interdisciplinary Research at the University of Tennessee