About Dan

Prof. Dan HornbachDan Hornbach

John S. Holl Professor of Environmental Studies

Teaching Interests:  My interests include areas of both Biology and Environmental Science. I the past I have taught Ecology, Invertebrate Biology, Physiological Ecology and Introductory Biology. More recently my courses have included Aquatic Ecology, Environmental Science and Lakes, Streams and Rivers.

Research Interests:  I was broadly trained in the area of organismal biology and ecology. My recent research has been dealing with the biology and ecology of freshwater mussels in river systems. In general, I am interested in exploring the factors that influence the distribution and abundance of these animals. In our current world, this includes examining human impacts on the rivers that may influence the mussels that reside there. As part of my research, I become involved in the conservation of endangered species of mussels. As a group, mussels are one of the most endangered groups in North America.

More recently, I’ve been engaged in studies that examine ecosystem metabolism and temperature variation in ponds. Small standing water bodies, including ponds, constitute a larger percentage of the freshwater systems on the earth. They can have a significant role in carbon cycling which depends on the temperature stratification in the ponds and the balance of photosynthesis and respiration.

Selected Recent Publications:

Hopper, G., E. Miller, W. Haag, C. Vaughn, D. Hornbach, J. Jones, and C. Atkinson. 2024. A test of the loose-equilibrium concept with long-lived organisms: evaluating temporal change in freshwater mussel communities. Journal of Animal Ecology 93: 281-293. https://doi.org10.1111/1365-2656.14046.

Bakshi, B. R.W. Bouchard, Jr., R. Dietz, D. Hornbach, P. Monson, B. Sietman and D. Wasley. 2023. Freshwater mussels, ecosystem services, and clean water regulation in Minnesota: formulating an effective conservation strategy. Water 15: 2560. doi.org/10.3390/w15142560.

Hornbach, D.J., J.L. Kozarek, N. Blinick, M.C. Hove, P. Grams, M. Kaplinski, K.R. MacGregor, C. Milliren and A.T. Riesgraf. 2023. Distribution pattern of the Zebra Mussel (Dreissena polymorpha) in White Bear Lake, Minnesota: a spatial scale analysis. Journal of Freshwater Ecology 38: 2202700. doi.org/ 10.1080/02705060.2023.2202700.

Holgerson, M.A., D.C. Richardson, J. Roith, L.E. Bortolotti, K. Finlay, D.J. Hornbach, K. Gurung, A. Ness, M.R. Andersen, S. Bansal, J.C. Finlay, J.A. Cianci-Gaskill, S. Hahn*, B.D. Janke, C. McDonald, J.P. Mesman, R.L. North, C.O. Roberts, J.N. Sweetman, and J.R. Webb. 2022. Classifying mixing regimes in ponds and shallow lakes. Water Resources Research 58: e2022WR032522. doi.org/10.1029/2022WR032522.

Moore, A.P., N. Galic, R.A. Brain, D.J. Hornbach, and V.E. Forbes. 2021. Towards representing listed mussel species in ecological risk assessment: a database and multivariate analysis of freshwater mussel life-history traits. Aquatic Conservation: Marine and Freshwater Ecosystems 31: 3386-3402. doi.org/10.1002/aqc.3713.

Hornbach, D.J., K.L. Shea, J.J. Dosch, C.L. Thomas, T.B. Gartner, A. Aguilera, L.J. Anderson, K. Geedey, C. Mankiewicz, B.R. Pohlad and R.E. Schultz 2021. Decomposition of leaf litter from native and non-native woody plants in terrestrial and aquatic systems in the eastern and upper midwestern US. American Midland Naturalist 186: 51-75.

HornbachD.J., H.N. Stutzman*H.N., M.C. HoveJ. L. Kozarek, K. R. MacGregor, T. J. Newton and P.R. Ries. 2021. Influence of surrounding land-use on mussel growth and glycogen levels in the St. Croix and Minnesota River Basins. Hydrobiologia 848: 3045-3063. doi/10.1007/s10750-019-04016-z

Hornbach, D.J. 2021. Multi-year monitoring of ecosystem metabolism in two branches of a cold-water stream. Environments 8: 19. DOI: 10.3390/environments8030019

Hornbach, D.J., E.G. Schilling and H. Kundel*. 2020. Ecosystem metabolism in small ponds: the effects of floating-leaved macrophytes. Water 12: 1458. doi.org/10.3390/w12051458

Hornbach, D.J., H.N. Stutzman*, H.N., M.C. Hove, J. L. Kozarek, K. R. MacGregor, T. J. Newton and P.R. Ries. 2019. Influence of surrounding land-use on mussel growth and glycogen levels in the St. Croix and Minnesota River Basins. Hydrobiologia. doi.org/10.1007/s10750-019-04016-z

Hornbach, D.J., M.C. Hove, K.R. MacGregor, J.L. Kozarek, B.E. Sietman, and M. Davis. 2019. A comparison of freshwater mussel assemblages along a land use gradient in MinnesotaAquatic Conservation: Marine and Freshwater Ecosystems 29:1826–1838. doi.org/10.1002/aqc.3167

Santosh, K., J. Kozarek, D. Hornbach, M. Hondzo and J. Hong. 2019. Experimental investigation of turbulent flow over live mussels. Environmental Fluid Mechanics. doi.org/10.1007/s10652-019-09664-2

Hornbach, D.J., D.C. Allen, M.C. Hove and K.R. MacGregor. 2018. Long-term decline of native freshwater mussel assemblages in a federally protected river. Freshwater Biology 63: 243-263 (DOI: 10.1111/fwb.13055)

Hornbach, D.J., M.C. Hove, M.W. Ensley-Field*, M.R. Glasenapp*, I.A. Goodbar*, J.D. Harman*, B.D. Huber*, E.A. Kangas*, K.X. Liu*, M. Stark-Ragsdale* and L.K. Tran*. 2017. Comparison of ecosystem processes in a woodland and prairie pond with different hydroperiods. Journal of Freshwater Ecology, 32:1, 675-695, DOI: 10.1080/02705060.2017.1393468.

Hornbach, D., M Hove, M. Agata*, E. Arnold*, E. Cavazos*, C. Friedman*, K. Jay*, E. Johnson*, K. Johnson*, and A. Staudenmaier. 2016. Ecosystem Structure and Function in two branches of an eastern Minnesota trout stream. Journal of Freshwater Ecology 31: 487-507.

Hove, M., B. Sietman, M. Berg, E. Frost, K. Wolf, T. Brady, S. Boyer and D. Hornbach. 2016. Early life history of the sheepnose (Plethobasus cyphyus) (Mollusca: Bivalvia: Unionoida). Journal of Natural History 50: 523-542.

Hansen, A.T., J. A. Czuba, J. Schwenk, A. Longjas, M. Danesh-Yazdi, D. J. Hornbach and E. Foufoula-Georgiou. 2016. Coupling freshwater mussel ecology and river dynamics using a simplified dynamic interaction model. Freshwater Science 35: 200–215.

Hornbach, D.J., R. Beckel*, E.N. Hustad*, D.P. McAdam*, I.M. Roen*, and A.J. Wareham*. 2015. The influence of riparian vegetation and season on stream metabolism of Valley Creek, Minnesota. Journal of Freshwater Ecology 30: 569-588.

Simmons, J.A., M. Anderson, W. Dress, C. Hannac, D.J. Hornbach, A. Janmaat, F. Kuserk, J. G. March, T. Murray, J. Niedzwiecki, D. Panvini, B. Pohlad, C. Thomas, and L. Vasseurk. 2014. A comparison of the stream temperature regime under forested and non-forested riparian 4 zones at eleven sites across North America. River Research and Applications 31: 964-974. DOI: 10.1002/rra.2796.

Hornbach, D.J. M.C. Hove, H. Liu*, F.R. Schenck*, D. Rubin* and B.J. Sansom*. 2014. The influence of two differently sized dams on mussel assemblages and growth. Hydrobiologia : 724: 279-291.

Sansom. B.J.*, D.J. Hornbach, M.C. Hove, and J.S. Kilgore. 2013. Effects of flow restoration on mussel growth in a Wild and Scenic River North American River. Aquatic Biosystems 9: 6 (11 pages).

Hove, M.C., M. T. Steingraeber, T. J. Newton, D. J. Heath, C. L. Nelson, J. A. Bury, J. E. Kurth, M. R. Bartsch, W. S. Thorpe, M. R. McGill, and D. J. Hornbach. 2012. Early life history of the winged mapleleaf mussel (Quadrula fragosa). American Malacological Bulletin 30: 47–57.

Szumowski*, S.C., S.L. Boyer, D.J. Hornbach and M.C. Hove. 2012. Genetic diversity of two common freshwater mussel species, Lampsilis cardium and Quadrula pustulosa (Bivalvia, Unionidae), in a large federally protected waterway (St. Croix River, Minnesota/Wisconsin, U.S.A.). American Malacological Bulletin 30: 1-14.

Panahbehagh, B., D.R. Smith, M. Salehi, D.J. Hornbach, and J.A. Brown. 2011. Multi-species attributes as the condition for adaptive sampling of rare species using two-stage sequential sampling with an auxiliary variable, pp. 2093-2099 In Chan, F., D. Marinova, and R.S. Anderssen (eds.) MODSIM2011, 19th International Congress on Modelling and Simulation. Modelling and Simulation Society of Australia and New Zealand, December 2011. (ISBN: 978-0-9872143-1-7)

Bowne, D.R., A.L. Downing, M.F. Hoopes, K. LoGiudice, C.L. Thomas, L.J. Anderson, T. Gartner, D.J. Hornbach, K.Kuers, J. Machado, B.R. Pohlad and K. L. Shea. 2011. Transforming ecological science at primarily undergraduate institutions through collaborative networks. BioScience 61:386-392.

Hove, M.C., B.E. Sietman, J.E. Bakelaar, J.A. Bury, D.J. Heath, V.E. Pepi, J.E. Kurth, J.M. Davis, D.J. Hornbach and A. R. Kapuscinski. 2011. Early Life History and Distribution of Pistolgrip (Tritogonia verrucosa (Rafinesque, 1820)) in Minnesota and Wisconsin. American Midland Naturalist 165:338-354.

Hornbach, D.J. V.J. Kurth*, and M.C. Hove. 2010. Variation in freshwater mussel shell sculpture and shape along a river gradient. American Midland Naturalist 164:22-36.

Hornbach, D.J., M.C. Hove, B. Dickinson*, K. MacGregor and J.R. Medland. 2010. Estimating population size and habitat associations of two federally endangered mussels in the St. Croix River, Minnesota and Wisconsin, USA. Aquatic Conservation: Marine and Freshwater Ecosystems 20: 250-260.

Baker, S.M. and D.J. Hornbach. 2008. Zebra mussels (Dreissena polymorpha) attached to native mussels (Unionidae) or inanimate substrates: Comparison of physiological rates and biochemical composition. American Midland Naturalist 160:20-28.

* indicates student co-authors

My CV is available as a PDF document here.