Dept. of Biological Sciences
Schrenk Hall, Room 110-E
Missouri University of Science & Technology
Rolla, MO 65409-1120
· Postdoc, Dept. of Zoology, University of Otago, Dunedin, New Zealand (2000-02)
· Ph.D., Environmental Biology, University of Colorado (1999)
· B.A., Biology, Swarthmore College (1989)
S&T students at the Bray Conservation Area outside Rolla.
My research centers on the effects of stress on ecosystem processes, including primary production and litter decomposition, in streams. Both natural and anthropogenic stresses affect almost all aquatic ecosystems. A "stress," such as mine drainage or agriculture, can pose several distinct stressors (having a negative influence), or in some cases subsidies (having a positive influence), to streams. I am most interested in how the effects of stress on ecosystem processes are mediated by the biological communities that perform those processes. The biomass, diversity, and specific taxa of communities can all affect the rates of ecosystem processes in stressed systems.
Stress > Stressors/subsidies > Biota > Ecosystem process
My dissertation research at the University of Colorado examined the effects of mine drainage on ecosystem processes in streams, including primary production, decomposition, and nutrient cycling. Acid mine drainage poses several stresses to downstream ecosystems, including low pH, elevated concentrations of toxic metals, and deposition of metal oxides. These individual stresses have different effects on stream biota and the ecosystem processes that the biota control. For example, invertebrate consumers of leaf litter (called “shredders”) were affected mostly by dissolved metals, such as zinc, whereas microbes involved in litter breakdown were more affected by metal oxide deposition. Shredder activity was the key determinant of litter breakdown in my streams, as has been found in other streams.
My postdoctoral research focused on the effects of agricultural land use on streams in New Zealand. This topic is challenging because agriculture provides both subsidies (e.g., light and nutrients) and stresses (e.g., sediments) to streams. Small increases in light and nutrients at low levels of catchment development may lead to increases in ecological responses, including biodiversity and process rates. Large increases may lead to eutrophication and the loss of sensitive taxa. Sediment would usually have only a negative effect on ecological responses. Consequently, the net effect of catchment development on stream health follows a complex, nonlinear pattern.
· Kitto, J.A.J, D.P. Gray, J.S. Harding, H.S. Greig, and D.K. Niyogi. 2015. Meta-community theory and stream restoration: evidence that spatial position constrains stream invertebrate communities in a mine impacted landscape. Restoration Ecology. DOI: 10.1111/rec.12179.
· Niyogi, D.K., J.S. Harding, and K.S. Simon. 2013. Organic matter breakdown as a measure of stream health in New Zealand streams affected by acid mine drainage. Ecological Indicators. 24:510-517.
· Greenwood, M.J., J.S. Harding, D.K. Niyogi, and A.R. McIntosh. 2012. Improving the effectiveness of riparian management for aquatic invertebrates in a degraded agricultural landscape: stream size and land-use legacies. Journal of Applied Ecology. 49:213-222.
· Greig, H.S., D.K. Niyogi, K.L. Hogsden, P.G. Jellyman, and J.S. Harding. 2010. Heavy metals: confounding factors in the response of New Zealand freshwater fish assemblages to natural and anthropogenic acidity. Science of the Total Environment. 48:3240-3250.
· Niyogi, D.K., J.M. Bandeff, C. Selman, and D.E. Menke. 2010. Nutrient flux, uptake, and transformation in a spring-fed stream in the Missouri Ozarks, USA. Aquatic Sciences. 72:203-212.
· Niyogi, D.K., C.A. Cheatham, W.H. Thomson, and J.M. Christiansen. 2009. Litter breakdown and fungal diversity in a stream affected by mine drainage. Fundamental and Applied Limnology. 175:39-48.
· Lear, G., Niyogi, D., J. Harding, Y. Dong, and G. Lewis. 2009. Biofilm bacterial community structure in streams affected by acid mine drainage. Applied and Environmental Microbiology. 75:3455-3460.
· Bray, J.P., P.A. Broady, D.K. Niyogi, and J.S. Harding. 2008. Periphyton communities in New Zealand streams impacted by acid mine drainage. Marine and Freshwater Research. 59:1084-1091.
· Niyogi, D., and J. Harding. 2007. Coal mine drainage: complex effects on streams. New Zealand Water and Wastes Association Journal. November 2007 issue, pp. 50-53.
· Niyogi, D.K., M. Koren, C.A. Arbuckle, and C.R. Townsend. 2007. Longitudinal changes in biota along four New Zealand streams: declines and improvements in stream health related to land use. New Zealand Journal of Marine and Freshwater Research. 41:63-75.
· Simon, K.S., D.K. Niyogi, R. Frew, and C.R. Townsend. 2007. Nitrogen dynamics in streams along a gradient of agricultural development. Limnology and Oceanography. 52:1246-1257.
· Niyogi, D.K., M. Koren, C.A. Arbuckle, and C.R. Townsend. 2007. Stream community structure along a catchment land-use gradient: subsidy-stress responses to pastoral development. Environmental Management. 39:213-225.
· Niyogi, D.K., K.S. Simon, and C.R. Townsend. 2004. Land use and stream ecosystem functioning: nutrient uptake in streams that contrast in agricultural development. Archiv fur Hydrobiolgie. 160:471-486.
· Niyogi, D.K., K.S. Simon, and C.R. Townsend. 2003. Breakdown of tussock grass in streams along a gradient of agricultural development. Freshwater Biology. 48:1698-1708.
· Niyogi, D.K., W.M. Lewis, Jr, and D.M. McKnight. 2003. Direct and indirect effects of mine drainage on bacterial processes in mountain streams. Journal of the North American Benthological Society. 22:276-291.
· Niyogi, D.K., D.M. McKnight, and W.M. Lewis, Jr. 2002. Fungal communities and biomass in mountain streams affected by mine drainage. Archiv für Hydrobiologie. 155:255-271.
· Niyogi, D.K., D.M. McKnight, and W.M. Lewis, Jr. 2002. Effects of mine drainage on breakdown of aspen litter in mountain streams. Water, Air and Soil Pollution: Focus. 2:329-341.
· Niyogi, D.K., W.M. Lewis, Jr, and D.M. McKnight. 2002. Effects of stress from mine drainage on diversity, biomass, and function of primary producers in mountain streams. Ecosystems. 5:554-567.
· Niyogi, D.K., W.M. Lewis, Jr, and D.M. McKnight. 2001. Litter breakdown in mountain streams affected by mine drainage: biotic mediation of abiotic controls. Ecological Applications. 11:506-516.
· McKnight, D.M., D.K. Niyogi, A.S. Alger, A. Bomblies, P.A. Conovitz, and C.M. Tate. 1999. Antarctic Dry Valley streams: Ecosystems waiting for water. BioScience. 49:985-995.
· Niyogi, D.K., D.M. McKnight, and W.M. Lewis, Jr. 1999. Influences of water and substrate quality for periphyton in a montane stream affected by acid mine drainage. Limnology and Oceanography. 44:804-809.
· Niyogi, D.K., C.M. Tate, D.M. McKnight, J.H. Duff, and A.S. Alger. 1997. Species composition and primary production of algal communities in dry valley streams in Antarctica: examination of the functional role of biodiversity. In: Ecosystem Processes in Antarctic Ice-Free Landscapes, eds. W.B. Lyons, C. Howard-Williams, and I. Hawes, pp. 171-179, Balkema Press, Amsterdam.
A native of East Tennessee, I grew up with a fondness for natural ecosystems. After studying biology in college, I worked for several years as a marine toxicologist at the Battelle Marine Sciences Laboratory in Sequim, Washington (on the scenic Olympic Peninsula). I continued my education by attending graduate school in Colorado, and then worked as a postdoc in New Zealand for 2 years prior to joining MST.
In addition to science, I enjoy most outdoor activities. I also have genetic and environmental propensities to play lots of soccer. See below for a friendly team photo of one of my recent teams. More recently, my wife and I have had a couple of kids, which adds a whole new level of craziness to our lives. See below for a picture of Sam and me practicing mutual grooming activities commonly seen in most primates or click here for a family photo from a while back.
We currently live in Kirkwood, Missouri, a suburb of St. Louis. Let me know if you are ever in the middle of North America and want to visit.