John C. Holz
Hello, my name is John C. Holz, and I’m a research assistant professor in the School of Natural Resources.
My academic areas of emphasis include fisheries and wildlife and, more predominately, aquatic ecology and hydrologic science.
Large inputs of nutrients such as nitrogen and phosphorus to lakes and reservoirs are well known to cause a variety of water quality problems such as excessive vegetation growth, noxious odors, poor water transparency, oxygen depletion and fish kills. Substantial progress has been made in improving the quality of U.S. surface waters. Nevertheless, much work remains to be done.
The U.S. Environmental Protection Agency is charged with establishing national standards and criteria for assessing lake water quality. It is, however, increasingly evident that a single set of national water quality standards that do not take into account regional hydrogeologic and ecological differences will not be viable, since lakes clearly have different capacities to meet these standards.
My research focuses on how to create a more accurate evaluation mechanism for lakes.
My team is examining the interaction between agriculture and surface water to develop a model lake and watershed classification system suited to agricultural areas. They've sampled more than 300 Nebraska lakes and reservoirs and are developing methods to compare current and historical water quality to develop tools to more accurately determine realistic water quality goals. Finding ways to remotely monitor water quality instead of sampling at each lake is also a major goal.
Developing research-based tools to classify and monitor lakes and reservoirs in agricultural areas should help natural resources and environmental agencies protect water quality and determine which are the best candidates for restoration. Remote sensing of water quality should make monitoring easier and less expensive.
I also have active areas of research in phytoplankton ecology and lake restoration ecology. Here, we seek to understand the basic ecological factors that structure algal communities (for example, nutrients and herbivory) and investigate the effectiveness of new lake management tools such as phosphorus inactivation, aeration, and macrophyte bottom barriers.
I received my bachelor’s, master’s and doctoral degrees from UNL in 1991, 1994 and 1998, respectively. I have been at UNL working on these types of issues since 1999.
Personnel Information
| Name | John C. Holz |
| University Title | Assistant Professor |
| Address | 507 Hardin Hall, Lincoln NE 68583-0995 |
| Phone | 402-472-6648 |
| Fax | 402-472-2946 |
| jholz1@unl.edu | |
| Related Websites | n/a |
Go to John's Full Profile
Key Publications
General-audience publications:
- Barrow, T.M. and J.C. Holz. 2004. Controlling pond plant growth with bottom barriers. NebGuide. University of Nebraska Cooperative Extension G03-1529-A.
- Holz, J.C. 2000. Controlling pond algae with barley straw. NebFact. University of Nebraska Cooperative Extension NF00-429.
Professional journal articles:
- Holz, J.C. and K.D. Hoagland. 1999. Effects of phosphorus reduction on water quality: comparison of alum-treated and untreated portions of a hypereutrophic lake. Journal of Lake and Reservoir Management 15, 70-82.
- Holz, J.C., K.D. Hoagland, R.L. Spawn, A. Popp, and J.L. Anderson. 1997. Phytoplankton community response to reservoir aging. Hydrobiologia 346, 183-192.
- Holz, J.C. and K.D. Hoagland. 1996. Experimental microcosm study of the effects of phosphorus reduction on plankton community structure. Canadian Journal of Fisheries and Aquatic Sciences 53, 1754-1764.
