Research Program                                 

I am quasi-retired but maintain selected laboratory and field studies.  My research has focused on coastal ecosystems, particularly salt marshes, estuaries and coastal lagoons along the Atlantic and Gulf coasts of the USA and in the Mediterranean. In these various ecosystems I have studied nutrient cycling, especially the nitrogen and carbon cycles, and energy flow. While initial interests were in the microbial communities and processes, their importance and regulation; my research has often taken broader perspective. Thus I have studied primary production of macrophytes, food webs, and ecosystem state changes. My work has had laboratory, field and modeling components. Much of my efforts have been devoted to network analysis as a mathematical tool for the comparisons among and within ecosystems. I have been active in promoting large-scale studies. These efforts have been associated with the U.S. Long-term Ecological Research (LTER) and International LTER programs and the Coastal Module of the Global Terrestrial Observing System (GTOS), a program of the United Nations. I served as chair of the panel that developed the plan for the Coastal module of GTOS.

Courses Taught

BIOL 3220, 3221. Microbiology.

BIOL 3550, 4550. Network Biology

BIOL 5270. Marine Community Ecology

BIOL 6280, 6281. Systems Ecology

BIOL 6850, 6850. Global Issues in Coastal Ecology

Recent Publications (since 2006)

Keramitsoglou I., C. Kontoes, N. Sifakis, Chr. Haffner-Sifakis, E. Fitoka, R.R. Christian, A. Serebryakova, P. Tomas-Vives, and A. Kouvelis S., Dimiza. 2006 Towards a standardised methodology for inventorying and monitoring Mediterranean wetlands using Earth observation. Proceedings of Globwetland Symposium. 19-20 September 2006, Frascati, Rome, Italy. 

Christian, R. R., P. M. DiGiacomo, T. C. Malone, and L. Talaue-McManus. 2006. Opportunities and challenges of establishing coastal observing systems. Estuaries and Coasts 29: 871-875.

Borrett, S. R., S. J. Whipple, B. C. Patten, and R. R. Christian. 2006. Indirect effects and distributed control in ecosystems: Temporal variation of indirect effects in a seven-compartment model of nitrogen flow in the Neuse River Estuary, USA—Time series analysis. Ecological Modelling 194:178-188.

Dame, J. K., and R. R. Christian. 2006. Uncertainty and the use of network analysis for ecosystem-based fishery management. Fisheries 31: 331-341.

Paerl, H. W., L. M. Valdez, A. R. Joyner, B. L. Peierls, M. F. Piehler, S. R. Riggs, R. R. Christian, L. A. Eby, L. B. Crowder, J. S. Ramus, E. J. Clesceri, C. P. Buzzelli, and R. A. Luettich, Jr. 2006. Ecological response to hurricane events in the Pamlico Sound System, NC and implications for assessment and management in a regime of increased frequency. Estuaries and Coasts. 29(6A):1033-1045.

Rheinhardt, R. D., M. M. Brinson, R. R. Christian, K. H. Miller, and G. F. Meyer. 2007. A referenced-based framework for evaluating the ecological condition of stream networks in small watersheds. Wetlands: 27: 524-542.

Dame, J. K., and R. R. Christian. 2007. A statistical test of network analysis: can it detect differences in food web properties? Ecosystems 10: 906-923.

Christian, R. R., and S. Mazzilli. 2007.  Defining the coast and sentinel ecosystems for coastal observations of global change. Hydrobiologia 577: 55-70. (see Hydrobiologia 583:385 for erratum on order of authorship from original. It should read Mazzilli and Christian)

Dame. J. K. and R. R. Christian. 2008. Evaluation of ecological network analysis: validation of output. Ecological Modelling 210: 327-338.

Day, J. W., R. R. Christian, D. M. Boesch, A. Yáñez-Arancibia, J. T. Morris, R. R. Twilley, L. Naylor, L. Schaffner, and C. Stevenson 2008. Consequences of Climate Change on the Ecogeomorphology of Coastal Wetlands. Estuaries and Coasts 31: 477-491.

Peterson, C. H., R.T. Barber, K. L. Cottingham, H. K. Lotze, C. A. Simenstad, R. R. Christian. M. F. Peihler, J. Wilson. 2008. Chapter 7. National Estuaries. pp. 7-1 to 7-108. In CCSP, 2008: Preliminary review of adaptation options for climate-sensitive ecosystems and resources. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. [Julius, S.H., J.M. West (eds.), J.S. Baron, L.A. Joyce, P. Kareiva, B.D. Keller, M.A. Palmer, C.H. Peterson, and J.M. Scott (Authors)]. U.S. Environmental Protection Agency, Washington, DC, USA, 873 pp.

Christian, R. R. 2009.  The value of healthy estuaries.  (An ActionBioscience original article). http://www.actionbioscience.org/environment/christian.html.

Christian, R.R., M.M. Brinson, J.K. Dame, G. Johnson, C.H. Peterson, and D. Baird.  2009.  Ecological network analyses and their use for establishing reference domain in functional assessment of an estuary.  Ecological Modelling 220: 3113–3122

Christian, R.R., C.M. Voss, C. Bondavalli, P. Viaroli, M. Naldi, A.C. Tyler, I.C. Anderson, K.J. McGlathery, R.E. Ulanowicz, and V. Camacho-Ibar.  2010.  Ecosystem Health Indexed through Networks of Nitrogen Cycling.  Pp. 73-91.  In M.J. Kennish and H.W. Paerl (eds.), Coastal Lagoons: Critical Habitats of Environmental Change.  Taylor & Francis Group LLC. Boca Raton, FL.  

Paerl, H.W., R. R, Christian, J. D. Bales, B. L. Peierls, N. S. Hall, A. R. Joyner, and S. R. Riggs.  2010.  Assessing the response of the Pamlico Sound, North Carolina, USA to human and climatic disturbances: Management implications.  Pp. 17-42,  In, M. Kennish and H.Paerl, (Eds.).  Coastal Lagoons:  Critical Habitats of Environmental Change.  CRC Press, Boca Raton, FL

Brinson, M. M., and R. R. Christian.  2010  Assessing functions of wetlands and the need for reference.  Biologia Ambientale 24:1-12.

Racchetti, E., M. Bartoli, E. Soana, D. Longhi, R.R. Christian, M. Pinardi, and P. Viaroli. 2010.  Influence of hydrological connectivity of riverine wetlands on nitrogen removal via denitrification.  Biogeochemistry DOI 10.1007/s10533-010-9477-7

Johnson, J.C., R.R. Christian, J.W. Brunt, C.R. Hickman, and R.B. Waide.  2010.  Evolution of Collaboration within the US Long-term Ecological Research Network.  BioScience 60: 931-940.

Kirwan, M. L., R. R. Christian, L. K. Blum, M. M. Brinson.  2011.   On the relationship between sea level and Spartina alterniflora production.  Ecosystems (In press)

Laboratory Personnel

Brooke Costanza, MS Biology, not pictured