Publications

Here is a list of recent and/or significant publications.  A more complete list can be seen in my CV.  Electronic versions (.pdf files) are available for most of these publications (* graduate student authors, ** post-doc authors).

Book Chapters:

Morris, D. P. 2009. Optical Properties of Water. In: Encyclopedia of Inland Waters. G.E. Likens, Editor. Oxford: Elsevier. (By agreement with the publisher I can not post the final version of the chapter to my web page. I have attached a link to an intermediate version. I am able to send the final version of the pdf file to anyone who requests it.) [.pdf]

*Osburn C.L. and D.P. Morris.  2003. Photochemistry of dissolved organic matter in natural waters, In: UV Effects in Aquatic Organisms and Ecosystems, E.W. Hebling and H.E. Zagarese [eds.]. European Society of Photobiology.  pp. 185-217. 

Articles in Refereed Journals:

Morris, D. P., D. Soto Benavides, A. Patricia Pérez, Marcela A. Ferraro, Diego A. Añón Suárez, Bruce R. Hargreaves,  Jorge Jaramillo, Patricio R. De los Ríos Escalante, Horacio E. Zagarese. Variability in the Rate of CDOM Photobleaching and its Control in Lakes. Biogeochemistry, (submitted).
 
*Belmont, P., Morris D.P., Pazzaglia F.J., and Peters S.C. 2009. Penetration of ultraviolet radiation in streams of eastern Pennsylvania: Topographic controls and the role of suspended particulates. Aquatic Sciences.[.pdf]

Stephen C. Peters, Jennifer L. Wollenberg*, D. P. Morris, and Jason Porter. 2007. Mercury Emission to the Atmosphere from Experimental Manipulation of DOC and UVR in Mesoscale Field Chambers in a Freshwater Lake.  Environmental Science and Technology 41:7356-7362.[.pdf]
 
G. L. Pérez, A. Torremorell, H. Mugni, P. Rodríguez, M. Solange Vera, M. do Nascimento, L. Allende, J. Bustingorry, R. Escaray, M. Ferraro, I. Izaguirre, H. Pizarro, C. Bonetto, D. P. Morris and H. Zagarese. 2007. Effects of the herbicide Roundup® on Freshwater Microbial Communities: A mesocosm Study. Ecological Applications, 17(8), 2310-2322. [.pdf]
 
* Belmont, P., B.R. Hargreaves, D. P. Morris, and C.E. Williamson. 2007. Estimating attenuation of ultraviolet radiation in streams: Field and laboratory methods. Photochemistry and Photobiology 83: 1-9. [.pdf]
 
*Galster, J. C., Pazzaglia, F. J., Hargreaves, B. R., Morris, D. P., Peters, S. C., and Weisman, R. N., 2006, Land use effects on watershed hydrology: The scaling of discharge with drainage area. Geology, v. 34, p. 713-716. [.pdf]
 
*Cooke, S.L., C.E. Williamson, B.R. Hargreaves, B.R., and D.P. Morris. 2006. Beneficial and detrimental interactive effects of dissolved organic matter and ultraviolet radiation on zooplankton in a transparent lake. Hydrobiologia 568: 15-28. [.pdf]

*Maloney, K.O., D.P. Morris, C.O. Moses, and C.L. Osburn. 2005. The role of iron and dissolved organic carbon in the absorption of ultraviolet radiation in humic lake water Biogeochemistry, 75:393-407. [.pdf]

**De Lange, H., D. P. Morris, and C.E. Williamson. 2003. Solar ultraviolet photodegradation of DOC may stimulate freshwater food webs. J. Plankton Research. 25(1): 111-117.[.pdf]
 
*Osburn C.L., D. P. Morris, K.A. Thorn, and R.E. Moeller. 2001.  Chemical and optical changes in freshwater dissolved organic matter exposed to solar radiation. Biogeochemistry. 54(3): 251-278. [.pdf]
 
*Osburn C.L., H.E. Zagarese, D.P. Morris, B.R. Hargreaves, and W. Cravero.  2001. Calculation of spectral weighting functions for the solar photobleaching of chromophoric dissolved organic matter in temperate lakes.  Limnology & Oceanography. 46(6): 1455-1467. [.pdf]
 
Williamson, C.E., D. P. Morris, and M.L. Pace. 1999. Dissolved organic carbon and nutrients as regulators of  lake ecosystems: Resurrection of a more integrated paradigm. Limnology & Oceanography. 44: 795-803.[.pdf]
 
Frost, T.M,  P.K. Montz, T.K. Kratz, T. Badillo, P.L. Brezonik, M.J. Gonzalez, R.G. Rada, C.J. Watras, K.E. Webster, J.G. Winer, C.E. Williamson, and D. P. Morris. 1999. Multiple stresses from a single agent: Diverse responses to the experimental acidification of  Little Rock Lake,  Wisconsin. Limnology & Oceanography. 44: 784-794. [.pdf]
 
Morris, D.P. and B.R. Hargreaves. 1997. The role of photochemical degradation of dissolved organic carbon in regulating the UV transparency of three lakes on the Pocono Plateau. Limnology & Oceanography. 42: 239-249. [.pdf]
 
*Ayoub, L.M., B.R. Hargreaves, and D.P. Morris. 1996. UVR attenuation in lakes: Relative contribution of dissolved and particulate material. SPIE Ocean Optics XII.
 
Williamson, C.E., R.S. Stemberger, D.P. Morris, T.M. Frost, and S. Paulsen. 1996. Attenuation of ultraviolet radiation in northeastern USA lakes. Limnology & Oceanography. 41:1024-1034. [.pdf]
 
Morris, D.P., H. Zagarese, C.E. Williamson, E.G. Balseiro, B. Hargreaves, B. Modenutti, R. Moeller, C. Cueimalinos. 1995. The attenuation of solar UV radiation in lakes and the role of dissolved organic carbon.  Limnology & Oceanography. 40: 1381-1391. [.pdf]
 
Kirk, J.T.O., B. Hargreaves, D.P. Morris, R. Coffin, B. David, D. Fredickson, D. Karentz, M. Lesser, S. Madronitch, J.H. Morrow, N. Nelson, N. Sculley.  1994. Measurement of UV-b radiation in freshwater ecosystems. Archiv. Hydrobiol. 43: 71-99.
 
Karentz, D. M.L. Bothwell, R.B. Coffin, A. Hanson, G.J. Herndl, S.S. Kilham, M.P. Lesser, M. Lindell, R.E. Moeller, D.P. Morris, P.J. Neal, R.W. Saunders, C.S. Weiler, R.G. Wetzel. 1994. Impact of UVB radiation on pelagic freshwater ecosystems: Report of the working group on bacteria and phytoplankton. Archiv. Hydrobiol. 43:31-69.
 
Morris, D. P. and W.M. Lewis, Jr. 1992. Nutrient limitation of bacterioplankton growth in Lake Dillon, Colorado. Limnology & Oceanography. 37:1179-1192. [.pdf]

Conference Proceedings:

Morris, D. P. and P. Belmont. Penetration of UV radiation in streams of eastern Pennsylvania, USA: Trophic controls and the role of suspended sediments. American Society of Limnology and Oceanography, Orlando, FL, June 2008.

Morris, D .P., W. Jeffrey, W. W. Sanders, J. M. Fischer, C. E. Williamson, and J. A. Porter. Effects of CDOM Additions and Photobleaching on Freshwater Microbial Communities: Results from Large-Scale Mesocosms. Chapman Conference: Lakes and Reservoirs as Sentinels, Integrators, and Regulators of Climate Change. Lake Tahoe, September 2008.

Cooke, S. L., J. M. Fischer, C. E. Williamson, and D. P. Morris. Effects of Increased Dissolved Organic Matter on Zooplankton Vertical Distribution in a UV-Transparent Lake: Results from Large-Scale Mesocosms. Chapman Conference: Lakes and Reservoirs as Sentinels, Integrators, and Regulators of Climate Change. Lake Tahoe, September 2008.

Fischer, J.M., K. Kessler, R.W. Sanders, C.E. Williamson, W.H. Jeffrey, R.E. Moeller, D.P. Morris, J.A. Porter, P.A. Neale, J.E. Saros, S.L. Cooke, A.L. Macaluso, E.P. Overholt, J.D. Pakulski, D. Schoener, and C. Scott. Effects of CDOM addition on crustacean zooplankton in an oligotrophic lake: carbon and nutrient subsidy or UV screen?  American Society of Limnology and Oceanography, Orlando, FL, June 2008.

*Mason, C. and D. P. Morris. The assessment of dissolved organic matter biolability in lotic systems. American Society of Limnology and Oceanography, Orlando, FL, June 2008.

**Porter, J.A., R.E. Moeller, A. Heinze, and D.P. Morris. 2008. Reactivity of Terrestrially Derived Dissolved Organic Matter in the Aquatic Ecosystem:  Investigating Issues of Source, Biolability, Photolability, and Nutrient Composition. AGU Chapman Conference on Lakes and Reservoirs as Sentinels, Integrators, and Regulators of Climate Change, Lake Tahoe, CA.

Sanders, W. W., J. M. Fischer, A. W. Heinze, W. Jeffrey, A. L. Macaluso,  R. E. Moeller, D. P. Morris, J. A. Porter,  C. E. Williamson. Dissolved Organic Carbon (DOC) Forcing of Plankton Dynamics in a Lake Ecosystem. Chapman Conference: Lakes and Reservoirs as Sentinels, Integrators, and Regulators of Climate Change. Lake Tahoe, September 2008.

**Porter, J.A., R.E. Moeller, A. Heinze, and D.P. Morris. 2008. Exposure of Terrestrial Dissolved Organic Matter to Ultraviolet Radiation Increases the Metabolic Potential of Freshwater Bacterial Communities. 108th General Meeting of the American Society for Microbiology.

* Belmont , P., Pazzaglia, F.J., and Morris, D.P. 2007.  Strong geomorphic controls on stream optical environments in eastern Pennsylvania GSA National Meeting. Denver ,  CO .

Morris, D.P. 2007. Variability in the rate of CDOM photobleaching and its control in the Lehigh River, Pennsylvania , USA . ASLO Aquatic Sciences Meeting, Santa Fe , NM.

**Porter, J.A., R.E. Moeller, and D.P. Morris. 2007. Response of microbial communities to dissolved organic matter of a terrestrial nature: Implications of ultraviolet radiation exposure. ASLO Aquatic Sciences Meeting, Santa Fe , NM .

Sanders, R.W., W.H. Jeffrey, R.E. Moeller, D.P. Morris, and J.A. Porter**. 2007. Microbial communities across a gradient of dissolved organic carbon (DOC): Results from mesocosm experiments. ASLO Aquatic Sciences Meeting, Santa Fe , NM .

*Belmont, P., B.R. Hargreaves, and D.P. Morris, 2006.  Empirical model for estimating attenuation of ultraviolet radiation in streams. NABS Annual meeting, Anchorage , Alaska . 

Kendig , C.A. , J.A. Porter**, D.P. Morris, B.R. Hargreaves, and S. C. Peters. 2006. Laboratory manipulation of lake water chemistry to examine changes in the spectral properties of chromophoric dissolved organic matter. ASLO Aquatic Sciences Meeting, Victoria , B.C. (Kendig was an undergraduate student whom I advised on a senior honors thesis.. Her work was honored as ASLO’s top ungergraduate poster at this meeting).

Moeller, R.E., B.R. Hargreaves, D.P. Morris, and C.E. Williamson. 2006 Correlations of rainfall, DOC, and water chemistry to decreasing trends of UV transparency in two slightly acidic lakes of Pennsylvania . ASLO Aquatic Sciences Meeting, Victoria , B.C.

Morris, D.P., Zagarese, H.E. and Hargreaves, B.R. 2006 Variability in the rate of CDOM photobleaching and its control. ASLO Aquatic Sciences Meeting, Victoria , B.C.

**Porter, J.A., Morris, D.P. 2006. The role of ultraviolet radiation in the assimilation and fate of allochthonous dissolved organic carbon. ASLO Aquatic Sciences Meeting, Victoria, B.C.

Ferraro, M., D.P. Morris, H. Zagarese, B.R. Hargraves, D. Soto, J. Jaramillo, P. Perez, Patricia1, and A. Suarez Diego. 2005. Variability of the rate of CDOM photobleaching and its control in lakes. Chilean Limnological Congress, Puerto Montt, Chille.

Hargreaves, B.R., D.P. Morris, F.J. Pazzaglia, R. N.Weisman, C. E. Williamson, S.C. Peters. 2005. Assessing the effects of land use, climate, and UV radiation on river ecosystems in northeastern USA , EPA STAR Project Review ( Washington DC ).

Morris, D.P. 2005. Control and consequences of CDOM photobleaching across a variety of aquatic ecosystems. Congresso Argentino de Limnologia, Camahue , Argentina . [Invited keynote talk].

**Porter, J.A. and D.P. Morris. 2005. The effect of photobleaching chromophoric dissolved organic matter on aquatic microbial communities: a mesocosm study. Annual Meeting of ASLO, Salt Lake City .

*Belmont, P. and D.P. Morris. 2004. Attenuation of ultraviolet radiation in several small Pennsylvania streams. North American Benthological Society. Vancouver , Canada.

*Cooke, S.L., C.E. Williamson, D.P. Morris, and B.R. Hargreaves. 2004. Allochthonous dissolved organic matter and UV radiation alter zooplankton community structure in a transparent lake. Ecological Society of America , Portland , OR .

Hargreaves, B.R., C.W. Forstall*, L.M. Nichols, D.P. Morris, F.J. Pazzaglia, C.E. Williamson, and R.N. Weisman. 2004. “ Lake model for ultraviolet attenuation adapted to streams.” International Society of Limnology (SIL), Finland , August 2004.

Morris, D.P., B. Hargreaves, F. Pazzaglia, R. Weisman, C. Williamson, 2004. Assessing the interactive effects of landscape, climate, and UV radiation on river ecosystems: Modeling transparency to UV radiation and the response of biota. EPA STAR Symposium, Washington DC .

Morris, D.P. and D.B. Frisbie*. Photobleaching potential of CDOM in the Lehigh River, Pennsylvania . 2004. North American Benthological Society. Vancouver, Canada .

*Belmont, P. and Morris, D.P. 2003. Initial inspection of spatial and temporal variables influencing the attenuation of ultraviolet radiation in streams. NEEC, Rutgers University , NJ.

Moeller, R.E., B.R. Hargreaves, D.P. Morris, C.E.Williamson, 2003. Seasonal, year-to-year and long term controls of UV attenuation in two mid-latitude lakes of contrasting wetland drainage and dissolved organic carbon content. ASLO Aquatic Sciences Meeting, Salt Lake City.

*Osburn, C.L., Pohlman, J.P., Boyd, T.J, Morris, D.P., and Coffin, R.B. (2002) Molecular and optical changes in dissolved organic matter from exposure to ultraviolet radiation.ASLO Aquatic Sciences Meeting, Albuquerque , NM. 

*Osburn, C. L., Morris, D. P., Hargreaves, B. R., Coffin, R. B., and Boyd, T. J. (2002) Photochemical reactivity of chromophoric dissolved organic matter in lakes and the coastalAtlantic Ocean .Annual Meeting of the American Society of Photobiology, Quebec City , Quebec (INVITED).

Hargreaves, B.R., Osburn*, C.L., Morris, D.P., and Moeller, R.E. (2001) Spectral slope response to solar and biotic processes: predictions of a photobleaching model and estimates from CDOM absorption and UV attenuation measurements. ASLO Aquatic Sciences Meeting.

*Osburn, C.L., Morris, D.P., Hargreaves, B.R., and Zagarese, H.E. (2001) Modeling the contribution of UV radiation to the photobleaching of CDOM in temperate lakes from North andSouth America .ASLO Aquatic Sciences Meeting.

**DeLange, H.J., D.P. Morris, and C.E. WiIliamson.  2000. The interaction between ultraviolet radiation, DOC, and zooplankton in freshwater. American Society for Limnology and Oceanography, Copenhagen , DK.

Hargreaves, B.R., D.P. Morris, R.E. Moeller, C.E.Williamson. 2000. Seasonal variation of utraviolet transparency in lakes. International meeting of ASLO, Copenhagen.

Hargreaves, B. R., C. Sopka*, and D. P. Morris. 2000. Water column experiments with CDOM: Seasonal changes in photochemical reactivity and daily photobleaching rates.EOS, ASLO/AGU Ocean Sciences Meeting, San Antonio.

Morris, D.P. 2000. The influence of photobleaching and microbial processing of DOM on UV optical properties of 2 lakes in northeastern Pennsylvania. I nternational Chemical Congress of Pacific Basin Societies, Honolulu.

*Osburn, C.L., Morris, D.P., and Bebout, G.E. 2000.  Seasonal production and photooxidation of CDOM in temperate lakes: evidence from stable isotopes. AGU/ASLO Ocean Sciences, OS21K-10.

*Osburn, C.L., D.P. Morris, and B.R. Hargreaves.  2000. Spectral dependence ofphotobleaching of CDOM in lake ecosystems. International Chemical Congress of Pacific BasinSocieties, Honolulu.

*Kresge, K.G. and D.P. Morris. 1999. Bacteria, UVR, and DOC: A complex interaction in freshwater lakes. Annual Meeting of the American Society for Limnology and Oceanography,Santa Fe , NM.

Morris, D.P. 1999. A bioreactor design for the determination of microbially labile dissolved organic carbon. Proceedings of the International Society of Environmental Toxicology and Chemistry . Philadelphia.

*Osburn, C.L., D.P. Morris, and B.R.  Hargreaves. 1999. Modeling the spectral dependence of photooxidation of dissolved organic matter using absorbance and fluorescence. Annual Meeting of the American Society for Limnology and Oceanography, Santa Fe , NM.

Morris, D.P. and B.R. Hargreaves. The role of solar photochemical degradation of DOC in regulating the UV transparency and spectral characteristics of the surface waters of lakes. Proceedings of the International Society of Environmental Toxicology and Chemistry.  Charlotte , NC .  November 1998.

Morris, D.P. The role of solar UV radiation in the production and utilization of labile dissolved organic carbon".  Proceedings of the 8th International Symposium on Microbial Ecology.Halifax , Nova Scotia , August 1998.

Morris, D.P. and B.R. Hargreaves. "The role of photochemical degradation of dissolved organic carbon in regulating UV transparency of lakes.  Gordon Research Conference, 1996. Environmental Sciences: Water.

Morris, D.P. and C. Stackpole.  Photolytic changes in the lability and optical properties of DOC following exposure to solar UV radiation. 1996 Annual Meeting of the American Society for Limnology and Oceanography, Madison , WI .