Research Interests

My primary research interests are evaluating the long term effects of atmospheric nitrogen (N) deposition on sensitive biotic communities, forest health (including pests and pathogens), soil chemistry and biology, nutrient cycling processes, and water quality. I am interested in multiple stress and multiple pollutant interactions as they impinge on forest sustainability, and water quality and quantity of chronic N deposition.

Education

• University of California, Ph.D. Plant Pathology 1986
• University of Arizona, B.Sc. Plant Pathology 1981

Featured Publications & Products

• Jones, M.E.; Fenn, M.E.; Paine, T.D. 2011. The effect of nitrogen additions on bracken fern and its insect herbivores at sites with high and low atmospheric pollution.
• Fenn, M.E.; Geiser, L.H. 2011. Temperate sierras, Chapter 15.
• Pardo, L.H.; Geiser, L.H.; Fenn, M.E.; Driscoll, C.T.; Goodale, C.L.; Allen, E.B.; Baron, J.S.; Bobbink, R.; Bowman, W.D.; Clark, C.M.; Emmett, B.; Gilliam, F.S.; Greaver, T.; Hall, S.J.; Lilleskov, E.A.; Liu, L.; Lynch, J.A.; Nadelhoffer, K.; Perakis, S.S.; Robin-Abbott, M.J.; Stoddard, J.L.; Weathers, K.C. 2011. Synthesis, Chapter 19.
• Fenn, M.E.; Allen, E.B. 2011. Southern semi-arid highlands, Chapter 14.
• Bowman, W.D.; Baron, J.S.; Geiser, L.H.; Fenn, M.E.; Lilleskov, E.A. 2011. Northwestern forested mountains, Chapter 8.

Publications

• Jovan, Sarah ; Fenn, Mark E.; Buhler, Monica ; Bytnerowicz, Andrzej ; Kovasi, Adrienne ; Hutten, Martin ; DiMeglio, Elisa ; Schweizer, Donald . 2021. Challenges characterizing N deposition to high elevation protected areas: A case study integrating instrument, simulated, and lichen inventory datasets for the Devils Postpile National Monument and surrounding region, USA.
• Root, Heather T.; Jovan, Sarah ; Fenn, Mark ; Amacher, Michael ; Hall, Josh ; Shaw, John D. 2021. Lichen bioindicators of nitrogen and sulfur deposition in dry forests of Utah and New Mexico, USA.
• Edgerton, Eric S.; Hsu, Yu-Mei ; White, Emily M.; Fenn, Mark E.; Landis, Matthew S. 2020. Ambient concentrations and total deposition of inorganic sulfur, inorganic nitrogen and base cations in the Athabasca Oil Sands Region.
• Valliere, Justin M.; Bucciarelli, Gary M.; Bytnerowicz, Andrzej ; Fenn, Mark E.; Irvine, Irina C.; Johnson, Robert F.; Allen, Edith B. 2020. Declines in native forb richness of an imperiled plant community across an anthropogenic nitrogen deposition gradient.
• Fenn, Mark E.; Preisler, Haiganoush K.; Fried, Jeremy S.; Bytnerowicz, Andrzej ; Schilling, Susan L.; Jovan, Sarah ; Kuegler, Olaf . 2020. Evaluating the effects of nitrogen and sulfur deposition and ozone on tree growth and mortality in California using a spatially comprehensive forest inventory.
• Clark, Christopher M.; Richkus, Jennifer ; Jones, Phillip W.; Phelan, Jennifer ; Burns, Douglas A.; de Vries, Wim ; Du, Enzai ; Fenn, Mark E.; Jones, Laurence ; Watmough, Shaun A. 2019. A synthesis of ecosystem management strategies for forests in the face of chronic nitrogen deposition.
• Du, Enzai ; Fenn, Mark E.; De Vries, Wim ; Ok, Yong Sik. 2019. Atmospheric nitrogen deposition to global forests: Status, impacts and management options.
• Bytnerowicz, Andrzej ; Fenn, Mark E.; Cisneros, Ricardo ; Schweizer, Donald ; Burley, Joel ; Schilling, Susan L. 2019. Nitrogenous air pollutants and ozone exposure in the central Sierra Nevada and White Mountains of California Distribution and evaluation of ecological risks.
• Sickman, James O.; James, Amanda E.; Fenn, Mark E.; Bytnerowicz, Andrzej ; Lucero, Delores M.; Homyak, Peter M. 2019. Quantifying atmospheric N deposition in dryland ecosystems: A test of the Integrated Total Nitrogen Input (ITNI) method.
• Walker, J.T. ; Beachley, G.M. ; Amos, H.M. ; Baron, J.S. ; Bash, J. ; Baumgardner, R. ; Bell, M.D. ; Benedict, K.B. ; Chen, X. ; Clow, D.W. ; Cole, A. ; Coughlin, J.G. ; Cruz, K. ; Daly, R.W. ; Decina, S.M. ; Elliott, E.M. ; Fenn, M.E. ; Ganzeveld, L. ; Gebhart, K. ; Isil, S.S. ; Kerschner, B.M. ; Larson, R.S. ; Lavery, T. ; Lear, G.G. ; Macy, T. ; Mast, M.A. ; Mishoe, K. ; Morris, K.H. ; Padgett, P.E. ; Pouyat, R.V. ; Puchalski, M. ; Pye, H.O.T. ; Rea, A.W. ; Rhodes, M.F. ; Rogers, C.M. ; Saylor, R. ; Scheffe, R. ; Schichtel, B.A. ; Schwede, D.B. ; Sexstone, G.A. ; Sive, B.C. ; Templer, P.H. ; Thompson, T. ; Tong, D. ; Wetherbee, G.A. ; Whitlow, T.H. ; Wu, Z. ; Yu, Z. ; Zhang, L. . 2019. Science needs for continued development of total nitrogen deposition budgets in the United States.
• Walker, J.T. ; Beachley, G. ; Amos, H.M. ; Baron, J.S. ; Bash, J. ; Baumgardner, R. ; Bell, M.D. ; Benedict, K.B. ; Chen, X. ; Clow, D.W. ; Cole, A. ; Coughlin, J.G. ; Cruz, K. ; Daly, R.W. ; Decina, S.M. ; Elliott, E.M. ; Fenn, M.E. ; Ganzeveld, L. ; Gebhart, K. ; Isil, S.S. ; Kerschner, B.M. ; Larson, R.S. ; Lavery, T. ; Lear, G.G. ; Macy, T. ; Mast, M.A. ; Mishoe, K. ; Morris, K.H. ; Padgett, P.E. ; Pouyat, R.V. ; Puchalski, M. ; Pye, H.O.T. ; Rea, A.W. ; Rhodes, M.F. ; Rogers, C.M. ; Saylor, R. ; Scheffe, R. ; Schichtel, B.A. ; Schwede, D.B. ; Sexstone, G.A. ; Sive, B.C. ; Sosa, R. ; Templer, P.H. ; Thompson, T. ; Tong, D. ; Wetherbee, G.A. ; Whitlow, T.H. ; Wu, Z. ; Yu, Z. ; Zhang, L. . 2019. Toward the improvement of total nitrogen deposition budgets in the United States.
• Du, Enzai; de Vries, Wim; McNulty, Steven; Fenn, Mark E. 2018. Bulk deposition of base cationic nutrients in China's forests: Annual rates and spatial characteristics.
• Horn, Kevin J.; Thomas, R. Quinn; Clark, Christopher M.; Pardo, Linda H.; Fenn, Mark E.; Lawrence, Gregory B.; Perakis, Steven S.; Smithwick, Erica A. H.; Baldwin, Douglas ; Braun, Sabine ; Nordin, Annika ; Perry, Charles H.; Phelan, Jennifer N.; Schaberg, Paul G.; St. Clair, Samuel B.; Warby, Richard ; Watmough, Shaun . 2018. Growth and survival relationships of 71 tree species with nitrogen and sulfur deposition across the conterminous U.S..
• Fenn, Mark E.; Bytnerowicz, Andrzej; Schilling, Susan L.; Vallano, Dena M.; Zavaleta, Erika S.; Weiss, Stuart B.; Morozumi, Connor; Geiser, Linda H.; Hanks, Kenneth. 2018. On-road emissions of ammonia: An underappreciated source of atmospheric nitrogen deposition.
• Fenn, Mark E.; Bytnerowicz, Andrzej; Schilling, Susan L. 2018. Passive monitoring techniques for evaluating atmospheric ozone and nitrogen exposure and deposition to California ecosystems.
• Carter, Therese S.; Clark, Christopher M.; Fenn, Mark E.; Jovan, Sarah; Perakis, Steven S.; Riddell, Jennifer; Schaberg, Paul G.; Greaver, Tara L.; Hastings, Meredith G. 2017. Mechanisms of nitrogen deposition effects on temperate forest lichens and trees.
• Clark, Christopher M.; Bell, Michael D.; Boyd, James W.; Compton, Jana E.; Davidson, Eric A.; Davis, Christine; Fenn, Mark E.; Geiser, Linda; Jones, Laurence; Blett, Tamara F. 2017. Nitrogen-induced terrestrial eutrophication: cascading effects and impacts on ecosystem services.
• Bytnerowicz, Andrzej; Fenn, Mark; Allen, Edith B.; Cisneros, Ricardo. 2016. Atmospheric chemistry.
• García-Gomez, Héctor; Izquieta-Rojano, Sheila; Aguillaume, Laura; González-Fernández, Ignacio; Valiño, Fernando; Elustondo, David; Santamaría, Jesús M.; Àvila, Anna; Fenn, Mark E.; Alonso, Rocío. 2016. Atmospheric deposition of inorganic nitrogen in Spanish forests of Quercus ilex measured with ion-exchange resins and conventional collectors.
• Hsu, Yu-Mei; Bytnerowicz, Andrzej; Fenn, Mark E.; Percy, Kevin E. 2016. Atmospheric dry deposition of sulfur and nitrogen in the Athabasca Oil Sands Region, Alberta, Canada.
• Wieder, R. Kelman; Vile, Melanie A.; Scott, Kimberli D.; Albright, Cara M.; McMillen, Kelly J.; Vitt, Dale H.; Fenn, Mark E. 2016. Differential effects of high atmospheric N and S deposition on bog plant/lichen tissue and porewater chemistry across the Athabasca Oil Sands Region.
• Sicard, P.; Augustaitis, A.; Belyazid, S.; Calfapietra, C.; De Marco, A.; Fenn, Mark E.; Bytnerowicz, Andrzej; Grulke, Nancy; He, S.; Matyssek, R.; Serengil, Y.; Wieser, G.; Paoletti, E. 2016. Global topics and novel approaches in the study of air pollution, climate change and forest ecosystems.
• Bytnerowicz, Andrzej; Hsu, Yu-Mei; Percy, Kevin; Legge, Allan; Fenn, Mark E.; Schilling, Susan; Frączek, Witold; Alexander, Diane. 2016. Ground-level air pollution changes during a boreal wildland mega-fire.
• Peña-Mendoza, E.R; Gómez-Guerrero, A.; Fenn, Mark; Hernández de la Rosa, P.; Alvarado Rosales, D. 2016. Nutrients in foliage and wet deposition of nitrate, ammonium and sulfate in washing tree top in Abies religiosa forests.
• Bytnerowicz, A.; Johnson, R.F.; Zhang, L.; Jenerette, G.D.; Fenn, M.E.; Schilling, S.L.; Gonzalez-Fernandez, I. 2015. An empirical inferential method of estimating nitrogen deposition to Mediterranean-type ecosystems: the San Bernardino Mountains case study.
• Fenn, Mark; Bytnerowicz, Andrzej; Schilling, Susan; Ross, C.S. 2015. Atmospheric deposition of nitrogen, sulfur and base cations in jack pine stands in the Athabasca Oil Sands Region, Alberta, Canada.
• Pardo, Linda H.; Robin-Abbot, Molly J.; Fenn, Mark E.; Goodale, Christine L.; Geiser, Linda H.; Driscoll, Charles T.; Allen, Edith B.; Baron, Jill S.; Bobbink, Roland; Bowman, William D.; Clark, Christopher M.; Emmett, Bridget; Gilliam, Frank S.; Greaver, Tara L.; Hall, Sharon J.; Lilleskov, Erik A.; Liu, Lingli; Lynch, Jason A.; Nadelhoffer, Knute J.; Perakis, Steven J.; Stoddard, John L.; Weathers, Kathleen C.; Dennis, Robin L. 2015. Effects and empirical critical loads of nitrogen for ecoregions of the United States.
• Fenn, Mark E.; Fried, Jeremy S.; Preisler, Haiganoush K.; Bytnerowicz, Andrzej; Schilling, Susan; Jovan, Sarah; Kuegler, Olaf. 2015. Remeasured FIA plots reveal tree-level diameter growth and tree mortality impacts of nitrogen deposition on California s forests.
• Perry, Charles H. (Hobie); Horn, Kevin J.; Thomas, R. Quinn; Pardo, Linda H.; Smithwick, Erica A.H.; Baldwin, Doug; Lawrence, Gregory B.; Bailey, Scott W.; Braun, Sabine; Clark, Christopher M.; Fenn, Mark; Nordin, Annika; Phelan, Jennifer N.; Schaberg, Paul G.; St. Clair, Sam; Warby, Richard; Watmough, Shaun; Perakis, Steven S. 2015. Repeated measures from FIA data facilitates analysis across spatial scales of tree growth responses to nitrogen deposition from individual trees to whole ecoregions.
• Clow, David W.; Roop, Heidi A.; Nanus, Leora; Fenn, Mark E.; Sexstone, Graham A. 2015. Spatial patterns of atmospheric deposition of nitrogen and sulfur using ion-exchange resin collectors in Rocky Mountain National Park, USA.
• Fenn, Mark; Driscoll, Charles; Zhou, Quingtao; Rao, Leela; Meixner, Thomas; Allen, Edith; Yuan, Fengming; Sullivan, Timothy. 2015. Use of combined biogeochemical model approaches and empirical data to assess critical loads of nitrogen.
• Fenn, Mark. 2015. Wet and dry deposition in the AOSR collected by ion exchange resin samplers.
• Fenn, M.E.; Nagel, H.-D.; Koseva, I.; Aherne, J.; Jovan, S.E., Dr.; Geiser, L.H.; Schlutow, A.; Scheuschner, T.; Bytnerowicz, A.; Gimeno, B.S.; Yuan, F.; Watmough, S.A.; Allen, E.B.; Johnson, R.F.; Meixner, T. 2014. A comparison of empirical and modelled nitrogen critical loads for Mediterranean forests and shrublands in California.
• Bytnerowicz, Andrzej; Fenn, Mark; Long, Jonathan W. 2014. Air quality.
• Shaw, Glenn D.; Cisneros, Ricardo; Schweizer, Donald; Sickman, James O.; Fenn, Mark E. 2014. Critical Loads of Acid Deposition for Wilderness Lakes in the Sierra Nevada (California) Estimated by the Steady-State Water Chemistry Model.
• Schirokauer, D.; Geiser, L.; Bytnerowicz, A.; Fenn, M.; Dillman, K. 2014. Monitoring air quality in Southeast Alaska s National Parks and Forests: Linking atmospheric pollutants with ecological effects.
• Clair, T.A.; Blett, T.; Aherne, J.; Aidar, M.P.M.; Artz, R.; Bealey, W.J.; Budd, W.; Cape, J.N.; Curtis, C.J.; Duan, L.; Fenn, M.E.; Groffman, P.; Haeuber, R.; Hall, J.R.; Hettelingh, J.-P.; López-Hernández, D.; Mathieson, B.; Pardo, L.; Posch, M.; Pouyat, R.V.; Spranger, T.; Sverdrup, H.; van Dobben, H.; van Hinsberg, A. 2014. The critical loads and levels approach for nitrogen.
• Watmough, Shaun A.; Whitfield, Colin J.; Fenn, Mark E. 2014. The importance of atmospheric base cation deposition for preventing soil acidification in the Athabasca Oil Sands Region of Canada.
• Allen, E.B.; Rao, L.E.; Tonnesen, G.; Johnson, R.F.; Fenn, M.E.; Bytnerowicz, A. 2014. Using fire risk and species loss to set critical loads for nitrogen deposition in southern California shrublands.
• Proemse, Bernadette C.; Mayer, Bernhard; Fenn, Mark E.; Ross, Christopher S. 2013. A multi-isotope approach for assessing industrial contributions to atmospheric nitrogen deposition in the Athabasca oil sands region in Alberta, Canada.
• Root, Heather T.; Geiser, Linda H.; Fenn, Mark E.; Jovan, Sarah, Dr.; Hutten, Martin A.; Ahuja, Suraj; Dillman, Karen; Schirokauer, David; Berryman, Shanti; McMurray, Jill A. 2013. A simple tool for estimating throughfall nitrogen deposition in forests of western North America using lichens.
• Fenn, Mark E.; Ross, Christopher S.; Schilling, Susan L.; Baccus, William D.; Larrabee, Michael A.; Lofgren, Rebecca A. 2013. Atmospheric deposition of nitrogen and sulfur and preferential canopy consumption of nitrate in forests of the Pacific Northwest, USA.
• Bytnerowicz, Andrzej; Fenn, Mark; Gertler, Alan; Preisler, Haiganoush; Zielinska, Barbara. 2013. Distribution of ozone, ozone precursors and gaseous components of atmospheric nitrogen deposition in the Lake Tahoe Basin.
• Bytnerowicz, Andrzej; Fenn, Mark; McNulty, Steven; Yuan, Fengming; Pourmokhtarian, Afshin; Driscoll, Charles; Meixner, Tom. 2013. Interactive effects of air pollution and climate change on forest ecosystems in the United States: current understanding and future scenarios.
• Clark, Christopher M.; Bai, Yongfei; Bowman, William D.; Cowles, Jane M.; Fenn, Mark E.; Gilliam, Frank S.; Phoenix, Gareth K.; Siddique, Ilyas; Stevens, Carly J.; Sverdrup, Harald U.; Throop, Heather L. 2013. Nitrogen deposition and terrestrial biodiversity.
• Vollenweider, Pierre; Fenn, Mark E.; Menard, Terry; Gunthardt-Goerg, Madeleine; Bytnerowicz, Andrzej. 2013. Structural injury underlying mottling in ponderosa pine needles exposed to ambient ozone concentrations in the San Bernardino Mountains near Los Angeles, California.
• McMurray, Jill A.; Roberts, Dave W.; Fenn, Mark E.; Geiser, Linda H.; Jovan, Sarah, Dr. 2013. Using epiphytic lichens to monitor nitrogen deposition near natural gas drilling operations in the Wind River Range, WY, USA.
• Proemse, Bernadette C.; Mayer, Bernhard; Fenn, Mark E. 2012. Tracing industrial sulfur emissions in atmospheric sulfate deposition in the Athabasca Oil Sands Region, Alberta, Canada.
• Burns, Douglas A.; Fenn, Mark E.; Baron, Jill S. 2011. Effects of acid deposition on ecosystems: Advances in the state of the science.
• Pardo, Linda H.; Fenn, Mark E.; Goodale, Christine L.; Geiser, Linda H.; Driscoll, Charles T.; Allen, Edith B.; Baron, Jill S.; Bobbink, Roland; Bowman, William D.; Clark, Christopher M.; Emmett, Bridget; Gilliam, Frank S.; Greaver, Tara L.; Hall, Sharon J.; Lilleskov, Erik A.; Liu, Lingli; Lynch, Jason A.; Nadelhoffer, Knute J.; Perakis, Steven S.; Robin-Abbott, Molly J.; Stoddard, John L.; Weathers, Kathleen C.; Dennis, Robin L. 2011. Effects of nitrogen deposition and empirical nitrogen critical loads for ecoregions of the United States.
• Yuan, Yuan; Meixner, Thomas; Fenn, Mark E.; Simunek, Jirka. 2011. Impact of transient soil water simulation to estimated nitrogen leaching and emission at high- and low-deposition forest sites in southern California.
• Fenn, M.E.; Allen, E.B.; Geiser, L.H. 2011. Mediterranean California, Chapter 13.
• Ochoa-Hueso, R.; Allen, E.B.; Branquinho, C.; Cruz, C.; Dias, T.; Fenn, Mark; Manrique, E.; Pérez-Corona, M.E.; Sheppard, L.J.; Stock, W.D. 2011. Nitrogen deposition effects on Mediterranean-type ecosystems: An ecological assessment.
• Fenn, Mark E; Lambert, Kathleen F.; Blett, Tamara F.; Burns, Douglas A.; Pardo, Linda H.; Lovett, Gary M.; Haeuber, Richard A.; Evers, David C.; Driscoll, Charles T.; Jeffries, Dean S. 2011. Setting limits: Using air pollution thresholds to protect and restore U.S.
• Bobbink, R.; Hicks, K.; Galloway, J.; Spranger, T.; Alkemade, R.; Ashmore, M.; Bustamante, M.; Cinderby, S.; Davidson, E.; Dentener, F.; Emmett, B.; Erisman, J.-W.; Fenn, M.; Gilliam, F.; Nordin, A.; Pardo, L.; De Vries, W. 2010. Global assessment of nitrogen deposition effects on terrestrial plant diversity: a synthesis.
• Fenn, M.E.; Allen, E.B.; Weiss, S.B.; Jovan, S.; Geiser, L.; Tonnesen, G.S.; Johnson, R.F.; Rao, L.E.; Gimeno, B.S.; Yuan, F.; Meixner, T.; Bytnerowicz, A. 2010. Nitrogen critical loads and management alternatives for N-impacted ecosystems in California.
• Grulke, N.E.; Minnich, R.A.; Paine, T.D.; Seybold, S.J.; Chavez, D.J.; Fenn, M.E.; Riggan, P.J.; Dunn, A. 2009. Air pollution increases forest susceptibility to wildfires: A case study in the San Bernardino Mountains in southern California.
• Nowinski, N.S.; Trumbore, S.E.; Jimenez, G.; Fenn, M.E. 2009. Alteration of belowground carbon dynamics by nitrogen addition in southern California mixed conifer forests.
• Johnson, D.W.; Fenn, M.E.; Miller, W.W.; Hunsaker, C.T. 2009. Fire effects on carbon and nitrogen cycling in forests of the Sierra Nevada.
• Allen, E.B.; Rao, L.; Steers, R.J.; Bytnerowicz, A.; Fenn, M.E. 2009. Impacts of atmospheric nitrogen deposition on vegetation and soils in Joshua Tree National Park.
• Gimeno, Benjamin S.; Yuan, Fengming; Fenn, Mark E.; Meixner, Thomas. 2009. Management options for mitigating Nitrogen (N) losses from N-saturated mixed-conifer forests in California.
• Fenn, M.E.; Sickman, J.O.; Bytnerowicz, A.; Clow, D.W.; Molotch, N.P.; Pleim, J.E.; Tonnesen, G.S.; Weathers, K.C.; Padgett, P.E.; Campbell., D.H. 2009. Methods for measuring atmospheric nitrogen deposition inputs in arid and montane ecosystems of western North America.
• Fenn, M.E.; Jovan, S., Dr.; Yuan, F.; Geiser, L.; Meixner, T.; Gimeno, B.S. 2008. Empirical and simulated critical loads for nitrogen deposition in California mixed conifer forests.
• Moody, B.; Castillo, J.V.; Fenn, M.E. 2008. Forest health conditions in North America.
• Meixner, T.; Fenn, Mark E.; Wohlgemuth, P.; Oxford, M.; Riggan, P. 2006. N saturation symptoms in chaparral catchments are not reversed by prescribed fire.
• Fenn, Mark E.; Perea-Estrada, V.M.; Bauer, L.I. de; Pérez-Suárez, M.; Parker, D.R.; Cetina-Alcalá, V.M. 2006. Nutrient status and plant growth effects of forest soils in the Basin of Mexico.
• Fenn, Mark E.; Huntington, T.G.; McLaughlin, S.B.; Eager, C.; Gomez, A.; Cook, R.B. 2006. Status of soil acidification in North America.
• Fenn, M. E. 2006. The Effects of Nitrogen Deposition, Ambient Ozone, and Climate Change on Forests in the Western U.S..
• Allen, Edith B.; Sirulnik, Abby G.; Egerton-Warburton, Louise; Kee, Sheila N.; Bytnerowicz, Andrzej; Padgett, Pamela E.; Temple, Patrick J.; Fenn, Mark E.; Poth, Mark A.; Meixner, Thomas. 2005. Air pollution and vegetation change in southern California coastal sage scrub: a comparison with chaparral and coniferous forest.
• Temple, Patrick J.; Bytnerowicz, Andrzej; Fenn, Mark E.; Poth, Mark A. 2005. Air pollution impacts in the mixed conifer forests of southern California.
• Fenn, Mark; Poth, Mark; Meixner, Thomas. 2005. Atmospheric nitrogen deposition and habitat alteration in terrestrial and aquatic ecosystems in southern California: implications for threatened and endangered species.
• Jordan, Fiona L.; Cantera, J. Jason L.; Fenn, Mark E.; Stein, Lisa Y. 2005. Autotrophic ammonia-oxidizing bacteria contribute minimally to nitrification in a nitrogen-impacted forested ecosystem.
• Grulke, Nancy; Dobrowolski, W.; Mingus, P.; Fenn, M.E. 2005. California black oak response to nitrogen amendment at a high O3, nitrogen-saturated site.
• Fenn, Mark E.; Poth, Mark A.; Terry, Joseph D.; Blubaugh, Timothy J. 2005. Nitrogen mineralization and nitrification in a mixed-conifer forest in southern California: controlling factors, fluxes, and nitrogen fertilization response at a high and low nitrogen deposition site.
• Jones, Michele Eatough; Paine, Timothy D.; Fenn, Mark E.; Poth, Mark A. 2004. Influence of ozone and nitrogen deposition on bark beetle activity under drought conditions.
• Fenn, Mark E.; Poth, Mark A. 2004. Monitoring nitrogen deposition in throughfall using ion exchange resin columns.
• Michalski, Greg; Meixner, Thomas; Fenn, Mark E.; Hernandez, Larry; Sirulnik, Abby; Allen, Edith; Thiemens, Mark. 2004. Tracing atmospheric nitrate deposition in a complex semiarid ecosystem using Δ17O.
• Fenn, Mark E.; Baron, Jill S.; Allen, Edith B.; Rueth, Heather M.; Nydick, Koren R.; Geiser, Linda; Bowman, William D.; Sickman, James O.; Meixner, Thomas; Johnson, Dale W.; Neitlich, Peter. 2003. Ecological effects of nitrogen deposition in the western United States.
• Fenn, Mark E.; Haeuber, Richard; Tonnesen, Gail S.; Baron, Jill S.; Grossman-Clarke, Susanne; Hope, Diane; Jaffe, Daniel A.; Copeland, Scott; Geiser, Linda; Rueth, Heather M.; Sickman, James O. 2003. Nitrogen emissions, deposition, and monitoring in the western United States.
• Arbaugh, Michael; Bytnerowicz, Andrzej; Grulke, Nancy; Fenn, Mark; Poth, Mark; Temple, Patrick; Miller, Paul. 2003. Photochemical smog effects in mixed conifer forests along a natural gradient of ozone and nitrogen deposition in the San Bernardino Mountains.
• Fenn, Mark E.; Poth, Mark A.; Arbaugh, Michael J. 2002. A throughfall collection method using mixed bed ion exchange resin columns.
• Fenn, Mark E.; de Bauer, L.I.; Hernández-Tejeda, Tomás. 2002. Summary of air pollution impacts on forests in the Mexico City air basin.
• Fenn, Mark E.; Poth, Mark A. 2001. A case study of nitrogen saturation in western U.S. forests.
• Fenn, Mark E.; Poth, Mark A.; Schilling, Susan L.; Grainger, David B. 2000. Throughfall and fog deposition of nitrogen and sulfur at an N-limited and N-saturated site in the San Bernardino Mountains, southern California.
• Fenn, Mark E.; Baur, L.I. De; Quevedo-Nolasco, A.; Rodriguez-Frausto, C. 1999. Nitrogen and sulfur desposition and forest nutrient status in the valley of Mexico.
• Fenn, Mark E.; Poth, Mark A. 1999. Temporal and spatial trends in streamwater nitrate concentrations in the San Bernardino mountains, southern California.
• Bytnerowicz, Andrzej; Fenn, Mark E.; Arbaugh, Michael J. 1998. Concentrations and deposition of nitrogenous air pollutants in a ponderosa/Jeffrey pine canopy.
• Fenn, Mark E.; Poth, Mark A. 1998. Indicators of nitrogen status in California forests.
• Poth, Mark A.; Fenn, Mark E. 1998. Mature ponderosa pine nutrient use and allocation responses to air pollution.
• Fenn, Mark E.; Poth, Mark A.; Aber, John D.; Baron, Jill S.; Bormann, Bernard T.; Johnson, Dale W.; Lemly, A. Dennis; McNulty, Steven G.; Ryan, Douglas F.; Stottlemyer, Robert. 1998. Nitrogen Excess in North American Ecosystems: Predisposing Factors, Ecosystem Responses, and Management Strategies.
• Fenn, Mark E.; Poth, Mark A.; Aber, John D.; Baron, Jill S.; Bormann, Bernard T.; Johnson, Dale W.; Lemly, A. Dennis; McNulty, Steven G.; Ryan, Douglas F.; Stottlemyer, Robert. 1998. Nitrogen excess in North American ecosystems: predisposing factors, ecosystem responses, and management strategies.
• Grulke, Nancy; Andersen, C.P.; Fenn, M.E.; Miller, P.R. 1998. Ozone exposure and nitrogen deposition lowers root biomass of ponderosa pine in the San Bernardino Mountains, California.
• Arbaugh, Michael J.; Bytnerowicz, Andrzej; Fenn, Mark E. 1998. Predicting nitrogen flux along a vertical canopy gradient in a mixed conifer forest stand of the San Bernardino Mountains in California.
• Fenn, Mark E.; Bytnerowicz, Andrzej. 1997. Summar throughfall and winter deposition in the San Bernardino mountains in southern California.
• Fenn, Mark A.; Poth, Mark A.; Johnson, Dale W. 1996. Evidence for nitrogen saturation in the San Bernardino Mountains in southern California.
• Bytnerowicz, Andrzej; Fenn, Mark E. 1996. Nitrogen deposition in California forests: a review.
• Fenn, Mark E.; Leininger, Theodor D. 1995. Uptake and Distribution of Nitrogen from Acidic Fog within a Ponderosa Pine (Pinus ponderosa Laws.)/Litter/Soil System.
• Fenn, Mark E.; Bytnerowicz, Andrzej. 1993. Dry deposition of nitrogen and sulfur to ponderosa and jeffrey pine in the San Bernardino National Forest in southern California.
• Fenn, Mark E. 1991. Increased site fertility and litter decomposition rate in high-pollution sites in the San Bernardino Mountains.
• Fenn, Mark E.; Dunn, Paul H. 1989. Litter decomposition across an air-pollution gradient in the San Bernardino Mountains.
• Fenn, Mark A.; Coffey, M.D. 1984. Studies on the in vitro and in vivo antifungal activity of fosetyl-al and phosphorous acid.

Research Highlights

Highlight	Title	Year
PSW-2012-03	Air-Pollution Thresholds Protect Ecosystems Research benefits air-quality specialists, land managers, scientists, and policymakers	2012
PSW-2010-006	Development of Critical Loads and Critical Load Exceedance Maps for Protecting California Ecosystems from Atmospheric Nitrogen Deposition More than 50,000 km2 of the land area in California receive atmospheric deposition inputs of at least 10 kg N/ha/yr. Many ecosystems are negativ ...	2010
PSW-2017-247	Ecosystem services affected by atmospheric nitrogen seposition Forest Service scientists describe the ecosystem services affected by chronic N deposition in the southern California coastal sage scrub vegetat ...	2017
PSW-2016-48	Effects of a Megafire on Air Quality Few studies have addressed the effects of forest fires on atmospheric levels of reactive nitrogen pollutants, which function as precursors to oz ...	2016
PSW-2012-02	Industrial Air Pollution May Have Ecological Consequences Elevated concentrations of ammonia can negatively impact lichen communities and elevated levels of nitrogen and sulfur deposition can potentiall ...	2012
PSW-2014-098	Vulnerability of High Elevation Lakes of the Sierra Nevada to Atmospheric Acidic Deposition In at least some years, hundreds of wilderness lakes are likely receiving acid loading in excess of their buffering capacity. The most vulnerabl ...	2014