Erica Smithwick


Director of Landscape Ecology at Penn State (LEAPS)


I work at the interface of landscape and ecosystem ecology, focusing on the influence of spatial patterns on ecosystem function. I am specifically interesting in the role of fire patterns (e.g., “pyrogeography”) on soil biogeochemistry and carbon storage. Fire reflects trends in both land use and ecosystem dynamics, thus requiring interdisciplinary scientific approaches. Fire also drives carbon flux dynamics between the biosphere and the atmosphere, thus requiring understanding of coupled climate-vegetation changes at multiple scales.  In the face of increasing concern about fire in human-dominated landscapes, the understanding of the causes and ecological consequences of fire is critical to local and landscape level management. As such, my research is relevant to landscape-level conservation management as well as global change biology.

Theoretically, I am interested in how scale and spatial patterns of disturbance processes can be better modeled – so that forecasts of climate change can better incorporate dominant fire dynamics.  Current models in my laboratory include Century, MC1, and Fire-BGC. However, I also integrate both laboratory and experimental studies on soil and ecosystem biogeochemistry, and am increasingly interested in spatial statistics (geostatistics), network theory, and Bayesian approaches for understanding and scaling ecosystem complexity.

I primarily work in three geographic locations: Africa (Ghana and South Africa), The Greater Yellowstone Ecosystem (Wyoming – USA), and the Northeast.  A majority of my research occurs in natural reserves or parks (Yellowstone, Appalachian Trail, Eastern Cape Parks Board - South Africa), which can serve as benchmarks for ecosystem function and coupled human-nature interactions.

Current research interests and activities

Consequences of Novel Disturbance Regimes on Climate-Induced Biogeographic Shifts along the Appalachian Trail
Department of Energy, National Institute of Climatic Change Research, $ 125,000

Northward biogeographical shifts are expected in the Eastern US with more southerly species (e.g., oak, hickory, pine) replacing northern hardwoods (e.g., maple, beech, birch).  The AT MEGA-Transect, an ecological monitoring program along this vector, provides an exceptional opportunity to test scientific hypotheses of disturbance-vegetation-climate interactions between southeast and northeast regions.  Fire is an extensive disturbance agent in the southeastern US but has a disputed historical role in the northeast. In this project, we hypothesize that under future climate, fire risk may be enhanced, resulting in positive feedbacks and sustaining northward migration of fire-prone vegetation.  Alternatively, in the absence of these fire-climate conditions, niche-based projections of northerly migration of fire-prone habitat may be overestimated.  This research will clarify how climate-induced shifts in species may interact with or produce novel disturbance regimes.  To explore this, we are developing a multi-scaled modeling approach that links a biogeographical model (MC1) with a species-specific model of potential suitable habitat called DISTRIB (Iverson et al., 2008). Model simulations will test fire-climate-vegetation feedbacks, allowing the dynamically generated fires of MC1 to influence the species composition predictions of DISTRIB and the species composition predictions of DISTRIB to influence the fuel load in MC1.  Models will be driven with new downscaled 4 km2 resolution climate datasets (historical PRISM baseline, 3 GCMs, 3 emission scenarios) to test fine-scale fire-climate-vegetation interactions along the AT.

Dominique Bachelet - Oregon State University
Louis Iverson - USDA Forest Service Northern Research Station
Anantha Prasad - USDA Forest Service Northern Research Station

Climate, Fire and Carbon: Tipping Points and Landscape Vulnerability in the Greater Yellowstone Ecosystem
USDI / Joint Fire Science Program, $140,653

Current model projections suggest that, by the end of the 21st C, climate conditions like those of 1988 (the year of the well-known Yellowstone Fires) will represent close to the average year rather than an extreme year. The consequences of a climate shift of this magnitude for the fire regime, post-fire succession and carbon (C) balance of western forest ecosystems are well beyond what scientists have explored to date, and may fundamentally change the potential of western forests to sequester atmospheric C.  In this project, we hypothesize that vegetation communities will contribute differentially to future landscape C flux because of different sensitivities to future climate and fire combinations, and the net result could qualitatively change the C dynamics of western forests. To explore this idea, we are focusing on the Greater Yellowstone Ecosystem (GYE) to address three overarching questions that are broadly relevant for many Rocky Mountain forests: (1) How great a change in climate and fire regime would be required to shift each of the dominant vegetation communities in the GYE from a net C sink to a net C source? (2) Do current projections indicate that changes of this magnitude are likely to occur in the next century, and if so, where in the GYE do they occur? (3) What are the integrated effects of changing climate, vegetation, and fire on spatial patterns of carbon flux across the GYE landscape as a whole?  To answer these questions, we are using observed relationships between climate and fire occurrence and downscaled climate data from general circulation models (GCMs) to determine future climate and fire regimes and develop spatially explicit maps of landscape C flux based on individual contributions of vegetation types to future climate and fire – determined from the CENTURY ecosystem model. 

Monica G. Turner - University of Wisconsin, Madison
Anthony Westerling - Sierra Nevada Research Institute and UC-Merced
William H. Romme - Colorado State University
Michael G. Ryan - USDA Forest Service RMRS

Collaborative Research: Climatic Extremes, Mining, and Mycobacterium ulcerans: A Coupled Systems Approach
NSF-Coupled Natural Human Systems, $1,421,997

In this project, we are working in Ghana to explore the emergence of Buruli ulcer (BU) at multiple temporal and spatial scales.  Our project considers BU emergence as a function of climatic changes that interact with human-modified landscapes, resulting in increases in flooding and stagnant water. We expect that human knowledge and behavior, which differ by occupation, age, location, and the degree of marginality people occupy in society, govern the resultant exposure to stagnant water bodies that may house the bacterium causing BU. We believe that the transmission of BU is due to previously unidentified thresholds in these coupled human-natural patterns that interact across spatial and temporal scales. We aim to make concrete recommendations about the conditions under which landscape rehabilitation would enhance human-ecosystem health and resilience. In addition, a key element of our project is the development of a sister-school approach, linking elementary, intermediate, and high schools from Penns Valley Area School District with partner schools in Tarkwa, Asankragwa, Deaso, and Dunkwa. Through collaborative activities, the students and teachers aim to understand human-modified landscapes and disease patterns in Pennsylvania and in Africa. 

Petra Tschakert (PI) Penn State University, USA
Joseph Oppong - University of North Texas, USA
Richard Amankwah - University of Mines and Technology, Ghana
Edith Parker - University of Iowa, USA
Simon Gawu, KNUST, Ghana
Kamini Singha - Penn State University, USA
Heidi Hausermann - Penn State University, USA
Erasmus Klutse - Ghana Health Directorate, Ghana
Ray Voegborlo - KNUST, Ghana
Frank Nyame - University of Ghana, Ghana
Annmarie Ward-  Penn State University, USA

GK-12: Carbon Education and Research Together for Humanity (Carbon EARTH)
NSF-GK12, $3,000,000

CarbonEARTH uses the interdisciplinary theme of carbon, broadly construed, as a unifying platform for investigation, discovery, training and education. Carbon is a ubiquitous element in our world, featured highly in a broad spectrum of basic and applied research areas, including materials science, energy science, geosciences, and life sciences.  Many challenges facing society today involve carbon, including global warming, waste disposal, renewable energy, and nanoelectronics and these issues are frequently addressed in the media, with varying degrees of scientific accuracy.  The majority of K-12 student achievement standards for science relate to these issues.  CarbonEARTH will provide teachers and students from a wide range of disciplines with science learning experiences that not only teach the concepts, but also develop the skills with scientific inquiry for approaching these problems scientifically.  Specifically, CarbonEARTH teams STEM graduate students with upper elementary and middle school science teachers from rural and urban school districts to teach PA standards-based science topics related to the themes of Energy, Matter & Materials, Earth Processes, and Ecosystems, focusing on inquiry-based teaching strategies. Recent government reports describe the severity of our nation’s need to increase the STEM pipeline and the multitude of underlying problems, such as lack of interest and retention in STEM by women, minorities, and low socioeconomic populations.  CarbonEARTH aims to increase representation of women, minorities, and low-socioeconomic populations by promoting STEM education and careers of underrepresented groups at all levels; enhancing graduate students’ research and other non-research skills needed for successful careers,  working with upper elementary and middle school teachers and students to promote deeper understanding of STEM concepts and skills in scientific inquiry, and providing experiences for upper elementary and middle school students that reflect the excitement and importance of STEM careers through interactions with graduate student role models.

PI and Co-PI(s)
Renee Diehl - Physics (PI)
Angela Lueking - Energy and Mineral Engineering
Erica Smithwick - Geography
Elizabeth Boyer - Forest Hydrology
Annmarie Ward - Education (CoPIs)
Faculty and Departments:  Rachel Brennan (Environmental Engineering); Nicole Brown (Wood Chem); Craig Cameron (Biochem and Molecular Bio); Kristen Fichthorn (Chem Engineering); Katherine Freeman (Geosciences); Heather Karsten (Crop Production and Ecology); Margot Kaye, (Forest Ecology); Jennifer Macalady (Geosciences); Erin Sheets (Chem); Jorge Sofo (Physics); Jun Zhu (Physics)

Spatial patterns of nutrient limitation and carbon storage in South African coastal lowland landscapes
National Science Foundation: EAGER, $150,000
George H. Deike, Jr. Research Grant, College of Earth and Mineral Sciences, $50,000

Geographically, Africa is one of the weakest links in the understanding of land-atmosphere carbon exchange.   The objectives of this research are to (1) employ a novel experimental design to determine how variation in nutrient availability determines spatial patterns in grassland carbon productivity and (2) provide the first-ever quantification of carbon storage in coastal and dune forests within two priority nature reserves in the southeastern coast of South Africa.  Contrasting fire and vegetation patterns within each reserve will allow for the development of new pyrogeographic perspectives on African carbon storage at landscape scales.  By studying carbon storage in priority conservation areas in coastal South Africa, this research will establish a deeper understanding of the role of African landscapes in conservation management and global ecosystem science. 

A current lack of understanding of complex interactions among fire, climate, and nutrient cycling hinders broad-scale modeling of ecosystem response to climate change.  This issue is particularly acute for Africa, which represents the largest source of fire-derived carbon emissions and for which carbon storage estimates are scarce. Direct measurement of carbon storage in new locations and identification of its limiting factors across multiple scales, as explored in this project, is critical for the development of future diagnostic modeling efforts. Understanding how fire and soil nutrients govern these patterns will contribute to landscape and conservation management in the region and globally.

This research is run in parallel with an education abroad program at Penn State, Parks and People, focused on interdisciplinary training of undergraduate students in collaborative international science.  Those interested in the study abroad program should visit: for further information.

Other projects

  • Understanding effects of prescribed burning on soil nitrogen availability in Pennsylvania (with Alan Taylor)
  • Response of tree root function to chronic nitrogen inputs (with Richard Bowden, Charley Driscoll, David Eissenstat, and Gary Lovett)
  • Modeling multiple disturbance interactions (fire + beetles) in the Greater Yellowstone Ecosystem (with Rachel Loehman, Martin Simard, Donald McKenzie, and Bob Keane)
  • Modeling the effects of fire severity and size on tree regeneration (with Mark Harmon)

Research Interests

  • landscape ecology
  • ecosystem ecology
  • biogeochemistry
  • fire ecology


  • Ph.D. Forest Science/Ecology, 2002, Oregon State
  • M.S. Resource Conservation (Forestry), University of Montana
  • B.S. cum laude Geological Sciences/Environmental Studies, Tufts University


  • Seth Wilberding, Ph.D. Geography (current)

  • Elizabeth Crisfield, Ph.D. Geography (current) “Biophysical Constraints on Seed Dispersal Along the Appalachian Trail: Implications for Climate-Induced Species Shifts,” expected graduation, May 2011.

  • Luke McCormack, Ph.D. Ecology (current), with David Eissenstate. "The role of mycorrhizal fungi in temperate forest productivity under elevated CO2," expected graduation May 2011.

  • Rachel Brimmer, Ph.D. Ecology (current), with Jason Kaye.

  • Jared Oyler, M.S. Geography (2009). "The Effect of Burn Severity on Short-Term Post-Fire Boreal Vegetation Recovery in Interior Alaska."

  • Michelle Williams-Tober, M.S. Ecology (2009). “Relative Nitrogen Availability Along a Condition Gradient in Headwater Wetlands in the Upper Juniata Watershed, Pennsylvania."

Courses Taught

  • GEOG 010
  • GEOG 311
  • GEOG 497
  • GEOG 597A


Smithwick, E.A.H. 2010. Pyrogeography and biogeochemical resilience.  In: Landscape Ecology of Fire, ed. D. McKenzie, D. Falk, C. Miller, in press.

Smithwick, E.A.H. 2010. Pyrogeography:  Lessons for future northeastern U.S. landscapes.  Penn State Environmental Law Review 18(2): 101-121.

Smithwick, E. A. H. 2010. Organized Oral Session 34. Disturbance ecology, biogeochemistry and resilience: three decades of inquiry. Bulletin of the Ecological Society of America 91:80-93.

Smithwick, E. A. H., D. M. Kashian, M. G. Ryan, and M. G. Turner. 2009. Long-Term Nitrogen Storage and Soil Nitrogen Availability in Post-Fire Lodgepole Pine Ecosystems. Ecosystems 12:792-806.

Smithwick, E. A. H., M. G. Ryan, D. M. Kashian, W. H. Romme, D. B. Tinker, and M. G. Turner. 2009. Modeling the effects of fire and climate change on carbon and nitrogen storage in lodgepole pine (Pinus contorta) stands. Global Change Biology 15:535-548.

Turner, M. G., E. A. H. Smithwick, D. B. Tinker, and W. H. Romme. 2009. Variation in foliar nitrogen and aboveground net primary production in young postfire lodgepole pine. Canadian Journal of Forest Research-Revue Canadienne De Recherche Forestiere 39:1024-1035.

Schoennagel, T., E. A. H. Smithwick, and M. G. Turner. 2008. Landscape heterogeneity following large fires: insights from Yellowstone National Park, USA. International Journal of Wildland Fire 17:742-753.

Metzger, K. L., E. A. H. Smithwick, D. B. Tinker, W. H. Romme, T. C. Balser, and M. G. Turner. 2008. Influence of coarse wood and pine saplings on nitrogen mineralization and microbial communities in young post-fire Pinus contorta. Forest Ecology and Management 256:59-67.

Turner, MG, Smithwick EAH, Metzger KL, Tinker DB, and Romme WH. 2007. Inorganic nitrogen availability following severe stand-replacing fire in the Greater Yellowstone Ecosystem, inaugural paper, Proceedings of the National Academy of Science 104 (12): 4782-4789.

Smithwick, E. A. H., M. E. Harmon, and J. B. Domingo. 2007. Changing temporal patterns of forest carbon stores and net ecosystem carbon balance: the stand to landscape transformation. Landscape Ecology 22:77-94.

Smithwick EAH. 2006. Editorial: Role of microbial communities in mediating ecosystem response to disturbance, Special Issue in Plant and Soil 289:1-3

Smithwick EAH. 2006. Gentle introduction to complexity on landscapes. Book Review for Ecology 87(11):2954-2955

Smithwick EAH, Harmon ME, Domingo JB. 2006. Changing temporal patterns of forest carbon stores and net ecosystem carbon balance: The stand to landscape transformation, Landscape Ecology 22(1): 77-94.

Smithwick EAH, Mack MC, Turner MG, Chapin III FS, Zhu J, Balser TC. 2005. Spatial heterogeneity and soil nitrogen dynamics after severe fire in a black spruce (Picea mariana) forest, Alaska: Distinct controls at different scales. Biogeochemistry 76: 517-537.

Smithwick EAH, Turner MG, Mack MC, Chapin III, FS. 2005. Post-fire soil nitrogen cycling in northern conifer landscapes affected by severe, stand-replacing fires. Ecosystems 8: 163-181.

Smithwick EAH, Turner MG, Metzger KL, Balser TC. 2005. Variation in NH4+ mineralization and microbial communities with stand age in lodgepole pine (Pinus contorta) forests, Yellowstone National Park (USA). Soil Biology and Biochemistry 37: 1546-1559.

Homann PS, Harmon ME, Remillard SM, Smithwick EAH. 2005. What the soil reveals: Maximum ecosystem C stores of the Pacific Northwest region, USA. Forest Ecology and Management 220: 270-283.

Miller JM, Turner MG, Smithwick EAH, Dent LC, Stanley EH. 2004. Extrapolation: the science of predicting ecological patterns and processes. Bioscience 54(4): 310-320

Smithwick EAH, Harmon ME, Domingo JB. 2003. Modeling multi-scale effects of light limitations and edge-induced mortality on carbon stores in forest landscapes. Landscape Ecology 18(7): 701-721.

Korontzi S, Ward DE, Susott RA, Yokelson RJ, Justice CO, Hobbs PV, Smithwick EAH, Hao WM. 2003. Seasonal variation and ecosystem dependence of emission factors for selected trace gases and PM2.5 for southern African savanna fires. Journal of Geophysical Research 108(D24), 4758.

Smithwick, E. A. H., M. E. Harmon, and J. B. Domingo. 2003. Modeling multiscale effects of light limitations and edge-induced mortality on carbon stores in forest landscapes. Landscape Ecology 18:701-721.

Smithwick EAH, Harmon ME, Acker SA, Remillard SM. 2002. Potential upper bounds of carbon stores in the Pacific Northwest. Ecological Applications 12(5): 1303-1317

Hoffa EA, Ward DE, Hao WM, Susott RA, Wakimoto RH. 1999. Seasonality of carbon emissions from biomass burning in a Zambian savanna. Journal of Geophysical Research 104: 13,841 - 13,853.