Assistant Professor and Undergraduate Faculty Advisor for Physical Geography
PH.D. University of Colorado, 2008
Hydroecology, landscape dynamics, complex environmental systems, environmental restoration
595 McCone Hall
Professor Larsen’s Lab website
I grew up in Florida, where I spent my childhood playing outdoors, mostly around water, reading, and solving puzzles. I never grew out of those things, and now they constitute a major part of my job. The puzzles that motivate me are: What makes landscapes evolve distinct patterns? How can we restore or manage landscapes to optimize particular functions? How do physical-biological interactions control large-scale geomorphology and biogeochemical processing? Water flows as a theme through this research as one of the components of the environment most critical to life and, indeed, perhaps the single most dominant factor sculpting the geography of Earth’s natural and human landscapes. Water is also one of the features of the physical environment most sensitive to global climate change and human management. In my research I try to tease apart the direct and indirect ways in which hydrologic changes impact ecosystems, and, conversely, how those ecological changes impact hydrology. It is only through a firm understanding of these dynamic interactions that we can predict future change in the hydrological and ecological components of landscapes.
One of the things I love about this area of research is that it requires a variety of tools and creativity in the design of new experiments and methods. A common approach is to study small-scale processes in the field and laboratory and then extrapolate that information to larger spatial scales and longer timescales using numerical simulations. I’ve used that approach in the Everglades to study the formation and degradation of a strikingly patterned landscape that is of prime interest in restoration activities. There, I needed to perform experiments in field and laboratory flumes to understand how organic sediment moved through canopies of marsh vegetation, monitor surface water and groundwater biogeochemistry to understand how evapotranspiration affected nutrient availability and plant growth, and develop new optical techniques for fingerprinting organic particles. The findings of this field and laboratory research led to the development of a simulation model that I used to test different hypotheses of landscape evolution. Now I am using similar techniques to evaluate whether radical new practices for restoring streams are sustainable (field site in Lancaster, PA), understand how hydrologic connectivity affects water quality and vegetation community patterning in the Brazilian Pantanal, and examine interactions between vegetation, biofilms, and land building processes in coastal marshes and river deltas.
Although field work and laboratory work are fun and create great stories (some of which I put into my children’s book about the Everglades!), they are also very expensive, time consuming, and difficult. One thing I would like to accomplish in my career is to find new ways to generalize across geographically and physically diverse landscapes. Is there a finite set of processes—albeit in different combinations—controlling these diverse environments, and if so, how do we detect what those processes are with a minimum set of data and then use our knowledge of them to predict the future? This ability would be particularly useful for solving water resource problems in ungaged basins in the developing world. To that end, I have an ongoing fascination with emerging quantitative analysis tools, particularly in information theory and medicine.
Larsen, L. G., J. Choi, M. K. Nungesser, and J. W. Harvey. 2012. Directional connectivity in hydrology and ecology. Ecological Applications. In press.
Cawley, K., K. D. Butler, G. R. Aiken, L. G. Larsen, T. G. Huntington, and D. M. McKnight. 2012. Identifying fluorescent pulp mill effluent in the Gulf of Maine and its watershed. Marine Pollution Bulletin. In press.
Larsen, L., N. Aumen, C. Bernhardt, V. Engel, T. Givnish, S. Hagerthey, J. Harvey, L. Leonard, P. McCormick, C. McVoy, G. Noe, M. Nungesser, K. Rutchey, F. Sklar, T. Troxler, J. Volin, and D. Willard. 2011. Recent and historic drivers of landscape change in the Everglades ridge, slough, and tree island mosaic. Critical Reviews in Environmental Science and Technology 41(S1):344-381.
Larsen, L. G. and J. W. Harvey, 2011. Modeling of hydroecological feedbacks predicts distinct classes of wetland channel pattern and process that influence ecological function and restoration potential. Geomorphology 126: 279-296.
Harvey, J. W., G. B. Noe, L. G. Larsen, D. J. Nowacki, and L. E. McPhillips, 2011. Field flume reveals aquatic vegetation’s role in sediment and particulate phosphorus transport in a shallow aquatic ecosystem. Geomorphology 126: 297-313.
Wheaton, J. M., C. Gibbins, J. Wainwright, L. Larsen, and B. McElroy, 2011. Preface: Multiscale feedbacks in ecogeomorphology.Geomorphology 126: 265-268.
L. Larsen, S. Moseman, A. Santoro, K. Hopfensperger, and A. Burgin. 2010. A complex-systems approach to predicting effects of sea level rise and nitrogen loading on nitrogen cycling in coastal wetland ecosystems. Pages 67-92 in P.F. Kemp[Ed.]. Eco-DAS VIII Symposium Proceedings. American Society of Limnology and Oceanography, doi:10.4319/ecodas.2010.978-0-9845591-1-4.67.
Larsen, L. G. and J. W. Harvey, 2010. How vegetation and sediment transport feedbacks drive landscape change in the Everglades and wetlands worldwide. The American Naturalist 176(3), E66-E79.
Larsen, L.G., G. R. Aiken, J. W. Harvey, G.B. Noe, and J. P. Crimaldi, 2010. Using fluorescence spectroscopy to trace seasonal DOM dynamics, disturbance effects, and hydrologic transport in the Florida Everglades. Journal of Geophysical Research 115, G03001, doi: 10.1029/2009JG001140.
Noe, G. B., J. W. Harvey, R. W. Schaffranek, and L. G. Larsen, 2010. Controls of suspended sediment concentration, nutrient content, and transport in a subtropical wetland. Wetlands 30:39-5.
Larsen, L. G., J. W. Harvey, and J. P. Crimaldi, 2009c. Prediction of bed shear stresses and landscape restoration potential in the Everglades. Ecological Engineering 35, 1773-1785.
Harvey, J.W., R.W. Schaffranek, G.B. Noe, L.G. Larsen, D. Nowacki, and B.L. O’Connor, 2009. Hydro-ecological factors governing surface-water flow on a low-gradient floodplain. Water Resources Research 45, W03421, doi:10.1029/2008WR007129.
Larsen, L. G., J. W. Harvey, and J. P. Crimaldi, 2009b. Morphologic and transport properties of natural organic floc, Water Resources Research 45, W01410, doi:10.1029/2008WR006990.
Larsen, L.G., J.W. Harvey, G. B. Noe, and J. P. Crimaldi, 2009a. Predicting organic floc transport dynamics in shallow aquatic ecosystems: Insights from the field, the laboratory, and numerical modeling, Water Resources Research 45, W01411, doi:10.1029/2008WR007221.
Larsen, L.G., J.W. Harvey, and J.P. Crimaldi, 2007. A delicate balance: ecohydrological feedbacks governing landscape morphology in a lotic peatland, Ecological Monographs 77(4), 591-61.
Larsen, L.G. and J.P. Crimaldi, 2006. The effect of photobleaching on PLIF (planar laser-induced fluorescence), Experiments in Fluids41(5), 803-812.
Racing bikes: Cyclocross and road. If you’ve never heard of cyclocross, google it! You’re in for a treat. Everyone loves cyclocross.
Cooking: There is definite positive feedback between cooking and racing bikes. I love to discuss food philosophy, and, ok, anything about food.
Poetry, guitar, dancing, and art (PGDA): The yin to the yang of my research. Food for the soul.
Hiking: Exerts a significant (p<0.05) positive effect on research and PGDA.
Doing all of the above with friends and dogs: Though maybe I’ll leave the dogs out of the bike racing. Like squirrels, dogs don’t go well with fast bikes.