Progress 10/01/08 to 09/30/13
Outputs
Target Audience: Science community - Our work has contributed to an improved understanding of how rivers process nutrients, and thus how they respond to nutrient enrichment. This is relevant to Florida's waterways, but also more broadly to other areas of the world. Our work has been cited by scientists around North America and overseas, underscoring that while our work is local, its impact is global. A recent workshop that we hosted on sensors and analysis was attended by over 40 scientists from all over the country, and received excellent feedback on content and design. Management Agencies - Our work has prompted local management agencies to invest heavily in new types of nutrient sensors to better understand and monitor the water resources of Florida. This major investment has been enabled by both the intellectual content of our work that shows that these sensors can provide important and unique insights about the health and trajectories of lakes and rivers, and by the protocols that we've developed for deploying, maintaining, and managing the data from these sensors. Professionals - Some of our work in the last year has focused on outreach to the industry of environmental professionals interested in water quality monitoring. Our work was featured in a national magazine for environmental science and technology professionals, and has also led to collaborations with local consulting firms interested in providing the capacity to take similar measurements. General Public - We have dedicated considerable effort to reaching out to the general public via speaking engagements, workshops, and conversations in the field. we believe that the public is more aware of the nutrient issues, and also the limitations of the current paradigms for thinking about nutrient impacts in flowing waters, as a result of our efforts. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Training Activities - We hosted and led a workshop on nutrient sensors (held in Gainesville FL in February 2013). Students affiliated with the project served as coordinators and instructors, as did the PI. It was attended by 40 scientists from around the country. Students and faculty have attended conferences (American Geophysical Union, Society for Freshwater Science, Society of Wetland Scientists) to share project results. How have the results been disseminated to communities of interest? In addition to the scientific outreach via peer reviewed publications, we have disseminated the results of our work via trade magazines and the newspapers. Our work was featured in the Environmental Monitor in June 2013 (http://www.fondriest.com/news/). Our work has also been featured in the press releases (related to forest management for water yield), and local newspapers (related to work challengingthe role of nutrients in creating algal blooms). What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
There are 3 main project accomplishments in the last year. 1) We have developed a new method for evaluating N dynamics in rivers using a Lagrangian (longitudinal) approach, rather than the typical Eulerian (point-based) approach. This has yielded new insights about the removal rates, time variation in removal, and also the kinetics of removal (i.e., how removal changes with concentration). All of these contribute to both our ability to assess N contamination in the context of Florida's waterways, but also more generally to water bodies all over the world, particularly larger rivers that have been scarcely studied because methods for analysis are not well developed. This work is under review at Limnology and Oceanography. A parallel effort to understand the kinetics of N removal, and thus the onset of nutrient limitation in flowing waters is in press at Freshwater Science. 2) We have recognized the coupling of N dynamics to other elements, and thus extended our approach to nitrogen to myriad elements across the periodic table. This includes, in particular, phosphorus and metals. Two recent publications document that effort, and illustrate how critical it is to explicitly acknowledge the coupled nature of biogeochemical cycles rather than considering each element as independent. This work is published in Ecological Monographs and Chemical Geology. 3) We have refined methods for hydrologic analysis of wetlands. While this work is slightly tangential to a direct emphasis on nutrient cycles, it sets the stage for a far more rigorous analysis of nutrient dynamics than has previously been possible. In particular, we can now verify the empirical measurement of evapotranspiration and groundwater exchange from analysis of fine scale variation in water levels. This work is published in Hydrological Processes, and applications of the method to understanding the ecosystem services that accrue from wetlands are published in Ecological Applications. Another application of the approach resulted in a model to evaluate the role of upland forest management on water yield (and by extension nutrient yield) in the Southeastern US. That work is published in the Journal of the American Water Resources Association.
Publications
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2013
Citation:
Kurz, M.J., V. de Montety, J.B. Martin, M.J. Cohen and C.R. Foster. In press. Controls of diel variations in metal concentrations in a karst river at seasonal scales. Chemical Geology
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
McLaughlin, D.L. , D.R. Kaplan and M.J. Cohen. 2013. Managing forests for increased regional water yield. Journal of the American Water Resources Association 49:953-965
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
McLaughlin, D.L. , and M.J. Cohen. 2013. Realizing ecosystem services: Wetland hydrologic function along a gradient of ecosystem condition. Ecological Applications 23:1619-1631
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2013
Citation:
McLaughlin, D.L. , and M.J. Cohen. 2012. Ecosystem specific yield for estimating evapotranspiration and groundwater exchange from diel surface water variation. Hydrological Processes doi:10.1002/hyp.9672
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Deimeke, E.*, M.J. Cohen and K.C. Reiss. 2013. Temporal stability of vegetation indicators of wetland condition. Ecological Indicators 34:69-75
- Type:
Journal Articles
Status:
Under Review
Year Published:
2013
Citation:
Hensley, R.H., M.J. Cohen, and L.V. Korhnak. In review. Inferring Nitrogen Removal Dynamics Using Longitudinal River Profiles. Limnology and Oceanography
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Cohen, M.J., M.J. Kurz*, J.B. Heffernan, J.B. Martin, R.L. Douglass*, C.R. Foster and R.G. Thomas. 2013. Diel Phosphorus Variation and the Stoichiometry of Ecosystem Metabolism in a Large Spring Fed River. Ecological Monographs 83:155176. http://dx.doi.org/10.1890/12-1497.1
- Type:
Journal Articles
Status:
Accepted
Year Published:
2013
Citation:
King, S.*, J.B. Heffernan and M.J. Cohen. In press. Nutrient flux, demand, and autotrophic limitation in lotic systems. Freshwater Science
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Progress 10/01/11 to 09/30/12
Outputs
OUTPUTS: Outputs on this CRIS project fall into three categories: 1) Refinement of our understanding of fate and transport of N in the aquifer, wetlands and rivers in north Florida, with an emphasis on novel observation tools (sensors) that allow us to understand the fine-scale dynamics of delivery and removal, and detailed hydrologic measurements that allow us to understand the fundamental processes of water movement through systems that governs how N retention happens. Specifically, we have used isotopes to understand how N is removed in spring-fed rivers, used a variety of novel methods to quantify denitrification in the Floridan Aquifer, used sensors to evaluate river nutrient concentrations using longitudinal profiling (a wholly new approach to thinking about river nutrient processing), and developed a new set of sensor tools that will work for nutrient sensing in blackwater rivers where the current sensors are unable to obtain high quality measurements. 2) Policy-related activities regarding the importance of nitrogen reduction in Florida, and the perils of overemphasizing the single causative importance of nitrogen in the ecological changes that are being observed in Florida's springs. This includes providing technical support for BMPs on forest fertilization, advising Senator Bob Graham on the role of N in the changing ecology of springs, working with stakeholders to understand N enrichment effects and plan springs restoration, and advising the St Johns River Water Management District on the development of a springs research and management initiative. 3) Coupling our emerging understanding of nitrogen in springs and rivers with improved analysis of other elements (e.g., phosphorus, calcium, carbon, sulfur). This research on coupled elemental cycles has importance at the local, regional and global scales as humans modify element budgets, and in so doing have unexpected consequences on ecosystem processes. For example, we have shown that cycles of P, Ca and a variety of other elements are coupled to C and N cycles, but in unexpected ways, implying overlapping pathways of nutrient retention and variation in cellular assimilation timing. PARTICIPANTS: PI - Matthew Cohen Personnel - Larry Korhnak, Bobby Hensley, Dina Liebowitz, Rachel Douglass, Marie Kurz, Daniel McLaughlin, Sean King, Jake Diamond, Courtney Reijo TARGET AUDIENCES: Hydrologic and biogeosciences research communities - WMD scientists and policy makers - General public (interested spring and wetland health) - Forest industry and Florida Forest Service PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
We have sought to impact to both the scholarly community and local regulatory and stakeholder communities. Evidence of success includes the following new knowledge: 1) nutrient retention in spring rivers is rapid and dominated by denitrification; 2) denitrification is occuring in the Floridan Aquifer (despite suppositions that it cannot), and leads to attenuation of over 30% of total N loaded from land; large variation in denitrification between springs remains unresolved; 3) the methods developed allow us to establish nutrient limitation is a more robust and defensible way, which provides an opportunity to manage water quality and land use more effectively; 4) despite the relevance of nitrogen to ecosystem processes, the dominant control on algal proliferation is the density of snails, populations of which respond strongly to dissolved oxygen concentrations in the spring water; 5) submerged aquatic vegetation exerts strong controls on river hydraulics, and creates conditions where a large fraction of water in the river has long residence times and therefore high capacity for nutrient removal; and 6) the kinetics of nutrient retention in streams and rivers can be studied using pulse additions of nutrients, which reveals information about the rate and mechanism. Each of these core findings has theoretical (e.g., challenging or refining assumptions and biogeochemical or hydrologic process) and practical significance (e.g., how best to manage water resources based on improved understanding of sources, fates, and consequences of nutrient contamination).
Publications
- Cohen, M.J., J.B. Heffernan, A. Albertin and J.B. Martin. 2012. Inference of Riverine Nitrogen Processing from Longitudinal and Diel Variation in Dual Nitrate Isotopes. Journal of Geophysical Research - Biogeosciences 117(G1), G01021
- Hensley, R.T., and M.J. Cohen. 2012. Controls on Solute Transport in Large Spring Fed Rivers. Limnology and Oceanography 57:912
- Kaplan, D.A., R. Paudel, M.J. Cohen and J.W. Jawitz. 2012. Orientation Matters: Patch Anisotropy Controls Discharge Competence and Hydroperiod in a Patterned Peatland. Geophysical Research Letters 39 (17), L17401
- McLaughlin, D.L., and M.J. Cohen. 2012. Ecosystem specific yield for estimating evapotranspiration and groundwater exchange from diel surface water variation. Hydrological Processes doi:10.1002/hyp.9672
- Liebenow, D.K., M.J. Cohen, T. Gumbricht, K.D. Shepherd and G. Shepherd. 2012. Do ecosystem services influence household wealth in rural Mali Ecological Economics 82:33-44
- Heffernan, J.B., A.R. Albertin, M.L. Fork, B.G. Katz and M.J. Cohen. 2012. Denitrification and inference of nitrogen sources in the karstic Floridan Aquifer. Biogeosciences 9:1671-1690
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Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: There are 5 areas in which to report outputs. First, we refined methods for evaluating how flowing water systems use N, using Florida's springs as model systems. We presented results at conferences (American Geophysical Union 2010, Society of Freshwater Science 2011). In particular, we developed a new method that allows spatial disaggregation of N removal by measuring N concentrations at high spatial resolution longitudinally (~50 cm). I gave a plenary talk on this material at a USGS workshop on optical sensors held in Shepherdstown WV in summer 2011. Second, we added capacity to evaluate P in the same way, which is relevant in providing insight into elemental coupling that occurs in rivers. This work was part of an invited talk at AGU (2010), and a pending manuscript. The third area is use of novel methods (isotopes, mass spectrometry, mass balance) to evaluate nutrients in Alexander River; findings suggest that these tools measure ecosystem nutrient limitation, which is relevant to setting numeric nutrient criteria. Fourth, I have been active on policy related work. I served as a member of the technical review team for Florida's new dissolved oxygen criteria (links to N contamination), and have been involved in the science required to evaluate recently proposed numeric nutrient criteria. Finally, we have recently completed work that permits real-time computation of the water budget in isolated wetlands, which is a critical prerequisite for understanding the N cycle both within wetlands and at the watershed scale. In these areas, my group (3 PhD Students, 1 Post-Doc) have made 15 presentations to national, state, local and UF audiences. PARTICIPANTS: PARTICIPANTS: PI - Matthew Cohen Personnel - Larry Korhnak, Bobby Hensley, Andrea Albertin, Dina Liebowitz, Chad Foster, Carolyn Ball, Rachel Douglass, Marie Kurz, Daniel McLaughlin, Sean King, Jake Diamond PARTNER ORGANIZATIONS: Duke University, Florida International University, St Johns River Water Management District, Florida Forest Service, Florida Department of Environmental Protection, National Science Foundation, USGS, National Council for Air and Stream Improvement, Rayonier. COLLABORATORS AND CONTACTS: Jim Heffernan, Wendy Graham, Patrick Inglett, Jon Martin, Brian Pellerin, Tom Frazer, Wil Wollheim, Todd Osborne, Jim Jawitz, Ray Thomas, Brian McGlynn, Emily Bernhardt. TRAINING AND PROFESSIONAL DEVELOPMENT: Trained 4 graduate students, and 2 post-doctoral researchers; work closely with WMD scientists to interpret and refine results; TARGET AUDIENCES: TARGET AUDIENCES: Hydrologic and biogeosciences research communities - WMD scientists and policy makers - General public (interested spring and wetland health) - Forest industry and Florida Forest Service EFFORTS - Numerous guest lectures - Multiple seminars (Wetlands, Geology, Water Institute) - Systems thinking curriculum (with Martha Monroe) for undergraduates and general public - Lead tours of springs/wetlands for students and citizens - Invited seminars to consulting firms, stakeholder groups, technical advisory groups - Workshop on optical sensors for inferring environmental processes PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
In keeping with the mission of the land grant universities, we have sought to impact to both the scholarly community and local regulatory and stakeholder communities. Evidence of success includes the following new knowledge: 1) some springs are N limited, most are not even at background concentrations, suggesting that remedial efforts to reduce N loading may not have the expected impacts, 2) diel P dynamics are evident in spring rivers, which result from the combined effects of geochemical and biological removal pathways, 3) the diel nitrate and phosphate signals yield plausible ecosystem-scale stoichiometry, the first time that such a computation has been possible, 4) top-down controls can be experimentally verified, with the additional observation that snail control is strong when algae are low density, but cannot reverse algal accumulation when it is severe, suggesting alternative stable states to spring-river ecosystems, 5) refinements to the White method make it possible, for the first time, to investigate site-level water budgets, and evaluate the provision of wetland ecosystem services, 6) isolated wetlands exert strong control over regional water table elevations, thereby affecting streamflow and other landscape hydrologic properties despite the absence of a direct surface connection to other water bodies, and 7) nutrient dynamics in streams can be discerned using pulse additions, which reveal strong concentration effects on removal rates, low-concentration saturation, and hystersis in the removal rate response. Each of these core findings has both theoretical significance (e.g., challenging or refining assumptions and biogeochemical or hydrologic process) and practical significance (e.g., how best to manage water resources based on improved understanding of sources, fates, and consequences of nutrient contamination.
Publications
- McLaughlin, D.L., and M.J. Cohen. 2012 In review. Ecosystem specific yield for estimating evapotranspiration and groundwater exchange from diel surface water variation. Ecohydrology.
- Cohen, M.J., D.L. Watts, J.B. Heffernan and T.Z. Osborne. 2011. Reciprocal Biotic Control on Hydrology, Nutrient Gradients and Landform in the Greater Everglades. Critical Reviews in Environmental Sciences 35:392-409
- Osborne, T.Z., S. Newman, P.I. Kalla, G.L. Bruland, M.J. Cohen, L.J. Scinto and L.R. Ellis. 2011. Landscape patterns of significant soil nutrients and contaminants in the Greater Everglades ecosystem: Past, present and future. Critical Reviews in Environmental Science and Technology 41:121-148
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Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: 1) The main outputs for the reporting period pertain to work on understanding controls of N cycling in rivers. That work has four areas, all of which have seen progress over the last year. The first focuses on new method development for understanding how N is used in larger rivers, using spring fed rivers in North Florida as a model system. We have presented on this new method at three conferences (American Geophysical Union in 2009 and 2010, and the American Society of Limnology and Oceanography in 2010). The implications of the method are tremendous in that it is scalable to rivers of different sizes, provides detailed new insight into the temporal dynamics of N use, and allows instantaneous estimates of elemental ratios in flowing water ecosystem primary production. As part of that work, I was invited to give a plenary talk at an upcoming USGS sensor workshop. A second area is on the use of dual stable isotopes to better understand controls and drivers of N removal pathways in rivers. We recently submitted a paper on this topic, and have presented work at the American Geophysical Union meeting in 2009. This work revealed evidence of diurnal variation in denitrification in rivers, driven presumably by varying concentrations of oxygen in response to photosynthesis, which counters broadly adopted assumptions about the temporal stability of heterotrophic processes in streams. As such, it marks a unique application of the dual isotope method, and one for which future work on mechanisms of diurnal variation will be required. Finally, we continue to focus attention on the hydraulics of these rivers since that physical process controls reactive solute behavior. An MS student in my lab was recently awarded the SFRC Thesis of the Year for his work characterizing karst river hydraulics, and he has submitted a manuscript that fills an important knowledge gap in our understanding of how vegetation affects flow in rivers. Finally, our work to understand alternatives to N enrichment as a cause for algal proliferation in springs has recently garnered state-wide attention with an article published in the Orlando Sentinel describing the research of one of my PhD students looking at the role of snail grazers in regulating algal accumulation. This work is of both theoretical and practical value, and is being prepared into what will be a high impact journal article. My group (1 post-doc, 3 students) have made 14 presentations to local, state, regional and national audiences on this entire body of work in 2010. Another facet focuses on wetland hydrology, and we have made considerable progress, with two manuscripts currently in press and several national state and local presentations. Our work focuses, for now, on describing wetland transpiration and primary production; we are actively seeking funds that link these measurement techniques to denitrification potential in wetlands. We are close to submitting a proposal to the National Science Foundation for a Science and Technology Center (ca. $25 million) that will establish a center to examine the global macro-elemental coupling between nitrogen and carbon in wetland ecosystems. PARTICIPANTS: PI - Matthew Cohen Personnel - Larry Korhnak, Bobby Hensley, Dina Liebowitz, Chad Foster, Jim Heffernan, Jason Evans, Rachel Douglass, Veronique de Montety, Marie Kurz, Lauren Long, Daniel McLaughlin, Joseph Delasantro, Jake Diamond Partner Organizations: Florida International University, St Johns River Water Management District, Southwest Florida Water Management District, Three Rivers Trust Inc., Florida Division of Forestry, Alachua County Environmental Protection Department, Florida Department of Environmental Protection, Suwannee River Water Management District, National Science Foundation, USGS, University of New Hampshire Collaborators and Contacts: Wendy Graham, Joe Delfino, Jon Martin, Brian Pellerin, Tom Frazer, Sky Notestein, Mark Brown, Jim Stevenson, Martha Monroe, Wil Wollheim, Brian Bergamaschi, Ramesh Reddy, Mark Clark, Todd Osborne, Jim Jawitz, Ray Thomas Training and Professional Development: Trained 3 graduate students, and 3 post-doctoral researchers; work closely with Water Management District Scientists to interpret and refine results; helped coordinate special sessions at American Geophysical Union, American Society of Limnology and Oceanography, Water Institute symposium on topics related to nutrients in aquatic ecosystems TARGET AUDIENCES: Hydrologic and biogeosciences research communities - Water management district scientists and policy makers - General public (interested in the health of springs and wetlands) - Forest industry and state division of forestry Efforts - Guest lectures in numerous classes - Multiple seminars on campus (Wetlands, Geological Sciences, Water Institute) - Systems thinking curriculum (with Martha Monroe) for undergraduates and the general public [project related to springs research on nutrient enrichment and the causes for algal proliferation] - Lead tours of wetlands for students and interested citizens - Invited seminars to local consulting firms, stakeholder groups, public working groups - Workshop on optical sensors for inferring environmental processes PROJECT MODIFICATIONS: Nothing significant to report this year.
Impacts
In keeping with the mission of the land grant universities, we have sought to impact to both the scholarly community and local regulatory and stakeholder communities. Evidence of success includes the following new knowledge: 1) aquifer denitrification is occurring in the Floridan, and confounds our ability to trace the sources of N contamination, 2) vegetation strongly regulates river hydraulic behavior, influencing in particular the mean residence time and distribution of residence times of water in these karst channels, 3) diel variation in nitrate concentrations is observed across a wide array of ecosystems, but not in those rivers that are demonstrably N limited, suggesting that diel variation may be a signal of luxury uptake and thus a good diagnostics indicator of riverine nutrient status, 4) snails are highly influential on algal accumulation rates in spring rivers, and appear to exert their influence most strongly above a density threshold at or near ambient concentrations, 5) the White method is highly applicable to ET estimation in surface water systems with several critical modifications to account for site geometry and sensor temperature sensitivity, 6) isolated wetlands exert strong control over regional water table elevations, thereby affecting streamflow and other landscape hydrologic properties despite the absence of a direct surface connection to other water bodies, 7) isotopes can be used to better understand the short time variation of N removal processes in rivers, and 8) a new measure of uptake length is a far more effective predictor of stream nutrient limitation than concentration alone. Each of these core findings has both theoretical significance (e.g., challenging or refining assumptions and biogeochemical or hydrologic process) and practical significance (e.g., how best to manage water resources based on improved understanding of sources, fates, and consequences of nutrient contamination.
Publications
- Kurz, M.J., V. de Montety, J.B. martin, M.J. Cohen, and C. Foster. 2011. Controls of diel variations in metal concentrations in a karst river at seasonal scales. Geochemica Cosmochemica Act (pending)
- Hensley, R.H. and M.J. Cohen. 2011. Vegetation controls on karst river hydraulics. Limnology and Oceanography: Fluids and Environments (pending)
- King, S., M.J. Cohen and J.B. Heffernan. 2011. Autotrophic uptake length as a predictor of stream ecosystem nutrient limitation. Limnnology and Oceanography (pending)
- Heffernan, J.B., A. Albertin, M. Fork, B.G. Katz and M.J. Cohen. 2011. Denitrification and inference of nitrogen sources in the karstic Floridan Aquifer. Nature Geoscience (pending)
- Cohen, M.J., J.B. Heffernan, A. Albertin and J.B. Martin. 2011. Dual Stable Isotopes of Nitrate for Deconvolving Nitrogen Removal in a Spring-Fed River. Journal of Geophysical Research - Biogeosciences (pending)
- McLaughlin, D., M.J. Cohen and M.T. Brown. 2011. The Ecohydrology of a Pioneer Wetland Species in a Drastically Altered Landscape. Ecohydrology (in press)
- McLauglin, D. and M.J. Cohen. 2011. Considerations for the Application of the White Method in Shallow Water Table Environments. Water Resources Research (in press)
- De Montety, V., J.B. Martin, M.J. Cohen, M.J. Kurz and C.R. Foster. 2011. Influence of diel biogeochemical cycles on carbonate equilibrium in a karst river. Chemical Geology doi:10.1016/j.chemgeo.2010.12.025
- Cohen, M.J., D.L. Watts, J.B. Heffernan and T.Z. Osborne. 2011. Biological controls on hydrology, nutrients and landform in the Everglades. Critical Reviews in Environmental Science and Technology 41:395-429 DOI: 10.1080/10643389.2010.531224
- Heffernan, J.B., and M.J. Cohen. 2010. Direct and indirect coupling of primary production and diel nitrate dynamics in a sub-tropical spring fed river. Limnology and Oceanography 55:677-688
- Heffernan, J.B., D.M. Liebowitz, T.K. Frazer, J.M. Evans and M.J. Cohen. 2010. Algal blooms and the nitrogen-enrichment hypothesis in Florida springs: Evidence, alternatives and adaptive management. Ecological Applications 20:816-829
- Heffernan, J.B., M.J. Cohen, T.K. Frazer, R.G. Thomas, T.J. Rayfield, J. Gulley, J.B. Martin, J.J. Delfino and W.D. Graham. 2010. Hydrologic and biotic influences on nitrate removal in a subtropical spring-fed river. Limnology and Oceanography 55:249-263
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: 1)Our work on the environmental costs of large scale bioethanol production (nitrogen and water use) was presented to the American Water Resources Association via their trade journal (Water Impacts) and was reported on in "Florida Trend", a major regional magazine. Moreover, results of that work were presented at both local and international conferences, including an invitation to speak at the 2009 Society of American Foresters. In addition, that work galvanized a large group of collaborating faculty across academia and government, and we have submitted several large proposals for follow-up work. Finally, I was invited to attend an international bioenergy workshop in Brazil sponsored by the National Science Foundation and their Brazilian and Argentinean counterparts. 2)Our work on sources and fate of nitrogen in riverine systems (using Florida's spring rivers as a model) generated considerable interest at several national and international conferences. In particular, my group has developed a new robust measure of nitrogen processing in rivers with broad applicability to rivers around the nation. This work was presented at the American Society for Limnology and Oceanography in Nice (France), at the North American Benthological Society Meeting, and at a special sensor workshop to which we were invited by the Consortium of Universities for the Advancement of Hydrologic Sciences (CUAHSI). Building on that method, we were able to extend inference possible from isotopic analyses of nitrate, work was recently presented at the American Geophysical Union Annual meeting. This work is of both theoretical and practical value; local water resource management agencies found the work sufficiently relevant to fund two projects that extend that work to new systems. Moreover, we have been able to also develop several new methods for inference of riverine hydraulic properties from dye tracing, which helps us better understand underlying reasons for observed N removal, and, more importantly, makes a strong case for vegetative restoration of river systems in which we work. Finally, our work on the causes of algal proliferation in Florida's springs has gathered a lot of attention. My group (including one post-doc and 2 students) have made 10+ presentations to local, state, regional and national audiences on this work, which suggests that the observations are more consistent with loss of algal grazers than with nitrogen enrichment. 3) To understand the nitrogen cycle in Florida's watersheds requires understanding the hydrology of wetlands that provide landscape treatment. There are numerous modern assumptions about the role of isolated wetlands in healthy watersheds, not least because of recent Supreme Court guidance on wetlands legally under Federal jurisdiction. We have work that seeks to better understand the hydrology of isolated wetlands (now largely unprotected), with a particular emphasis on hydrologic changes with changing land use, which ultimately affects their capacity to provide nitrogen removal services. We have presented preliminary findings of that work to the Environmental Protection Agency and several local environmental agencies. PARTICIPANTS: Individuals PI - Matthew Cohen Personnel - Larry Korhnak, Bobby Hensley, Dina Liebowitz, Chad Foster, Jim Heffernan, Jason Evans, Rachel Douglass, Veronique de Montety, Lauren Long, Daniel McLaughlin, Joseph Dellasantro Partner Organizations Florida International University, St Johns River Water Management District, Southwest Florida Water Management District, Three Rivers Trust Inc., Florida Division of Forestry, Alachua County Environmental Protection Department, Florida Department of Environmental Protection Collaborators and Contacts Wendy Graham, Joe Delfino, Jon Martin, Brian Pellerin, Tom Frazer, Sky Notestein, Mark Brown, Bob Knight, Jim Stevenson, Martha Monroe, Richard Lowrance, George Vellidis Training and Professional Development - Workshop on optical sensors (Burlington VT, August 2009) - Trained 3 graduate students, and 3 post-doctoral researchers - Work closely with Water Management District Scientists to interpret and refine results TARGET AUDIENCES: Target Audiences - Hydrologic and biogeosciences research communities - Water management district scientists and policy makers - General public (interested in the health of springs) - Forest industry and state division of forestry Efforts - Guest lectures in numerous classes - Multiple seminars on campus (Wetlands, Geological Sciences, Water Institute) - Systems thinking curriculum (with Martha Monroe) for undergraduates and the general public [project related to springs research on nutrient enrichment and the causes for algal proliferation] - Lead tours of wetlands for students and interested citizens - Invited seminars to local consulting firms, stakeholder groups, public working groups - Workshop on optical sensors for inferring environmental processes PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Changes in Knowledge 1) We have contributed to an improved understanding of the some of the environmental challenges of large-scale bioethanol production, and have presented information and an analytical framework that could be used to evaluate different feedstocks and processing pathways. 2) We have contributed to our collective understanding of the fate of nitrogen in large rivers, and on the strong coupling of nitrogen processing to other elemental cycles (particularly to production of labile carbon). 3) New knowledge about the hydrologic services provided by isolated wetlands, and the implications for water quality improvement, have been well-received by the EPA, which is seeking sound science to delineate the extent of Federal jurisdiction over wetlands Changes in Actions 1) Our work developing new methods for riverine N processing has already affected other research groups interested in inference from large river systems. In particular, the algorithms that we developed and sensor configurations we used have been adopted. 2) Our work on the root causes of algal proliferation have prompted major policy discussions at the management agencies in the state. To underscore the significance of that work, and the extent to which it is entering the policy dialog, we will be hosting a meeting of the primary Florida Senate committee for the setting of inland water policy in February of this year, with the principal objective of setting sound science-based policy that will help restore these valuable systems. Changes in Conditions 1) Our work is on processes that will engender more targeted policies and practices. As such, the direct link to changes in conditions is hard to assert. Moreover, most of our work deals with systems that have embedded in them long time lags making the inference of changing conditions difficult to establish over the short term.
Publications
- Cohen, M.J. 2008. Springshed nutrient loading, transport and transformations. In M. T. Brown [ed.], Summary and synthesis of the effects of nutrient loading on spring ecosystems and organisms. Florida Department of Environmental Protection, Tallahassee FL
- Cohen, M.J. and Evans J.M. 2008. The water resource implications of large-scale bioethanol production. Water Resources Impact 10(4): 22-26.
- Romanelli, T., M.J. Cohen, M. Milan and M.T. Brown. 2008. Systems Evaluation of Eucalyptus Production in Sao Paolo, Brazil. Forest Science 54:228-241
- Cohen, M.J., E.J. Dunne and G.L. Bruland. 2008. Spatial Structure of Isolated Forested Wetland Soils and Implications for Sampling Design and Condition Assessment. Wetlands 28:34-49
- Heffernan, J.B., M.J. Cohen, T.K. Frazer, R.G. Thomas, T.J. Rayfield, J. Gulley, J.B. Martin, J.J. Delfino and W.D. Graham. 2010. Hydrologic and biotic influences on nitrate removal in a subtropical spring-fed river. Limnology and Oceanography 55:249-263
- Evan, J.M. and M.J. Cohen. 2009. Regional water resource implication of bioethanol production in the Southeastern United States. Global Change Biology 15:2261-2273
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