Participating Faculty & Research Components

2011 Cohort

Click each faculty member’s name for more detailed information.

Participating Faculty

Principal Investigator: Dr. Mark Brown

Department of Environmental Engineering Sciences

Expertise: Mark Brown is a systems ecologist with special interests in modeling coupled human and natural systems. He is a professor in UF’s Department of Environmental Engineering Sciences, Director of the Center for Environmental Policy and acting Director of the Center for Wetlands. He teaches numerous graduate courses related to coupled human and natural systems including: Ecological Engineering, Ecological and General Systems, Environmental Planning, Adaptive Ecological Restoration, and Energy Analysis. More information can be found here.

Goals of the Systems Modeling Component: The prediction or extrapolation of reference (baseline) conditions with regard to the development and management of nutrient criteria and the use of models as tools for watershed management once nutrient criteria have been established.

1. Synthesize understanding of the suite of models used in watershed management.
2. Apply models to the study watershed to test their strengths and weaknesses.
3. Interface with other program components to provide an integrative framework.
4. Explore use of models as tools for communicating complex systems to stakeholders.

There is a plethora of models related to assessment of nutrients in surface waters, from evaluating within-system trophic conditions to estimating loading from entire watersheds. Most models were developed for use in temperate water bodies in North America and Europe, but few have been calibrated or applied to shallow, naturally eutrophic, sub-tropical lakes. Additionally many rely on national databases and thus are not regionally applicable, especially to Florida’s climatic and geologic conditions. Therein lays fruitful territory for our modeling efforts.

The modeling component of our program will focus on two areas with regard to the development and management of nutrient criteria. The first area is prediction or extrapolation of reference (baseline) conditions and the second area deals with the use of models as tools for watershed management once nutrient criteria have been established. Because the modeling component is synthetic in nature, it will interface with the other research areas and provide an integrative framework. Of particular interest is the interface with the social/policy dimensions of the program to determine how best to use models as tools for communicating information about complex system functioning to stakeholders.

Dr. Mark Brenner

Department of Geological Sciences

Expertise: Mark Brenner is a limnologist/paleolimnologist with special interests in tropical and subtropical lakes and watersheds. He is a Professor in UF’s Department of Geological Sciences and serves as Director of the Land Use and Environmental Change Institute (LUECI). He teaches courses in Paleolimnology, Limnology, Florida Lake Management, and Tropical Field Ecology, the latter in Mexico. He is Co-Editor-in-Chief of the Journal of Paleolimnology. More information can be found here.

Goals of the Paleolimnology Component: Evaluate baseline (predisturbance) conditions in lakes relative to target NCC values and develop alternative strategies for setting numeric criteria.

1. Compile existing paleolimnological data that demonstrate the range of trophic state responses to human disturbances.
2. Evaluate baseline nutrient concentrations among Florida lakes and establish if such predisturbance nutrient values in some regions exceed proposed NNCs.
3. Explore the potential for using paleolimnology to develop flexible NNCs for lakes.
4. Train students in paleolimnological methods and interpretation.

This work will use the sediment record of historic trophic state change in Florida lakes to test whether application of rigid NNCs is appropriate. Previous paleolimnological investigations used multiple lines of evidence (e.g. nutrients, diatoms, animal microfossils, algal pigments) in 210Pb-dated sediment cores to infer historical nutrient concentrations in Florida water bodies. In some cases, human disturbances clearly increased nutrient concentrations, which in turn caused biological changes. Diatom assemblages have proven to be reliable estimators of past water column nutrient levels, and measurements of plant pigments, especially those that pertain exclusively to cyanobacteria (myxoxanthophyll and oscillaxanthin), have been used to demonstrate that proliferation of blue-green algae has been a recent phenomenon in many water bodies. Pertinent to the issue of NNC implementation in Florida is the paleolimnological finding that many lakes, especially those in phosphate-rich regions, have naturally high nutrient concentrations. This suggests that some lakes are naturally eutrophic and do not require “restoration” to a low-nutrient state.

Dr. Mark Clark

Department of Soil and Water Science

Expertise: Mark Clark has expertise in wetland ecology, water quality and watershed processes. His research interest include wetland nutrient assimilation and storage processes, vegetative succession dynamics, wetland macrophyte ecophysiology, and ecological engineering design using natural and integrated processes to improve water quality and enhance ecological function of altered landscapes. He is an Associate Professor in the Soil and Water Science Department and is also an Extension Specialist of Wetlands and Water Quality with UF’s Institute of Food and Agricultural Sciences. He teaches courses in Wetlands and Water Quality.

Goals of the Nutrient BMPs Component: Once established, the capacity to achieve numeric nutrient criteria will depend on development and implementation of nutrient management strategies/practices that can address both new and “legacy” sources of nitrogen and phosphorus within a watershed. Regulatory provisions presently provide a presumption of compliance to agricultural operations if recommended BMPs are implemented, and urban landscaping and stormwater BMPs are being adopted into local and state regulations in an effort to meet various permit requirements. However, the capacity of BMPs to meet numeric nutrient criteria as well as the economic feasibility to implement those strategies necessary to achieve numeric nutrient criteria are uncertain. This component of the project will evaluate how effective existing BMPs might be at achieving numeric nutrient criteria as well as some of the tradeoffs between implementation of BMPs necessary to meet numeric nutrient criteria and the viability of agricultural and urban systems. Specific goals within this component are:

1. How effective will present agricultural and urban BMP’s be at meeting numeric nutrient criteria?
2. What level of BMP implementation will be required to meet numeric nutrient criteria and how do BMPs related to source control vs. treatment differ in effectiveness and for different land use types?
3. What are the implications of increased cost of BMP implementation on the viability of agricultural commodities and urban areas?
4. What are tradeoffs (in resources, production yield, cost, treatment etc.) between the degree of BMP implementation and the degree of certainty in meeting numeric nutrient criteria?
5. Can more effective reuse of the nutrient waste stream within and between agriculture and urban environments increase a systems ability to achieve numeric nutrient criteria or would it impact efforts to manage nutrient loads, and which approach would be more cost effective?

Dr. Matt Cohen

School of Forest Resources and Conservation

Expertise: Matt Cohen is an ecologist and hydrologist with particular interests in wetlands and rivers. He is an Assistant Professor in UF’s School of Forest Resources and Conservation. He teaches courses in Ecohydrology and Watershed Management. More information can be found here.

Goals of the Ecohydrology Component: Evaluate and predict river network nutrient losses and transformations under varying environmental, geomorphic and hydrologic settings, to aid in setting downstream protective values (DPVs), a core component of NNC for lotic systems. Specific Ecohydrology goals include:

1. Synthesize existing frameworks for predicting longitudinal and network-scale nutrient transformations.
2. Evaluate the applicability of these models (and embedded parameters) for Florida conditions (e.g., blackwater rivers, low-gradient systems, strong wetland interactions).
3. Develop and implement techniques for the empirical estimation of river network nutrient processing to evaluate and improve existing models.
4. Translate findings into guidance documents that can be used as the empirical basis for regulatory establishment of downstream protective values.

A critical and underappreciated facet of the numeric nutrient standards in flowing waters is adoption of “downstream protective values” (DPVs) that would set nutrient criteria for rivers and streams to protect lakes and estuaries downstream, even where in-stream biological responses to nutrient enrichment are not obvious. During passage through a river network, nutrients are processed to a highly variable degree in response to variation in water chemistry, flow, channel morphology and riparian interactions; the proposed standards consider distance from a sensitive water body and assume a fixed rate of removal in time and space. Although longitudinal nutrient removal rates have become increasingly well constrained in other parts of the, particularly for small streams, there is very little information available for Florida, or for the large rivers that, per unit length, do most of the removal work. Localized study is required to establish the controls and process rates for both nitrogen and phosphorus. Emerging methods for quantifying nutrient uptake and recycling kinetics in streams and rivers will be applied to help establish these DPVs.

Dr. Tom Frazer

Forest Resources and Conservation

Expertise: Tom Frazer is an aquatic ecologist whose recent research is focused on the transport, transformation and fate of nutrients in riverine, estuarine and nearshore coastal ecosystems. He is a Professor in UF’s School of Forest Resources and Conservation and serves also as Associate Director and Leader of the Fisheries and Aquatic Sciences Program. He teaches Marine Ecological Processes and Field Ecology of Aquatic Organisms. Additional information can be found here.

Goals of the Ecological Consequences of Nutrient Enrichment Component: To understand more fully the effects of increased nutrient delivery on key biogeochemical and ecological processes that, in turn, influence the structure and function of aquatic ecosystems. Specific Ecological Consequences of Nutrient Enrichment goals include:

1. Differentiate natural variation in water quality from persistent declines that arise from human activities and threaten to degrade rivers and estuarine systems.
2. Identify targets for diagnostic studies that optimize management actions.
3. Design effective and efficient long-term monitoring to document the success of management and guide responses to unforeseen circumstances.

Aquatic resources are threatened worldwide. More intensive land use, growing populations requiring water for drinking and irrigation, and pollution from urban, industrial and agricultural activities have disrupted the water cycle and transformed ecosystems. In addition, the quality and security of aquatic resources are stressed by extreme events such as hurricanes, monsoonal flooding, and droughts that may be intensified by climate change. These threats are particularly evident in Florida where aquatic systems provide significant commercial and recreational opportunities. In fact, stakeholders have raised serious concerns about our water and associated resources.

The overarching goals of my individual and collaborative research efforts are to develop and transfer into management a mechanistic understanding of the effects of nutrient enrichment in aquatic systems, with a major focus on spring-fed rivers and associated estuaries along Florida’s central Gulf coast. Achieving these goals involves attaining several inter-related objectives that stem from long-term, large-scale sampling programs implemented over the last decade. The patterns documented by these regional programs that regularly sample over 100 stations spanning more than 100 kilometers of coastline provide a spatial and temporal context for designing, implementing and interpreting interdisciplinary experiments that elucidate ecological processes shaping the structure and function of aquatic ecosystems.

Dr. Wendy Graham

Department of Agricultural and Biological Engineering

Expertise: Wendy Graham is the Carl S. Swisher Eminent Scholar in Water Resources in the Department of Agricultural and Biological Engineering at the University of Florida and Director of the University of Florida Water Institute. She conducts research in the areas of integrated hydrologic and water quality modeling; groundwater resources evaluation and remediation; evaluation of impacts of agricultural production on surface and groundwater quality; evaluation of impacts of climate variability and climate change on water resources; stochastic modeling and data assimilation. More information can be found here.

Goals of the Hydrologic Processes Component: The routing and flux of water dictates types and rates of physical, chemical and biological processes affecting transport and transformation of nutrients in watersheds. The goal of this facet of the program is to understand the local-scale couplings and feedbacks among climate, land-use, water use, and nutrient cycling in watersheds, and how these relationships scale-up to affect nutrient fluxes to springs, lakes, wetlands and estuaries. Potential research questions include:

1. How do climatic, geologic and anthropogenic drivers (land use and water use) determine the fluxes and flowpaths of water from the land to receiving waters (springs, rivers, lakes, estuaries)?
2. What are the sources of nutrients to the mobile water phase and how do climate, soils, geology, landscape position and land cover influence them?
3. What are the sinks of N and P from the mobile water phase and how do soils, geology, landscape position and land cover influence them?
4. How can new process knowledge gained by answering questions 1 though 3 above be most efficiently incorporated into integrated hydrologic-water quality models and used to improve the development of socially-acceptable, ecologically-protective nutrient management strategies at the watershed scale.

Dr. Christine Overdevest

Sociology, Criminology and Law

Expertise: Christine Overdevest is conducts research and writes about issues related to public policy and environmental governance. She is an Assistant Professor in the Department of Sociology, Criminology and Law at the University of Florida. More information can be found here.

Goals of the Environmental Policy and Governance Component: Understand technical, legal and policy issues related to interpretation and application of the numeric and narrative approaches to nutrient management, with a focus on how courts, agencies, and affected stakeholders mobilize and interpret scientific data, promote and adjudicate claims, and settle disputes and controversies. Specific Environmental Policy and Governance goals include:

Particular attention to key themes such as whether particular water bodies are over- or under-protected, the need for site-specific alternative criteria, and the adequacy of science will be addressed. The project findings will feed into debates about whether numeric nutrient management approaches enable adjustment and adaptation to local conditions, and/or significantly limit or increase societal capacity to learn from management, i.e., to broader questions regarding the normative desirability of rigid vs. flexible regulation for ‘good’ law/policy. These questions are especially timely because more flexible approaches such as the narrative nutrient standards are being replaced by rigid approaches without adequate understanding of the ecological or policy implications.

This social science and law aspect of this project will operate in collaboration with the biological, geological and ecological aspects to generate a comprehensive interdisciplinary approach to the evaluation of numeric vs. narrative approaches to management. In the course of developing their research projects, the Fellows will:

1. Search for and identify published administrative or judicial decisions that interpret narrative nutrient criteria.
2. Search for and analyze underlying agency files to determine how the narrative nutrient criteria were interpreted and applied, as well as any conflicting interpretations of data, policy or law and how they were resolved.
3. Identify published rules adopting numeric nutrient criteria, review the underlying administrative record, and identify cases in which numeric criteria were used in review of permit applications for significant technical and policy conflicts for review by a larger interdisciplinary group.
4. Identify and interview watershed stakeholders, managers, and policy makers in order to understand their interests/values/perceptions regarding the benefits and weaknesses of narrative vs. numeric nutrient criteria.