H31F-0720 

Associations between regional moisture gradient, tree species dominance, and downed wood abundance

* Johnson, A C (ajohnson03@fs.fed.us), USDA, Forest Service, Pacific Northwest Research Station, 620 SW Main, Suite 400, Portland, OR 97205, United States * Johnson, A C (ajohnson03@fs.fed.us), Portland State University, Environmental Sciences and Resources, PO Box 751, Portland, OR 97207, United States Mills, J (jmills@fs.fed.us), USDA, Forest Service, Pacific Northwest Research Station, 620 SW Main, Suite 400, Portland, OR 97205, United States

Downed wood functions as a source of nurse logs, physical structure in streams, food, and carbon. Because downed wood is important in upland and aquatic habitats, an understanding of wood recruitment along a continuum from wet to dry landscapes is critical for both preservation of biodiversity and restoration of natural ecosystem structure and function. We assessed downed wood in public and private forests of Washington and Oregon by using a subset of the Forest Inventory and Analysis (FIA) database including 15,842 sampled conditions. Multivariate regression trees, ANOVA, and t-tests were used to discern environmental conditions most closely associated with abundance of woody debris. Of the 16 parameters included in the analysis, rainfall, forest ownership, number of damaged standing trees, and forest elevation were most indicative of woody debris abundance. The Hemlock/spruce Group, including hemlock, spruce, cedar, and white pine, most associated with wetter soils, had significantly more downed wood than 12 other forest groups. The Ponderosa Pine Group, indicative of drier sites with higher fire frequencies, included ponderosa pine, sugar pine, and incense cedar, and had significantly less downed wood volume. Overall, the amount of woody debris in either the Spruce/hemlock Group or the Ponderosa Pine Group did not change significantly as tree age increased from 5 to 350 years. Plots within the Hemlock/spruce with greater standing tree volume also had significantly greater downed wood volume. In contrast, greater downed wood volume was not associated with greater standing tree volume in the Ponderosa Pine Group. Knowledge of linkages among environmental variables and stand characteristics are useful in development of regional forest models aimed at understanding the effects of climate change and disturbance on forest succession.

H31F-0721 

Forest Management Influence On Hydric Production in a Temperate Rain Forest: a Comparative Study of Small Watersheds

Alvarez, C (calvarezgarreton@gmail.com), Departamento de Ingenieria Civil, Facultad de Ciencias Fisicas y Matematicas. Universidad de Chile, Av. Blanco Encalada 2002, Santiago, RM 8370449, Chile * McPhee, J (jmcphee@ing.uchile.cl), Departamento de Ingenieria Civil, Facultad de Ciencias Fisicas y Matematicas. Universidad de Chile, Av. Blanco Encalada 2002, Santiago, RM 8370449, Chile

In this work we compare hydric production between two micro-watersheds (surface area less than 10 hectares) covered with Nothofagus oblicua and Nothofagus alpina saplings. One of the watersheds was subject to management by thinning on 2002, and contains 23% less trees, which is equivalent to 33% less basal surface respect to the unmanaged control basin. It is expected that differences be solely related to land use differences given that both watersheds have similar geomorphology. Four years (April 2003 through Jun 2007) of hourly streamflow and precipitation data collected on each watershed are analyzed by separating base flow and direct runoff for specific storms selected to represent different conditions of initial soil moisture. Several hydrograph- separation algorithms are tested in order to increase the robustness of our conclusions. Variations in rainfall- runoff coefficients are analyzed in relation to differences in soil cover and antecedent moisture. Preliminary results show that managed watersheds produce more direct runoff, albeit subject to initial moisture conditions. On the other hand a greater fraction of precipitation becomes baseflow for natural forests. This has important implications for ecosystem hydrologic services valuation and management.

H31F-0722 

The Value of Forest and Pasture to Water Supply in Kona, HI

* Brauman, K A (kbrauman@stanford.edu), Stanford University, Interdisciplinary Program in Environment and Resources, 397 Panama Mall, Stanford, CA 94305-2210, United States Daily, G C (gdaily@stanford.edu), Stanford University, Biological Sciences, 385 Serra Mall, Stanford, CA 94305-5020, United States Freyberg, D L (freyberg@stanford.edu), Stanford University, Civil and Environmental Engineering, 380 Panama Mall, Stanford, CA 94305-4020, United States

By quantifying the supply and value of ecosystem services flowing from private land, we can provide a mechanism for sustaining ecosystem services by compensating landowners for their supply. In order for compensation to occur, however, both suppliers and users of ecosystem services require information about the way different land management scenarios will affect ecosystem service flows. This case study in Kona, HI, takes advantage of the direct link between upland water source areas and municipal drinking water users in Kailua-Kona to explore the value of one type of hydrologic service. By quantifying the difference in aquifer recharge under paired forest and pasture sites, we assess the impact of each land-cover type on the volume of water potentially available to municipal water users. We use a water balance approach - measuring rainfall interception and water use by plants, then calculating the balance to be aquifer recharge because of the absence of surface runoff. We aim to integrate these biophysical measurements with information, including costs of pumping, well construction, and land-cover maintenance, provided by the water utility and landowners to ascertain the value of forest and pasture to water supply. By determining the value to water users in Kailua-Kona of the increase or decrease in water quantity that would result from upland land-cover change, we aim both to protect drinking water quantity and to help landowners offset financial pressure to convert their land.

H31F-0723 

Modeling Changes in Hydrology and Sedimentation for Forested Watersheds: an Approach for Land Managers

* Litschert, S E (sam@warnercnr.colostate.edu), Department of Geosciences, Colorado State University, Department of Geosciences, Warner College of Natural Resources, Colorado State University, Fort Collins, CO 80523-1482, United States MacDonald, L H (leemac@warnercnr.colostate.edu), Department of Forest, Rangeland, and Watershed Stewardship, Colorado State University, Department of Forest, Rangeland, and Watershed Stewardship, Warner College of Natural Resources, Colorado State University, Fort Collins, CO 80523-1472, United States

Hydrologic changes and sedimentation have long been recognized as critical concerns for forest management. Federal and state laws commonly require land managers to compare the cumulative effects of different forest management scenarios before management plans or policy changes can be implemented. Existing operational methods tend to be simple checklists, indices, or lumped models. Physically based, spatially explicit models are available but are not widely used because they are too data intensive, costly, and complex. Our goal is to find a middle ground by providing land managers with a suite of models that are easy-to-use, spatially and temporally explicit, and scientifically based. Delta-Q and FOREST (FORest Erosion Simulation Tools) are coupled models designed to meet these criteria. They calculate the hydrologic and sedimentary effects of roads, forest fires, and forest management using GIS. Delta-Q calculates annual changes in flow from a watershed using a simple linear recovery model. Required inputs are a GIS layer of forest management activities over time, the initial changes in flow, and the times to recovery for each activity. FOREST uses conceptual and empirical models to calculate sediment production and delivery from hillslopes and roads, and to route sediment through the stream network. Required inputs include sediment production and recovery coefficients, and GIS layers of fires, roads, streams, forest management, soils, and elevation. Online help files provide detailed instructions and summaries of published data to help users select coefficients. Model results include tables of annual changes in flow and sediment yield as well as GIS layers showing the spatial distribution of sediment production and delivery over the period being simulated. The models are now being finalized and will be validated against data from five different experimental forests across the U.S. Model results should be helpful for comparing different land management scenarios, recognizing key sediment sources, and identifying stream reaches susceptible to sedimentation or in need of restoration. http://www.warnercnr.colostate.edu/frws/people/faculty/macdonald/model.htm

H31F-0724 

Combining Water Quality and Cost-Benefit Analysis to Examine the Implications of Agricultural Best Management Practices

* Rao, N S (nsr7@cornell.edu), Department of Natural Resources, Fernow Hall Cornell University, Ithaca, NY 14853, United States * Rao, N S (nsr7@cornell.edu), Department of Biological and Environmental Engineering, Riley-Robb Hall Cornell University, Ithaca, NY 14853, United States Easton, Z M (zme2@cornell.edu), Department of Biological and Environmental Engineering, Riley-Robb Hall Cornell University, Ithaca, NY 14853, United States Lee, D R (drl5@cornell.edu), Department of Applied Economics and Management, Warren Hall Cornell University, Ithaca, NY 14853, United States Steenhuis, T S (tss1@cornell.edu), Department of Biological and Environmental Engineering, Riley-Robb Hall Cornell University, Ithaca, NY 14853, United States

Nutrient runoff from agricultural fields threatens water quality and can impair habitats in many watersheds. Agencies consider these potential risks as they determine acceptable levels of nutrient loading. For example, in the New York City (NYC) watershed, the Environmental Protection Agency's Total Maximum Daily Load (TMDL) for phosphorus (P) has been set at 15μg P L-1 to protect against eutrophication and bacterial outbreaks. In the NYC watersheds agricultural Best Management Practices (BMPs) are the primary means to control nonpoint source P loading. BMPs include riparian buffers, filter strips, manure storage facilities, crop rotation, stripcropping, tree planting and nutrient management plans (NMPs). Water quality research on BMPs to date has included studies on site-specificity of different BMPs, short and long term BMP efficacy, and placement of BMPs with respect to critical source areas. A necessary complement to studies addressing water quality aspects of different BMPs are studies examining the cost-benefit aspects of BMPs. In general, there are installment, maintenance and opportunity costs associated with each BMP, and there are benefits, including cost share agreements between farmers and farm agencies, and increased efficiency of farm production and maintenance. Combining water quality studies and related cost-benefit analyses would help planners and watershed managers determine how best improve water quality. Our research examines the costs-benefit structure associated with BMP scenarios on a one-farm headwater watershed in the Catskill Mountains of NY. The different scenarios include "with and without" BMPs, combinations of BMPs, and different BMP placements across agricultural fields. The costs associated with each BMP scenarios are determined using information from farm agencies and watershed planning agencies. With these data we perform a cost-benefit analysis for the different BMP scenarios and couple the water quality modeling using the Variable Source Loading Function (VSLF) model (Schneiderman et al., 2007) with the cost-benefit analysis to look at the specific water quality and economic consequences of different watershed management scenarios. The results of our study will be useful for planners and watershed managers in determining how best to reduce nonpoint source pollution in a cost-effective manner. References Schneiderman, E.M., T.S. Steenhuis, D.J. Thongs, Z.M. Easton, M.S. Zion, G.F. Mendoza, M.T. Walter, and A.C. Neal. 2007. Incorporating variable source area hydrology into curve number based watershed loading functions. Hydrol. Proc. (In Press).

H31F-0725 

Integrated Science, Modeling and Ecological Decision-making in the Upper San Pedro Basin, AZ

Brookshire, D (brookshi@unm.edu), MSCO5-3060, Department of Economics, University of New Mexico, Albuquerque, NM 87131, * Goodrich, D C (Dave.Goodrich@ars.usda.gov), USDA-ARS-SWRC, 2000 E. Allen Rd., Tucson, AZ 85719, United States

Decision-makers and natural resource managers increasingly require much more sophisticated levels of expert findings and scientific results, coupled with economic information, to make informed decisions. No single scientific discipline is typically capable of providing integrated solutions for decision-makers and managers. Significant effort beyond the traditional scientific method is required conduct interdisciplinary science across the physical, ecological, and economic sciences. Even greater effort is required to effectively integrate this research with policy and decision makers for effective and sustainable management of natural resources. This presentation will provide an overview of the evolution of natural resources research in the San Pedro Basin into a integrated science and decision making program which is of sufficient maturity for ecological valuation efforts to be successful. The presentation will discuss the transition in research from a focus on science and research for understanding; through science for addressing a need; to integrated science and policy development; to ecological valuation. At each stage the research conducted became more interdisciplinary, first across abiotic disciplines (hydrology, remote sensing, atmospheric science), then by merging abiotic and biotic disciplines (adding ecology and plant physiology), with further integration elected official and decision makers, and finally the economic sciences. The majority of the presentation will focus on the methods and status of the hydro-bio- economic valuation effort. By building on the strong scientific foundation in the San Pedro the typical reliance on vague program descriptions and imperfect measures of the change in resource quality or quantity in stated- preference valuation studies can be overcome. Transferability to other southwestern systems will be briefly discussed. Lessons learned from this experience will also be reviewed with the intent providing guidance to ensure that hydrologic and watershed research is socially and scientifically relevant and will directly address the needs of policy makers and resource managers.

H31F-0726 

Biogeochemcial Phosphorus Hotspots: Hydrology, Microbial Ecology, and Soil Chemistry

* Giri, S (skg29@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, MY 14850-5701, United States Valdivia, M V (mvv2@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, MY 14850-5701, United States Marjerison, R D (rdm95@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, MY 14850-5701, United States Archibald, J A (jaa78@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, MY 14850-5701, United States Richards, B K (bkr2@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, MY 14850-5701, United States Walter, M (mtw5@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, MY 14850-5701, United States

Eutrophication due to anthropogenic phosphorus (P) sources is a persistent and critical national water quality problem. Although agricultural land is a recognized nonpoint source (NPS) of P, current risk assessment tools and best management practices for addressing P are limited by our incomplete understanding of the processes controlling P mobility. The Cornell Soil and Water Laboratory and Ecohydrology Research Groups are pursuing a campaign of projects focused on improving our understanding of the ecohydrological factors - both natural and anthropogenic - that control P mobility. Specific projects are designed to identify specific roles of microbial ecology, soil chemistry, and landscape position or propensity to soil-saturation on P transport potential. This presentation synthesizes findings across these projects that access our best understanding of ecohydrological controls on P mobility and highlight persistent challenges in unraveling this puzzle as well as implications for land management.

H31F-0727 

Denitrification Hotspots: Hydrology and Biogeochemistry

* Molodovskaya, M (mm433@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, NY 14850-5701, Singurindy, O (os43@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, NY 14850-5701, Faulkner, J W (jwf24@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, NY 14850-5701, Zhang, W (wz47@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, NY 14850-5701, Richards, B K (bkr2@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, NY 14850-5701, Anderson, T R (tra8@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, NY 14850-5701, Geohring, L D (ldg5@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, NY 14850-5701, Steenhuis, T S (tss1@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, NY 14850-5701, Walter, M (mtw5@cornell.edu), Cornell University, Biological & Environmental Engineering, Ithaca, NY 14850-5701,

Nitrogen (N) is a critical pollutant in many northeastern US watersheds and globally. Many forms of N, especially NO3, pose serious threats to coastal marine ecosystems. Agricultural land that receives fertilizers or animal manures is a principal source of anthropogenic N loading to the environment. The most effective mechanism to reduce N in streams is probably microbial denitrification, i.e., the transformation of nitrate into gaseous N2 or, in some cases, smaller amounts of N2O. Unfortunately, N2O is a greenhouse gas that may contribute to global warming. Currently, magnitudes of denitrification rates at landscape scales are "tentative" at best, largely based on watershed-scale budgets in which denitrification was estimated by difference. Denitrification and N2O net production strongly depend on both natural (temperature, soil moisture, microbial activity, soil organic matter) and anthropogenic (nitrogen fertilization, crop type, tillage) parameters. Denitrification occurs primarily under anaerobic conditions by heterotrophic microbes and is expected to be vigorous in wet soils high in organic carbon. There is good evidence that these conditions correlate strongly with hydrological sensitivity or high propensity for saturated conditions, thus by juxtaposing hydrology and biogeochemistry we can elucidate the distribution of denitrification hotspots across the landscape. Upon this hydrologic-biogeochemical framework we can ultimately develop BMPs to meet the program research priorities to improve water resource protection and promote sustainable agricultural systems that minimize environmental impact. The Cornell Soil and Water and Ecohydrology Research Groups have engaged in a variety of projects to elucidate the primary controls or quantify denitrification rates for different ecohydrological conditions including those that have been specifically designed to reduce N loading to streams. This presentation highlights recent findings of rates, controls, and spatio-temporal distributions of dentirification as well as N mineralization and other N fluxes.

H31F-0728 

An approach for strategic, targeted prioritization of streamside restoration

* Baker, M (matt.baker@usu.edu), Utah State University, 5210 Old Main Hill, logan, UT 84322-5210, United States Weller, D (wellerd@si.edu), Smithsonian Environmental Research Center, PO Box 28 647 Contees Wharf Rd, Edgewater, MD 21037-0028, United States Jordan, T (jordanth@si.edu), Smithsonian Environmental Research Center, PO Box 28 647 Contees Wharf Rd, Edgewater, MD 21037-0028, United States

Recent research has highlighted tremendous expenditures associated with streamside restoration projects aimed at improving water quality. Many of these projects involve the restoration of vegetated riparian zones as filters for the retention or transformation of nutrients from upslope non-point sources, despite variable results along field-to-stream transects in the published literature. Further, despite widespread local field studies, few investigations have documented effective filtering across whole watersheds. We employ recently developed methods for quantifying distributional patterns of riparian buffers to test for evidence of significant buffer effects across 200 watersheds in Coastal Plain and Piedmont of the Chesapeake Bay drainage. In each physiographic region, cropland proportions adjusted to reflect patterns of riparian buffers substantially improved predictions of nitrate discharge after controlling for other potential nutrient sources. We provide evidence of buffer effects on nutrient discharge under a variety of physiographic and land-use contexts and discuss confounding factors that may have limited past efforts. We also show how relatively simple analyses can be used to aid strategic restoration planning and in developing realistic expectations both within and among watersheds despite tremendous uncertainty in both buffer performance and restoration success.

H31F-0729 

Season influences of wood on stream nitrate dynamics in forested headwater streams in the northeast US

* Warren, D R (drw23@cornell.edu), Cornell University, Dept. Natural Resources, Ithaca, NY 14853, United States Judd, K E (kjudd2@emich.edu AF: AF: AF:

Forested headwater streams play an important role in watershed nutrient cycles and woody debris may be key to in-stream nutrient retention. We conducted an experimental manipulation of in-stream wood to specifically investigate influences of woody debris on nitrogen dynamics in streams of the Hubbard Brook Experimental Forest. In summer and fall 2005, prior to manipulation, nitrate uptake was measured in each of three replicate streams. In late fall 2005, wood was removed from one stream, wood was added to another, and a third stream reach was not manipulated. Uptake measurements were then repeated in summer and fall 2006. A comparison of changes in nitrate dynamics before versus after wood manipulation (relative to each other and to the reference reach) indicates that nitrate processing increased in response to wood manipulations in the fall. However, changing wood abundance in streams had a limited influence on nitrogen dynamics in mid-summer. This work highlights the importance seasonal biogeochemical processes in streams and the importance of wood in stream management and stream restoration

H31F-0730 

Rehabilitation of Abandoned Quarries to Calcareous Fens: Ecohydrological Insights from Natural Systems

* Duval, T P (duvaltp@mcmaster.ca), School of Geography and Earth Sciences, McMaster University, 1280 Main St W, Hamilton, ON L8S4K1, Canada Waddington, J M (wadding@mcmaster.ca), School of Geography and Earth Sciences, McMaster University, 1280 Main St W, Hamilton, ON L8S4K1, Canada Branfireun, B A (brian.branfireun@utoronto.ca), Department of Geography, University of Toronto at Mississauga, 3359 Mississauga Rd N, Mississauga, ON L5L1C6, Canada

Calcareous fens are some of the most species diverse ecosystems in temperate North America and often occur in watersheds where groundwater flows through easily weathered limestone or dolostone bedrock. Many limestone aggregate quarries are abandoned when it is no longer cost-effective to mine below the water table. The remaining disturbed site then represents a possible habitat for the many calciphilic species that comprise a calcareous fen. Thus, there exists an opportunity for industry to implement sound ecohydrological management protocols to provide an overall biodiversity increase at extraction sites. This study explores the ecohydrological controls on calcareous fen species distribution at three natural sites in the headwaters of a southern Ontario watershed. We also present initial work on the feasibility of rehabilitating an adjacent abandoned aggregate quarry to a calcareous fen through transplant experiments. Vegetation communities between the natural sites were significantly different in almost all cases, with individual species responding differently to hydroperiod. These community differences were related to the hydrogeomorphic setting of the natural sites, which controlled the amount and source area of water to the wegetation. At the plot-scale, species richness was negatively correlated with mean water table depth and peat carbonate content, and positively correlated to peat organic matter content. In the quarry transplant experiments, total number of stems and aboveground biomass were significantly greater in a treatment amended with topsoil, and regardless of soil treatment, biomass in plots placed in shallow water (15 cm below ground) was significantly less than plots in deeper water. These results demonstrate the range of hydrological conditions influencing the ecology of calcareous fens, in addition to shedding light on some key constraints on rehabilitation efforts.

H31F-0731 

Ecologically Significant Monitoring Strategies for Watershed Managers and Applied Ecohydrologists

* Buchanan, B P (bb386@cornell.edu), Cornell University Department of Biological and Environmental Engineering, 222 Riley- Robb Hall, Ithaca, NY 14853, United States Walter, T (mtw5@cornell.edu), Cornell University Department of Biological and Environmental Engineering, 222 Riley- Robb Hall, Ithaca, NY 14853, United States

Upper Klamath Lake in Southern Oregon is home to a unique and increasingly rare strain of redband rainbow trout (Oncorhynchus mykiss newberrii). Populations connected to perennial lake systems such as the Upper Klamath have evolved adfluvial life histories and may possess unique adaptations that underscore their importance as units of conservation. Anthropogenic disturbance including stream channelization, timber harvest, livestock grazing and irrigation diversion have resulted in a 41 percent reduction in the redband's historic habitat and the disappearance of 11 redband trout populations throughout Oregon, Washington, and Idaho. In an effort to actively conserve this sensitive subspecies, a stream creation project was undertaken with the goal of increasing viable spawning and rearing habitat in Crooked Creek, a tributary to Upper Klamath Lake. A combination of analogue, empirical and analytical techniques were employed in the design of the created channel morphology (i.e. channel planform, profile, and cross-section), the sizing of bed substrate and spawning gravels and the design of in-stream habitat and scour structures. The project, completed in the fall of 1996, was qualitatively judged a success (e.g. trout were observed actively spawning and young-of-the-year were collected during unsystematic surveys). Unfortunately, as is often the case in the stream enhancement/restoration field, funding and personnel time were lacking for the implementation of a robust post-construction monitoring plan. Thus, project success was ascertained through cursory analyses and anecdotal reports. An opportunity to implement a similar stream creation project in a nearby watershed has afforded us the chance to return to the project site and conduct a more comprehensive, quantitative analysis of the project's success. A discussion of the original design methods and a review of several state of the art monitoring strategies are provided to assist watershed managers and applied ecohydrologists in their efforts to adaptively manage and restore the structure and function of dynamic stream systems.

H31F-0732 

Quantifying Wetland Dynamics and Hydrologic Function with Landsat Thematic Mapper

* Rover, J A (jrover@usgs.gov), SAIC, contractor to the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science, 47914 252nd St, Sioux Falls, SD 57198, United States Wright, C (chwright@usgs.gov), Independant contractor to the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science, 47914 252nd St, Sioux Falls, SD 57198, United States Wylie, B K (wylie@usgs.gov), SAIC, contractor to the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science, 47914 252nd St, Sioux Falls, SD 57198, United States Euliss, N H (ceuliss@usgs.gov), U.S. Geological Survey (USGS), Northern Prairie Wildlife Research Center, 8711 37th St SE, Jamestown, ND 58401, United States

The Prairie Pothole Region (PPR) of North America spans the glaciated prairies from Alberta, Canada, to central Iowa. The region contains hundreds of thousands of wetlands that provide habitat for an estimated 50 to 80 percent of North America's waterfowl. The composition of species that use the PPR are a function of wetland water chemistry. The water chemistry is driven by wetland functional processes that determine hydrogeochemical interactions of surface water, ground water, and their connectivity to other wetlands. As wetlands cycle from drought to deluge, significant surface water fluctuations can alter water chemistry and hydroperiods, influencing the composition of wetland communities. We quantified these temporal water dynamics with Landsat TM and ETM+ imagery, spanning a 17-year period during a drought-deluge cycle. Using clustering techniques, we grouped wetlands based on their functional responses to climate and quantified the traits of each cluster. We found that wetlands receiving groundwater discharge respond very differently to climatic shifts than wetlands functioning as recharge basins. In addition, wetlands with closed basins are less dynamic than wetlands located in open basins. Accuracies of the initial classification ranged from 75 to 100 percent. This study offers the first insight into wetland dynamics at a regional scale with implications for modeling biogeochemistry and ecosystem services across the PPR. Although this method was developed in the Missouri Coteau and nearby drift plains of the PPR, we believe this technique is applicable to other regions.

H31F-0733 

Retrieval of Water Quality Parameters in a Highly Turbid Estuary from Hyperspectral Remote Sensing Imagery

* Hestir, E L (elhestir@ucdavis.edu), University of California Davis, Dept. of Land, Air, and Water Resources One Shields Ave., Davis, CA 95616, United States * Hestir, E L (elhestir@ucdavis.edu), University of California Davis, Center for Spatial Technologies and Remote Sensing One Shields Ave., Davis, CA 95616, United States Greenberg, J A (greenberg@ucdavis.edu), University of California Davis, Center for Spatial Technologies and Remote Sensing One Shields Ave., Davis, CA 95616, United States Ustin, S L (slustin@ucdavis.edu), University of California Davis, Dept. of Land, Air, and Water Resources One Shields Ave., Davis, CA 95616, United States Ustin, S L (slustin@ucdavis.edu), University of California Davis, Center for Spatial Technologies and Remote Sensing One Shields Ave., Davis, CA 95616, United States

The Sacramento-San Joaquin River Delta is a highly turbid inland estuary that drains into the Pacific Ocean via the San Francisco Bay. The Delta has become a major ecological concern over the past decade, and the decline of the endangered fish, Delta smelt, has been attributed in part to decreasing turbidity in the Delta. Measuring and monitoring turbidity and Secchi disk depth are important to ecosystem health management and water quality monitoring of inland case-2 waters. The spectral determination of water quality parameters is dependent on (i) the inherent optical properties of water, such as the load of total suspended solids, suspended sediments, humic acids and dissolved organic matter, and planktonic content and composition, and (ii) the apparent optical properties of water which depend on both the medium and the geometric structure of light (surface reflectance, vertical diffuse attenuation). Water quality parameters such as turbidity and Secchi disk depth can be retrieved from hyperspectral remote sensing imagery, remote sensing data collected with many narrow spectral bands, using semi-empirical methods that require regression analysis, or from radiative transfer calculations that model apparent optical properties. We compared the accuracy of both semi-empirical and radiative transfer methods to retrieve turbidity and Secchi disk depths from airborne hyperspectral remote sensing imagery (the HyMap sensor, 450-2500 nm, 10-15nm bandwidth) of the Delta collected in June 2007. Results were validated using extensive field data collected concurrent with image acquisition. Additionally, we examined the effect of resampling the hyperspectral data to multispectral resolutions more commonly found on spaceborne instruments on the accuracy of water constituent retrieval from inland, case-2 waters.

Author(s) (2007), Title, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract #####-##.