Shingobee Headwaters Aquatic Ecosystems Project (SHAEP) Completed
For 43 years, the Shingobee Headwaters Aquatic Ecosystems Project (SHAEP) brought together scientists from the USGS along with students and professors from universities in Minnesota, North Dakota, Wisconsin, and California to study the physical, chemical, and biological processes of lakes, wetlands, and streams at local and watershed scales. In early 2022, The University of Minnesota and Bemidji State University took over this project and will continue this important work in the future.
Current Status
In early 2022, responsibility for the Shingobee Headwaters Aquatic Ecosystems Project (SHAEP) was transferred to The University of Minnesota and Bemidji State University. The information below is being preserved for historical reference, but is no longer current. For up-to-date information about the project, please contact Leslie Ludtke (ludtk028@umn.edu), Joe Magner (jmagner@umn.edu), or Miriam Rios-Sanchez (Miriam.Rios-Sanchez@bemidjistate.edu).
Historical Overview
The Shingobee Headwaters Aquatic Ecosystems Project (SHAEP) brings together scientists from the U.S. Geological Survey, and students and professors from universities in Minnesota, North Dakota, Wisconsin, and California for a unique and cooperative study opportunity. This diverse group of scientists conducts research on physical, chemical, and biological processes of lakes, wetlands, and streams and investigates interfaces (air-water, air-land, land-water) on local and watershed scales. Scientists who might not normally work together learn from each other's approaches and develop new ideas for collaborative research. Each highly specialized study adds to a collective body of information that leads to a better understanding of the processes that occur in and adjacent to lakes, wetlands, and streams. By focusing on the interfaces of these multiple scientific disciplines, SHAEP hopes to provide a broader scientific perspective than could be achieved without such a cooperative integration. The Shingobee River Fact Sheet provides more detailed information about the site location and specific research goals.
Interdisciplinary research is not a new idea, but it was rarely accomplished in 1989 when this study began. The prospect was so novel that this effort initially was known as the Interdisciplinary Research Initiative, or IRI. IRI was changed to SHAEP to better reflect the site location and the overarching goals of the research conducted there.
Brief History of the Project
In 1987 a group of scientists from the former National Research Program of the Water Resources Division of the US Geological Survey met to discuss the state of watershed science. The committee agreed that proper management of our Nation's water resources required knowledge of how atmospheric water, surface water, and ground water function as integrated systems. It was obvious that an interdisciplinary approach to studying lakes and watersheds was needed. The committee decided to focus initially on lakes, because lakes are a natural integrator of hydrologic processes. Rather than focus these efforts on one lake, with the hope that the information learned about this lake would transfer to other lakes the committee decided to select a paired-lake site, where two nearby lakes would have greatly different water and chemical residence times. By studying two lakes, and comparing the results, they would be able to determine which processes were important to both lakes, and which were unique to one or the other lake.
A nationwide search resulted in the selection of the upper Shingobee River watershed located in north-central Minnesota. This watershed offered two lakes that had greatly different hydrologic settings even though they were close to each other. Several different types of wetlands offered a broad scope of wetlands research, and the headwaters of the Shingobee River presented a great opportunity for in-stream and riparian-corridor-scale research. Research to date has focused on Williams Lake and Shingobee Lake, as well as on processes occurring along the Shingobee River and within a nearby fen.
Shingobee Field Station
Dallas Hudson is the resident technician based at the Shingobee Field Station. Dallas collects hydrologic, atmospheric, biological and water-quality information that constitutes the data backbone of the SHAEP effort. Dallas is available to assist with project-specific data-collection efforts as time allows.
With the exception of Dallas, all who work at the SHAEP do so on a part-time and voluntary basis. Each has other duties and commitments, but all come to work at the Shingobee site to learn from colleagues with different perspectives, and make new discoveries about the SHAEP lakes and the land around them.
Amenities at the Shingobee Field Station include:
- Wireless access to internet
- Two bedrooms for visiting scientists
- Kitchen, laundry, storage
- Direct access to Shingobee Lake
- 3-season meeting room
- Boat available to those with USGS motorboat-safety training
- Assistance from Dallas Hudson can be arranged
Current Research
Current interdisciplinary research is focused on three main topics:
- Processes associated with the carbon budgets of the two lakes
- Physical, chemical and biological processes in the Little Shingobee Fen
- Physical, chemical and biological processes along the Shingobee River
Refinement of hydrologic budget for Shingobee Lake (Rosenberry, Hudson)
The "Great Wall of Shingobee" at the outlet to Shingobee Lake was working well to restrict and accelerate very slow flow at the outlet to allow us to make accurate measurements of stream discharge from Shingobee Lake. In spite of Dallas’s Herculean efforts to keep beaver dams at bay, the ever persistent critters built large dams well downstream, out of Dallas’s reach. Flow at the outlet slowed to the point where accurate discharge measurements were no longer possible. An extension of the great wall did the trick and we are back in business.
Temporal and spatial variability in discharge of springs (Rosenberry, Hudson)
Groundwater discharge to Shingobee Lake via numerous near-shore springs continues to vary over time in ways that are not always related to weather or lake stage. We are in the process of collecting water-quality samples from several of the springs in an effort to determine ages and flow paths for ground water discharging from the springs. A MODFLOW groundwater-flow model is in need of further refinement should someone be interested in joining this effort.
Source of carbon to Shingobee Lake (Striegl et al.) Gas-flux research (Dornblaser et al.)
Rob Striegl and Mark Dornblaser continue to home in on quantifying several of the carbon fluxes associated with Williams and Shingobee lakes. Manual and/or synoptic-scale measurements are needed to support data provided by gas-flux sensors installed on rafts deployed in Williams and Shingobee Lakes.
Lake sediment chemistry (Schuster et al.)
Paul Schuster and colleagues published a paper in 2003 in Hydrological Processes in which they characterized and contrasted the chemical characteristics of the shallow, near-shore sediments of Williams Lake in an area where ground water discharges to the lake, and another area where lake water flows to the groundwater system. That was then; this is well over a decade later. It would be very interesting to repeat this study to see what processes continue and what has changed with increasing open-water periods and evolving ecosystems.
Paleolimnology (in need of a new lead)
Several papers were published in 2003 related to the paleolimnology of the site. Walter Dean and colleagues discussed the effect of groundwater on accumulation of iron and manganese in the deep-lake sediments (Dean et al., 2003, Ground Water). Sheryl Filby and company modeled the hydrology of the site during the mid-Holocene (Filby et al., 2003, Quaternary Research). Antje Schwalb reported on lacustrine ostracodes related to climate dynamics during the Holocene (Schwalb, 2003, Journal of Paleolimnology). After that, emphasis shifted to Steel Lake, situated between Williams and Shingobee Lakes, where varved sediments presented a fantastic view into the post-glacial past (Nelson et al., 2004, Proceedings of the National Academy of Sciences; Nelson et al., 2007, Microbial Ecology; Nelson et al., 2008, New Phytologist; Tian et al, 2005, The Holocene; Tian et al., 2006, Geophysical Research Letters; Wright et al., 2005, Quaternary Science Reviews). Walt Dean and Lisa Doner then moved the focus to Little Shingobee Lake and adjacent fen, where sediment cores yielded pollen and geochemical evidence that the lake ecosystem was changing profoundly to a changing climate as the prairie-forest boundary transitioned past the site (Dean and Doner, 2012, Journal of Paleolimnology). Their results are directly relevant to what appears to be a rapidly changing climate at the site right now.
Glacial mapping (Melchior)
Bob Melchior completed his long-awaited USGS report on the glacial history of the Shingobee headwaters area (Melchior, 2014, USGS SIR). Melchior reports that a large glacial lake occupied nearly the entire Shingobee watershed until an ice-cored dam broke, creating a catastrophic flood that eroded the large valley through which the modern-day Shingobee River flows. Bob also discusses the creation of sub-glacial tunnel valleys and eskers just north of Shingobee Lake. The carving out of nearby Leech Lake along with the associated creation of large hills between Leech Lake and Shingobee Lake a “hill-hole pair,” is a new concept advanced by Bob. If this paper isn’t fascinating enough, a road log of the geology of northern Minnesota, including the Shingobee site, extends the glacial picture to well beyond the Shingobee headwaters area (Rosenberry et al., 2011, Geological Society of America Field Guide).
Survey of vegetation type related to hydrologic setting (Melchior)
Bob Melchior has shifted from geology to botany as he continues his research in the Shingobee headwaters area. Bob is always looking for field help should anyone care to assist with this effort.
Growth rate of northern pike in Shingobee Lake (Hudson, Carlson)
Imagine catching a 39-inch northern, wrestling it into the boat, recording the tag number, length, girth, weight, and then tossing it back in the water; and then catching another just like it later in the same day. This is an ichthyologists’ dream and this happens on a regular basis at Shingobee Lake. Some of these lunkers have been caught nearly 20 times. Little did we know that Dallas, in part due to these pursuits, is the most interesting man in Minnesota, but the proof is in a feature article in the Sunday Minneapolis Tribune (Tribune link from the NRP web pages here). Dallas Hudson keeps this study going in his spare time and Bruce Carlson, retired research scientist from the University of Michigan and current resident of nearby Ten Mile Lake, makes sense of the plethora of data produced by the 10,000 or so tagged northerns. Andy Hafs from Bemidji State and his graduate student, John Kempe, have recently joined the effort.
Phenology of the Shingobee headwaters area (Hudson)
Dallas Hudson records first sightings, numbers, last sightings, and several other phenological observations for several hundred species of mammals, insects, and flora. We are in need of someone to help make sense of all these valuable data that contain some very interesting trends. Dallas also has been the first observer of several species in Hubbard County, several of which have never been observed so far north.
Research of lakes, streams and wetlands in a small-watershed setting
Watershed-scale research has been a significant component of hydrologic and ecological disciplines for many decades, and small-watershed studies have been especially common and useful because of their scale. It is much easier to quantify processes, assess heterogeneities and extrapolations of results, and scale those results when studying a watershed that is relatively small. The Upper Shingobee watershed is only 28 square kilometers in area and much of the research is focused on subwatersheds within the Shingobee headwaters area. An overview of research highlights from studies conducted at Williams Lake, Shingobee Lake, the Shingobee River upstream of Shingobee Lake, and the Little Shingobee Fen, was presented at the First Interagency Conference on Research in the Watersheds during Fall 2003 (Rosenberry et al., 2003, Conference proceedings), and serves as a template for continuing ecosystems research opportunities at Shingobee.
Available Data from the Shingobee Site
Much data has been collected from the Shingobee site since its inception. Some data are collected only once or infrequently during synoptic studies for special research interests. However some data are collected during regular intervals and include:
- climate data
- water-chemistry data from Williams Lake, Shingobee Lake and the Shingobee River
- hydrology data
While some data have not yet been processed, checked for errors, or analyzed, many of these data are available upon request. Please contact Richard Webb (rmwebb@usgs.gov) with request for climate, water-chemistry or hydrology data.
Selected USGS Publications from the Shingobee Headwaters Aquatic Ecosystems Project appear below. You can also download a complete bibliography for the project.
Watershed-scale research from many perspectives : the Interdisciplinary Research Initiative at the Shingobee River headwaters area, Minnesota
Carbon dioxide partial pressure and 13C content of north temperate and boreal lakes at spring ice melt
Water source to four U.S. wetlands: Implications for wetland management
The concept of hydrologic landscapes
Nitrogen biogeochemistry and surface-subsurface exchange in streams
The use of principal component analysis for interpreting ground water hydrographs
Plants as indicators of focused ground water discharge to a northern Minnesota lake
Evidence of Climate Change over the Last 10,000 Years from the Sediments of Lakes in the Upper Mississippi Basin
Magnitude and Significance of Carbon Burial in Lakes, Reservoirs, and Northern Peatlands
Estimating lake-atmosphere CO2 exchange
The carbon cycle and biogeochemical dynamics in lake sediments
Magnitude and significance of carbon burial in lakes, reservoirs, and peatlands
A mini drivepoint sampler for measuring pore water solute concentrations in the hyporheic zone of sand-bottom streams
- Overview
For 43 years, the Shingobee Headwaters Aquatic Ecosystems Project (SHAEP) brought together scientists from the USGS along with students and professors from universities in Minnesota, North Dakota, Wisconsin, and California to study the physical, chemical, and biological processes of lakes, wetlands, and streams at local and watershed scales. In early 2022, The University of Minnesota and Bemidji State University took over this project and will continue this important work in the future.
Current Status
In early 2022, responsibility for the Shingobee Headwaters Aquatic Ecosystems Project (SHAEP) was transferred to The University of Minnesota and Bemidji State University. The information below is being preserved for historical reference, but is no longer current. For up-to-date information about the project, please contact Leslie Ludtke (ludtk028@umn.edu), Joe Magner (jmagner@umn.edu), or Miriam Rios-Sanchez (Miriam.Rios-Sanchez@bemidjistate.edu).
Historical Overview
The Shingobee Headwaters Aquatic Ecosystems Project (SHAEP) brings together scientists from the U.S. Geological Survey, and students and professors from universities in Minnesota, North Dakota, Wisconsin, and California for a unique and cooperative study opportunity. This diverse group of scientists conducts research on physical, chemical, and biological processes of lakes, wetlands, and streams and investigates interfaces (air-water, air-land, land-water) on local and watershed scales. Scientists who might not normally work together learn from each other's approaches and develop new ideas for collaborative research. Each highly specialized study adds to a collective body of information that leads to a better understanding of the processes that occur in and adjacent to lakes, wetlands, and streams. By focusing on the interfaces of these multiple scientific disciplines, SHAEP hopes to provide a broader scientific perspective than could be achieved without such a cooperative integration. The Shingobee River Fact Sheet provides more detailed information about the site location and specific research goals.
Interdisciplinary research is not a new idea, but it was rarely accomplished in 1989 when this study began. The prospect was so novel that this effort initially was known as the Interdisciplinary Research Initiative, or IRI. IRI was changed to SHAEP to better reflect the site location and the overarching goals of the research conducted there.
Brief History of the Project
In 1987 a group of scientists from the former National Research Program of the Water Resources Division of the US Geological Survey met to discuss the state of watershed science. The committee agreed that proper management of our Nation's water resources required knowledge of how atmospheric water, surface water, and ground water function as integrated systems. It was obvious that an interdisciplinary approach to studying lakes and watersheds was needed. The committee decided to focus initially on lakes, because lakes are a natural integrator of hydrologic processes. Rather than focus these efforts on one lake, with the hope that the information learned about this lake would transfer to other lakes the committee decided to select a paired-lake site, where two nearby lakes would have greatly different water and chemical residence times. By studying two lakes, and comparing the results, they would be able to determine which processes were important to both lakes, and which were unique to one or the other lake.
A nationwide search resulted in the selection of the upper Shingobee River watershed located in north-central Minnesota. This watershed offered two lakes that had greatly different hydrologic settings even though they were close to each other. Several different types of wetlands offered a broad scope of wetlands research, and the headwaters of the Shingobee River presented a great opportunity for in-stream and riparian-corridor-scale research. Research to date has focused on Williams Lake and Shingobee Lake, as well as on processes occurring along the Shingobee River and within a nearby fen.
Shingobee Field Station
Dallas Hudson is the resident technician based at the Shingobee Field Station. Dallas collects hydrologic, atmospheric, biological and water-quality information that constitutes the data backbone of the SHAEP effort. Dallas is available to assist with project-specific data-collection efforts as time allows.
With the exception of Dallas, all who work at the SHAEP do so on a part-time and voluntary basis. Each has other duties and commitments, but all come to work at the Shingobee site to learn from colleagues with different perspectives, and make new discoveries about the SHAEP lakes and the land around them.
Amenities at the Shingobee Field Station include:
- Wireless access to internet
- Two bedrooms for visiting scientists
- Kitchen, laundry, storage
- Direct access to Shingobee Lake
- 3-season meeting room
- Boat available to those with USGS motorboat-safety training
- Assistance from Dallas Hudson can be arranged
Current Research
Current interdisciplinary research is focused on three main topics:
- Processes associated with the carbon budgets of the two lakes
- Physical, chemical and biological processes in the Little Shingobee Fen
- Physical, chemical and biological processes along the Shingobee River
Refinement of hydrologic budget for Shingobee Lake (Rosenberry, Hudson)
The "Great Wall of Shingobee" at the outlet to Shingobee Lake was working well to restrict and accelerate very slow flow at the outlet to allow us to make accurate measurements of stream discharge from Shingobee Lake. In spite of Dallas’s Herculean efforts to keep beaver dams at bay, the ever persistent critters built large dams well downstream, out of Dallas’s reach. Flow at the outlet slowed to the point where accurate discharge measurements were no longer possible. An extension of the great wall did the trick and we are back in business.
Temporal and spatial variability in discharge of springs (Rosenberry, Hudson)
Groundwater discharge to Shingobee Lake via numerous near-shore springs continues to vary over time in ways that are not always related to weather or lake stage. We are in the process of collecting water-quality samples from several of the springs in an effort to determine ages and flow paths for ground water discharging from the springs. A MODFLOW groundwater-flow model is in need of further refinement should someone be interested in joining this effort.
Source of carbon to Shingobee Lake (Striegl et al.) Gas-flux research (Dornblaser et al.)
Rob Striegl and Mark Dornblaser continue to home in on quantifying several of the carbon fluxes associated with Williams and Shingobee lakes. Manual and/or synoptic-scale measurements are needed to support data provided by gas-flux sensors installed on rafts deployed in Williams and Shingobee Lakes.
Lake sediment chemistry (Schuster et al.)
Paul Schuster and colleagues published a paper in 2003 in Hydrological Processes in which they characterized and contrasted the chemical characteristics of the shallow, near-shore sediments of Williams Lake in an area where ground water discharges to the lake, and another area where lake water flows to the groundwater system. That was then; this is well over a decade later. It would be very interesting to repeat this study to see what processes continue and what has changed with increasing open-water periods and evolving ecosystems.
Paleolimnology (in need of a new lead)
Several papers were published in 2003 related to the paleolimnology of the site. Walter Dean and colleagues discussed the effect of groundwater on accumulation of iron and manganese in the deep-lake sediments (Dean et al., 2003, Ground Water). Sheryl Filby and company modeled the hydrology of the site during the mid-Holocene (Filby et al., 2003, Quaternary Research). Antje Schwalb reported on lacustrine ostracodes related to climate dynamics during the Holocene (Schwalb, 2003, Journal of Paleolimnology). After that, emphasis shifted to Steel Lake, situated between Williams and Shingobee Lakes, where varved sediments presented a fantastic view into the post-glacial past (Nelson et al., 2004, Proceedings of the National Academy of Sciences; Nelson et al., 2007, Microbial Ecology; Nelson et al., 2008, New Phytologist; Tian et al, 2005, The Holocene; Tian et al., 2006, Geophysical Research Letters; Wright et al., 2005, Quaternary Science Reviews). Walt Dean and Lisa Doner then moved the focus to Little Shingobee Lake and adjacent fen, where sediment cores yielded pollen and geochemical evidence that the lake ecosystem was changing profoundly to a changing climate as the prairie-forest boundary transitioned past the site (Dean and Doner, 2012, Journal of Paleolimnology). Their results are directly relevant to what appears to be a rapidly changing climate at the site right now.
Glacial mapping (Melchior)
Bob Melchior completed his long-awaited USGS report on the glacial history of the Shingobee headwaters area (Melchior, 2014, USGS SIR). Melchior reports that a large glacial lake occupied nearly the entire Shingobee watershed until an ice-cored dam broke, creating a catastrophic flood that eroded the large valley through which the modern-day Shingobee River flows. Bob also discusses the creation of sub-glacial tunnel valleys and eskers just north of Shingobee Lake. The carving out of nearby Leech Lake along with the associated creation of large hills between Leech Lake and Shingobee Lake a “hill-hole pair,” is a new concept advanced by Bob. If this paper isn’t fascinating enough, a road log of the geology of northern Minnesota, including the Shingobee site, extends the glacial picture to well beyond the Shingobee headwaters area (Rosenberry et al., 2011, Geological Society of America Field Guide).
Survey of vegetation type related to hydrologic setting (Melchior)
Bob Melchior has shifted from geology to botany as he continues his research in the Shingobee headwaters area. Bob is always looking for field help should anyone care to assist with this effort.
Growth rate of northern pike in Shingobee Lake (Hudson, Carlson)
Imagine catching a 39-inch northern, wrestling it into the boat, recording the tag number, length, girth, weight, and then tossing it back in the water; and then catching another just like it later in the same day. This is an ichthyologists’ dream and this happens on a regular basis at Shingobee Lake. Some of these lunkers have been caught nearly 20 times. Little did we know that Dallas, in part due to these pursuits, is the most interesting man in Minnesota, but the proof is in a feature article in the Sunday Minneapolis Tribune (Tribune link from the NRP web pages here). Dallas Hudson keeps this study going in his spare time and Bruce Carlson, retired research scientist from the University of Michigan and current resident of nearby Ten Mile Lake, makes sense of the plethora of data produced by the 10,000 or so tagged northerns. Andy Hafs from Bemidji State and his graduate student, John Kempe, have recently joined the effort.
Phenology of the Shingobee headwaters area (Hudson)
Dallas Hudson records first sightings, numbers, last sightings, and several other phenological observations for several hundred species of mammals, insects, and flora. We are in need of someone to help make sense of all these valuable data that contain some very interesting trends. Dallas also has been the first observer of several species in Hubbard County, several of which have never been observed so far north.
Research of lakes, streams and wetlands in a small-watershed setting
Watershed-scale research has been a significant component of hydrologic and ecological disciplines for many decades, and small-watershed studies have been especially common and useful because of their scale. It is much easier to quantify processes, assess heterogeneities and extrapolations of results, and scale those results when studying a watershed that is relatively small. The Upper Shingobee watershed is only 28 square kilometers in area and much of the research is focused on subwatersheds within the Shingobee headwaters area. An overview of research highlights from studies conducted at Williams Lake, Shingobee Lake, the Shingobee River upstream of Shingobee Lake, and the Little Shingobee Fen, was presented at the First Interagency Conference on Research in the Watersheds during Fall 2003 (Rosenberry et al., 2003, Conference proceedings), and serves as a template for continuing ecosystems research opportunities at Shingobee.
Available Data from the Shingobee Site
Much data has been collected from the Shingobee site since its inception. Some data are collected only once or infrequently during synoptic studies for special research interests. However some data are collected during regular intervals and include:
- climate data
- water-chemistry data from Williams Lake, Shingobee Lake and the Shingobee River
- hydrology data
While some data have not yet been processed, checked for errors, or analyzed, many of these data are available upon request. Please contact Richard Webb (rmwebb@usgs.gov) with request for climate, water-chemistry or hydrology data.
- Publications
Selected USGS Publications from the Shingobee Headwaters Aquatic Ecosystems Project appear below. You can also download a complete bibliography for the project.
Watershed-scale research from many perspectives : the Interdisciplinary Research Initiative at the Shingobee River headwaters area, Minnesota
No abstract available.AuthorsD. O. RosenberryFilter Total Items: 54Carbon dioxide partial pressure and 13C content of north temperate and boreal lakes at spring ice melt
Carbon dioxide (CO2) accumulates under lake ice in winter and degasses to the atmosphere after ice melt. This large springtime CO2 pulse is not typically considered in surface-atmosphere flux estimates, because most field studies have not sampled through ice during late winter. Measured CO2 partial pressure (pCO2) of lake surface water ranged from 8.6 to 4,290 Pa (85-4,230 ??atm) in 234 north tempAuthorsRobert G. Striegl, Pirkko Kortelainen, J. P. Chanton, K.P. Wickland, G.C. Bugna, M. RantakariWater source to four U.S. wetlands: Implications for wetland management
Results of long-term field studies of wetlands in four different hydrogeologic and climatic settings in the United States indicate that each has considerably different sources of water, which affects their response to climate variability and land-use practices. A fen wetland in New Hampshire is supplied almost entirely by ground water that originates as seepage from Mirror Lake; therefore, streamAuthorsT. C. Winter, D. O. Rosenberry, D.C. Buso, D.A. MerkThe concept of hydrologic landscapes
Hydrologic landscapes are multiples or variations of fundamental hydrologic landscape units. A fundamental hydrologic landscape unit is defined on the basis of land-surface form, geology, and climate. The basic land-surface form of a fundamental hydrologic landscape unit is an upland separated from a lowland by an intervening steeper slope. Fundamental hydrologic landscape units have a complete hyAuthorsT. C. WinterNitrogen biogeochemistry and surface-subsurface exchange in streams
No abstract available.AuthorsJohn H. Duff, Frank J. TriskaThe use of principal component analysis for interpreting ground water hydrographs
Principal component analysis was used to define patterns in water table hydrographs at four small, lake-watershed research sites in the United States. The analysis provided insights into (1) characteristics of ground water recharge in different parts of the watersheds; (2) the effect of seepage from lakes on water table fluctuations; and (3) the effect of differences in geologic properties on wateAuthorsT. C. Winter, S.E. Mallory, T.R. Allen, D. O. RosenberryPlants as indicators of focused ground water discharge to a northern Minnesota lake
Determining the discharge of ground water to Shingobee Lake (66 ha), north-central Minnesota, is complicated by the presence of numerous springs situated adjacent to the lake and in the shallow portion of the lakebed. Springs first had to be located before these areas of more rapid discharge could be quantified. Two methods that rely on the distribution of aquatic plants are useful for locating spAuthorsD. O. Rosenberry, Robert G. Striegl, D.C. HudsonEvidence of Climate Change over the Last 10,000 Years from the Sediments of Lakes in the Upper Mississippi Basin
The study of lake sediments as recorders of past climate change has been a major focus of the Geologic Division's Global Change and Climate History Program. In particular, lakes of the Upper Mississippi Basin (UMB) provide some of the most detailed records of climate and environmental change during the Holocene (last 10,000 years). The UMB is particularly sensitive to climate change because the thAuthorsMagnitude and Significance of Carbon Burial in Lakes, Reservoirs, and Northern Peatlands
It is estimated that freshwater lakes in the world have a total area of about 1.5x1012 m2 (Shiklomanov, 1993; table 1). Including saline inland seas in this total would add another 1x1012 m2. The 28 largest (area of each > 5,000 km2) freshwater lakes in the world have a total area of 1.18x1012 m2 or about 79 percent of the total area of all freshwater lakes. If the 28 large lakes bury organic carbAuthorsEstimating lake-atmosphere CO2 exchange
Lake‐atmosphere CO2 flux was directly measured above a small, woodland lake using the eddy covariance technique and compared with fluxes deduced from changes in measured lake‐water CO2 storage and with flux predictions from boundary‐layer and surface‐renewal models. Over a 3‐yr period, lake‐atmosphere exchanges of CO2 were measured over 5 weeks in spring, summer, and fall. Observed springtime CO2AuthorsD.E. Anderson, Robert G. Striegl, D.I. Stannard, C.M. Michmerhuizen, T.A. McConnaughey, J. W. LaBaughThe carbon cycle and biogeochemical dynamics in lake sediments
The concentrations of organic carbon (OC) and CaCO3 in lake sediments are often inversely related. This relation occurs in surface sediments from different locations in the same lake, surface sediments from different lakes, and with depth in Holocene sediments. Where data on accumulation rates are available, the relation holds for organic carbon and CaCO3 accumulation rates as well. An increase ofAuthorsW.E. DeanMagnitude and significance of carbon burial in lakes, reservoirs, and peatlands
Globally, lakes are currently accumulating organic carbon (OC) at an estimated annual rate of about 42 Tgṁyr−1. Most of the OC in all but the most oligotrophic of these lakes is autochthonous, produced by primary production in the lakes. The sediments of reservoirs accumulate an additional 160 Tg annually, and peatlands contribute 96 Tg annually. These three carbon pools collectively cover less tAuthorsW.E. Dean, E. GorhamA mini drivepoint sampler for measuring pore water solute concentrations in the hyporheic zone of sand-bottom streams
A new method for collecting pore-water samples in sand and gravel streambeds is presented. We developed a mini drivepoint solution sampling (MINIPOINT) technique to collect pore-water samples at 2.5-cm vertical resolution. The sampler consisted of six small-diameter stainless steel drivepoints arranged in a 10-cm-diameter circular array. In a simple procedure, the sampler was installed in the streAuthorsJohn H. Duff, Fred Murphy, Christopher C. Fuller, F. Triska, Judson W. Harvey, Alan P. Jackman