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Research Highlights - Clean Air and Water

Northeastern and Midwestern forests are vital for providing abundant clean water and air for the regions’ many rural and urban inhabitants. For example, water that has passed through forests is cleaner than water than that has drained from roads or disturbed lands. By taking up carbon dioxide for use in photosynthesis, trees help reduce greenhouse gases and improve the local and global environment. Forests also receive harmful atmospheric pollutants such as acid precipitation and mercury, which alter the soil and harm tree health and alter lake ecosystems.

2014 Research Highlights

New Tool for Predicting Smoke Dispersion During Low-Intensity Fires

Anticipating effects of prescribed fires on air quality enhances safety

Smoke from a low-intensity prescribed fire in the New Jersey Pine Barrens affecting visibility on a nearby highway.  Photo by Warren Heilman, USDA Forest Service
Smoke from a low-intensity prescribed fire in the New Jersey Pine Barrens affecting visibility on a nearby highway. Photo by Warren Heilman, USDA Forest Service

The effects low-intensity prescribed fires used for fuels management have on air quality are a particular concern for fire and air-quality management communities throughout the United States. Smoke from prescribed fires, which are often used in wildland-urban-interface (WUI) areas and in areas where forest vegetation has a significant impact on the local meteorology, can linger for relatively long periods of time and adversely affect human health and safety. The planning and tactical management of low-intensity prescribed fires can be enhanced with models and decision-support tools that are able to predict the ambient and fire-induced meteorological environment at forested burn sites and the effect of that environment on local smoke transport. Forest Service researchers collaborated with colleagues at Michigan State University to develop and evaluate a coupled meteorological/particle-dispersion model suitable for predicting local meteorological and air-quality impacts of low-intensity wildland fires in forested environments. The modeling system was tested using meteorological and air-quality data collected during prescribed fires conducted by the New Jersey Forest Fire Service in the New Jersey Pine Barrens and is now being evaluated as a potential real-time operational tool for fire and smoke management.


Products & Resources:

Estimating Greenhouse Gas Fluxes in Managed Forests

Cover of “Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory,”  Photos by USDA
Cover of “Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory,” Photos by USDA

Farms and forests are sources and sinks of greenhouse gases (GHGs), and land management practices can reduce GHG emissions and increase carbon storage. The 2008 Farm Bill directed USDA to develop technical guidelines to help forest, farm, and ranch managers quantify the changes in their GHG footprint that could result from a change in management practices. Forest Service scientists played key roles in developing the methods recommended for measuring changes in GHG emissions and carbon storage in managed forests. The team’s goal was to produce transparent and scientifically sound guidelines, and these methods were reviewed by federal GHG specialists, academic experts, and the public. The report, “Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory,” was published in July 2014 and will serve as the blueprint for the development of user-friendly web-based GHG inventory tools. These tools will enable landowners to estimate changes in GHG emissions and carbon stocks that result from changes in forest management practices, allowing them to participate in emerging markets for carbon and other ecosystem services.

Partners


Products & Resources:

Linking Land Use to Water Quality

Modeled spring runoff total phosphorus (mg/L) and turbidity (NTU) for watersheds with observed values (gauged) and based on landscape variables only (unguaged) for Lake Michigan.  Gray areas are the portions of the basin not modeled. Map by USDA Forest Service
Modeled spring runoff total phosphorus (mg/L) and turbidity (NTU) for watersheds with observed values (gauged) and based on landscape variables only (unguaged) for Lake Michigan. Gray areas are the portions of the basin not modeled. Map by USDA Forest Service

The Great Lakes Restoration Initiative is investing hundreds of millions of dollars to improve the quality of the Great Lakes. One of the projects promotes nearshore health and prevention of harmful algal blooms. But might these problems be minimized through wise management and stewardship of the lakes’ watersheds? Forest Service scientists demonstrated that sediment and phosphorus delivery to the lakes is influenced by land use and land cover and their change over time. For example, phosphorus levels in Lake Superior increased with the proportion of persisting forest, forest disturbed during 2000-2009, and agricultural land; sediments (turbidity) increased with the proportion of persisting forest, forest disturbed during 2000–2009, agricultural land, and urban land. In both cases, agriculture and forest disturbance were the most important predictors of water quality impairment. However, water quality is not measured everywhere. Forest Service scientists developed models to predict likely water quality problems in streams that are not monitored. This will allow land managers to prioritize restoration investments and management activities across the entire basin, monitored and not monitored. The supporting inventory and forest canopy cover change data were published for the public’s use in their own assessments.


Products & Resources:

Contrasting Effects of Invasive Insects and Fire on Forest Carbon Dynamics

Oak- and pine-dominated forests in the New Jersey Pinelands can recover more rapidly from prescribed fires than from invasive insect damage

A prescribed fire burning at the Cedar Bridge carbon flux tower in the New Jersey Pinelands. Photo by Kenneth Clark, USDA Forest Service
A prescribed fire burning at the Cedar Bridge carbon flux tower in the New Jersey Pinelands. Photo by Kenneth Clark, USDA Forest Service

Forest Service scientists quantified changes in forest structure and measured water use and net carbon dioxide (CO2) exchange from towers in forest stands that were burned in prescribed fires or defoliated by invasive insects. Prescribed burns resulted in little change to nitrogen in foliage during the following growing season, while insect defoliation and subsequent tree mortality reduced canopy nitrogen pools. Ecosystem Water Use Efficiency (WUEe) was reduced to 60 percent and 46 percent of pre-disturbance values in oak-dominated and mixed stands during defoliation; prescribed fire had little effect. Over a decade, carbon sequestration by an intensively studied defoliated stand totaled about 5.4 tons C per hectare, while a burned stand sequestered 10.6 ton carbon per hectare. These results indicate that forest carbon dynamics, and especially rates of net CO2 exchange, are more sensitive to disturbance than hydrologic fluxes, and disturbances that result in large nitrogen transfers within stands may have long-term effects on rates of carbon sequestration. This work improves scientists’ ability to predict interactions between carbon and water cycles under climate change scenarios that result in a greater probability of insect invasions, wildfire, or other disturbances.


Products & Resources:

Best Management Practice Monitoring Training Delivered to National Forests

Pam Edwards provides National Best Management Practices Training to USDA Forest Service employees.  Photo by USDA Forest Service
Pam Edwards provides National Best Management Practices Training to USDA Forest Service employees. Photo by USDA Forest Service

Best management practices (BMPs) include planning and field techniques to control pollutants attributable to diverse types of land uses. For the Forest Service, the largest land management agency in the United States, BMPs are fundamental to protecting water quality and aquatic health. The National BMP Monitoring Protocols were developed to monitor BMP use and effectiveness for all of the major types of land-disturbing activities and features managed by the Forest Service. As the result of several directives, including the new planning rule, all agency units are now required to conduct monitoring annually. National Forest System field personnel identified training as a priority need to implement BMP monitoring. Forest Service scientists who played a lead role in the development of the monitoring protocols, are also leading the training efforts. A Forest Service scientist worked with a soil scientist from the Kaibab National Forest to conduct 2-day training sessions during summer 2014 at more than a dozen locations, from Georgia to California and from Alaska to Louisiana. Each training session was followed by field site monitoring at locations chosen by the host unit. Overall, more than 150 Forest Service employees participated in the training, and some of those individuals will help train others in future sessions.


Products & Resources:

2013 Research Highlights

Seed Orchards Help Battle Beech Bark Disease

Regional beech seed orchards to provide seedlings to state and national forests for restoration plantings

American beech flowers, Photo by Vern Wilkins, Indiana University
American beech flowers, Photo by Vern Wilkins, Indiana University

Forest Service researchers and colleagues have developed a test for identifying American beech trees resistant to the invasive beech scale insect responsible for initiating beech bark disease and are training personnel from state and national forests to use it. Once resistant trees are identified, dormant branches are grafted onto seedlings and these grafted clones are being planted in seed orchards. Genetic studies of resistant parent trees destined for one orchard have shown that about half of the seedlings produced will inherit resistance to beech bark disease. The seeds produced will be made available to state and national forests to grow seedlings for use in planting healthy American beech trees in areas where beech bark disease is prevalent. Personnel at the Eastern Region’s Oconto River Seed Orchard (ORSO) in White Lake, WI, have recently joined the battle against beech bark disease by assisting with grafting efforts. Currently, three regional seed orchards are being installed thanks to funding support from Northeastern Area State and Private Forestry and the collaborative efforts of FS Research, ORSO, the Allegheny, Monongahela, and Hiawatha National Forests, the Holden Arboretum in Kirtland, OH, and the states of Michigan, Pennsylvania, and West Virginia.


Products & Resources:

Trees Using Water More Efficiently as Atmospheric Carbon Dioxide Rises

Rising atmospheric carbon dioxide levels show direct and unexpectedly strong influence on ecosystem

The top of a flux tower at the Howland Forest in Maine. Instruments on the tower measure tree carbon dioxide uptake and water use. Photo by John Lee, University of Maine​, used with permission.
The top of a flux tower at the Howland Forest in Maine. Instruments on the tower measure tree carbon dioxide uptake and water use. Photo by John Lee, University of Maine​, used with permission.

Forest Service scientists working with Harvard University and other partners analyzed direct, long-term measurements of whole-ecosystem carbon and water exchange and found a substantial increase in water-use efficiency in temperate and boreal forests of the Northern Hemisphere over the past two decades. This increase has implications for ecosystem function, services, and feedbacks to the climate system, including enhanced timber yields and improved water availability, which could partially offset the effects of future droughts. Their results suggest that increases in carbon dioxide are already changing the way forests function. Data came from seven sites in the midwestern and northeastern United States that are part of the AmeriFlux Network, including the Forest Service’s Bartlett Experimental Forest in New Hampshire and the Howland Cooperating Experimental Forest in Maine. Additional data from 14 other Northern Hemisphere sites confirmed the trends.


Products & Resources:

Supporting research and international training through the International Soil Carbon Network

Advancing belowground carbon understanding, monitoring, and reporting

Carbon dioxide (CO2) is removed from the atmosphere by trees planted in mined and industrial lands and then is transferred from the tree to the soil where it is stored as carbon.​
Carbon dioxide (CO2) is removed from the atmosphere by trees planted in mined and industrial lands and then is transferred from the tree to the soil where it is stored as carbon.​

Soils are the great unknown in understanding the global carbon cycle because the amounts, cycling, and effects of management on soil carbon are often difficult to measure or understand. The International Soil Carbon Network (ISCN) database, a research tool developed by Forest Service scientists with the help of many partners, facilitated several synthesis projects, including one that assessed the effects of afforestation on soil carbon in the continental United States. The ISCN also works internationally, having expanded from the former National Soil Carbon Network in response to interest among the international scientific community, and several highlights in FY2013 stem from this international growth. The ISCN added three more renowned scientists from different countries to its steering group (bringing the total to 21), worked with international efforts to expand global data coverage, and facilitated a training workshop for agency and academic scientists from Colombia, Ecuador, Honduras, Mexico, and Peru. The workshop focused on measuring and reporting belowground carbon stocks.

Partners

  • Luke Nave, University of Michigan
  • FS International Programs; National Forest Systems National Soils Program; Hiawatha National Forest
  • US Agency for International Development; USDA Natural Resources Conservation Service, Agricultural Research Service, & National Institute of Food and Agriculture; USDI Geological Survey; U.S. Environmental Protection Agency; and the U.S. Department of Energy.
  • Microsoft Research and the National Council for Air and Stream Improvement.

Products & Resources:

Scaling Up Aspen-FACE Experiment Results to Century and Landscape Scales

How elevated carbon dioxide and ozone will affect future tree species composition in northern forests

Aerial view of the Aspen-FACE experiment near Rhinelander, WI. Photo by Eric Gustafson, U.S. Forest Service.
Aerial view of the Aspen-FACE experiment near Rhinelander, WI. Photo by Eric Gustafson, U.S. Forest Service.

The Forest Service’s Aspen-FACE Experiment generated 11 years of data on the effects of elevated carbon dioxide (CO2) and ozone on the growth of field-grown trees (maple, birch, and six aspen clones) in northern Wisconsin. It is not known how these short-term plot-level responses might play out at the landscape scale over multiple decades. The scientists used a forest landscape model (LANDIS-II) to scale these site level results to broader temporal and spatial scales and several general principles emerged: 1) The productivity of a species under future conditions is the primary determinant of short-term dominance; 2) Longer term, longevity and shade tolerance may supersede productivity as the determinant of importance, depending on the disturbance regime; 3) Changes in the abundance of species were mostly gradual and none of the species disappeared from the landscape, even under treatments for which they were poorly adapted; 4) Different species fared relatively well under different treatments; 5) Accounting for spatial processes is important because seed dispersal and establishment may limit the ability of some species to colonize available habitat. Thus, there will be species “winners and losers,” but managers may have considerable control over outcomes by managing disturbance and landscape spatial pattern.


Products & Resources:

2012 Research Highlights

Biomass Potential of Poplar Energy Crops in Minnesota and Wisconsin

Industrial poplar farm.
Ron Zalesny, U.S. Forest Service
Industrial poplar farm.

Short-rotation woody crops such as poplars (Populus spp. and their hybrids) are a significant component of the total biofuels and bioenergy feedstock resource in the U.S. Woody production systems and conversion technologies are needed to maintain healthy forests and ecosystems, create high paying manufacturing jobs, and meet local/regional energy demands. Poplars are dedicated energy crops that can be strategically placed in the landscape to conserve soil and water, recycle nutrients, and sequester carbon. But production of these crops may result in large-scale land conversion, which leads to questions about their economic, logistic, and ecologic feasibility. To address these concerns, Northern Research Station scientists used social (i.e., land ownership and cover) and biophysical (i.e., climate, soil characteristics) spatial data to map eligible lands suitable for establishing and growing poplar biomass for bioenergy crops across Minnesota and Wisconsin.

Partners

William Headlee and Richard Hall, Iowa State University; David Coyle, University of Georgia; Raymond Miller, Michigan State University; Brian Stanton, GreenWood Resources, Inc.; Dan Langseth and Mike Young, Verso Paper; Bernie McMahon and Bill Lazarus, University of Minnesota


Improving Environmental Health and Community Vitality in Agricultural Landscapes

Prairie strip embedded in an agricultural (corn) watershed. The prairie strips increase nutrient and sediment retention, reduce runoff, and increase biodiversity.
Matt Helmers, Iowa State University
Prairie strip embedded in an agricultural (corn) watershed. The prairie strips increase nutrient and sediment retention, reduce runoff, and increase biodiversity.

Traditional agricultural practices have led to a number of environmental problems including increased erosion, high nutrient losses, loss of diversity, and degraded surface and ground water resources. Northern Research Station scientists and their partners are helping midwestern farming communities understand how to transform portions of the agricultural landscape into perennial plant communities. In ongoing studies in Iowa, scientists are testing strategically placed prairie strips in agricultural watersheds. Already they are seeing compelling results of the benefits of those strips in reducing sediment and nutrient transport to streams (and ultimately to the Gulf of Mexico). The partners have developed a handbook for growers and agency personnel describing the potential benefits of perennials in agricultural landscapes and techniques that achieve those benefits. The results are now being incorporated into field days and training for Iowa farmers.

Contact

Randy Kolka

Partners

National Agroforestry Center, USDA Agriculture Research Service`s National Laboratory for Agriculture and the Environment; Neil Smith National Wildlife Refuge; Iowa State University; the Leopold Center for Sustainable Agriculture; University of Michigan


Modeling Altered River Flows that Affect Fish in the North Atlantic

An Atlantic salmon smolt, ready to migrate to the ocean.
Steve McCormick. Used with permission.
An Atlantic salmon smolt, ready to migrate to the ocean.

Rivers flowing into the North Atlantic Ocean, both eastern North America and northwestern Europe, have long been modified for human use. Facing increasing demands for water and hydropower energy, and with fisheries and other ecosystem services at risk, managers desperately need sound science for informed decisionmaking. Northern Research Station researchers reviewed the state of science relating river flow regimes to fish populations and outlined a framework for meeting research needs. They made the case that, to generate robust predictions, models need to acknowledge the complex life-histories of riverine fishes and integrate stage-specific effects on population dynamics.

Contact

Keith Nislow

Partners

U.S. Geological Survey, Conte Anadromous Fish Research Center; Marine Scotland Freshwater Laboratory


Forest Management Impacts on Soil Carbon

Heavily thinned Allegheny hardwood plots on the Kane Experimental Forest, Pennsylvania. Unthinned Allegheny hardwood plots on the Kane Experimental Forest, Pennsylvania.
Coeli Hoover, U.S. Forest Service
Heavily thinned (left) and unthinned (right) Allegheny hardwood plots on the Kane Experimental Forest, Pennsylvania.

Forests remove carbon dioxide from the atmosphere, and maintaining or increasing their role in this function is becoming a more common objective for forest managers to consider. In many forests there can be more carbon stored in the soil than in the trees themselves, so it is important to understand the effects of common forest management practices on soil carbon stocks. Northern Research Station researchers measured soil and forest floor carbon in six long-term forest management studies in five northern states to assess the effects of partial and complete harvesting practices on these carbon stores. The study found no differences in the amount of carbon in the upper layers of soil between the sites that had no cutting, light thinning, heavy thinning, or complete harvests. The results show that it is unlikely that standard management practices as applied in northern hardwood forests lead to a loss of carbon from the soil, although the carbon in the forest floor may decline temporarily.

Contact

Coeli Hoover

Partners

National Forest System: Monongahela, Allegheny, Chequamegon-Nicolet, and White Mountain National Forests; SUNY Heiberg Memorial Forest


2011 Research Highlights

Global Forests Sequester One-third of Annual Fossil Fuel Emissions, Much More Than Previously Thought

[photo:] Forest interior in a permanent plot in Amazonian Peru; note the buttressed tree being measured at 5m with the help of a ladder - photographer: Abel Monteagudo-Mendoza, University of Leeds, UK (used with permission)Forested land plays a much larger role in removing carbon from the atmosphere than was previously thought, according to Forest Service scientists working with an international team of scientists. One of the key findings in the study is that global forests have annually removed 2.4 billion tons of carbon (8.8 billion tons of carbon dioxide) from the atmosphere, about one-third of annual fossil fuel emissions for the period of 1990-2007.

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Global forests have annually removed 2.4 billion tons of carbon (8.8 billion tons of carbon dioxide) from the atmosphere, about one-third of annual fossil fuel emissions during 1990 to 2007. This forest carbon sink (the net gain of C by forests) is found in every continent on
Earth. The size of the sink varies over time and by region. Understanding the location of the current sink, and the wide range of mechanisms responsible for it, is an important step towards understanding Earth’s changing climate system. An international team of scientists from 14 institutes, led by two Forest Service scientists, estimated the global forest carbon sink based on millions of on-the-ground measurements in forests around the world. The study reveals the dominant role of tropical forests for the exchange of carbon between the land and atmosphere and illustrates the importance of reducing tropical deforestation to limit the buildup of atmospheric carbon dioxide. The study also highlights the risk of passively relying on forests to continue to remove carbon from the atmosphere, for such carbon sequestration can be reversed by increased drought, wildfires, and forest degradation.

NRS Investigators

Yude Pan and Richard Birdsey

Partners

Jingyun Fang and Shilong Piao, Peking University; Richard Houghton, Woods Hole Research Center; Pekka Kauppi and Aapo Rautianien, University of Helsinki; Werner Kurz, Canada Forest Service; Oliver Phillips, Simon Lewis, and Steven Sitch, University of Leeds, UK; Anatoly Shvidenko, International Institute for Applied Systems Analysis, Austria; Josep Canadell, CSIRO, Australia; Phillippe Ciais, Laboratoire des Sciences du Climat et de l’Environnement, France; Robert Jackson, Duke University; Stephen Pacala, Princeton University; David McGuire, U.S. Geological Survey; Daniel Hayes, Oak Ridge National Laboratory

More Information

Pan, Yude; Birdsey, Richard A.; Fang, Jingyun; Houghton, Richard; Kauppi, Pekka E.; Kurz, Werner A.; Phillips, Oliver L.; Shvidenko, Anatoly; Lewis, Simon L.; Canadell, Josep G.; Ciais, Philippe; Jackson, Robert B.; Pacala, Stephen W.; McGuire, A. David; Piao, Shilong; Rautiainen, Aapo; Sitch, Stephen; Hayes, Daniel. 2011. A large and persistent carbon sink in the world's forests. Science. 333: 988-993.




Chloride Concentrations in Recovered Hydraulic Fracturing Fluid Increase With Depth of Tank

[photo:] Sampling tank-stored fracing fluids. Photo by Pam Edwards, USDA Forest Service Northern Research StationThe hydraulic fracturing fluid used in natural gas extraction in the northeastern Appalachians raises concerns about safe disposal. Forest Service scientists are studying the chemistry of the recovered injected fluid, called flowback, which often contains high concentrations of chloride. They found that the concentrations increase with the depth of the storage tank and that results of laboratory analysis are more accurate than those from field test kits.

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Natural gas production has increased in recent years in the northeastern Appalachian forests. The natural gas generally is extracted by a procedure known as hydraulic fracturing or “fracking.” A mixture of acids, water, gasses, and other additives is injected under high pressure into the bore hole to fracture the bedrock and thus releasing the natural gas. Once fracturing is completed, a portion of the injected fluid, called flowback, is recovered and stored in open pits or tanks. Because flowback often has high chloride concentrations, it is important that flowback chemistry is properly characterized so that disposal can be carried out safely. Northern Research Station scientists tested two technologies that measure chloride concentrations and determined that the concentrations increased with the depth in the tank. They also found that laboratory analyses were more accurate than field test kits.

NRS Investigator

Pam Edwards

Partners

National Forest System, Monongahela National Forest; Berry Energy Corporation

More Information

Edwards, Pamela J.; Tracy, Linda L.; Wilson, William K. 2011. Chloride concentration gradients in tank-stored hydraulic fracturing fluids following flowback. Res. Pap. NRS-14. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 14 p.




Assessing the Vulnerability of Northern Wisconsin’s Forests to Climate Change

[photo:] A new assessment provides information on the effects of climate change on Northern Wisconsin's forested landscape - photographer: Patricia Butler, NIACS 
A team of scientists and managers from the Forest Service and other organizations assessed the vulnerability of northern Wisconsin forests to climate change. The assessment summarizes multiple scientific research efforts and synthesizes the issues most salient to land managers.

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The potential effects of climate change on the forests of northern Wisconsin were assessed and summarized in a recent publication---The Ecosystem Vulnerability Assessment and Synthesis. Scientists from the Northern Research Station and University of Wisconsin modeled climate change effects on forest productivity and the suitability of habitat for specific tree species as well as the potential changes in forests that are most important for land management. This assessment is part of the larger Northwoods Climate Change Response Framework project in Minnesota, Michigan, and Wisconsin, which is developing an integrated set of tools, partnerships, and actions to support “climate-smart” conservation and management.

NRS Investigator

Chris Swanston

Partners

Forest Service: National Forest System, Eastern Region and Chequamegon-Nicolet National Forest; State & Private Forestry, Northeastern Area

External: Michigan Technological University; University of Wisconsin; Wisconsin Department of Natural Resources; Wisconsin Initiative on Climate Change Impacts

More Information

Swanston, Chris; Janowiak, Maria; Iverson, Louis; Parker, Linda; Mladenoff, David; Brandt, Leslie; Butler, Patricia; St. Pierre, Matt; Prasad, Anantha; Matthews, Stephen; Peters, Matthew; Higgins, Dale; Dorland, Avery. 2011. Ecosystem vulnerability assessment and synthesis: a report from the Climate Change Response Framework Project in northern Wisconsin. Gen. Tech. Rep. NRS-82. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 142 p.




Environmental and Economic Benefits of Short-Rotation Poplar Energy Crops

[photo:] Industrial energy crop plantation - photographer: Dr. Ron Zalesny, US Forest Service, Northern Research Station, NRS13Woody production systems and conversion technologies help maintain healthy forests and ecosystems, create high-paying manufacturing jobs, and meet local/regional energy demands. Poplars are dedicated energy crops that also conserve soil and water, recycle nutrients, and sequester carbon

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Poplar energy crops have been extensively studied throughout North America for over half a century and are one of many alternative feedstocks contributing to energy security. Building on work that began in late 1960s, Forest Service scientists and their partners have completed extensive studies that tested the genetics, physiology, and silviculture of poplar crops in a regional network of field trials first established in 1995. They are currently studying the carbon implications of 10- and 20-year-old plantations throughout the Midwest. They have analyzed biomass, rooting, and other important traits from hundreds of genotypes grown throughout the northern United States, as well as tree growth regulating mechanisms in the face of varying environments and changing climate. These results are currently being used to increase the energy potential of the trees and increase the efficiency of plantation establishment, which help meet U.S. energy demands.

NRS Investigator

Ronald S. Zalesny, Jr.

More Information

Lazarus William F.; Tiffany, Doug G.; Zalesny, Ronald S. Jr. 2011. Economic impacts of short rotation woody crops for energy or oriented strand board: a Minnesota case study. Journal of Forestry 109:149-156.




2010 Research Highlights

Climate change effects on streamflow

[photo:] Stream flowing through snow covered forest.Climate change has the potential to alter streamflow regimes, which has ecological, economic, and social implications. In the northeastern United States, it is unclear how climate change may affect the surface water supply, which is critically important in this densely populated region.

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NRS scientist John Campbell and collaborators have been evaluating the impact of climate change on streamflow at small gauged watersheds at the Hubbard Brook Experimental Forest in New Hampshire. These headwater streams are the source waters for larger rivers and therefore, may serve as an indicator for potential climate change effects. Campbell’s research evaluates past long-term hydrologic data and modeled future streamflow through the end of the 21st century using several climate change scenarios. Preliminary results indicate that earlier snowmelt and the diminishing snowpack is advancing the timing and reducing the magnitude of peak discharge associated with snowmelt. However, there is little change in the overall quantity of streamflow because increases in precipitation offset increases in water loss via evaporation and plant transpiration. This study is improving our understanding of the hydrological consequences of climate change, and will begin to provide a foundation for sound future decision-making on climate change policy.

These data show that conifer canopies are very important contributors of mercury inputs to watersheds and that fires mobilize considerable stored mercury that is deposited locally. Thus, using fire as tool to lessen fuel loads is problematic from a mercury deposition perspective, particularly if this increased local deposition finds its way into the food chain.

Partners

Charley Driscoll and Afshin Pourmokhtarian at Syracuse University; Katharine Hayhoe at Texas Tech University




Watershed-scale erosion model accuracy improved

[photo:] researcher measures erosion.The Revised Universal Soil Loss Equation (RUSLE) is a computer model commonly used to estimate sediment delivery to streams from forested watersheds. However, much of the coefficient development and validation of RUSLE has been based on results from plot studies, or from extrapolation of data collected from agricultural fields. From 1999-2008, NRS scientist Pam Edwards measured sediment delivery annually from an entire forested watershed and compared these measurements to those generated from RUSLE.

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Edwards and her co-investigators Hamons and Wang, found that the RUSLE estimates greatly overestimated the measured soil losses, probably because RUSLE assumes sheet erosion from the entire watershed surface. The results of the field measurements showed that most sediment delivered to the stream originated within 20 horizontal meters of the stream.

Partners

Dr. Jingxin Wang, West Virginia University; Mr. Greg Hamons, formerly West Virginia University




Critical loads of nitrogen deposition for United States ecoregions

[photos:] Show difference between control and treated grasslandsNitrogen (N) deposition has reached a level that has caused or is likely to cause alterations and damage in ecosystems across the United States. NRS scientists Linda Pardo, Erik Lilleskov, and Molly Robin-Abbott used the critical loads approach to determine levels of N deposition by synthesizing current research relating atmospheric N deposition to effects in terrestrial and aquatic ecosystems.

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Responses to increased N deposition included changes in biological community structure, altered soil N cycling, increased N leaching to soil and surface waters, increases in susceptibility to secondary stresses, increases in invasive species, and altered fire regime. The range of critical loads for nutrient N they found for U.S. ecoregions, inland surface waters, and wetlands is 1 to 39 kg N/ha/yr. In some regions, the critical load for sensitive receptors has been exceeded. This approach is an ecosystem assessment tool with great potential for simplifying complex scientific information and effectively communicate with the policy community and the public.

Partners

Mark Fenn, and Linda Geiser, U.S. Forest Service - Pacific Northwest Research Station; Christine Goodale, Cornell University; Charles Driscoll, Syracuse University; Edith Allen & Robert Johnson, University of California, Riverside; Jill Baron & Steve Perakis, U.S. Geological Survey; Roland Bobbink, B-WARE Research Center, the Netherlands; William Bowman, University of Colorado; Bridget Emmett, CEH, United Kingdom; Frank Gilliam, Marshall University; Christopher Clark, Tara Greaver, Lingli Liu, Jason Lync, & John Stoddard, U.S. Environmental Protection Agency; Sharon Hall, Arizona State University; Knute Nadelhoffer, University of Michigan; Kathleen Weathers, Cary Institute of Ecosystem Studies




The First Continental-scale forest age map of North America

[image:] Thumbnail image of North America forest age map Forest age determines its growth rate and whether it sequesters or emits carbon. Over large regions, forest age reflects past management actions and disturbances that continue to affect forest functions for future decades. To help support the U.S. response to climate change, NRS scientist Yude Pan analyzed forest age dynamics to determine what kinds of management activities can be applied to increase carbon sequestration or reduce emissions of greenhouse gases.

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When mapped over whole nations, forest age data will help develop policies and improve monitoring of the atmosphere for verifying compliance with climate treaties. This North American forest age map was developed and published in collaboration with scientists at the University of Toronto, Canada, and is a major Forest Service contribution to the multi-agency North American Carbon Program.

Citation:
Pan, Y.; Chen, J.M.; Birdsey, R.; McCullough, K. He, L.; Deng, F. 2010, Age structure and disturbance legacy of North American forests. Biogeosciences Discuss., 7, 979-1020.




2009 Research Highlights

Influence of fire on mercury deposition

[photo:] Collecting a precipitation sample located under a deciduous canopy in Boundary Waters Canoe Wilderness Area of the Superior National Forest.A large forest blowdown event in 1999 in Minnesota’s Boundary Waters Canoe Wilderness Area damaged 370,000 acres and raised concerns about the fuel load of downed trees. Prescribed burning is one method to reduce fuel loads, but many are concerned about the effect of fire on mercury availability in aquatic systems.

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Because little research has studied the effects of fire on mercury cycling, this blowdown area presented an ideal opportunity.

As part of a larger study of the effects of fire on the watershed cycling of mercury, NRS scientist Randy Kolka and colleagues assessed the influence of fire on the deposition of mercury. In nonfire conditions, they found that forest canopy type and density were the primary influences on total deposition of mercury (THg) and methyl mercury (MeHg, which is the bioaccumulative form of Hg). Precipitation falling through conifer canopies tended to have higher concentrations of both THg and MeHg when compared to deciduous canopies or forest openings. Similarly, conifer canopies had four times higher concentrations of THg and 10 times higher concentrations of MeHg after fires than before. Higher concentrations were also found under deciduous canopies and in forest openings post-fire.

These data show that conifer canopies are very important contributors of mercury inputs to watersheds and that fires mobilize considerable stored mercury that is deposited locally. Thus, using fire as tool to lessen fuel loads is problematic from a mercury deposition perspective, particularly if this increased local deposition finds its way into the food chain.

Partners

Superior National Forest; University of Minnesota; U.S. Geological Survey




Improving water quality in the corn belt

[photo:] Farm pond in Benton County, IowaIn the last 200 years, upwards of 80 percent of the land in the U.S. Corn Belt agro-ecosystem has been converted from natural perennial vegetation (trees, shrubs, and forbs) to intensive rowcrop agriculture.

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While this provides many important benefits, the practices used also cause significant ecological problems, including significant effects on water quality at both the local and larger scale. Despite research showing how re-integration of perennial vegetation at strategic landscape positions can reduce the decline in water quality, the land area devoted to row-crop production in the Corn Belt continues to increase.

NRS researcher Lynne Westphal and others sought to improve understanding of how Corn Belt stakeholders make conservation decisions. They found that the adoption of conservation practices is based not only on profitability but also on the interplay between contextual factors at three distinct levels of the system: 1) compatibility with farm priorities, profitability, practices, and technologies; 2) community-level reinforcement through local social networks, norms, and support structures; and 3) consistent, straightforward, flexible, and well targeted incentives and regulations. Potential solutions include engaging in collaborative learning at the community level that would result in locally relevant changes with significant regional impacts, which could lead to more adoption of perennial cover in the Corn Belt.

Partners

Ryan Atwell, then Ph.D. Candidate, Iowa State University, now
AAAS Fellow with FS Research; Lisa Schulte Moore, Iowa State
University




Climate change effects on ephemeral forest pools

[photo:] This ephemral pool located on the Quabbin Reservation is part of a study of pool hydrology and macroinvertebrate fauna.Northern Research Station researcher Robert Brooks has been studying ephemeral (vernal) forest pools on the Quabbin Reservoir watershed in central Massachusetts. The long-term study has revealed numerous aspects of the structure and function of these critical and sensitive habitats.

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Vernal pools are the preferred breeding habitat for mole salamanders and wood frogs; support a rich, diverse, and abundant macroinvertebrate community; and contribute to overall forest biodiversity. The hydrology of ephemeral pools is determined principally by weather patterns and is likely to be particularly sensitive to changes in climate. Built on the foundation of this long-term study, a review paper on the potential impacts of projected climate change on ephemeral waters was published in 2009 in the journal Climatic Change. More>>

Partners

Massachusetts Department of Environmental Conservation




Forest carbon monitoring

[image:] Cover from Hoover's book  - Field Measurements for Forest Carbon Monitoring A Landscape - Scale Approach The role of forests in the global carbon cycle is becoming increasingly important, partly because forests can provide lower-cost greenhouse gas mitigation options and a variety of co-benefits. Characterizing and monitoring forest carbon stocks and fluxes is a key research need to help scientists and managers understand how to sustain and enhance the carbon storage capacity of our nation’s forests. NRS scientists led an effort to capture, in a single handbook, a landscape-scale monitoring program for all major forest carbon pools and fluxes.

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In collaboration with the North American Carbon Program and scientists from U.S. and Canadian institutions, NRS scientists designed a landscape-scale forest carbon monitoring program. Because forest carbon studies involve scientists in many different fields, it is unlikely that any single researcher would have experience in all of the types of measurements needed to conduct forest carbon research at scales larger than a forest stand. NRS scientist Coeli Hoover is the editor of the comprehensive handbook on the methods and measurements used in forest carbon inventory and monitoring. The book, Field Measurements for Forest Carbon Monitoring: A Landscape-Scale Approach was published by Springer.

Partners

North American Carbon Program




Revisiting long-term silviculture experiments

[photo:] Collecting increment cores from the trees to quantify annual growth patterns. Forest managers seek strategies to develop forests that are capable of sustaining forest productivity, habitat quality, and other ecosystem services under changing and variable climatic conditions.

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Also, because rising levels of atmospheric carbon dioxide are a major driver of climate change, forest managers are being asked to mitigate climate change by maximizing carbon storage and sequestration in forest ecosystems. Meeting these objectives is a challenge for forest managers. NRS scientist John Bradford is addressing this challenge by re-evaluating long-term silvicultural experiments. Originally designed to identify methods for maximizing timber growth and yield, decades-long NRS datasets and measurement plots are being examined to determine forest management strategies that can be used to adapt to climate change. So far, analyses suggest that there is a tradeoff between forests managed for high growth rates and forests managed for maximum carbon storage. Also, these studies suggest that lower stocking levels can lead to highcomplexity forests, which may be capable of greater adaptation. NRS researchers compiled and analyzed data from five long-term studies and began to focus on contemporary climate change questions.

Partners

University of Minnesota; Chippewa National Forest; Superior
National Forest; U.S. Forest Service, Region 9




2008 Research Highlights

Scientists seek the cause and conditions for mercury contamination

[photo:] Bowdown area in Boundary Waters Canoe Area, MinnesotaMercury is the number-one contaminant in U.S. lakes and streams, causing health concerns for both humans and animals when they consume fish from contaminated waters. The form of mercury that poisons the food chain is an organically complex form known as methyl-mercury (MeHg).

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Northern Research Station scientists and colleagues have gained ground in understanding the contributing factors and environments conducive to the methylation of mercury. Increased levels of sulfur and carbon have been found in conjunction with higher rates of methyl-mercury in northern Minnesota. These conditions are prevalent in marshy areas because of the abundance of mercury, carbon and sulfates, while there are low levels of oxygen.

By understanding the conditions and ecology associated with methyl-mercury creation, land managers can make land-use decisions that buffer these areas from land or aquatic systems that feed into a region’s animal and plant life. More>>




Studies show North American ecosystems absorbing less carbon

[photo:] The eddy flux tower at Silas Little Experimental Forest.  Measurements of energy, water vapor and net CO2 exchange started in April 2004.  Annual net CO2 exchange (NEEyr) measured at this site ranges between 187 and -293 g C m-2 yr-1, with the largest C loss value corresponding with complete defoliation by Gypsy moth in 2007.  Forests and oceans absorb about half of the world’s carbon emissions. However, two separate studies by Northern Research Station scientists report that the world is getting less of a helping hand from nature.

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One study has tracked springtime and autumn temperatures in the northern hemisphere and correlates those temperatures to carbon emissions and sequestering by vegetation. A trend of warmer, earlier springs was viewed as helpful because as plants increased the amount of time photosynthesizing, they also increased the amount of carbon they absorbed. However, this warming trend has continued into autumn, where shorter days reduced the amount of time plants were photosynthesizing. The warmer weather also caused the plants and soil to respire more, thereby increasing carbon emissions. The net result is: autumn carbon output is outpacing the increased springtime uptake.

These findings support a trend found in an assessment of sources of carbon emissions and sequestering in North America, sponsored by the U.S. Climate Change Science Program and led by NRS scientists and cooperators. Forest-specific results indicate that North American forests still absorb more carbon than they produce. However, the amount of sequestration done by U.S. forests appears to be declining, based on inventory data from 1952 to the present. More>>

Partners

  • The North American Carbon Program, which is sponsored by 11 U.S. agencies and scientists from around the world


2007 Research Highlights

Fostering broader participation in greenhouse gas registries and carbon markets

[photo:] Technician measures tree growthIn 2007, NRS scientists developed advanced decision-support tools that enable organizations to participate in the U.S. Department of Energy’s national greenhouse gas registry. The tools permit public and private entities to inexpensively report activities that increase carbon storage in forests or reduce greenhouse gas emissions.

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Such activities can help reduce the demand for energy or substitute biomass for fossil fuel, provide cleaner air, and reduce the threat of adverse climate change impacts. In addition, the Chicago Climate Exchange began using Forest Service-developed methods to estimate and report accomplishments and begin payments to landowners for registering their forests.

Partners

  • National Council for Air and Stream Improvement
  • Winrock International
  • U.S. Forest Service— National Forest System and State and Private Forestry

Predicting prescribed fire effects on watershed cycling of mercury

[photo:] shows a  prescribed fireWith funding through the Joint Fire Sciences program, NRS scientists are studying possible effects of prescribed fire on mercury cycling in the forest system. Prescribed fires set in the Boundary Waters Canoe Area Wilderness to reduce wildfire threats are the primary study focus.

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Early findings indicate that both wild and prescribed fires are significant sources of mercury to the atmosphere. A fraction of that mercury is redeposited directly into lakes or wetlands potentially affecting fish and posing a health risk to those who consume it. This project was awarded a Chief's Rise to the Future Award in 2006.

Partners

  • University of Minnesota
  • Superior National Forest
  • U.S. Geological Survey
  • Minnesota Pollution Control Agency


Woody crops produce energy and reduce pollution

[photo:] study site for wood energ  crops workNRS scientists are combining intensive forestry and waste management methods to increase the uses of wood for fiber and energy, while decreasing the environmental degradation associated with waste disposal and wastewater production. Trees take up some of the contaminants reducing the potential for leaching into the soil and nearby waterways.

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Scientists and resource managers are studying the response of specific tree species to wideranging contamination sources. Application of this research provides the opportunity for ecologically sustainable production of alternative biomass feedstock for bioenergy using irrigation and fertilization from waste waters including landfill leachate. The resulting energy system helps maintain environmental quality and the natural resource base on which agriculture, forestry, and recreation depend.

Partners

  • Oneida County Wisconsin Solid Waste Department
  • Wisconsin Department of Natural Resources
  • Iowa State University
  • University of Wisconsin-Madison