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Forest Disturbance Processes

Climate Change and Events

Northern Research Station scientists are deeply involved in research to understand the processes and extent of global climate change and their probable/possible effects on forest ecosystems. What processes in forest ecosystems are sensitive to physical and chemical changes in the atmosphere? How will future physical and chemical climate changes influence the structure, function, and productivity of forest and related ecosystems, and to what extent will forest ecosystems change in response to atmospheric changes? What are the implications for forest management and how must forest management activities be altered to sustain forest productivity, health, and diversity?

Climate Change Research from NRS

[photo:] Boardwalk leading to and surrounding SPRUCE experiment site on Marcell Experimental Forest.The Spruce-Peatland Response Under Climate and Environmental Change (SPRUCE) Experiment
Through collaboration with the U.S. Department of Energy and Oak Ridge National Lab, a large chamber experiment is being initiated to test the effects of increased soil and air temperature and elevated carbon dioxide levels on northern peatland ecosystems.  The experiment will provide a platform for testing mechanisms controlling vulnerability of wetland ecosystems to important climate change variables. 


[photo:] Poplar energy crops recently harvested for evaluation of aboveground carbon storage.Carbon Implications of Poplar Energy Crops Throughout the Energy Supply Chain
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. However, key environmental and economic uncertainties preclude broad-scale production of biofuels/bioproducts from poplar wood. Therefore, building on decades of research conducted at our Institute and throughout the region, we are evaluating the fate of carbon in soils and woody biomass, soil greenhouse gas emissions, and conversion efficiency barriers throughout the energy supply chain.


[image:] Output from a havitat suitability simulation.Cumulative Effects of Succession, Management, and Disturbance on Forest Landscapes
Multi-resource forest planning and management requires knowledge of the long-term, large-scale cumulative effects of alternative management strategies.  For common management goals such as sustaining forest biodiversity, providing habitat for desired wildlife species, and reducing forest fragmentation this requires spatially explicit forecasting tools that enable resource managers to map the spatial arrangement of forest size structure, species composition, wildlife habitat suitability, timber volume, and other attributes over time for large forest landscapes.   


[image:] An example of how models are linked to understand climate and disturbance impacts on forested landscapes.  Linking Population, Ecosystem, Landscape, and Climate Models to Evaluate Climate Adaptation Strategies
Climate change and forest mortality from disturbance agents such as fire and insects are among the top challenges facing natural resource management.  Landscape change will result from interactions among climate change; land use and management; and population, ecosystem, and landscape processes.  Approaches to forecasting landscape change have commonly addressed a subset of these factors but rarely have they all be considered.  Land managers and planners need knowledge of how these factors will interact and modeling tools to assess the effects of mitigation strategies.   


[photo] The Northern Forest Ecosystem Experiment is a large-scale, long-term field experiment in which harvested forests regenerate in atmospheres with enhanced concentrations of carbon dioxide (CO2), ozone (O3) or both gasses combined.  The physiology, genetics, and distribution of ponderosa pine species vary with changes in elevation and environmental conditions
In the desert southwest, significant variations in moisture and temperature occur along steep gradients in elevation.  Notably, the endemic ponderosa pine species vary with changes in elevation and the differences in elevation are repeated throughout the ranges of the species.  The long-term goal of the study is to provide a foundation for future regional studies of species range limitations by water or temperature stress. 


[photo] The Northern Forest Ecosystem Experiment is a large-scale, long-term field experiment in which harvested forests regenerate in atmospheres with enhanced concentrations of carbon dioxide (CO2), ozone (O3) or both gasses combined.  Northern Forest Ecosystem Experiment
The Northern Forest Ecosystem Experiment is a large-scale, long-term field experiment in which harvested forests regenerate in atmospheres with enhanced concentrations of carbon dioxide (CO2), ozone (O3) or both gasses combined.


 NIACS artworkNorthern Institute of Applied Climate Science
The Northern Institute of Applied Climate Science (NIACS) is a collaborative effort of the Forest Service, universities, and forest industry to provide ecological, economic, and social information that can be used to manage forests for the sequestration of atmospheric carbon. Forests store and/or retain carbon while simultaneously producing sustainable supplies of renewable energy and materials that help society. There are significant uncertainties, however, about how forest systems might respond to future climate change and how forest management could be used to ameliorate any negative effects.


[image:]  Diagram shows modeling process. Landscape Ecological Modeling: Species Habitat Modeling under Future Climates

Combining spatially distributed data related to organisms, climate, soils, and topography (as collected from ground surveys, satellites and geographic information systems) with statistical modeling techniques provides ever-increasing capabilities in modeling past, present, and potential future ecosystems at multiple scales. This research team specializes in this type of modeling, including understanding the potential consequences of climate change on the habitat of 134 tree and 147 bird species across the eastern United States. Using empirical data, we derive statistical species-based models of current habitat associations based on climate and landscape characteristics. These results provide a statistically based prospective of the potential future habitat for trees and birds.


[image:] Chestnut flowerThe Adaptive Tradeoffs between Boreal and Temperate Conifers in a Warming World
In a warming world, trees growing in seasonally cold environments may encounter new winter stresses associated with delayed acclimation, midwinter deacclimation, winter respiration, and light stress, even if they are well-adapted to surviving low-temperature stress in existing climatic regimes. Boreal and temperate conifers that maintain foliage through the winter months may be especially vulnerable.


[image:] Chestnut flowerAmerican Chestnut Restoration
The American chestnut is a tree species of unique ecological and economic value that was virtually eliminated following a blight caused by the fungal pathogen, Cryphonectria parasitica (Murr.) Barr that was accidentally introduced about a century ago.  In order to restore this economically and ecologically valuable species, multiple approaches to decrease the virulence of the pathogen or increase the resistance of the tree have been evaluated. 


[image:] Status of weather anomalies around the U.S. in early 2002, compiled by the National Weather Service. Adapting Forests to Climate Change
Climate models have projected significant increases in temperature over the next century for the Northeast and Midwest.  Climate change will also affect rainfall patterns, but scientists cannot yet predict how regional rainfall patterns will change.  Growing seasons will lengthen further in both spring and fall.  According to the Intergovernmental Panel on Climate Change, there is very high confidence that the vulnerability of North America depends on the effectiveness and timing of adaptation and the distribution of coping capacity, which vary spatially and among sectors. Climate change will constrain North America’s over-allocated water resources, increasing competition among agricultural, municipal, industrial and ecological uses (very high confidence).


[photo] The Aspen FACE siteAspen FACE Experiment
The Aspen FACE (Free-Air Carbon Enrichment) Experiment (1997 – 2009), a multi-disciplinary study, was designed to assess the effects of increasing tropospheric ozone and carbon dioxide levels on the structure and function of northern forest ecosystems.


[photo:] An example of the effect of a freezing rain disturbance event on forest vegetation.Atmospheric Disturbance Climatology System
Understanding the spatial and temporal patterns of these and other climate variables throughout the region is important in developing effective land management strategies that can sustain our natural resources.


[image:] Total number of thaw-freeze occurrences over the north central and northeastern U.S. from 1950 to 1998, with a thaw-freeze event defined as maximum daily near-surface air temperatures exceeding or equaling 1 C for at least one day followed by daily minimum near-surface air temperatures equalling or falling below -10 C for at least one day in the succeeding ten days since the last day of thaw.Climatic Indicators of Forest Health
Managers often need frequent, updated assessments of current and developing conditions on which to base management decisions and respond to public concerns. No methodology has been developed to indicate when a forest population is at risk to specific local and regional climate and air pollution stressors.


[image:] Yellow-cedar declineClimate Change and Yellow-Cedar Decline
Yellow-cedar is an ecologically, economically, and culturally important tree species that has experienced dramatic mortality in Alaska and nearby British Columbia for about 100 years. The extensive mortality, referred to as yellow-cedar decline, has now been documented on over 200,000 hectares and is not associated with any biotic factor (insect or disease) as a causal agent of decline.


[photo:] Delaware River basinThe Delaware River Basin: Collaborative Environmental Research and Monitoring
In 1998 the USDA Forest Service, the U.S. Geological Survey, and the National Park Service formed the Collaborative Environmental Monitoring and Research Initiative (CEMRI) to test strategies for integrated environmental monitoring among the agencies.  The initiative combined monitoring and research efforts of the participating Federal programs to evaluate health and sustainability of forest and freshwater aquatic systems in the Delaware River Basin. 


[photo:] Second generation jack pine provenance tests.Enhanced Adaptation to Climate Change of Conifer Species and Provenances in Northern Forest Ecosystems
Over 12 million trees were distributed from Wisconsin state forest nurseries in 2007. The success of such regeneration programs depends upon the development of adaptation strategies for enhanced ecosystem sustainability under changing climates. There is a need to identify species and seed sources with enhanced adaptation to climate change pressures to ensure biologically and economically sustainable reforestation, afforestation, and gene conservation.


[photo:] Northern Michigan forest landscape with snowcover and water in distance.Forest Management for an Uncertain Climate Future: Tools and Training
Land managers need specific information, strategies, and tools to address the unique challenges of managing forests under uncertain and changing climate and ecosystem response. Sustainable forest management is critical for both the adaptation of forests to changing climatic conditions as well as mitigation of increased levels of atmospheric greenhouse gases. The uncertainty of future climatic conditions necessitates adaptive techniques and strategies that provide flexibility and enhance ecosystem resistance and resilience.


[image:]  Aspen FACE Facility Free-air CO<sub>2</sub> and O<sub>3</sub> Enrichment Project Global Climate Change Research at Harshaw Research Farm, Harshaw WIFoliar biochemical indicators of environmental change and their relationship with site productivity
Methods are needed to assess the positive or negative impact of environmental pollution on forest productivity in an asymptomatic forest stand. A goal of several research groups in the Northern Research Station (NRS) is to develop a set of physiological and biochemical markers that can assess the early onset of stress in forests due to environmental factors, before injury is visible.


[image:] Changes in climate, atmospheric components, land use and disturbance regimes affect forest carbon sequestration and biofuel product. It is important to understand these processes and attribute the effects to different causesImpacts of Disturbances and Climate on Carbon Sequestration and Biofuels
Currently, U.S. forests and forest products offset about 20% of the nation’s fossil fuel emissions. However, recent findings cast doubt on the sustainability of this offset. First, the strength of the U.S. forest carbon offset may be weakening due to forest ageing, climate variability, and increasing natural disturbances. Second, climate change is expected to further increase frequencies of insect outbreaks and wildfire, and alter species composition in forest ecosystems, consequently influencing forest carbon pools in a significant way.  These current and projected forest carbon cycle dynamics need to be considered in strategic forest planning and management decisions in coming decades if the nation’s forests are to provide stable or even increasing ecosystem services.


[image:] Graph indicating Forest Carbon BudgetForest Carbon Models and Budgets
There is increasing interest in accurate estimates of national, regional, state, and local carbon fluxes, and identification of the causes of land / atmosphere / ocean exchange of carbon.  Because forests store large quantities of carbon and these stocks are affected by many factors, accurate monitoring of forest carbon stocks and fluxes is a critical component of strategies to manage greenhouse gas emissions and sequestration. 


[image:]   The method of DNA fingerprinting --Schematic provided by Craig Echt, Southern Research StationEstimating fine root biomass with DNA fingerprints
Because the aspen stands at the Aspen FACE experiment are a mixture of five clones, the development of highly discriminating molecular-methods are needed to assign fine-root fragments to individual clones.


[image:] Fragmented forest landscapeIntegrating Landscape-scale Forest Measurements with Remote Sensing and Ecosystem Models to Improve Carbon Management Decisions
Managing forests to increase carbon stocks and reduce emissions requires knowledge of how management practices and natural disturbances affect carbon pools over time, and cost-effective techniques for monitoring and reporting.


[photo:] Aerial view of the Forest-Atmosphere Carbon Transfer and Storage (FACTS-II) study site near Rhinelander, WI, where the impacts of elevated carbon dioxide and ozone concentrations on forest microclimates are being studied along with may other climate-change related studies.Greenhouse Gas Impacts on Forest Microclimates
Our ability to predict the future impacts of increasing greenhouse gas concentrations and associated changes in the climate system on forest ecosystems requires an understanding of how vegetation responses to increased greenhouse gas concentrations can further alter the local atmospheric environment within forest ecosystems.  It is this local atmospheric environment that governs many of the basic physical and biological processes within forest ecosystems.


[image:] Example output (longwave radiation flux at the surface) from the National Center for Atmospheric Research Community Climate System Model (Version 3), which is being used by NRS-06 scientists and collaborators to examine the impacts of land-cover changes (including afforestation) on the global climate system. Impacts of Land Management on the Climate System
New research is needed to examine the potential impacts of land cover changes, including afforestation, on the climate system in order to provide the scientific basis for adopting land use decisions that are meant to mitigate global warming. 


[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.  Monitoring and Understanding Forest/Atmosphere Carbon Dioxide Exchange: the NRS Flux Tower Network
Data from flux sites help test physiological models of C exchange and are critical to relating fluxes and remote sensing data. Companion physiological and ecological measurements enable partitioning carbon fluxes into plant and soil components and reveal mechanisms responsible for these fluxes. At some sites, biomass-based estimates of C storage have validated C budgets from direct flux data, and vice-versa. Data from the flux sites have been applied in ecology, weather forecasting, and climate studies, especially for sites with several years of data to quantify inter-annual flux variations.


[image:]   The method of DNA fingerprinting --Schematic provided by Craig Echt, Southern Research StationTracing the movement of an invasive insect using stable isotopes
To better understand the response of insect populations to increasing environmental pollution, we are using stable isotope analysis to trace the movement of an invasive insect in mixed tree communities grown under different air quality conditions.


[photo:] Birch tree at Aspen FACE siteEastern Area Modeling Consortium
The Eastern Area Modeling Consortium (EAMC) is a multi-agency coalition of researchers, fire managers, air-quality managers, and natural resource managers at the federal, state, and local levels. As part of this group, NRS researchers are working to (1) increase understanding of fire behavior and smoke dispersion; (2) expand knowledge of the physics of fire–atmosphere interactions; (3) enhance prediction and response to the dangers of prescribed fires and wildfires; and (4) develop products and transfer new technologies related to national and regional fire-weather and air-quality dynamics. In addition, the EAMC provides two types of weather products for fire managers: maps showing current and future weather patterns over various regions of the United States and time series products indicating likely weather changes in at a given location over a 48-hour period.


[image:] Map of predicted losses of nitrogen from forested lands of the Chesapeake Bay watershed under no nitrogen deposition, current nitrogen deposition, and doubled nitrogen deposition (Pan et al. 2004).Mid-Atlantic Forests and the Chesapeake Bay Watershed
Forest landscapes are changing as a consequence of climate and environmental change. These changes affect people and the forest ecosystems they depend on for clean water, clean air and forest products, and recreation. How can we best manage our forest resources to sustain this array of ecosystem services under increasing environmental stress and a changing climate?


[photo:] Birch tree at Aspen FACE siteEffects of Global Atmospheric Change on Forest Insects
We are studying seasonal and annual changes in forest insect populations at the Aspen FACE experiment site in northern Wisconsin where trees are growing under both elevated CO2 (+200 ppm above ambient) and ozone (+50% above ambient).


[photo:]   Lake Baikai, Siberia by Eric GustafsonPredicting global change effects on forest biomass and composition in south-central Siberia
Multiple global changes such as timber harvest of previously unexploited areas and climate change will undoubtedly affect the composition and spatial distribution of boreal forests, which will in turn affect the ability of these forests to sequester carbon.  To reliably predict future states of the boreal forest it is necessary to understand the complex interactions among forest regenerative processes (succession), natural disturbances (e.g., fire, wind and insects) and anthropogenic disturbances (e.g., timber harvest). 


[photo:] Amatina jacksonianaTropical Forest Mycology
The Center for Forest Mycology Research (CFMR, part of the Northern Research Station of the US Forest Service) leads critical research on the biology of tropical fungi native to Hawaii, US territories in the Caribbean (Puerto Rico and the US Virgin Islands) and to other countries in the Caribbean Basin.


[photo:] Fall foliage in the mountains of Stowe, Vermont.  Photo by Paula MurakamiRed Leaf Color as an Indicator of Environmental Stress
Vistas of colorful fall foliage hold tremendous public and media interest, and associated tourism to the Northern Forest is estimated to add billions of dollars to the regional economy each year.  This natural spectacle of diverse leaf coloration is based on the physiology of leaf pigments.  In addition to its aesthetic value, the biology of one pigment (anthocyanin) may provide insights to how some trees survive environmental stress.


PhotoChequamegon Ecosystem-Atmosphere Study (CHEAS)
As part of the cooperative Chequamegon Ecosystem Atmosphere Study (ChEAS), NRS scientists have been studying the energy, water vapor and CO2 exchange between forest ecosystems and the atmosphere to understand the dynamics of forest productivity.


[photo:] Poplar planted in soils heavily contaminated with petroleum hydrocarbons. Acid Rain and Calcium Depletion
Acid rain and other anthropogenic factors can leach calcium (Ca) from forest ecosystems and mobilize potentially toxic aluminum (Al) in soils.  Considering the unique role Ca plays in the physiological response of cells to environmental stress, we propose that depletion of biological Ca would impair basic stress recognition and response systems, and predispose trees to exaggerated injury following exposure to other environmental stresses. 


Image of workers planting a Tree in Baltimore, MDBaltimore Ecosystem Study
The Baltimore Ecosystem Study is part of the National Academy of Science’s Long-Term Ecosystem Research (LTER) Program and its 40-m AmeriFlux Tower near Baltimore is the first such permanent tower to estimate carbon flux and carbon sequestration built in an urban/suburban forest ecosystem. It has been in used continually since 2001 to study carbon dioxide CO2 concentration; H2O flux, and the effects of multiple air pollutants on the urban forests. Initial results of our profile system have validated the common-sense expectation that daily CO2 cycles show higher levels associated with energy use and rush hour traffic and decreased levels at other times and on weekends. Metropolitan areas have an average tree cover of 33.4% (urban counties) and support 25% of the USA's total tree canopy cover, and their inclusion in climate models is essential for accuracy.

Forest Service Research & Development
Climate Change

Image of the Earth from spaceForest Service Research and Development provides long term research, scientific knowledge, and tools that can be used to manage, restore, and conserve forests and rangelands. The research is both basic (foundation for future understanding) and applied (for use by practitioners).

See what the Forest Service’s Research & Development program is doing about climate change in your region of the country.


Last Modified: 07/01/2013

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