Development of Technology to Enhance Carbon Sequestration in Forests

Increased carbon sequestration by forests is an important element of a comprehensive strategy to reduce net emissions of greenhouse gases that contribute to climate change. United States forests currently remove 200 million tons of carbon from the atmosphere each year, offsetting 10% of emissions from fossil fuels. There is an opportunity to develop and apply forest management technology that is designed to maintain and potentially enhance the role of forests as carbon sinks. Scientists in the Northern Research Station are working with states and the private sector to identify land management practices that are compatible with other forest values, have the potential to provide additional income to forest landowners from sale of carbon credits, and can reduce atmospheric greenhouse gasses. We are also developing decision-support tools that will make it easier for land managers to determine the impacts of their management practices on ecosystem carbon balance, leading to a selection of alternatives that contribute to solving the greenhouse gas problem.

Selected Research Studies

Tracing Carbon Flux and Stabilization Using Ecosystem-scale Radiocarbon Enrichment
Most carbon in forests is not in the trees, but is actually in the soil.  If we ultimately seek to predict how carbon will cycle through the forest ecosystem, we first need to understand how carbon cycles through the soil.  Questions of interest are then: how does carbon enter the soil, how is it stabilized, and how is it released?

Mesocosm
The Mesocosm will reproduce a natural system, but allow for replicated and controlled tests of the effects of climate change scenarios on ecosystem function. The Mesocosm consists of 24 1m3 stainless steel bins that will be filled with forest soils or peatlands. These bins are accessible both aboveground and through a belowground laboratory. 

Rhizotron
The Rhizotron is a major tool in helping to improve the understanding of belowground forest processes. As one of only two of its kind located in a northern forest ecosystem, it provides researchers the ability to observe and monitor soil carbon accumulation, especially activities that occur
in the chemically active zone near roots, without causing disturbance to the soil or soil organisms.

Northern 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.

Carbon and Forest Management
Forests play an important role in the global carbon cycle – forests take up carbon dioxide from the atmosphere as they grow.  This carbon is "sequestered", or temporarily removed from the atmosphere.   Since forest carbon sequestration can help offset emissions, it is important to learn how much carbon our forests are storing, and how management practices affect the rate of carbon sequestration (storage) in the forests of our region. 

Phyto-Recurrent Selection: A Method for Selecting Genotypes for Phytotechnologies
The success of certain phytotechnologies has prompted the use of wastewaters as a combination of irrigation and fertilization for woody crops such Populus species and their hybrids (i.e., poplars). A common protocol for such efforts has been to utilize a limited number of readily-available genotypes with decades of deployment in other applications, such as fiber or windbreaks. However, it is possible to increase phytoremediation success with proper genotypic screening and selection, followed by the field establishment of clones that exhibited favorable potential for clean-up of specific contaminants. While such efforts are limited for environmental remediation, centuries of plant selection success in agronomy, horticulture, and forestry validate the need for similar approaches in phytotechnologies. 

Biofuels, Bioenergy, and Bioproducts from Short Rotation Woody Crops
We are testing the genetics, physiology, and silviculture of poplar crops. Specific areas of interest include quantitative genetic analyses of biomass, rooting, and other important traits from hundreds of genotypes grown throughout the North Central United States, as well as analyses of tree growth regulating mechanisms in the face of varying environments and changing climate. Our silviculture research includes a range of studies from vegetation management to yield trials.

Integrating 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.

Breeding and Selecting Poplar for Biofuels, Bioenergy, and Bioproducts
Hybridization of poplars occurs naturally among certain taxonomic sections, as well as from planned breeding efforts. Given that most of the variability of poplars is at the species level, both intra- and inter-specific hybridization have been vital tools for producing progeny that outperform either or both parents for biologically and economically important traits. It is important to refine breeding, testing, and selection protocols so that new, superior poplar genotypes can replace their underperforming counterparts.

Genetics and Genotype × Environment Interactions Affecting Adventitious Rooting and Early Establishment of Poplar Energy Crops
Gaining knowledge about the genetics and genotype × environment interactions affecting adventitious rooting is important for energy crop production. First, rapid and extensive rooting reduces establishment costs by permitting the use of unrooted cuttings as commercial stock rather than rooted cuttings. Second, assuming concomitant and well-balanced shoot development, rapid and extensive rooting promotes early growth, reducing vegetation management costs and the time period to crown closure. Third, rapid and extensive rooting that is stable in the face of varying environmental conditions can increase the period of time during which successful planting can occur, increasing operational flexibility.  

Sustainable Production of Woody Energy Crops with Associated Environmental Benefits
Increasing human population levels at regional, national, and global scales have heightened the need for proper management of residential and industrial waste. Contaminants from this waste stream have polluted water, air, and soil much faster than traditional technologies could remediate the problem. Therefore, we are combining intensive forestry and waste management methods to increase the potential for producing woody crops for energy and fiber, along with decreasing the environmental degradation associated with waste disposal and subsequent waste water production.

Salt Tolerance and Salinity Thresholds of Woody Energy Crops Irrigated with High-salinity Waste Waters
There is a need for environmental practices that merge intensive forestry with waste management. Producing short rotation woody crops for energy, fiber, and environmental benefits requires adequate irrigation and fertilization, which can be supplied via waste waters including landfill leachate. Yet, leachate often contains elevated levels of salts such as chloride and sodium that cause leaf chlorosis and necrosis, decreased biomass accumulation, and increased mortality. Therefore, there is a pressing need to learn about the response of poplar energy crops when salts are taken up into root, leaf, and woody (stem + branch) tissues, as well as identifying thresholds of salt concentrations and salinity that can be recommended for these crops in both field testing and production plantations.

Global Change Research
The goal of global change research is to establish a sound scientific basis for making regional, national, and international resource management and policy decisions in the context of global change issues. The Northern Global Change Research Program currently emphasizes scientific inquiry into the effects of multiple air pollutants and climate changes on forest ecosystems. As the program matures, the impacts of prospective changes on interactions between forest ecosystems and social and economic processes will be evaluated, as will policy options for mitigating or adapting to predicted changes.