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.
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.
This study concerns 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).
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, 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? This research is leading to the development of effective strategies to adapt to these long-term changes.
The EAMC is a multi-agency coalition of researchers and managers at the Federal, State, and local levels that is focused on fire weather, fire behavior, and smoke transport issues in the north central and northeastern U.S. The EAMC carries out core fire science research and product development related to physical fire processes (including small-scale fire-fuel-atmosphere interactions and smoke plume behavior), fire characteristics at multiple scales, and fire danger assessment (including atmospheric processes associated with fire-weather development and evolution).
Data from flux sites help test physiological models of carbon 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. 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.
Studies on carbon dioxide concentration, CO2 and H2O flux, and the effects of multiple air pollutants on urban forests are being conducted in Baltimore. Urban conditions may represent possible future scenarios: elevated carbon dioxide, ozone, nitrogen deposition and elevated temperatures. A 40 m Forest Service lookout tower near Baltimore is used to conduct air quality and meteorological flux research. This is the first permanent tower to estimate carbon flux and carbon sequestration in an urban/suburban forest ecosystem. 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.
Young communities of trembling aspen (Populus tremuloides) have been grown under elevated concentrations of carbon dioxide and elevated ozone at the Aspen FACE site, Harshaw, WI. We are using microsatellite markers to generate distinct DNA fingerprints for each of the five-aspen clones. These DNA fingerprints will be used to quantify fine-root biomass, in particular to monitor changes that occur when trees are exposed to atmospheric pollutants.
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.
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. This project laid the foundation for what is now the Climate Change Response Framework, in addition to several other projects.