As the Earth's climate warms over the next century, ecosystems throughout the northern hemisphere also will be exposed to elevated rates of atmospheric nitrogen (N) deposition. Understanding this complex environmental change lies at the heart of our ability to anticipate the degree to which forests will sequester human-produced carbon dioxide from the atmosphere. An interdisciplinary team of scientists will investigate the interaction between climate warming and simulated atmospheric N deposition using a long-term, regional-based, field experiment located in sugar maple-dominated forest ecosystems common throughout eastern North America. Over the past 10 years, simulated atmospheric nitrogen deposition at rates expected to occur by 2050 have increased tree growth and slowed the decay of dead leaves and roots, increasing the amount of carbon stored in this wide-spread ecosystem. However, it is uncertain whether carbon storage will stabilize at a higher equilibrium over the long-term as atmospheric nitrogen deposition increases, or whether expected warming will counteract this effect. The proposed research will quantify the amounts of carbon stored in overstory trees, forest floor and soil over the next decade, allowing this team of scientists to test hypotheses regarding the interaction of climate warming and atmospheric nitrogen deposition on ecosystem carbon sequestration.
The results of this project will be disseminated to other global change scientists, K-12 teachers, and the general public through the development of user-friendly, web-based tools. In addition the team of investigators will continue conducting the annual Global Change Teachers Institute. Through lectures and field-based learning, middle and high school teachers develop an understanding of the causes and ecological impacts of global environmental change, thereby bringing this information into science curricula.
