Collaborative Research: Testing Paleo to Present Tree Carbon Capture Across Ontogeny, Atmospheric CO2 and Productivity Gradients

Oregon State University, Corvallis OR

Investigators

Abstract

The goal of this research is a realistic assessment of how atmospheric CO2 concentrations affect carbon capture by forests. Environmental factors, such as temperature and water availability, and tree age greatly influence how tree growth and forest carbon capture are influenced by atmospheric CO2. Tree rings in ancient and modern wood will be used as an archive of tree growth at known points in time, and when combined with independent estimates of climate and CO2 levels over the past 14,000 years, will provide information on how tree growth responds to atmospheric CO2. The tree core samples will be collected for different tree ages and in different environments. Models that predict carbon capture over a broad range of forest age and environmental conditions will be developed from information on several isotope indicators found in the tree rings of modern and ancient wood combined with measurements of photosynthesis in living trees. To date, the influence of CO2 enrichment on forest growth has only been studied in young trees exposed to artificially elevated levels of CO2 in a limited number of costly short-term field studies. The broad applicability of these studies remains uncertain because forest carbon capture depends strongly on tree age and its interactions with site-specific growth environments. This new research provides a unique opportunity to test and enhance understanding of how forest ecosystems respond to climate change. The results will have important implications for policy decisions concerning carbon emissions, land-use and forest management to optimize carbon capture.