A realistic assessment of how atmospheric CO2 concentrations affect carbon capture by forests is the goal of this research. Other environmental factors and tree age greatly influence how tree growth and forest carbon capture will be 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 samples will be collected for different tree ages and in different environments. This will be further enhanced by incorporating multiple isotopic indicators in modern and ancient wood combined with measurements of photosynthesis in living trees to generate models that predict carbon capture over a broad range of forest age and environmental conditions.
To date, the impact 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.
