Toward a Predictive Understanding of the Response of Belowground Microbial Carbon Turnover to Climate Change Drivers in a Boreal Peatland

• Main Authors: Kostka, Joel, Chanton, Jeffrey P., Schadt, Christopher W.
• Language: unknown
• Published: 2019
• Subjects: 54 ENVIRONMENTAL SCIENCES; Arctic; Climate change
• Online Access: http://www.osti.gov/servlets/purl/1508979; https://www.osti.gov/biblio/1508979; https://doi.org/10.2172/1508979

Peatlands are wetlands that act as giant "carbon banks", storing approximately one-third of Earth's soil carbon. Peatland carbon banks cover large areas in northern latitudes including the Arctic and evidence from previous work suggests that northern peatlands store a lot of carbon partly because they are cold and microbes don't work very fast to decompose organic matter in the cold. The concern is that with increasing temperatures, microbes will be become more active and release more carbon from the "bank" as greenhouse gases, carbon dioxide and natural gas (methane). However, there are many more factors that could determine why peatlands store so much carbon such as the fact that they are acidic, low in oxygen, or because they contain a peat moss carpet. All of these factors have been shown to slow down the activity of microbes that release greenhouse gases through the decomposition of organic matter. For example, peat mosses naturally produce organic chemical compounds that are thought to poison microbes, thereby limiting their activity. For this reason, peat moss was used in the past as a food preservative. As the amount of carbon dioxide increases in Earth's atmosphere, it also predicted that plants will become more active and produce more usable organic matter for microbes. Therefore, this project addressed the resilience of the peatland carbon bank to warming and the accumulation carbon dioxide in the atmosphere. The project was conducted at the Marcell Experimental Forest (MEF), northern Minnesota, where the Oak Ridge National Lab (ORNL) has established an experimental site known as Spruce and Peatland Response Under Climatic and Environmental Change (SPRUCE). The SPRUCE site simulates environmental change at the ecosystem scale, allowing us to understand how all organisms, from microbes to trees, will respond to higher temperatures and increased carbon dioxide in the atmosphere. From 2014 to 2017, the response of peatlands to environmental change was evaluated through multiple field campaigns each year ...