Ecosystem – At root

  • Fine root growth

    A belowground snapshot reveals the complex maze of tree and shrub roots and their fungal partners in carbon-rich peatland soils. Credit: Colleen Iversen/ORNL, U.S. Dept. of Energy

  • SPRUCE experiment

    Scientists use the Spruce and Peatland Responses Under Changing Environments experiment in Minnesota to assess the response of northern peatlands to increases in temperature and atmospheric carbon dioxide. Credit: ORNL, U.S. Dept. of Energy

  • Fine root growth

    A belowground snapshot reveals the complex maze of tree and shrub roots and their fungal partners in carbon-rich peatland soils. Credit: Colleen Iversen/ORNL, U.S. Dept. of Energy

  • SPRUCE experiment

    Scientists use the Spruce and Peatland Responses Under Changing Environments experiment in Minnesota to assess the response of northern peatlands to increases in temperature and atmospheric carbon dioxide. Credit: ORNL, U.S. Dept. of Energy

Oak Ridge National Laboratory scientists evaluating northern peatland responses to environmental change recorded extraordinary fine-root growth with increasing temperatures, indicating that this previously hidden belowground mechanism may play an important role in how carbon-rich peatlands respond to warming.

The team working at DOE’s whole-ecosystem warming experiment in northern Minnesota found that shrub fine-root growth increased linearly by 130% for every degree increase in soil temperature – a response 20 times greater than other ecosystems. This was driven by soil drying in the usually sodden peatlands, which store one-third of the world’s soil carbon.

According to published results, this response could explain why shrub coverage is increasing in these landscapes, which could shade out Sphagnum moss – a key species for carbon fixation in peatlands – and have downstream effects on peatland carbon storage.

“This work helps us understand a previously unknown aspect of these ecosystems, the world belowground,” said Avni Malhotra of Stanford University, formerly of ORNL.

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