Nutrient availability in the bog.We deployed ion-exchange resins across hummock-hollow microtopography in two locations in each SPRUCE experimental plot. Resins are retrieved every 28 days during the growing season to assess plant-available NH4-N, NO3-N, and PO4 throughout the peat profile, and to track changes in plant-available nutrients in response to warming and elevated [CO2].
Thus far, warming—combined with a longer frost-free period—has increased the amount of NH4-N adsorbed to ion-exchange resins in the warmest treatment plots . However, the increase in nutrients was much greater below the rooting zone, potentially indicating plant uptake in surface peat (i.e., greater competition for nutrients). |
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Publications.Iversen CM, Childs J, Norby RJ, Ontl TA, Kolka RK, Brice DJ, McFarlane KJ, Hanson PJ. 2018. Fine-root growth in a forested bog is seasonally dynamic, but shallowly distributed in nutrient-poor peat. Plant and Soil 424: 123-143.
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This research is funded by the Office of Biological and Environmental Research in the U.S. Department of Energy's Office of Science.