1 / 11

Volcanic eruption effects on temperate and boreal tree growth

Volcanic eruption effects on temperate and boreal tree growth . Nir Y Krakauer 1* , Nicole V Smith 1 , James T Randerson 2 1. Geological and Planetary Sciences, Caltech 2. Earth Systems Science, UC Irvine * niryk@caltech.edu. Motivation.

margret
Download Presentation

Volcanic eruption effects on temperate and boreal tree growth

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Volcanic eruption effects on temperate and boreal tree growth Nir Y Krakauer1*, Nicole V Smith1, James T Randerson2 1. Geological and Planetary Sciences, Caltech 2. Earth Systems Science, UC Irvine * niryk@caltech.edu

  2. Motivation • Why did the atmospheric CO2 growth rate drop for 2 years after the 1991 Pinatubo eruption? • An enhanced carbon sink also followed the 1982 El Chichón and 1963 Agung eruptions

  3. How would eruptions lead to a carbon sink? • Roderick et al (2001) and Gu et al (2003): light scattering by aerosols boosts canopy photosynthesis for 1-2 years after eruptions • Jones and Cox (2001) and Lucht et al (2002): soil respiration is lower because of cooling; boreal photosynthesis might decrease Gu et al 2003 Lucht et al 2002

  4. What we did • What happened to tree ring widths after past eruptions? • Large eruptions since 1000 from ice core sulfate profiles • 40,000 ring width series from the International Tree Ring Data Bank (ITRDB) Crowley 2000

  5. Width changes by latitude

  6. above 45°N: by genus

  7. The 1990s: Harvard Forest

  8. Conclusions • Boreal trees had narrower rings up to 8 years after Pinatubo-size eruptions • Temperate-zone trees showed smaller effects. American trees has wider rings for 2 years after eruptions • From this sample, negative influences on NPP appear to dominate positive ones, at least in boreal forests

  9. Research directions • Are there tree groups that show large growth enhancements after eruptions (understory trees, moisture-stressed trees…)? • What’s the impact of eruptions on global NPP? • Can we tell what happens to trees’ physiology after eruptions (short growing season, nutrient stress…)? • Why are boreal rings narrower so long after eruptions?

More Related